Afatinib is an oral, selective epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) indicated for the treatment of metastatic non-small cell lung cancer (NSCLC) with non-resistant EGFR mutations and in platinum-resistant metastatic NSCLC (not selected for EGFR). Clinically, EGFR expression has been associated with poor prognosis, development of metastasis, and resistance to chemotherapy, hormonal therapy, and radiation therapy. First-line treatment with afatinib was associated with a significant improvement in progression-free survival (PFS) compared with combination cisplatin and pemetrexed in patients with advanced NSCLC and non-resistant EGFR mutations. Treatment with afatinib also significantly improved overall survival and PFS compared with erlotinib in patients with platinum-resistant, metastatic NSCLC who were not selected for EGFR mutations in a separate randomized, open-label clinical trial.
General Administration Information
For storage information, see the specific product information within the How Supplied section.
Hazardous Drugs Classification
-NIOSH 2016 List: Group 1
-NIOSH (Draft) 2020 List: Table 2
-Observe and exercise appropriate precautions for handling, preparation, administration, and disposal of hazardous drugs.
-Use gloves to handle. Cutting, crushing, or otherwise manipulating tablets/capsules will increase exposure.
Emetic Risk
-Minimal/Low
-Administer prn antiemetics as necessary.
Route-Specific Administration
Oral Administration
NOTE: Information on FDA-approved tests for the detection of EGFR mutations in NSCLC is available at: http://www.fda.gov/CompanionDiagnostics.
-Afatinib must be given orally on an empty stomach, 1 hour before or 2 hours after the ingestion of food. Administer at the same time each day. Do not administer with food.
-Do not administer a missed dose within 12 hours of the next dose.
Diarrhea was the most common gastrointestinal adverse event reported with afatinib, occurring in 96% of afatinib-treated patients (n = 229) in one randomized, open-label, phase 3 study of patients with EGFR-positive metastatic NSCLC; 15% was grade 3 and occurred within the first 6 weeks of therapy. Diarrhea was more common in patients treated with afatinib (n = 392) compared with erlotinib (n = 395) in another multicenter, randomized, open-label clinical trial of patients with metastatic squamous NSCLC (all grade, 75% vs. 41%; grade 3 or 4, 11% vs. 3%); patients in this study were not required to have EGFR mutations. Patients should be instructed to use loperamide at the onset of diarrhea and to continue anti-diarrheal therapy until loose bowel movements stop for 12 hours. Hold afatinib therapy if a patient develops grade 3 or higher diarrhea, or grade 2 diarrhea that lasts more than 48 hours. Treatment may resume at an appropriate dose reduction when diarrhea is grade 1 or less. GI perforation, including fatal cases, has been reported in 0.2% of patients treated with afatinib (n = 3,212) across 17 randomized controlled trials. Permanently discontinue afatinib in patients who develop GI perforation. Renal failure occurred in 6% to 7% of patients treated with afatinib (grade 3, 1.3% to 2%); this could be exacerbated by dehydration. Periodically monitor serum creatinine and electrolytes and hold therapy if grade 2 renal failure (unspecified) occurs (serum creatinine greater than 1.5 X upper limit of normal). Additional gastrointestinal adverse events reported with afatinib in patients with EGFR-positive metastatic NSCLC include stomatitis (including oral ulceration) (all grade, 71%; grade 3, 9%; grade 4, 0.4%), decreased appetite (all grade, 29%; grade 3, 4%), nausea (all grade, 25%; grade 3, 4%), vomiting (all grade, 23%; grade 3, 4%), weight loss (all grade, 17%; grade 3, 1%), cheilitis (all grade, 12%), and constipation (all grade, 2.6%). Compared with erlotinib, afatinib-treated patients with metastatic squamous NSCLC (unselected for EGFR mutations) additionally reported stomatitis (all grade, 30% vs. 11%; grade 3 or 4, 4% vs. 1%), decreased appetite (all grade, 25% vs. 26%; grade 3 or 4, 3% vs. 2%), nausea (all grade, 21% vs. 16%; grade 3 or 4, 2% vs. 1%), and vomiting (all grade, 13% vs. 10%; grade 3 or 4, 1% vs. 1%). Of these adverse effects, only diarrhea resulted in treatment discontinuation in 1.3% to 4.1% of patients.
Rash (unspecified) was the most commonly reported skin and subcutaneous tissue adverse events in afatinib clinical trials. Acneiform rash (including acne vulgaris) occurred in 90% (grade 3, 16%) of EGFR-positive metastatic NSCLC patients during afatinib therapy (n = 229). In a separate study of patients with metastatic NSCLC, unselected for EGFR status, the incidence of acneiform rash was 70% (grade 3 or 4, 7%) in patients who received afatinib (n = 392) compared with 70% (grade 3 or 4, 11%) of those treated with erlotinib (n = 395). The appearance of the rash is typically erythematous and maculopapular (maculopapular rash) and may resemble acne with follicular pustules, but is histopathologically different. It commonly occurs on the face, upper chest, and back and may be severe with desquamation. Sun may worsen the reaction. Skin hyperpigmentation or dry skin (xerosis) (all grade, 29.3% to 31%; grade 3, less than or equal to 0.4%) with or without digital skin fissures may occur. Rash will usually diminish or even resolve with temporary cessation of therapy, and may respond to a variety of topical therapies, including erythromycin ointment, as well as oral tetracycline antibiotics. Bullous (bullous rash), blistering or exfoliative skin conditions developed in 0.2% of patients treated with afatinib across clinical trials (n = 4,257); postmarketing cases consistent with toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS) have also been reported with afatinib use. The mechanism for development of TEN and SJS differs from other dermatologic toxicities secondary to the action of the drug on the epidermal growth factor receptor. Discontinue treatment if a patient develops a bullous, blistering, or exfoliative skin condition, including suspected TEN or SJS. Additional adverse events reported in patients with EGFR-positive metastatic NSCLC include pruritus (all grade, 18.8%; grade 3, 0.4%) and palmar-plantar erythrodysesthesia (hand and foot syndrome) (all grade, 7%). Patients with metastatic NSCLC, unselected for EGFR status, also reported pruritus (all grade, 10%) and palmar-plantar erythrodysesthesia (all grade, 1.5%), but with a lower incidence. If a patient experiences a prolonged grade 2 skin reaction that lasts more than 7 days, or any grade 3 skin reaction, hold afatinib. Treatment may resume with the appropriate dose reduction after resolution to grade 1 or less. Nail disorders, not including infection, occurred in 2.8% to 9.2% of afatinib-treated patients.
In a randomized, open-label, grade III clinical trial of patients with EGFR-positive metastatic NSCLC, paronychia (nailbed infection) was reported in 58% (grade 3, 11%) of patients treated with afatinib (n = 229) and resulted in discontinuation of therapy in 0.9% of patients. Paronychia occurred at a lower incidence (all grade, 11%; grade 3 or 4, 1%) in metastatic NSCLC patients who received afatinib and were not selected for EGFR status (n = 392) in a separate multicenter, open-label clinical trial. Additional infectious adverse events reported with afatinib in EGFR-positive NSCLC include cystitis (all grade, 13%; grade 3, 1%), and conjunctivitis (all grade, 11%); pneumonia and sepsis were each fatal in 0.43% of patients. Keratitis was reported in 0.7% (grade 3 or 4, 0.05%) of afatinib-treated patients across clinical trials (n = 4,257); it occurred in 2.2% (grade 3, 0.4%) of patients with EGFR-positive metastatic NSCLC and in 0.3% of afatinib-treated patients with metastatic NSCLC who were not selected for EGFR status in separate clinical trials. Treatment should be held in patients experiencing acute or worsening ocular inflammation, lacrimation, photosensitivity, blurred vision, ocular pain, or red eye. If keratitis is diagnosed, the risks and benefits of continuing treatment should be considered; a continued interruption or discontinuation of afatinib therapy should be considered if a diagnosis of ulcerative keratitis is confirmed. Permanently discontinue afatinib for persistent ulcerative keratitis.
