Imipenem; cilastatin; relebactam is a parenteral combination of a carbapenem antibacterial, a renal dihydropeptidase inhibitor, and a beta-lactamase inhibitor indicated for the treatment of complicated urinary tract infections, including pyelonephritis, and complicated intraabdominal infections in adults who have limited or no alternative treatment options as well as for the treatment of hospital-acquired and ventilator-associated pneumonia in adults. Imipenem; cilastatin; relebactam retains activity in the presence of tested efflux pumps and has shown activity against some isolates of P. aeruginosa and Enterobacteriaceae that produce relebactam-susceptible beta-lactamases concomitant with loss of entry porins. Relebactam protects imipenem from degradation by certain serine beta-lactamases; however, imipenem; cilastatin; relebactam is still not active against most isolates containing metallo-beta-lactamases (MBL) and some oxacillinases with carbapenemase activity. Seizures have been reported with imipenem; cilastatin, especially when the recommended dosage is exceeded and most commonly in patients with central nervous system (CNS) disorders and/or impaired renal function.
General Administration Information
For storage information, see the specific product information within the How Supplied section.
Route-Specific Administration
Injectable Administration
-Visually inspect parenteral products for particulate matter and discoloration prior to administration whenever solution and container permit. Constituted solutions of imipenem; cilastatin; relebactam range from colorless to yellow.
-Each vial contains 1.25 g of imipenem; cilastatin; relebactam (500 mg imipenem, 500 mg cilastatin, and 250 mg relebactam).
Intravenous Administration
Reconstitution and Dilution:
-Using aseptic technique, constitute the vial with an appropriate diluent, including 0.9% Sodium Chloride Injection, 5% Dextrose Injection, 5% Dextrose and 0.9% Sodium Chloride Injection, 5% Dextrose and 0.45% Sodium Chloride Injection, or 5% Dextrose and 0.225% Sodium Chloride Injection.
-Imipenem; cilastatin; relebactam has low aqueous solubility. To ensure complete dissolution, it is important to adhere to the following instructions.
--Use diluents available in 100 mL prefilled infusion bags or aseptically withdraw 100 mL of the desired diluent and transfer to an empty infusion bag.
-Withdraw two 10 mL aliquots of diluent from the appropriate 100 mL infusion bag, and constitute the vial with one 10 mL aliquot of the diluent.
-After constitution, shake the vial well and transfer the resulting suspension into the remaining 80 mL of the infusion bag.
-Add the second 10 mL aliquot of infusion diluent to the vial and shake well to ensure complete transfer of vial contents. Transfer the resulting suspension to the infusion solution.
-Agitate the resulting mixture until clear.
-The volume of the prepared solution to be administered is determined based upon renal function.
--CrCl 90 mL/minute or more: Use final volume of 100 mL [1.25 g imipenem; cilastatin; relebactam (500 mg imipenem, 500 mg cilastatin, and 250 mg relebactam)].
-CrCl 60 to 89 mL/minute: Remove 20 mL from the 100 mL infusion bag for a final volume of 80 mL [1 g imipenem; cilastatin; relebactam (400 mg imipenem, 400 mg cilastatin, and 200 mg relebactam)].
-CrCl 30 to 59 mL/minute: Remove 40 mL from the 100 mL infusion bag for a final volume of 60 mL [750 mg imipenem; cilastatin; relebactam (300 mg imipenem, 300 mg cilastatin, and 150 mg relebactam)].
-CrCl 15 to 29 mL/minute or ESRD on hemodialysis: Remove 60 mL from the 100 mL infusion bag for a final volume of 40 mL [500 mg imipenem; cilastatin; relebactam (200 mg imipenem, 200 mg cilastatin, and 100 mg relebactam)].
-Storage: Constituted solutions maintain satisfactory potency for at least 2 hours at room temperature (up to 30 degrees C or 86 degrees F) or 24 hours under refrigeration (2 to 8 degrees C or 36 to 46 degrees F). Do not freeze.
Intermittent IV infusion:
-Administer IV over 30 minutes.
