ERYTHROMYCIN ETHYLSUCCINATE (Generic for E.E.S. 200)

General Administration Information
For storage information, see the specific product information within the How Supplied section.

Route-Specific Administration

Oral Administration
-Most formulations are well absorbed and can be given without regard to meals. However, optimal absorption is achieved in the fasting state (1/2 hour before meals or 2 hours after meals). If GI irritation occurs, may be administered with food.
Oral Solid Formulations
-Erythromycin ethylsuccinate film-coated tablets: Swallow whole; do not crush, break, or chew. May be administered without regard to meals.
-Erythromycin stearate: Swallow whole; do not crush, break, or chew. Administer in the fasting state or immediately prior to meals.
-Erythromycin base, delayed-release tablets or capsules (enteric coated): Swallow whole; do not crush, chew, or open. May be given without regard to meals.

Oral Liquid Formulations
-Erythromycin ethylsuccinate suspension: FDA-approved labeling states that may be given without regard to meals; however, studies have shown better absorption when given with milk or food.
-Shake well before administration. Administer using a calibrated measuring device.

Extemporaneous Compounding-Oral
Reconstitution
-Review the manufacturer's reconstitution instructions for the particular product and package size; the amount of water to be used for reconstitution may vary between manufacturers.
-Prior to constitution, tap the bottle several times to loosen the powder.
-Add approximately half of the total amount of water needed and shake well. Add the remaining water and shake well. Resultant concentration will be 40 or 80 mg/mL.
-Storage: The prepared oral suspension should be refrigerated and used within 10 days.



Injectable Administration
-Visually inspect parenteral products for particulate matter and discoloration prior to administration whenever solution and container permit.
Intravenous Administration
Powder Vials for Injection

Reconstitution
-Reconstitute each 500 mg vial with 10 mL of Sterile Water for Injection to yield 50 mg/mL.
-Do not use diluents containing preservatives or inorganic salts. Other diluents may cause precipitation during reconstitution.
-Storage: Reconstituted solutions are stable for 24 hours at room temperature or 14 days under refrigeration.
Dilution
-Dilute appropriate dose in at least 100 mL of 0.9% Sodium Chloride for Injection, Lactated Ringer's Injection, or Normosol-R.
-Do not use other diluents as acidic solution are unstable and lose their potency.
-For intermittent infusion, dilute to a final concentration of 1 to 5 mg/mL.
-For continuous infusion, dilute to a final concentration of 1 mg/mL.
-Storage: The final diluted solution should be completely administered within 8 hours.

ADD-Vantage Vials
Reconstitution
-Reconstitute only in 100 mL flexible container with 0.9% Sodium Chloride for Injection or 5% Dextrose for Injection.
-Storage: Reconstitute immediately before administration. The diluted solution should be completely administered within 8 hours when reconstituted in 0.9% Sodium Chloride for Injection and 2 hours when reconstituted in 5% Dextrose for Injection.

Intermittent IV Infusion
-Administer IV over 20 to 60 minutes.

Continuous IV infusion
Completely administer each infusion bag within 8 hours of dilution.



Topical Administration
-Do not use topical preparations near the eyes, nose, mouth, or other mucous membranes.
-Cleanse and pat dry the affected area prior to application.
-Wash hand after use.
Other Topical Formulations
Topical Gel and Solution*
-Apply a thin film to the cleansed affected area as prescribed.

Saturated Erythromycin Pledgets*
-Apply solution to cleansed affected area by gently rubbing pledgets over affected skin. Several pledgets may be required per application.



Ophthalmic Administration
-Apply topically to the eye taking care to avoid contamination.
-Instruct patient on proper instillation of eye ointment.
-Do not touch the tip of the tube to the eye, fingertips, or other surface.

Hypersensitivity reactions, including urticaria, rash (unspecified), and interstitial nephritis, have occurred with erythromycin. Anaphylactoid reactions, erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis have been reported rarely.

Erythromycin has been associated with infantile hypertrophic pyloric stenosis (IHPS), especially in newborns younger than 1 month. Pyloric stenosis rarely affects infants older than 3 months. In a cohort study of 157 newborns who were given erythromycin for pertussis prophylaxis, 7 neonates (5%) developed symptoms of non-bilious emesis or irritability with feeding and were subsequently diagnosed as having IHPS requiring surgical pyloromyotomy. This represented approximately a 7-fold increase in IHPS cases over the time period used for historical comparison. A possible dose-response effect was described with an absolute risk of IHPS of 5.1% for infants who took erythromycin for 8 to 14 days and 10% for infants who took erythromycin for 15 to 21 days. In another retrospective cohort study in over 14,000 infants, systemic erythromycin during the first 2 weeks of life was associated with a 10-fold higher risk of IHPS; an approximately 5-fold risk was noted for infants 3 months and younger. Since erythromycin may be used in the treatment of conditions in infants which are associated with significant mortality or morbidity (such as pertussis or neonatal Chlamydia trachomatis infections), the benefit of erythromycin therapy needs to be weighed against the potential risk of developing IHPS. Azithromycin is the preferred agent for pertussis prophylaxis and treatment in children, particularly neonates and infants. Parents should be informed to contact their physician if vomiting or irritability with feeding occurs.