In a randomized, open-label, grade III clinical trial of patients with EGFR-positive metastatic NSCLC, epistaxis was reported in 17% of patients treated with afatinib (n = 229). Additional general adverse events reported with afatinib therapy included rhinorrhea (11%) and fatigue (1.7%).
Pulmonary toxicity consisting of interstitial lung disease (ILD)-like events (including lung infiltration, pneumonitis, acute respiratory distress syndrome (ARDS), or allergic alveolitis) occured with an overall incidence of 1.6% of afatinib-treated patients across clinical trials (n = 4,257), and has resulted in death in 0.4%. In a clinical trial of patients with EGFR-positive metastatic NSCLC, >= grade 3 ILD occurred in 1.3% (grade 5, 1%) of patients who received afatinib (n = 229), while in a separate trial of patients with metastatic NSCLC who were not selected for EGFR status, the incidence of >= grade 3 ILD in afatinib-treated patients was 0.9% (grade 5, 0.8%) (n = 392). Across clinical trials, ILD appears to be higher in patients of Asian ethnicity compared to Caucasians (2.3% vs. 1%). In the event of acute onset of new or progressive, unexplained pulmonary symptoms such as dyspnea, cough, fever, or ARDS, afatinib therapy should be interrupted pending diagnostic evaluation. If ILD is confirmed, afatinib should be discontinued and appropriate treatment instituted as necessary.
Left ventricular heart failure has been reported in EGFR-positive metastatic NSCLC patients treated with afatinib. In a randomized, open-label, phase III trial (n = 345), grade 1/2 ventricular dysfunction (diastolic dysfunction, left ventricular dysfunction, or ventricular dilation) was reported in 2.2% of patients treated with afatinib monotherapy, compared with 0.9% of patients treated with pemetrexed/cisplatin combination therapy. Permanently discontinue afatinib therapy for patients experiencing symptomatic left ventricular dysfunction.
Liver test abnormalities have been reported in 9.7% of patients treated with afatinib across clinical trials (n = 4,257); hepatic failure resulting in death occurred in 0.2%. In one clinical trial of patients with EGFR-positive metastatic NSCLC (n= 229), liver test abnormalities occurred in 17.5% of those treated with afatinib (grade 3 or 4, 3.5%); elevated hepatic enzymes have included increased ALT (all grade, 54%; grade 3 or 4, 3%), increased alkaline phosphatase (all grade, 49%; grade 3 or 4, 2%), increased AST (all grade, 46%; grade 3 or 4, 3%), and hyperbilirubinemia (all grade, 16%; grade 3 or 4, 1%). In a separate trial of patients with metastatic NSCLC, not selected for EGFR status, liver test abnormalities occurred in 6% of afatinib-treated patients (n = 392) (grade 3 or 4, 0.2%). Increased alkaline phosphatase was reported in 34% (grade 3 or 4, 2%) of patients treated with afatinib in this trial, compared with 31% of those who received erlotinib (n = 395); afatinib-treated patients also reported increased ALT (all grade, 10%; grade 3 or 4, 1%), increased AST (all grade, 7%; grade 3 or 4, 1%), and hyperbilirubinemia (all grade, 3%). Periodic liver function testing is recommended. In the setting of worsening liver function, therapy should be held; permanently discontinue afatinib in patients who develop severe hepatic impairment.
The following hematologic adverse events were reported in a clinical trial of patients with EGFR-positive metasatic NSCLC who received afatinib (n = 229): anemia (all grade, 3.1%; grade 3 or 4, 0.4%), leukopenia (all grade, 1.7%; grade 3 or 4, 0.4), and neutropenia (all grade, 0.9%; grade 3 or 4, 0.4%); lymphocytopenia was also reported in 38% (grade 3 or 4, 9%) of afatinib-treated patients. In a separate randomized, open-label trial of metastatic NSCLC not selected for EGFR status, leukopenia occurred in 12% (grade 3 or 4, 1%) of patients treated with afatinib (n = 392) compared with 8% (grade 3 or 4, 1%) of those who received erlotinib (n = 395).
Hypokalemia was reported in 30% (grade 3 or 4, 8%) of patients with EGFR-positive metastatic NSCLC who received afatinib (n = 229) and in 11% (grade 3 or 4, 1%) of afatinib-treated patients with metastatic NSCLC who were not selected for EGFR status (n = 392) in clinical trials.
In postmarketing surveillance, pancreatitis was reported in patients who received afatinib. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Interstitial pulmonary disease and interstitial lung disease-like adverse reactions (e.g., lung infiltration, pneumonitis, acute respiratory distress syndrome, or allergic alveolitis) have been associated with the use of afatinib. The incidence appears to be higher in Asian patients (2.3%) compared to White patients (1%). In the event of acute onset of new or progressive, unexplained pulmonary symptoms or respiratory insufficiency such as dyspnea, cough, and fever, afatinib therapy should be interrupted pending diagnostic evaluation. If interstitial lung disease is diagnosed, afatinib should be discontinued and appropriate treatment instituted as necessary.
Diarrhea, which can result in dehydration and renal failure or renal impairment, has been associated with the use of afatinib in the majority of patients; some of these cases were fatal. Periodically monitor renal function and serum electrolytes in patients at risk of dehydration. Patients should be instructed to take an anti-diarrheal agent (e.g., loperamide) at the onset of diarrhea, and to continue therapy until 12 hours after the last loose stool. Interrupt afatinib for grade 2 diarrhea lasting more than 48 hours, or any grade 3 and higher diarrhea. Therapy may be resumed with the appropriate dose reduction when diarrhea resolves to grade 1 or less.
Afatinib may cause symptoms consistent with ocular disease. Patients who develop an onset of new eye symptoms or visual disturbance such as ocular pain, inflammation, lacrimation, light sensitivity, blurred vision, and/or red eye should be evaluated and managed appropriately. Interrupt afatinib if patients present with acute or worsening ocular pain or suspected keratitis. If keratitis is diagnosed, consider the risks and benefits of continuing treatment; a continued interruption or discontinuation of therapy is necessary if ulcerative keratitis is diagnosed. Ocular disorders such as abnormal eyelash growth, keratoconjunctivitis, and keratitis are known risk factors for corneal perforation and ulceration; the use of contact lenses is also a risk factor. Afatinib should be used with caution in patients with a history of keratitis, ulcerative keratitis, or severe dry eye.
Serious rash and skin disease, including bullous, blistering, and exfoliating lesions, has been reported with the use of afatinib, in addition to post-marketing cases consistent with toxic epidermal necrolysis (TEN) and Stevens Johnson syndrome (SJS); more common cutaneous toxicities including acneiform rash, erythema, and palmar-plantar erythrodysesthesia syndrome (hand-foot syndrome) have also been reported. Discontinue afatinib in patients who develop life-threatening bullous, blistering, or exfoliating lesions, or if TEN or SJS is suspected. For patients who develop prolonged grade 2 cutaneous adverse reactions, or if skin reactions are intolerable, hold afatinib therapy until resolution to grade 1 or less and resume therapy with an appropriate dose reduction.
Patients with HER2-positive metastatic breast cancer treated with afatinib in combination with vinorelbine had decreased overall survival compared with patients who received vinorelbine in combination with trastuzumab at an interim analysis of a randomized, controlled, phase III clinical trial (LUX-Breast 1). Additionally, adverse reactions including diarrhea, rash, infection (with fatalities), and progressive disease occurred more frequently in the afatinib group. Another randomized, open-label, phase II clinical trial of patients with HER2-positive breast cancer and brain metastases (LUX-Breast 3) failed to show benefit of afatinib monotherapy or afatinib in combination with vinorelbine over other treatments (investigator's choice) in the primary endpoint of patient benefit at 12 weeks, or secondary endpoints of progression-free survival or overall survival.
Hepatotoxicity has occurred in patients treated with afatinib; some cases have been fatal. Periodically monitor liver function tests. Hold afatinib therapy in patients who develop worsening liver function, and discontinue treatment if severe hepatic impairment occurs. Use afatinib with caution in patients with pre-existing hepatic disease.