Serious and occasionally fatal hypersensitivity reactions, including anaphylactoid reactions, have been reported in patients receiving beta-lactams. If a hypersensitivity reaction occurs, discontinue imipenem; cilastatin; relebactam immediately. Rash, including generalized and erythematous rash, was reported in 4.1% of patients treated with imipenem; cilastatin; relebactam during clinical trials.
Central nervous system (CNS) adverse reactions, such as seizures, confusion, and myoclonia have been reported during treatment with imipenem; cilastatin, especially when the recommended dosage is exceeded. If CNS adverse reactions including seizures occur, perform a neurological evaluation to determine whether imipenem; cilastatin; relebactam discontinuation is necessary. Headache has been reported in 4% of patients treated with imipenem; cilastatin; relebactam during clinical trials. Other central nervous system adverse reactions occurring in 1% of patients treated with imipenem; cilastatin; relebactam during clinical trials included agitation, apathy, confusional states, delirium, disorientation, slow speech, and drowsiness.
Gastrointestinal adverse events reported with imipenem; cilastatin; relebactam during clinical trials include diarrhea (6% to 7.9%), nausea (6%), vomiting (3%), and constipation (4.1%).
Microbial overgrowth and superinfection can occur with antibiotic use. C. difficile-associated diarrhea (CDAD) or pseudomembranous colitis has been reported with imipenem; cilastatin; relebactam. If pseudomembranous colitis is suspected or confirmed, ongoing antibacterial therapy not directed against C. difficile may need to be discontinued. Institute appropriate fluid and electrolyte management, protein supplementation, C. difficile-directed antibacterial therapy, and surgical evaluation as clinically appropriate.
Anemia was reported in 1% to 10.5% of patients treated with imipenem; cilastatin; relebactam during clinical trials. Decreased hemoglobin (1%) and thrombocytopenia (less than 4%) were also reported in patients treated with imipenem; cilastatin; relebactam during clinical trials. Other hematologic adverse events reported with imipenem; cilastatin include agranulocytosis, hemolytic anemia, increased eosinophils, and positive Coombs' test.
Phlebitis and injection site reaction, including infusion site erythema and pain, were reported in 2% of patients treated with imipenem; cilastatin; relebactam during clinical trials.
Fever was reported in 2% to 4.1% of patients treated with imipenem; cilastatin; relebactam during clinical trials.
Elevated hepatic enzymes, including increased AST (3% to 11.7%) and ALT (3% to 9.8%), were reported in patients treated with imipenem; cilastatin; relebactam during clinical trials. Other hepatobiliary disorders reported with imipenem; cilastatin include hepatic failure and jaundice.
Hypertension and elevated blood pressure occurred in 2% of patients treated with imipenem; cilastatin; relebactam during clinical trials.
Hypokalemia (7.9%) and hyponatremia (6.4%) were reported in patients treated with imipenem; cilastatin; relebactam during clinical trials. Other general laboratory investigation adverse events reported in patients treated with imipenem; cilastatin; relebactam during clinical trials include increased lipase (1%) and increased serum creatinine (less than 1%). Laboratory investigation adverse events noted with imipenem; cilastatin include increased serum lactate dehydrogenase.
Imipenem; cilastatin; relebactam is contraindicated in patients with a history of known severe carbapenem hypersensitivity, cilastatin hypersensitivity, or relebactam hypersensitivity. Serious and occasionally fatal hypersensitivity reactions have been reported in patients being treated with beta-lactams. Before starting imipenem; cilastatin; relebactam therapy, make careful inquiry concerning previous carbapenem hypersensitivity, penicillin hypersensitivity, cephalosporin hypersensitivity, or other beta-lactam or allergen hypersensitivity.
Use imipenem; cilastatin; relebactam cautiously in patients with brain lesions, a history of seizure disorder, or other neurological disease or condition that may lower the seizure threshold, such as head trauma. Seizures may occur when patients have compromised renal function. The risk of imipenem-induced seizures increases when imipenem is given at doses higher than recommended. Continue anticonvulsant therapy in patients with known seizure disorders. Also, use imipenem with caution in patients concomitantly receiving other drugs where potential central nervous system (CNS) effects may be additive.
Consider pseudomembranous colitis in patients presenting with diarrhea after antibacterial use. Careful medical history is necessary as pseudomembranous colitis has been reported to occur over 2 months after the administration of antibacterial agents. Almost all antibacterial agents, including imipenem; cilastatin; relebactam, have been associated with pseudomembranous colitis or C. difficile-associated diarrhea (CDAD) which may range in severity from mild to life-threatening. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile.
Imipenem; cilastatin; relebactam dosage reduction is necessary for patients with renal impairment (CrCl less than 90 mL/minute). Imipenem; cilastatin; relebactam is not recommended for use in patients with renal failure (CrCl less than 15 mL/minute) unless hemodialysis is instituted within 48 hours.
Imipenem; cilastatin; relebactam is known to be substantially excreted by the kidney, and the risk of toxic reactions is greater in patients with impaired renal function. Because geriatric patients are more likely to have impaired renal function, take care in dose selection; it may be useful to monitor renal function. Base dosage adjustments for geriatric patients on renal function. The federal Omnibus Budget Reconciliation Act (OBRA) regulates medication use in residents (e.g., geriatric adults) of long-term care facilities (LTCFs). According to OBRA, use of antibiotics should be limited to confirmed or suspected bacterial infections. Antibiotics are non-selective and may result in the eradication of beneficial microorganisms while promoting the emergence of undesired ones, causing secondary infections such as oral thrush, colitis, or vaginitis. Any antibiotic may cause diarrhea, nausea, vomiting, anorexia, and hypersensitivity reactions.
Imipenem; cilastatin; relebactam use may result in laboratory test interference. A false-positive reaction for glucose in the urine has been observed in patients receiving imipenem and using copper-reduction tests (e.g., Benedict's solution, Fehling's solution, and Clinitest tablets). This reaction, however, has not been observed with glucose oxidase tests (e.g., Tes-tape, Clinistix, Diastix). Additionally, a positive Coombs' test has been observed during imipenem; cilastatin use.
There are insufficient human data to establish whether there is a drug-associated risk for major birth defects, miscarriage, or adverse maternal or fetal outcomes with imipenem; cilastatin; relebactam use during pregnancy. A small study showed that imipenem crossed the placenta with amniotic fluid concentrations averaging approximately 47% (+/- 39%) of the maternal concentration in plasma. The imipenem mean concentration in umbilical venous and arterial blood averaged approximately 33% (+/- 12%) and 31% (+/- 13%) of maternal blood concentrations, respectively. Animal developmental toxicity studies with imipenem; cilastatin revealed no evidence of teratogenicity. When imipenem; cilastatin 100 mg/kg/day IV (approximately equivalent to the maximum recommended human daily dose, MRHD) was given to pregnant cynomolgus monkeys, an increase in embryonic loss was observed. An imipenem; cilastatin dose of 40 mg/kg IV given to pregnant cynomolgus monkeys caused significant maternal toxicity including death and embryofetal loss. In animal studies with relebactam given at plasma exposures equivalent to 8 times the human exposure at the MRHD, there was no associated fetal toxicity, developmental delays, or impaired reproduction in first-generation offspring.
There are insufficient data on the presence of imipenem; cilastatin; relebactam in human breast milk, and no data on the effects on the breast-fed child, or the effects on milk production. Relebactam is present in the milk of lactating rats. Consider the developmental and health benefits of breast-feeding along with the mother's clinical need for imipenem; cilastatin; relebactam and any potential adverse effects on the breast-fed child from imipenem; cilastatin; relebactam or the underlying maternal condition.