Gastrointestinal (GI) perforation, sometimes fatal, has occurred with afatinib. Geriatric patients, patients receiving concomitant nonsteroidal anti-inflammatory drugs (NSAIDs), antiangiogenic agents, or corticosteroid therapy, and those who have an underlying history of GI ulceration (e.g., peptic ulcer disease), diverticular disease (e.g., diverticulitis), or bowel metastases may be at increased risk for perforation. Permanently discontinue afatinib in patients who develop GI perforation.
Although there are no adequate studies in pregnant women using afatinib, based on findings for animal studies and its mechanism of action, afatinib may cause fetal harm when administered during pregnancy. Pregnancy should be avoided during treatment and for at least 2 weeks after the last dose of afatinib. If afatinib is used during pregnancy or if a patient becomes pregnant while receiving this drug, she should be apprised of the potential harm to the fetus or the potential for the loss of the pregnancy. Administration of afatinib to pregnant rabbits during organogenesis at exposures approximately 0.2 times or more the exposure by AUC at the recommended human dose of 40 mg resulted in increased post-implantation loss; in animals showing maternal toxicity, abortion at late gestational stages occurred. At higher exposures (0.7 times the exposure by AUC at the recommended human dose), there were decreased fetal weights, increased incidence of runts, as well as visceral and dermal variations. Skeletal alterations (including incomplete or delayed ossifications) and reduced fetal weight occurred in an embryo-fetal development study in rats exposed to afatinib at approximately twice the exposure based on AUC at the recommended human dose.
Counsel patients about the reproductive risk and contraception requirements during afatinib treatment. Afatinib can be teratogenic if taken by the mother during pregnancy. Females should avoid pregnancy and use effective contraception during and for at least 2 weeks after treatment with afatinib. Females of reproductive potential should undergo pregnancy testing prior to initiation of afatinib. Women who become pregnant while receiving afatinib should be apprised of the potential hazard to the fetus. In addition, based on animal data, afatinib treatment may result in impaired fertility or infertility in both females and males of reproductive potential; it is unknown if these effects are reversible.
It is not known if afatinib is excreted in human breast milk. Due to the potential for serious adverse reactions in the nursing infant, women should avoid breast-feeding during treatment and for 2 weeks after the last dose.
For the treatment of patients with metastatic non-small cell lung cancer (NSCLC):
-for the first-line treatment of patients with metastatic non-small cell lung cancer (NSCLC) whose tumors have non-resistant epidermal growth factor receptor (EGFR) mutations as detected by an FDA-approved test:
NOTE: Information on FDA-approved tests for the detection of non-resistant epidermal growth factor receptor (EGFR) mutations is available at www.fda.gov/CompanionDiagnostics.
Oral dosage:
Adults: 40 mg orally once daily until disease progression or unacceptable toxicity; afatinib should be taken on an empty stomach. Coadministration of certain drugs may need to be avoided or dosage adjustments may be necessary; review drug interactions. Afatinib monotherapy (n = 230) was compared with pemetrexed and cisplatin combination therapy (n = 115) in a randomized, multicenter, open label phase III trial of patients with EGFR positive, metastatic NSCLC. The primary endpoint of progression-free survival (PFS) was significantly improved in patients treated with afatinib compared with chemotherapy (11.1 months vs. 6.9 months); overall response rate was also improved (50.4% vs. 19.1%). There was no statistically significant difference in overall survival at the final pre-planned analysis (28.2 vs. 28.2 months). A preplanned exploratory subgroup analysis found that patients with EGFR exon 19 deletions responded to afatinib therapy better that those with exon 12 (L858R) substitution mutations or a combination of exon 19 deletions and exon 12 (L858R) substitutions (PFS: HR, 0.28 vs. 0.73 vs. 0.47; OS: HR, 0.55 vs. 1.3 vs. 0.82). Afatinib was also effective in a pooled analysis of NSCLC patients with non-resistant EGFR mutations other than exon 19 deletions or exon 21 L858R substitutions (S768I, L861Q, and G719X) (n = 32).
-for the treatment of metastatic squamous NSCLC, progressing after platinum-based chemotherapy:
Oral dosage:
Adults: 40 mg orally once daily until disease progression or unacceptable toxicity; afatinib should be taken on an empty stomach. Coadministration of certain drugs may need to be avoided or dosage adjustments may be necessary; review drug interactions. Patients with platinum-resistant metastatic squamous NSCLC were treated with either afatinib (n = 398) or erlotinib (n = 397) until disease progression in a randomized, multicenter, open-label clinical trial. Patients treated with afatinib experienced significant improvements in the primary outcome of progression-free survival (PFS) by independent review committee (IRC) compared with erlotinib (2.4 months vs. 1.9 months), as well as in overall survival (OS) (7.9 months vs. 6.8 months). The overall response rate (ORR) by IRC was 3% (95% CI, 1.7% to 5.8%) for patients treated with afatinib compared with 2% (95% CI, 0.8% to 4.3%) for those who received erlotinib.
Therapeutic Drug Monitoring:
Dose Adjustments for Treatment-Related Toxicities:
Gastrointestinal:
-Grade 2 diarrhea lasting more than 48 hours, or any grade 3 diarrhea or higher: Hold afatinib therapy until the toxicity resolves to grade 1 or less, then resume therapy at a reduced dose (i.e., 10 mg/day less than the dose causing toxicity). Anti-diarrheal therapy should begin at the onset of diarrhea and continue until no loose bowel movement for 12 hours. Permanently discontinue therapy if toxicity persists at a dose of 20 mg/day.
-Gastrointestinal perforation: Permanently discontinue afatinib treatment.
Dermatologic:
-Grade 2 cutaneous reactions that last more than 7 days or are intolerable: Hold afatinib therapy until the toxicity resolves to grade 1 or less, then resume therapy at a reduced dose (i.e., 10 mg/day less than the dose causing toxicity). Permanently discontinue afatinib treatment if toxicity persists at a dose of 20 mg/day.
-Grade 3 or higher: Hold afatinib therapy until the toxicity resolves to grade 1 or less, then resume therapy at a reduced dose (i.e., 10 mg/day less than the dose causing toxicity). Permanently discontinue therapy if toxicity persists at a dose of 20 mg/day.
-Life-threatening bullous, blistering, or exfoliating skin lesions, including suspected toxic epidermal necrolysis (TEN) or Stevens Johnson syndrome (SJS): Permanently discontinue afatinib treatment.
Pulmonary:
-Suspected interstitial lung disease (ILD)/pneumonitis: Hold afatinib therapy during evaluation; permanently discontinue afatinib if a diagnosis of ILD/pneumonitis is confirmed.
Ocular:
-Keratitis: Hold afatinib therapy for suspected keratitis. If confirmed, continued treatment should be considered after weighing the risks and benefits.
-Ulcerative keratitis: Hold afatinib and consider discontinuation of therapy. Permanently discontinue afatinib treatment for persistent ulcerative keratitis.
Cardiac:
-Symptomatic left ventricular dysfunction: Permanently discontinue afatinib treatment.
Any grade 3 or higher adverse event: Hold afatinib therapy until the toxicity resolves to grade 1 or less, then resume therapy at a reduced dose (i.e., 10 mg/day less than the dose causing toxicity). Permanently discontinue therapy if toxicity persists at a dose of 20 mg/day.
Any severe or intolerable adverse event that occurs at a dose of 20 mg/day: Permanently discontinue afatinib treatment.
Dosage Guidance in Patients on P-glycoprotein (P-gp) Inhibitors/Inducers:
P-gp inhibitors: If concomitant use of a P-gp inhibitor is required, reduce the initial daily afatinib dosage to 30 mg/day if not tolerated. Resume original dose after discontinuation of the P-gp inhibitor as tolerated.