Per the manufacturer, this drug has been shown to be active against most strains of the following microorganisms either in vitro and/or in clinical infections: Acinetobacter baumannii, Acinetobacter calcoaceticus, Bacteroides caccae, Bacteroides fragilis, Bacteroides ovatus, Bacteroides stercoris, Bacteroides thetaiotaomicron, Bacteroides uniformis, Bacteroides vulgatus, Citrobacter freundii, Citrobacter koseri, Eggerthella lenta, Enterobacter asburiae, Enterobacter cloacae, Enterococcus faecalis, Escherichia coli, Fusobacterium necrophorum, Fusobacterium nucleatum, Fusobacterium varium, Haemophilus influenzae (beta-lactamase negative), Haemophilus influenzae (beta-lactamase positive), Klebsiella aerogenes, Klebsiella oxytoca, Klebsiella pneumoniae, Parabacteroides distasonis, Parabacteroides goldsteinii, Parabacteroides merdae, Parvimonas micra, Peptoniphilus harei, Peptostreptococcus anaerobius, Prevotella bivia, Pseudomonas aeruginosa, Serratia marcescens, Staphylococcus aureus (MSSA), Streptococcus anginosus, Streptococcus constellatus, Streptococcus pneumoniae, Veillonella parvula
NOTE: The safety and effectiveness in treating clinical infections due to organisms with in vitro data only have not been established in adequate and well-controlled clinical trials.
For the treatment of complicated urinary tract infection (UTI), including pyelonephritis, in patients with limited or no alternative treatment options as well as cystitis* and pyelonephritis due to infections with difficult-to-treat resistance:
-for the treatment of uncomplicated cystitis due infections with difficult-to-treat resistance*:
Intravenous dosage:
Adults: 1.25 g (500 mg imipenem, 500 mg cilastatin, and 250 mg relebactam) IV every 6 hours for 3 to 7 days.
-for the treatment of complicated urinary tract infection (UTI), including pyelonephritis, in patients with limited or no alternative treatment options or infections with difficult-to-treat resistance:
Intravenous dosage:
Adults: 1.25 g (500 mg imipenem, 500 mg cilastatin, and 250 mg relebactam) IV every 6 hours for 7 to 14 days. The FDA-approved duration is 4 to 14 days.
For the treatment of complicated intraabdominal infections in patients with limited or no alternative treatment options, including infections due to resistant gram-negative organisms:
Intravenous dosage:
Adults: 1.25 g (500 mg imipenem, 500 mg cilastatin, and 250 mg relebactam) IV every 6 hours for 4 to 14 days.
For the treatment of nosocomial pneumonia, such as hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), including infections due to resistant gram-negative organisms:
Intravenous dosage:
Adults: 1.25 g (500 mg imipenem, 500 mg cilastatin, and 250 mg relebactam) IV every 6 hours for 7 days. The FDA-approved duration is 4 to 14 days.
Maximum Dosage Limits:
-Adults
5 g/day (2 g imipenem, 2 g cilastatin, and 1 g relebactam) IV.
-Geriatric
5 g/day (2 g imipenem, 2 g cilastatin, and 1 g relebactam) IV.
-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
Specific guidelines for dosage adjustments in hepatic impairment are not available; it appears that no dosage adjustments are needed.
Patients with Renal Impairment Dosing
CrCl 90 mL/minute or more: No dosage adjustment necessary.
CrCl 60 to 89 mL/minute: 1 g (400 mg imipenem, 400 mg cilastatin, and 200 mg relebactam) IV every 6 hours.
CrCl 30 to 59 mL/minute: 750 mg (300 mg imipenem, 300 mg cilastatin, and 150 mg relebactam) IV every 6 hours.
CrCl 15 to 29 mL/minute: 500 mg (200 mg imipenem, 200 mg cilastatin, and 100 mg relebactam) IV every 6 hours.
CrCl less than 15 mL/minute and not on dialysis: Do not use imipenem; cilastatin; relebactam unless hemodialysis is instituted within 48 hours.
Intermittent hemodialysis
500 mg (200 mg imipenem, 200 mg cilastatin, and 100 mg relebactam) IV every 6 hours. Administer after hemodialysis and at intervals timed from the end of that hemodialysis session.
Peritoneal dialysis
There is inadequate information to recommend imipenem; cilastatin; relebactam use in patients undergoing peritoneal dialysis.
*non-FDA-approved indication
Desogestrel; Ethinyl Estradiol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Dienogest; Estradiol valerate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Disulfiram: (Moderate) Disulfiram is potentially neurotoxic. Additive effects can occur if it is administered concomitantly with other neurotoxic medications including imipenem; cilastatin.
Drospirenone: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Drospirenone; Estetrol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Drospirenone; Estradiol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Drospirenone; Ethinyl Estradiol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Drospirenone; Ethinyl Estradiol; Levomefolate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Elagolix; Estradiol; Norethindrone acetate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Estradiol; Levonorgestrel: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Estradiol; Norethindrone: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Estradiol; Norgestimate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Ethinyl Estradiol; Norelgestromin: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Ethinyl Estradiol; Norethindrone Acetate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Ethinyl Estradiol; Norgestrel: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Ethynodiol Diacetate; Ethinyl Estradiol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Etonogestrel; Ethinyl Estradiol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Ganciclovir: (Major) Avoid concomitant use of imipenem; cilastatin and ganciclovir unless the potential benefits outweigh the risks. Generalized seizures have occurred in patients who were receiving imipenem; cilastatin concomitantly with ganciclovir.
Leuprolide; Norethindrone: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Levonorgestrel: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Levonorgestrel; Ethinyl Estradiol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Levonorgestrel; Ethinyl Estradiol; Ferrous Bisglycinate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Levonorgestrel; Ethinyl Estradiol; Ferrous Fumarate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Norethindrone Acetate; Ethinyl Estradiol; Ferrous fumarate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Norethindrone: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Norethindrone; Ethinyl Estradiol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Norethindrone; Ethinyl Estradiol; Ferrous fumarate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Norgestimate; Ethinyl Estradiol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Norgestrel: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Oral Contraceptives: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Probenecid: (Major) Concomitant use of imipenem and probenecid is not recommended. Probenecid competitively inhibits renal tubular secretion and causes increased serum concentrations of imipenem and prolonged half-life.
Probenecid; Colchicine: (Major) Concomitant use of imipenem and probenecid is not recommended. Probenecid competitively inhibits renal tubular secretion and causes increased serum concentrations of imipenem and prolonged half-life.
Relugolix; Estradiol; Norethindrone acetate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Segesterone Acetate; Ethinyl Estradiol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Sodium picosulfate; Magnesium oxide; Anhydrous citric acid: (Major) Prior or concomitant use of antibiotics with sodium picosulfate; magnesium oxide; anhydrous citric acid may reduce efficacy of the bowel preparation as conversion of sodium picosulfate to its active metabolite bis-(p-hydroxy-phenyl)-pyridyl-2-methane (BHPM) is mediated by colonic bacteria. If possible, avoid coadministration. Certain antibiotics (i.e., tetracyclines and quinolones) may chelate with the magnesium in sodium picosulfate; magnesium oxide; anhydrous citric acid solution. Therefore, these antibiotics should be taken at least 2 hours before and not less than 6 hours after the administration of sodium picosulfate; magnesium oxide; anhydrous citric acid solution.
Theophylline, Aminophylline: (Moderate) Generalized seizures have occurred in patients who were receiving imipenem-cilastatin concomitantly with aminophylline. The mechanism of this interaction is not known. Patients should be monitored for signs of CNS toxicity during coadministration. (Moderate) Generalized seizures have occurred in patients who were receiving imipenem-cilastatin concomitantly with theophylline. The mechanism of this interaction is not known. Patients should be monitored for signs of CNS toxicity during coadministration.
Valganciclovir: (Major) Avoid concomitant use of imipenem; cilastatin and valganciclovir unless the potential benefits outweigh the risks. Generalized seizures have occurred in patients who were receiving imipenem; cilastatin concomitantly with ganciclovir.