P-gp inducers: If concomitant use of a P-gp inducer is required, increase the initial daily afatinib dosage to 50 mg/day as tolerated. Resume original dose 2 to 3 days after discontinuation of the P-gp inducer.
Maximum Dosage Limits:
-Adults
40 mg/day PO; 50 mg/day PO if taking a P-glycoprotein inducer.
-Geriatric
40 mg/day PO; 50 mg/day PO if taking a P-glycoprotein inducer.
-Adolescents
Safety and efficacy have not been established.
-Children
Safety and efficacy have not been established.
-Infants
Safety and efficacy have not been established.
-Neonates
Safety and efficacy have not been established.
Patients with Hepatic Impairment Dosing
Baseline Hepatic Impairment:
-Mild to moderate hepatic impairment (Child-Pugh class A or B): No adjustment to the starting dose is needed.
-Severe hepatic impairment (Child-Pugh class C): Afatinib has not been studied in these patients, however it is not extensively metabolized in the liver. Closely monitor these patients and adjust the dose if not tolerated.
Treatment-Related Hepatotoxicity:
-Hold afatinib therapy in patients who develop worsening liver function. When toxicity resolves to grade 1 or less, resume therapy at a reduced dose (i.e., 10 mg/day less than the dose causing hepatotoxicity). Permanently discontinue therapy for severe drug-induced hepatic impairment or if hepatotoxicity persists at a dose of 20 mg/day.
Patients with Renal Impairment Dosing
Baseline Renal Impairment:
-Mild to moderate renal impairment (CrCL 30 mL/minute or more): No adjustment to the starting dose is needed. Closely monitor patients and adjust the afatinib dose if not tolerated.
-Severe renal impairment (CrCL 15 to 29 mL/minute as calculated by the Modification of Diet in Renal Disease (MDRD) formula): Reduce the starting dose of afatinib to 30 mg once daily.
-CrCL less than 15 mL/minute or dialysis: Afatinib has not been studied in this population; recommendations for dosing cannot be made.
Treatment-Related Nephrotoxicity:
-Grade 2 or higher (SCr greater than 1.5 times upper limit of normal (ULN)): Hold afatinib therapy until the toxicity resolves to grade 1 or less (SCr less than 1.5 x ULN), then resume therapy at a reduced dose (i.e., 10 mg/day less than the dose causing nephrotoxicity). Permanently discontinue therapy if nephrotoxicity persists at a dose of 20 mg/day.
*non-FDA-approved indication
Abrocitinib: (Moderate) If the concomitant use of abrocitinib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of abrocitinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and abrocitinib is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Adagrasib: (Moderate) If the concomitant use of adagrasib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of adagrasib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and adagrasib is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC of afatinib was 119% when coadministered with the same P-gp inhibitor, and 111% when the inhibitor was administered 6 hours after afatinib.
Amiodarone: (Moderate) If the concomitant use of amiodarone and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of amiodarone. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and amiodarone is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC of afatinib was 119% when coadministered with the same P-gp inhibitor, and 111% when the inhibitor was administered 6 hours after afatinib.
Amoxicillin; Clarithromycin; Omeprazole: (Moderate) If the concomitant use of clarithromycin and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of clarithromycin. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and clarithromycin is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Apalutamide: (Major) Increase the daily dose of afatinib by 10 mg as tolerated if the concomitant use with apalutamide is necessary; resume the previous dose of afatinib 2 to 3 days after discontinuation of apalutamide. Afatinib is a P-glycoprotein (P-gp) substrate and apalutamide is a weak P-gp inducer; coadministration may decrease plasma concentrations of afatinib. Pre-treatment with another strong P-gp inducer decreased afatinib exposure by 34%.
Atazanavir; Cobicistat: (Moderate) If the concomitant use of cobicistat and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of cobicistat. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and cobicistat is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Brigatinib: (Moderate) If the concomitant use of brigatinib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of brigatinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate. Brigatinib is a P-gp inhibitor in vitro and may have the potential to increase concentrations of P-gp substrates. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Cabozantinib: (Moderate) If the concomitant use of cabozantinib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of cabozantinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate. Cabozantinib is a P-gp inhibitor and has the potential to increase plasma concentrations of P-gp substrates; however, the clinical relevance of this finding is unknown. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Cannabidiol: (Moderate) If the concomitant use of cannabidiol and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of cannabidiol. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and cannabidiol is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Capmatinib: (Moderate) If the concomitant use of capmatinib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of capmatinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and capmatinib is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Carbamazepine: (Major) Increase the daily dose of afatinib by 10 mg as tolerated if the concomitant use with carbamazepine is necessary; resume the previous dose of afatinib 2 to 3 days after discontinuation of carbamazepine. Afatinib is a P-glycoprotein (P-gp) substrate and carbamazepine is a P-gp inducer; coadministration may decrease plasma concentrations of afatinib. Pre-treatment with another strong P-gp inducer decreased afatinib exposure by 34%.
Carvedilol: (Moderate) If the concomitant use of carvedilol and afatinib is necessary, consider reducing the afatinib dose by 10 mg per day if the original dose is not tolerated; resume the previous dose of afatinib as tolerated after discontinuation of carvedilol. Afatinib is a P-glycoprotein (P-gp) substrate and inhibitor in vitro, and carvedilol is a weak P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration of another P-gp inhibitor, ritonavir (200 mg twice daily for 3 days), 1 hour before afatinib (single dose) increased the afatinib AUC and Cmax by 48% and 39%, respectively; there was no change in the afatinib AUC when ritonavir was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with ritonavir, and 111% and 105% when ritonavir was administered 6 hours after afatinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise.
Cholera Vaccine: (Moderate) Patients receiving immunosuppressant medications may have a diminished response to the live cholera vaccine. When feasible, administer indicated vaccines prior to initiating immunosuppressant medications. Counsel patients receiving immunosuppressant medications about the possibility of a diminished vaccine response and to continue to follow precautions to avoid exposure to cholera bacteria after receiving the vaccine.
Clarithromycin: (Moderate) If the concomitant use of clarithromycin and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of clarithromycin. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and clarithromycin is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Cobicistat: (Moderate) If the concomitant use of cobicistat and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of cobicistat. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and cobicistat is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Conivaptan: (Moderate) If the concomitant use of conivaptan and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of conivaptan. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and conivaptan is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Cyclosporine: (Moderate) If the concomitant use of cyclosporine and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of cyclosporine. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and cyclosporine is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Daclatasvir: (Moderate) If the concomitant use of daclatasvir and afatinib is necessary, consider reducing the afatinib dose by 10 mg per day if the original dose is not tolerated; resume the previous dose of afatinib as tolerated after discontinuation of daclatasvir. Afatinib is a P-glycoprotein (P-gp) substrate and inhibitor in vitro, and daclatasvir is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. The ratio of digoxin Cmax, AUC, and Cmin when administered with daclatasvir (60 mg daily) or alone was 1.65, 1.27, and 1.18, respectively. Administration of another P-gp inhibitor, ritonavir (200 mg twice daily for 3 days), 1 hour before afatinib (single dose) increased the afatinib AUC and Cmax by 48% and 39%, respectively; there was no change in the afatinib AUC when ritonavir was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with ritonavir, and 111% and 105% when ritonavir was administered 6 hours after afatinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise.
Danicopan: (Moderate) If the concomitant use of danicopan and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of danicopan. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and danicopan is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC of afatinib was 119% when coadministered with the same P-gp inhibitor, and 111% when the inhibitor was administered 6 hours after afatinib.
Daridorexant: (Moderate) If the concomitant use of daridorexant and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of daridorexant. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and daridorexant is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC of afatinib was 119% when coadministered with the same P-gp inhibitor, and 111% when the inhibitor was administered 6 hours after afatinib.