Valproic Acid, Divalproex Sodium: (Major) Avoid concomitant carbapenem and valproic acid use. Consider alternative antibacterial therapies other than carbapenems to treat infections in patients whose seizures are well controlled with valproic acid or divalproex sodium. If coadministered, monitor valproic acid concentrations. Coadministration of carbapenems with valproic acid or divalproex sodium may reduce the serum concentration of valproic acid potentially increasing the risk of breakthrough seizures. Carbapenems may inhibit the hydrolysis of valproic acid's glucuronide metabolite (VPA-g) back to valproic acid, thus decreasing valproic acid serum concentrations.
Warfarin: (Moderate) The concomitant use of warfarin with many classes of antibiotics, including carbapenems, may result in an increased INR thereby potentiating the risk for bleeding. Inhibition of vitamin K synthesis due to alterations in the intestinal flora may be a mechanism; however, concurrent infection is also a potential risk factor for elevated INR. Monitor patients for signs and symptoms of bleeding. Additionally, increased monitoring of the INR, especially during initiation and upon discontinuation of the antibiotic, may be necessary.
Imipenem, a carbapenem beta-lactam antibiotic, is mainly bactericidal. It inhibits the third and final stage of bacterial cell wall synthesis by preferentially binding to specific penicillin-binding proteins (PBPs) that are located inside the bacterial cell wall. PBPs are responsible for several steps in the synthesis of the cell wall and are found in quantities of several hundred to several thousand molecules per bacterial cell. PBPs vary among different bacterial species. Imipenem binds to all PBP subtypes but has highest affinity for PBP-2 and PBP-1B. At PBP-3, where cephalosporins bind, imipenem has minimal activity. Antimicrobial activity of imipenem is a result of binding to PBP-1A, PBP-1B, and PBP-2. Because little activity is exerted at PBP-3 (the protein responsible for bacterial septum formation), long, filamentous forms are not produced after imipenem exposure. PBP-2 is responsible for maintaining the rod-like shape. Binding of imipenem to PBP-2 causes bacteria to form spheroplasts or ellipsoidal cells without filament formation. Binding to PBP-1, which is responsible for formation of the cell wall, causes these cells to lyse rapidly. Lysis is mediated by bacterial cell wall autolytic enzymes (i.e., autolysins). The relationship between PBPs and autolysins is unclear, but it is possible that the beta-lactam antibiotic interferes with an autolysin inhibitor. Prevention of the autolysin response to beta-lactam antibiotic exposure through loss of autolytic activity (mutation) or inactivation of autolysin (low-medium pH) by the microorganism can lead to tolerance to the beta-lactam antibiotic resulting in bacteriostatic activity. Imipenem also has greater ability to penetrate the outer membrane of gram-negative bacteria than do the other beta-lactam antibiotics.
Beta-lactams, including imipenem, exhibit concentration-independent or time-dependent killing. In vitro and in vivo animal studies have demonstrated that the major pharmacodynamic parameter that determines efficacy for beta-lactams is the amount of time free (non-protein bound) drug concentrations exceed the minimum inhibitory concentration (MIC) of the organism (free T above the MIC). This microbiological killing pattern is due to the mechanism of action, which is acylation of PBPs. There is a maximum proportion of PBPs that can be acylated; therefore, once maximum acylation has occurred, killing rates cannot increase. Free beta-lactam concentrations do not have to remain above the MIC for the entire dosing interval. The percentage of time required for both bacteriostatic and maximal bactericidal activity is different for the various classes of beta-lactams. Carbapenems require free drug concentrations to exceed the MIC for 20% of the dosing interval for bacteriostatic activity and 40% of the dosing interval for maximal bactericidal activity. Carbapenems also are reported to have a post-antibiotic effect (PAE). PAE is defined as the suppression of bacterial growth that continues after the antibiotic concentration falls below the bacterial MIC. PAE has been reported to be 1.3 to 4 hours with imipenem.
Cilastatin is a reversible, competitive inhibitor of dehydropeptidase-1 (DHP-1), an enzyme found in the brush border of the proximal tubular cells of the kidneys that breaks down imipenem to inactive metabolites. By inhibiting this enzyme, cilastatin prevents the renal metabolism of imipenem, which results in an increase in urinary concentrations of imipenem from 15% to 20% up to 60% to 70% and minimizes the nephrotoxicity observed when imipenem is administered alone. Cilastatin has no antimicrobial activity, nor does it interfere with imipenem's actions.