Darunavir; Cobicistat: (Moderate) If the concomitant use of cobicistat and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of cobicistat. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and cobicistat is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Darunavir; Cobicistat; Emtricitabine; Tenofovir alafenamide: (Moderate) If the concomitant use of cobicistat and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of cobicistat. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and cobicistat is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Dengue Tetravalent Vaccine, Live: (Moderate) Patients receiving immunosuppressant medications may have a diminished response to the dengue virus vaccine. When feasible, administer indicated vaccines at least 2 weeks prior to initiating immunosuppressant medications. If vaccine administration is necessary, consider revaccination following restoration of immune competence. Counsel patients receiving immunosuppressant medications about the possibility of a diminished vaccine response and to continue to follow precautions to avoid exposure after receiving the vaccine.
Dextromethorphan; Quinidine: (Moderate) If the concomitant use of quinidine and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of quinidine. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and quinidine is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Dronedarone: (Moderate) If the concomitant use of dronedarone and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of dronedarone. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and dronedarone is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Elacestrant: (Moderate) If the concomitant use of elacestrant and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of elacestrant. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and elacestrant is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC of afatinib was 119% when coadministered with the same P-gp inhibitor, and 111% when the inhibitor was administered 6 hours after afatinib.
Elexacaftor; tezacaftor; ivacaftor: (Moderate) If the concomitant use of ivacaftor and afatinib is necessary, consider reducing the afatinib dose by 10 mg per day if the original dose is not tolerated; resume the previous dose of afatinib as tolerated after discontinuation of ivacaftor. Afatinib is a P-glycoprotein (P-gp) substrate and inhibitor in vitro. Ivacaftor and its M1 metabolite are weak P-gp inhibitors; coadministration may increase plasma concentrations of afatinib. Coadministration of ivacaftor with digoxin, a sensitive P-gp substrate, increased digoxin exposure by 1.3-fold. Administration of another P-gp inhibitor, ritonavir (200 mg twice daily for 3 days), 1 hour before afatinib (single dose) increased the afatinib AUC and Cmax by 48% and 39%, respectively; there was no change in the afatinib AUC when ritonavir was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with ritonavir, and 111% and 105% when ritonavir was administered 6 hours after afatinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise.
Eliglustat: (Moderate) If the concomitant use of eliglustat and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of eliglustat. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and eliglustat is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Alafenamide: (Moderate) If the concomitant use of cobicistat and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of cobicistat. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and cobicistat is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Disoproxil Fumarate: (Moderate) If the concomitant use of cobicistat and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of cobicistat. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and cobicistat is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Enasidenib: (Moderate) If the concomitant use of enasidenib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of enasidenib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and enasidenib is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Erdafitinib: (Moderate) If the concomitant use of erdafitinib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of erdafitinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and erdafitinib is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC of afatinib was 119% when coadministered with the same P-gp inhibitor, and 111% when the inhibitor was administered 6 hours after afatinib.
Erythromycin: (Moderate) If the concomitant use of erythromycin and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of erythromycin. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and erythromycin is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Etravirine: (Moderate) If the concomitant use of etravirine and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of etravirine. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and etravirine is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Flibanserin: (Moderate) If the concomitant use of flibanserin and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of flibanserin. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and flibanserin is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Fosamprenavir: (Major) Increase the daily dose of afatinib by 10 mg as tolerated if the concomitant use with fosamprenavir is necessary; resume the previous dose of afatinib 2 to 3 days after discontinuation of fosamprenavir. Afatinib is a P-glycoprotein (P-gp) substrate and fosamprenavir is a P-gp inducer; coadministration may decrease plasma concentrations of afatinib. Pre-treatment with another strong P-gp inducer decreased afatinib exposure by 34%.
Fosphenytoin: (Major) Increase the daily dose of afatinib by 10 mg as tolerated if the concomitant use with fosphenytoin is necessary; resume the previous dose of afatinib 2 to 3 days after discontinuation of fosphenytoin. Afatinib is a P-glycoprotein (P-gp) substrate and fosphenytoin is a P-gp inducer; coadministration may decrease plasma concentrations of afatinib. Pre-treatment with another strong P-gp inducer decreased afatinib exposure by 34%.
Fostamatinib: (Moderate) If the concomitant use of fostamatinib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of fostamatinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and fostamatinib is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Futibatinib: (Moderate) If the concomitant use of futibatinib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of futibatinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and futibatinib is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Gilteritinib: (Moderate) If the concomitant use of gilteritinib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of gilteritinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and gilteritinib is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Glecaprevir; Pibrentasvir: (Moderate) If the concomitant use of glecaprevir and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of glecaprevir. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and glecaprevir is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib. (Moderate) If the concomitant use of pibrentasvir and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of pibrentasvir. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and pibrentasvir is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Grapefruit juice: (Major) Due to the potential for increased afatinib exposure, patients should be advised to avoid intake of grapefruit or grapefruit juice during afatinib therapy. Afatinib is a P-glycoprotein (P-gp) substrate and inhibitor in vitro, and grapefruit juice is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration of another P-gp inhibitor 1 hour before afatinib (single dose) increased the afatinib AUC and Cmax by 48% and 39%, respectively; there was no change in the afatinib AUC when the Pgp inhibitor was administered at the same time as afatinib or 6 hours later. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at an afatinib dose of 20 mg per day, but does not address a minimum dose otherwise.
Isoniazid, INH; Pyrazinamide, PZA; Rifampin: (Major) Increase the daily dose of afatinib by 10 mg as tolerated if the concomitant use with rifampin is necessary; resume the previous dose of afatinib 2 to 3 days after discontinuation of rifampin. Afatinib is a P-glycoprotein (P-gp) substrate and rifampin is a P-gp inducer; coadministration may decrease plasma concentrations of afatinib. Pre-treatment with rifampin decreased afatinib exposure by 34%.
Isoniazid, INH; Rifampin: (Major) Increase the daily dose of afatinib by 10 mg as tolerated if the concomitant use with rifampin is necessary; resume the previous dose of afatinib 2 to 3 days after discontinuation of rifampin. Afatinib is a P-glycoprotein (P-gp) substrate and rifampin is a P-gp inducer; coadministration may decrease plasma concentrations of afatinib. Pre-treatment with rifampin decreased afatinib exposure by 34%.
Istradefylline: (Moderate) If the concomitant use of istradefylline and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of istradefylline. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate. Istradefylline inhibits P-gp. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Itraconazole: (Moderate) If the concomitant use of itraconazole and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of itraconazole. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and itraconazole is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Ivacaftor: (Moderate) If the concomitant use of ivacaftor and afatinib is necessary, consider reducing the afatinib dose by 10 mg per day if the original dose is not tolerated; resume the previous dose of afatinib as tolerated after discontinuation of ivacaftor. Afatinib is a P-glycoprotein (P-gp) substrate and inhibitor in vitro. Ivacaftor and its M1 metabolite are weak P-gp inhibitors; coadministration may increase plasma concentrations of afatinib. Coadministration of ivacaftor with digoxin, a sensitive P-gp substrate, increased digoxin exposure by 1.3-fold. Administration of another P-gp inhibitor, ritonavir (200 mg twice daily for 3 days), 1 hour before afatinib (single dose) increased the afatinib AUC and Cmax by 48% and 39%, respectively; there was no change in the afatinib AUC when ritonavir was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with ritonavir, and 111% and 105% when ritonavir was administered 6 hours after afatinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise.
Ketoconazole: (Moderate) If the concomitant use of ketoconazole and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of ketoconazole. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and ketoconazole is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Lansoprazole; Amoxicillin; Clarithromycin: (Moderate) If the concomitant use of clarithromycin and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of clarithromycin. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and clarithromycin is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Lapatinib: (Moderate) If the concomitant use of lapatinib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of lapatinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and lapatinib is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Lasmiditan: (Moderate) If the concomitant use of lasmiditan and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of lasmiditan. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and lasmiditan is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Ledipasvir; Sofosbuvir: (Moderate) If the concomitant use of ledipasvir; sofosbuvir and afatinib is necessary, consider reducing the afatinib dose by 10 mg per day if the original dose is not tolerated; resume the previous dose of afatinib as tolerated after discontinuation of ledipasvir; sofosbuvir. Afatinib is a P-glycoprotein (P-gp) substrate and inhibitor in vitro, and ledipasvir is a weak P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration of another P-gp inhibitor, ritonavir (200 mg twice daily for 3 days), 1 hour before afatinib (single dose) increased the afatinib AUC and Cmax by 48% and 39%, respectively; there was no change in the afatinib AUC when ritonavir was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with ritonavir, and 111% and 105% when ritonavir was administered 6 hours after afatinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise.
Lenacapavir: (Moderate) If the concomitant use of lenacapavir and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of lenacapavir. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and lenacapavir is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC of afatinib was 119% when coadministered with the same P-gp inhibitor, and 111% when the inhibitor was administered 6 hours after afatinib.
Levoketoconazole: (Moderate) If the concomitant use of ketoconazole and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of ketoconazole. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and ketoconazole is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Lomitapide: (Moderate) If the concomitant use of lomitapide and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of lomitapide. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and lomitapide is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Lonafarnib: (Moderate) If the concomitant use of lonafarnib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of lonafarnib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and lonafarnib is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Lopinavir; Ritonavir: (Moderate) If the concomitant use of ritonavir and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of ritonavir. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and ritonavir is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Lorlatinib: (Major) Increase the daily dose of afatinib by 10 mg as tolerated if the concomitant use with lorlatinib is necessary; resume the previous dose of afatinib 2 to 3 days after discontinuation of lorlatinib. Afatinib is a P-glycoprotein (P-gp) substrate and lorlatinib is a P-gp inducer; coadministration may decrease plasma concentrations of afatinib. Pre-treatment with another strong P-gp inducer decreased afatinib exposure by 34%.
Lumacaftor; Ivacaftor: (Major) Avoid coadministration of afatinib with lumacaftor; ivacaftor if possible, due to unpredictability of clinical effect. Although the clinical significance of this interaction is unknown, concurrent use of afatinib and lumacaftor; ivacaftor may alter afatinib exposure; caution and close monitoring are advised if these drugs are used together. Afatinib is a substrate of the drug transporter P-glycoprotein (P-gp). In vitro data suggest that lumacaftor; ivacaftor has the potential to both induce and inhibit P-gp. The net effect of lumacaftor; ivacaftor on P-gp transport is not clear, but substrate exposure may be affected leading to either decreased efficacy of afatinib or increased or prolonged therapeutic effects and adverse events. FDA-approved labeling for afatinib recommends reducing the dose by 10 mg per day if the original dose is not tolerated when administered with P-gp inhibitors, and increasing the dose by 10 mg/day as tolerated when given with P-gp inducers. Administration of the P-gp inhibitor, ritonavir (200 mg twice daily for 3 days), 1 hour before afatinib (single dose) increased the afatinib AUC and Cmax by 48% and 39%, respectively; there was no change in the afatinib AUC when ritonavir was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with ritonavir, and 111% and 105% when ritonavir was administered 6 hours after afatinib. Pre-treatment with a strong P-gp inducer, rifampicin (600 mg daily for 7 days), decreased the afatinib AUC by 34% and the Cmax by 22%. (Moderate) If the concomitant use of ivacaftor and afatinib is necessary, consider reducing the afatinib dose by 10 mg per day if the original dose is not tolerated; resume the previous dose of afatinib as tolerated after discontinuation of ivacaftor. Afatinib is a P-glycoprotein (P-gp) substrate and inhibitor in vitro. Ivacaftor and its M1 metabolite are weak P-gp inhibitors; coadministration may increase plasma concentrations of afatinib. Coadministration of ivacaftor with digoxin, a sensitive P-gp substrate, increased digoxin exposure by 1.3-fold. Administration of another P-gp inhibitor, ritonavir (200 mg twice daily for 3 days), 1 hour before afatinib (single dose) increased the afatinib AUC and Cmax by 48% and 39%, respectively; there was no change in the afatinib AUC when ritonavir was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with ritonavir, and 111% and 105% when ritonavir was administered 6 hours after afatinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise.
Lumacaftor; Ivacaftor: (Major) Avoid coadministration of afatinib with lumacaftor; ivacaftor if possible, due to unpredictability of clinical effect. Although the clinical significance of this interaction is unknown, concurrent use of afatinib and lumacaftor; ivacaftor may alter afatinib exposure; caution and close monitoring are advised if these drugs are used together. Afatinib is a substrate of the drug transporter P-glycoprotein (P-gp). In vitro data suggest that lumacaftor; ivacaftor has the potential to both induce and inhibit P-gp. The net effect of lumacaftor; ivacaftor on P-gp transport is not clear, but substrate exposure may be affected leading to either decreased efficacy of afatinib or increased or prolonged therapeutic effects and adverse events. FDA-approved labeling for afatinib recommends reducing the dose by 10 mg per day if the original dose is not tolerated when administered with P-gp inhibitors, and increasing the dose by 10 mg/day as tolerated when given with P-gp inducers. Administration of the P-gp inhibitor, ritonavir (200 mg twice daily for 3 days), 1 hour before afatinib (single dose) increased the afatinib AUC and Cmax by 48% and 39%, respectively; there was no change in the afatinib AUC when ritonavir was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with ritonavir, and 111% and 105% when ritonavir was administered 6 hours after afatinib. Pre-treatment with a strong P-gp inducer, rifampicin (600 mg daily for 7 days), decreased the afatinib AUC by 34% and the Cmax by 22%.
Maribavir: (Moderate) If the concomitant use of maribavir and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of maribavir. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and maribavir is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Mefloquine: (Moderate) If the concomitant use of mefloquine and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of mefloquine. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and mefloquine is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Meropenem: (Major) Increase the daily dose of afatinib by 10 mg as tolerated if the concomitant use with meropenem is necessary; resume the previous dose of afatinib 2 to 3 days after discontinuation of meropenem. Afatinib is a P-gp substrate and meropenem is a P-gp inducer; coadministration may decrease plasma concentrations of afatinib. Pre-treatment with another strong P-gp inducer decreased afatinib exposure by 34%.
Meropenem; Vaborbactam: (Major) Increase the daily dose of afatinib by 10 mg as tolerated if the concomitant use with meropenem is necessary; resume the previous dose of afatinib 2 to 3 days after discontinuation of meropenem. Afatinib is a P-gp substrate and meropenem is a P-gp inducer; coadministration may decrease plasma concentrations of afatinib. Pre-treatment with another strong P-gp inducer decreased afatinib exposure by 34%.
Mifepristone: (Moderate) If the concomitant use of mifepristone and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of mifepristone. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and mifepristone is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Mitapivat: (Moderate) If the concomitant use of mitapivat and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of mitapivat. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and mitapivat is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Nelfinavir: (Moderate) If the concomitant use of nelfinavir and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of nelfinavir. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and nelfinavir is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Neratinib: (Moderate) If the concomitant use of neratinib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of neratinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and neratinib is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Nirmatrelvir; Ritonavir: (Moderate) If the concomitant use of ritonavir and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of ritonavir. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and ritonavir is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Osimertinib: (Moderate) If the concomitant use of osimertinib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of osimertinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate. Osimertinib inhibits P-gp. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Pacritinib: (Moderate) If the concomitant use of pacritinib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of pacritinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and pacritinib is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Phenobarbital: (Major) Increase the daily dose of afatinib by 10 mg as tolerated if the concomitant use with phenobarbital is necessary; resume the previous dose of afatinib 2 to 3 days after discontinuation of phenobarbital. Afatinib is a P-glycoprotein (P-gp) substrate and phenobarbital is a P-gp inducer; coadministration may decrease plasma concentrations of afatinib. Pre-treatment with another strong P-gp inducer decreased afatinib exposure by 34%.
Phenobarbital; Hyoscyamine; Atropine; Scopolamine: (Major) Increase the daily dose of afatinib by 10 mg as tolerated if the concomitant use with phenobarbital is necessary; resume the previous dose of afatinib 2 to 3 days after discontinuation of phenobarbital. Afatinib is a P-glycoprotein (P-gp) substrate and phenobarbital is a P-gp inducer; coadministration may decrease plasma concentrations of afatinib. Pre-treatment with another strong P-gp inducer decreased afatinib exposure by 34%.