Relebactam is a bacterial beta-lactamase inhibitor and has no intrinsic antibacterial activity. Relebactam protects imipenem from degradation by certain serine beta-lactamases such as Sulfhydryl Variable (SHV), Temoneira (TEM), Cefotaximase-Munich (CTX-M), Enterobacter cloacae P99 (P99), Pseudomonas-derived cephalosporinase (PDC), and Klebsiella pneumoniae carbapenemase (KPC). The pharmacodynamic parameter that best predicts the activity of relebactam is the ratio of the 24-hour unbound plasma relebactam AUC to imipenem/relebactam MIC (fAUC/MIC).
The susceptibility interpretive criteria for imipenem; cilastatin; relebactam are delineated by pathogen. The MICs are defined for Enterobacterales (K. aerogenes, E. cloacae, E. coli, K. pneumoniae, C. freundii, K. oxytoca) as susceptible at 1/4 mcg/mL or less, intermediate at 2/4 mcg/mL, and resistant at 4/4 mcg/mL or more. The MICs are defined for P. aeruginosa and A. calcoaceticus-baumannii complex as susceptible at 2/4 mcg/mL or less, intermediate at 4/4 mcg/mL, and resistant at 8/4 mcg/mL or more. The MICs are defined for H. influenzae as susceptible at 4/4 mcg/mL or less. The MICs are defined for anaerobes (B. caccae, B. fragilis, B. ovatus, B. stercoris, B. thetaiotaomicron, F. nucleatum, P. distasonis) as susceptible at 4/4 mcg/mL or less, intermediate at 8/4 mcg/mL, and resistant at 16/4 mcg/mL or more.
Mechanisms of beta-lactam resistance in gram-negative organisms include the production of beta-lactamase, up-regulation of efflux pumps, and loss of outer membrane porins. Imipenem; cilastatin; relebactam retains activity in the presence of tested efflux pumps and has shown activity against some isolates of P. aeruginosa and Enterobacterales that produce relebactam-susceptible beta-lactamases concomitant with loss of entry porins. Imipenem has a high degree of stability in the presence of beta-lactamases, including both penicillinases and cephalosporinases produced by gram-negative and gram-positive bacteria. It is a potent inhibitor of beta-lactamases from certain gram-negative bacteria that may be inherently resistant to many beta-lactam antibiotics (e.g., P. aeruginosa, Serratia sp., and Enterobacter sp.). Imipenem; cilastatin; relebactam is not active against most isolates containing metallo-beta-lactamases (MBL), some oxacillinases with carbapenemase activity, as well as certain alleles of GES. Imipenem; cilastatin; relebactam demonstrates in vitro activity against some Enterobacterales isolates genotypically characterized for some beta-lactamases and extended-spectrum beta-lactamases (ESBLs) of the following groups: KPC, TEM, SHV, CTX-M, CMY, DHA, and ACT/MIR. Imipenem; cilastatin; relebactam demonstrates in vitro activity against genotypically characterized P. aeruginosa isolates containing certain known resistance factors: some chromosomal PDC alleles with ESBLs, and those with loss of outer membrane porin (OprD) that co-expressed up-regulated efflux pumps (MexAB, MexCD, MexXY). P. aeruginosa isolates that were not susceptible encoded some MBL, KPC, PER, GES, VEB, and PDC alleles.
No cross-resistance with other classes of antimicrobials has been identified. Some isolates resistant to carbapenems, including imipenem, and cephalosporins may be susceptible to imipenem; cilastatin; relebactam.