Phenytoin: (Major) Increase the daily dose of afatinib by 10 mg as tolerated if the concomitant use with phenytoin is necessary; resume the previous dose of afatinib 2 to 3 days after discontinuation of phenytoin. Afatinib is a P-glycoprotein (P-gp) substrate and phenytoin is a P-gp inducer; coadministration may decrease plasma concentrations of afatinib. Pre-treatment with another strong P-gp inducer decreased afatinib exposure by 34%.
Pirtobrutinib: (Moderate) If the concomitant use of pirtobrutinib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of pirtobrutinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and pirtobrutinib is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC of afatinib was 119% when coadministered with the same P-gp inhibitor, and 111% when the inhibitor was administered 6 hours after afatinib.
Posaconazole: (Moderate) If the concomitant use of posaconazole and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of posaconazole. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and posaconazole is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Pretomanid: (Moderate) If the concomitant use of pretomanid and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of pretomanid. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and pretomanid is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC of afatinib was 119% when coadministered with the same P-gp inhibitor, and 111% when the inhibitor was administered 6 hours after afatinib.
Primidone: (Major) Increase the daily dose of afatinib by 10 mg as tolerated if the concomitant use with primidone is necessary; resume the previous dose of afatinib 2 to 3 days after discontinuation of primidone. Afatinib is a P-glycoprotein (P-gp) substrate and primidone is a P-gp inducer; coadministration may decrease plasma concentrations of afatinib. Pre-treatment with another strong P-gp inducer decreased afatinib exposure by 34%.
Propafenone: (Moderate) If the concomitant use of propafenone and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of propafenone. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and propafenone is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Quinidine: (Moderate) If the concomitant use of quinidine and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of quinidine. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and quinidine is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Ranolazine: (Moderate) If the concomitant use of ranolazine and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of ranolazine. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and ranolazine is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Rifampin: (Major) Increase the daily dose of afatinib by 10 mg as tolerated if the concomitant use with rifampin is necessary; resume the previous dose of afatinib 2 to 3 days after discontinuation of rifampin. Afatinib is a P-glycoprotein (P-gp) substrate and rifampin is a P-gp inducer; coadministration may decrease plasma concentrations of afatinib. Pre-treatment with rifampin decreased afatinib exposure by 34%.
Ritonavir: (Moderate) If the concomitant use of ritonavir and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of ritonavir. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and ritonavir is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Rolapitant: (Moderate) If the concomitant use of rolapitant and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of rolapitant. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and rolapitant is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Saquinavir: (Moderate) If the concomitant use of saquinavir and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of saquinavir. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and saquinavir is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Sarecycline: (Moderate) If the concomitant use of sarecycline and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of sarecycline. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate; sarecycline is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
SARS-CoV-2 (COVID-19) vaccines: (Moderate) Patients receiving immunosuppressant medications may have a diminished response to the SARS-CoV-2 virus vaccine. When feasible, administer indicated vaccines prior to initiating immunosuppressant medications. Counsel patients receiving immunosuppressant medications about the possibility of a diminished vaccine response and to continue to follow precautions to avoid exposure to SARS-CoV-2 virus after receiving the vaccine.
SARS-CoV-2 Virus (COVID-19) Adenovirus Vector Vaccine: (Moderate) Patients receiving immunosuppressant medications may have a diminished response to the SARS-CoV-2 virus vaccine. When feasible, administer indicated vaccines prior to initiating immunosuppressant medications. Counsel patients receiving immunosuppressant medications about the possibility of a diminished vaccine response and to continue to follow precautions to avoid exposure to SARS-CoV-2 virus after receiving the vaccine.
SARS-CoV-2 Virus (COVID-19) mRNA Vaccine: (Moderate) Patients receiving immunosuppressant medications may have a diminished response to the SARS-CoV-2 virus vaccine. When feasible, administer indicated vaccines prior to initiating immunosuppressant medications. Counsel patients receiving immunosuppressant medications about the possibility of a diminished vaccine response and to continue to follow precautions to avoid exposure to SARS-CoV-2 virus after receiving the vaccine.
SARS-CoV-2 Virus (COVID-19) Recombinant Spike Protein Nanoparticle Vaccine: (Moderate) Patients receiving immunosuppressant medications may have a diminished response to the SARS-CoV-2 virus vaccine. When feasible, administer indicated vaccines prior to initiating immunosuppressant medications. Counsel patients receiving immunosuppressant medications about the possibility of a diminished vaccine response and to continue to follow precautions to avoid exposure to SARS-CoV-2 virus after receiving the vaccine.
Selpercatinib: (Moderate) If the concomitant use of selpercatinib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of selpercatinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and selpercatinib is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Sodium Phenylbutyrate; Taurursodiol: (Moderate) If the concomitant use of taurursodiol and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of taurursodiol. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and taurursodiol is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC of afatinib was 119% when coadministered with the same P-gp inhibitor, and 111% when the inhibitor was administered 6 hours after afatinib.
Sofosbuvir; Velpatasvir: (Moderate) If the concomitant use of velpatasvir and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of velpatasvir. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and velpatasvir is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Sofosbuvir; Velpatasvir; Voxilaprevir: (Moderate) If the concomitant use of velpatasvir and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of velpatasvir. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and velpatasvir is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib. (Moderate) If the concomitant use of voxilaprevir and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of voxilaprevir. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and voxilaprevir is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Sorafenib: (Moderate) If the concomitant use of sorafenib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of sorafenib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate. Sorafenib inhibits P-gp in vitro and may increase the concentrations of concomitantly administered drugs that are P-gp substrates. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Sotorasib: (Moderate) If the concomitant use of sotorasib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of sotorasib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and sotorasib is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Sparsentan: (Moderate) If the concomitant use of sparsentan and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of sparsentan. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and sparsentan is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC of afatinib was 119% when coadministered with the same P-gp inhibitor, and 111% when the inhibitor was administered 6 hours after afatinib.
St. John's Wort, Hypericum perforatum: (Major) Increase the daily dose of afatinib by 10 mg as tolerated if the concomitant use with St. Johns Wort is necessary; resume the previous dose of afatinib 2 to 3 days after discontinuation of St. Johns Wort. Afatinib is a P-glycoprotein (P-gp) substrate and St. Johns Wort is a P-gp inducer; coadministration may decrease plasma concentrations of afatinib. Pre-treatment with another strong P-gp inducer decreased afatinib exposure by 34%.
Tacrolimus: (Moderate) If the concomitant use of tacrolimus and afatinib is necessary, consider reducing the afatinib dose by 10 mg per day if the original dose is not tolerated; resume the previous dose of afatinib as tolerated after discontinuation of tacrolimus. Afatinib is a P-glycoprotein (P-gp) substrate and inhibitor in vitro. While data is conflicting, tacrolimus may be a weak P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration of another P-gp inhibitor, ritonavir (200 mg twice daily for 3 days), 1 hour before afatinib (single dose) increased the afatinib AUC and Cmax by 48% and 39%, respectively; there was no change in the afatinib AUC when ritonavir was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with ritonavir, and 111% and 105% when ritonavir was administered 6 hours after afatinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise.
Tedizolid: (Moderate) If possible, stop use of afatinib temporarily during treatment with oral tedizolid. If coadministration cannot be avoided, closely monitor for afatinib-associated adverse events. Afatinib plasma concentrations may be increased when administered concurrently with oral tedizolid. Afatinib is an in vitro substrate of the Breast Cancer Resistance Protein (BCRP); oral tedizolid inhibits BCRP in the intestine.
Temsirolimus: (Moderate) If the concomitant use of temsirolimus and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of temsirolimus. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and temsirolimus is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Tepotinib: (Moderate) If the concomitant use of tepotinib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of tepotinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and tepotinib is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Tezacaftor; Ivacaftor: (Moderate) If the concomitant use of ivacaftor and afatinib is necessary, consider reducing the afatinib dose by 10 mg per day if the original dose is not tolerated; resume the previous dose of afatinib as tolerated after discontinuation of ivacaftor. Afatinib is a P-glycoprotein (P-gp) substrate and inhibitor in vitro. Ivacaftor and its M1 metabolite are weak P-gp inhibitors; coadministration may increase plasma concentrations of afatinib. Coadministration of ivacaftor with digoxin, a sensitive P-gp substrate, increased digoxin exposure by 1.3-fold. Administration of another P-gp inhibitor, ritonavir (200 mg twice daily for 3 days), 1 hour before afatinib (single dose) increased the afatinib AUC and Cmax by 48% and 39%, respectively; there was no change in the afatinib AUC when ritonavir was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with ritonavir, and 111% and 105% when ritonavir was administered 6 hours after afatinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise.
Tipranavir: (Major) Increase the daily dose of afatinib by 10 mg as tolerated if the concomitant use with tipranavir (boosted with ritonavir) is necessary; resume the previous dose of afatinib 2 to 3 days after discontinuation of tipranavir/ritonavir). Afatinib is a P-glycoprotein (P-gp) substrate. When administered with ritonavir, P-gp is inhibited with the first dose of tipranavir followed by strong induction over time; coadministration may decrease plasma concentrations of afatinib. Pre-treatment with another strong P-gp inducer decreased afatinib exposure by 34%.
Trandolapril; Verapamil: (Moderate) If the concomitant use of verapamil and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of verapamil. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and verapamil is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Tucatinib: (Moderate) If the concomitant use of tucatinib and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of tucatinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and tucatinib is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Vemurafenib: (Moderate) If the concomitant use of vemurafenib and afatinib is necessary, consider reducing the afatinib dose by 10 mg per day if the original dose is not tolerated; resume the previous dose of afatinib as tolerated after discontinuation of vemurafenib. Afatinib is a P-glycoprotein (P-gp) substrate and inhibitor in vitro, and vemurafenib is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Coadministration of vemurafenib (960 mg twice daily for 22 days) with digoxin (single dose, 0.25 mg), a sensitive P-gp substrate, to 22 cancer patients increased the digoxin AUC and Cmax by 1.8-fold and 1.5-fold, respectively. Administration of another P-gp inhibitor, ritonavir (200 mg twice daily for 3 days), 1 hour before afatinib (single dose) increased the afatinib AUC and Cmax by 48% and 39%, respectively; there was no change in the afatinib AUC when ritonavir was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with ritonavir, and 111% and 105% when ritonavir was administered 6 hours after afatinib. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise.
Venetoclax: (Moderate) If the concomitant use of venetoclax and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of venetoclax. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and venetoclax is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Verapamil: (Moderate) If the concomitant use of verapamil and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of verapamil. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and verapamil is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Voclosporin: (Moderate) If the concomitant use of voclosporin and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of voclosporin. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-gp substrate and voclosporin is a P-gp inhibitor. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib. The manufacturer of voclosporin recommends to reduce dosage of certain P-gp substrates with a narrow therapeutic window when co-administered with voclosporin.
Vonoprazan; Amoxicillin; Clarithromycin: (Moderate) If the concomitant use of clarithromycin and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of clarithromycin. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and clarithromycin is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Zonisamide: (Moderate) If the concomitant use of zonisamide and afatinib is necessary, monitor for afatinib-related adverse reactions, especially when starting or stopping zonisamide or changing the zonisamide dose. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of zonisamide. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and zonisamide is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Afatinib is a 4-anilinoquinazoline tyrosine kinase inhibitor that irreversibly inhibits tyrosine kinase autophosphorylation by covalently binding to the kinase domains of EGFR (ErbB1), HER2 (ErbB2), and HER4 (ErbB4). This results in blockage of downstream EGFR signal transduction pathways, cell cycle arrest, and inhibition of angiogenesis.
Ligand binding (e.g., EGF, PDGF) activates receptor tyrosine kinases, causing phosphorylation of tyrosine residue in different substrates and leading to cell proliferation, differentiation, migration, metabolism, and apoptosis. Certain EGFR mutations, including non-resistant mutations in its kinase domain, can result in autophosphorylation of the receptor, leading to receptor activation (sometimes in the absence of ligand binding). Non-resistant mutations are those occurring in exons constituting the kinase domain of EGFR that lead to increased receptor activation, the most common of which are exon 21 L858R substitutions and exon 19 deletions. Afatinib inhibited autophosphorylation and/or in vitro proliferation of cell lines expressing wild-type EGFR and in those expressing selected EGFR exon 19 deletion mutations, exon 21 L858R mutations, or other less common non-resistant mutations, at concentrations achieved in patients; it also inhibited in vitro proliferation of cell lines overexpressing HER2.
Afatinib is administered orally, and is approximately 95% bound to plasma proteins. Total body clearance after a dose of 40 mg at steady state is 1,070 mL/min and volume of distribution is 2,870 L. Time to reach steady state is approximately 8 days. The elimination half-life is approximately 37 hours. Afatinib is primarily excreted as unchanged drug via the feces (85%), with renal elimination accounting for 4%. Only 12% of the recovered dose is present as metabolites.
Affected cytochrome P450 isoenzymes and drug transporters: P-glylcoprotein (P-gp)
Afatinib undergoes minimal enzymatic metabolism, mainly via Michael adduct formation to proteins and nucleophilic small molecules. Approximately 9% of the total metabolic turnover is a result of CYP450-dependent reactions, and 2% of the dose is metabolized by flavin containing monooxygenase 3 (FMO3). Based on in vitro data, afatinib is both a substrate and an inhibitor of P-glycoprotein; concomitant use with inhibitors or inducers of P-gp may affect exposure to afatinib.
-Route-Specific Pharmacokinetics
Oral Route
Afatinib is slowly absorbed, with peak plasma levels occurring 2 to 5 hours after dosing. Relative bioavailability after tablet administration compared to an oral solution is 92%. Afatinib exposure increases in a non-linear, greater than dose-proportional manner. Over a range of 20 to 50 mg, the mean AUC at steady state is 380 to 1,130 ng x hours/mL and Cmax 24.5 to 77 ng/mL. When given with a high-fat meal, Cmax decreases by 50%, and AUC decreases by 39%. Afatinib should be given on an empty stomach due to the potential for decreased efficacy resulting from the decrease in exposure.
-Special Populations
Hepatic Impairment
Afatinib is primarily eliminated by biliary and fecal excretion. Following a single dose, afatinib exposure was not affected by mild to moderate hepatic impairment (Child Pugh A and B). Afatinib has not been studied in patients with severe hepatic impairment (Child Pugh C).
Renal Impairment
The geometric mean AUC of afatinib was 50% higher in patients with severe renal impairment (CrCL 15 to 29 mL/min; n = 8) and 22% higher in patients with moderate renal impairment (CrCL 30 to 59 mL/min; n = 8) compared to patients with normal renal function (CrCL > 90 mL/min; n = 14) in a single-dose pharmacokinetic study. The geometric mean Cmax was 22% higher in patients with severe renal impairment compared to normal renal function; the Cmax of patients with moderate renal impairment was comparable to patients with normal renal function. Afatinib has not been studied in patients with CrCL < 15 mL/min or on dialysis.
Pediatrics
The pharmacokinetic parameters of afatinib in pediatric patients (age 2 to 16 years; afatinib dosed at 80% of the adult dose per BSA) were within range of values in adults in a single-arm, open-label, multicenter trial (n = 37); no new safety signals were observed.
Geriatric
No significant differences in pharmacokinetics, safety, or efficacy are observed based upon patient age.
Gender Differences
No significant pharmacokinetic differences are observed based upon patient gender.
Ethnic Differences
No significant pharmacokinetic differences are observed based upon patient ethnicity.
Obesity
No significant pharmacokinetic differences are observed based upon patient weight.