Imipenem; cilastatin; relebactam is administered intravenously. The binding of imipenem and cilastatin to plasma proteins is approximately 20% and 40%, respectively. The binding of relebactam to plasma proteins is approximately 22% and is independent of concentration at a range of 5 to 50 microM. Imipenem is distributed into most body tissues and fluids, including heart valve, bone, uterus, ovary, intestine, saliva, sputum, bile, as well as peritoneal, pleural, and wound fluids. However, imipenem achieves low concentrations within the CSF, and it is not indicated in the treatment of meningitis. The penetration of imipenem and relebactam into pulmonary epithelial lining fluid is similar, with concentrations around 55% and 54% of unbound plasma concentrations, respectively. The steady-state volume of distribution (Vd) of imipenem, cilastatin, and relebactam is 24.3 L, 13.8 L, and 19 L, respectively in subjects after multiple doses.
Imipenem, cilastatin, and relebactam are mainly excreted by the kidneys. When administered alone, imipenem is rapidly metabolized in the brush border of the proximal renal tubule by dehydropeptidase 1 (DHP-1), resulting in low concentrations of imipenem recovered in human urine. Cilastatin inhibits this enzyme and effectively prevents renal metabolism of imipenem so that when given concomitantly, adequate concentrations of imipenem are achieved in the urine to enable antibacterial activity. Cilastatin is metabolized in the kidneys to N-acetylcilastatin, which is also an inhibitor of DHP-1. Relebactam is minimally metabolized. Unchanged relebactam is the only drug-related component detected in human plasma. After multiple-dose administration, approximately 63% of the administered imipenem dose and 77% of the administered cilastatin dose are recovered as unchanged parent drugs in the urine. The renal excretion of imipenem and cilastatin involves both glomerular filtration and active tubular secretion. More than 90% of the administered relebactam dose was excreted unchanged in urine. The unbound renal clearance of relebactam is greater than the glomerular filtration rate, suggesting that in addition to glomerular filtration, active tubular secretion is involved in renal elimination, accounting for approximately 30% of the total clearance. The mean half-life of imipenem is 1 hour, and the mean half-life of relebactam is 1.2 hours.
Affected cytochrome P450 isoenzymes and drug transporters: OAT3, OAT4, MATE1, MATE2K
Relebactam is a substrate of OAT3, OAT4, MATE1 and MATE2K transporters. However, no clinically significant differences in the pharmacokinetics of imipenem or relebactam were observed with concomitant use of probenecid, an OAT3 inhibitor.
-Route-Specific Pharmacokinetics
Intravenous Route
After standard multiple doses, the AUC0-24 for imipenem is 570.6 to 771 microM-hr, and the AUC0-24 for relebactam is 415.8 to 692.9 microM-hr. The Cmax for imipenem is 116.1 to 122.7 microM, and the Cmax for relebactam is 62.1 to 80 microM.
-Special Populations
Hepatic Impairment
Imipenem, cilastatin, and relebactam are primarily cleared renally; therefore, hepatic impairment is not likely to have any effect on their exposures.
Renal Impairment
In a single-dose study using 250 mg imipenem; 250 mg cilastatin; 125 mg relebactam, the mean AUC was higher in subjects with CrCl less than 90 mL/minute when compared to healthy subjects with CrCl 90 mL/minute or more. The mean AUC increases in subjects with CrCl 60 to 89 mL/minute were 1.1-fold for imipenem and 1.2-fold for cilastatin and relebactam. The mean AUC increases in subjects with CrCl 30 to 59 mL/minute were 1.7-fold for imipenem, 2-fold for cilastatin, and 2.2-fold for relebactam. The mean AUC increases in subjects with CrCl 15 to 29 mL/minute were 2.6-fold for imipenem, 5.5-fold for cilastatin, and 4.7-fold for relebactam. In subjects with end-stage renal disease (ESRD) on hemodialysis, imipenem, cilastatin, and relebactam are efficiently removed by hemodialysis with extraction coefficients of 66% to 87% for imipenem, 46% to 56% for cilastatin, and 67% to 87% for relebactam.
Geriatric
No clinically significant differences in the pharmacokinetics of imipenem, cilastatin, or relebactam were observed based on age.
Gender Differences
No clinically significant differences in the pharmacokinetics of imipenem, cilastatin, or relebactam were observed based on gender.
Ethnic Differences
No clinically significant differences in the pharmacokinetics of imipenem, cilastatin, or relebactam were observed based on race/ethnicity.