Erythromycin has been associated with acute generalized exanthematous pustulosis (AGEP). The non-follicular, pustular, erythematous rash starts suddenly and is associated with fever above 38 degrees C. Drugs are the main cause of AGEP. A period of 2-3 weeks after an inciting drug exposure appears necessary for a first episode of AGEP. Unintentional re-exposure may cause a second episode within 2 days.

Nausea, vomiting, abdominal pain, diarrhea, and anorexia are all common GI effects of oral erythromycin. These effects are often dose-related. Administering erythromycin with food may minimize GI toxicity.

Hepatic dysfunction (i.e., hepatic failure), including elevated hepatic enzymes and hepatocellular and/or cholestatic hepatitis, with or without jaundice, has been reported with erythromycin therapy. The incidence of hepatotoxicity is approximately 4.7% in adults ; however, the occurrence in children is rare. Symptoms of hepatotoxicity usually resolve within a few days of therapy discontinuation. Pancreatitis has been reported rarely.


Rare cases of serious cardiovascular adverse events, including QT prolongation, cardiac arrest, torsade de pointes, and other ventricular arrhythmias (i.e., ventricular tachycardia), resulting in fatalities, have been observed with systemic erythromycin use, including in neonates. It has been recommended that patients who may be predisposed to torsade de pointes and require IV erythromycin should have erythromycin infused at a rate of less than 15 mg/minute (at least 20 minutes). To minimize the risk of cardiotoxicity in neonates and children, an infusion rate of at least 60 minutes has been suggested. Risk factors for torsade de pointes, such as electrolyte abnormalities, should also be eliminated prior to erythromycin therapy.

Seizures have been reported rarely during erythromycin therapy.

Erythromycin has been associated with isolated cases of reversible hearing loss in adult patients. Most of the reported cases have occurred in patients receiving IV administration of large doses or in patients with renal failure. Cases of ototoxicity have not been reported in children; 1 case was reported in an adolescent patient with renal failure. Patients with renal or hepatic impairment may be at increased risk for developing hearing loss.

Intravenous administration of erythromycin is extremely irritating and pain and phlebitis along the vein may occur during infusion. Slow administration of the infusion (over at least 20-60 minutes) may minimize symptoms. Patients should be monitored for an injection site reaction any time erythromycin is administered intravenously.

Ocular irritation, redness, and hypersensitivity reactions have been reported with the use of erythromycin ophthalmic ointment.

Microbial overgrowth and superinfection can occur with antibiotic use. C. difficile-associated diarrhea (CDAD) or pseudomembranous colitis has been reported with erythromycin. 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.

The Jarisch-Herxheimer reaction is a self-limiting systemic reaction that has been reported in the setting of spirochete infections, such as Lyme disease, syphilis, relapsing fever, and leptospirosis, after the initiation of antimicrobial therapy. It is characterized by fever, chills, myalgias, headache, exacerbation of cutaneous lesions, tachycardia, hyperventilation, vasodilation with flushing, and mild hypotension. Less commonly, symptoms may include meningitis, pulmonary failure, hepatic and renal dysfunction, myocardial injury, premature uterine contractions in pregnant patients, and worsening cerebral function as well as strokes and seizures. The reaction has been noted in up to 30% of patients with early Lyme disease. The timing of the reaction varies by underlying infection but typically presents within a few hours after the initiation of antibiotics. For Lyme disease, the reaction usually begins within 1 to 2 hours after starting therapy and disappears within 12 to 24 hours. The reaction after treatment in syphilis usually starts at 4 hours, peaks at 8 hours, and subsides by 16 hours whereas it starts at about 1 to 2 hours, peaks at 4 hours, and subsides by 8 hours after treatment in relapsing fever. The pathogenesis of this reaction is unknown but may be due to the release of spirochetal heat-stable pyrogen. Fluids and antipyretics can be used to alleviate symptoms and duration of the reaction if severe.

Erythromycin may interfere with determination of urinary catecholamines using the fluorometric method.

Patients who have shown macrolide hypersensitivity or sensitivity to any macrolide antibiotic should not be given erythromycin. Erythromycin can cause rare, but serious allergic reactions, including angioedema and anaphylaxis. There is a risk of cross sensitivity with other macrolide antibiotics.

Use erythromycin with caution and with proper monitoring in young infants and neonates; there have been reports of infantile hypertrophic pyloric stenosis (IHPS) occurring in infants after erythromycin therapy. Because erythromycin is sometimes used for the treatment of conditions that are associated with significant mortality or morbidity (e.g., pertussis or neonatal Chlamydia trachomatis infections), weigh the benefit of erythromycin therapy against the potential risk of developing IHPS. Inform parents and other caregivers to contact their physician if vomiting or irritability with feeding occurs. In a cohort study of 157 newborns who were given erythromycin for pertussis prophylaxis, seven neonates (5%) developed symptoms of non-bilious vomiting or irritability with feeding and were subsequently diagnosed as having IHPS requiring surgical pyloromyotomy. This represented an approximately 7-fold increase in IHPS cases over the time period used for historical comparison. A possible dose-response effect was described with an absolute risk of IHPS of 5.1% for infants who took erythromycin for 8-14 days and 10% for infants who took erythromycin for 15-21 days. In another retrospective cohort study in over 14,000 infants, systemic erythromycin during the first 2 weeks of life was associated with a 10-fold higher risk of IHPS; an approximately 5-fold risk was noted for infants <= 3 months.

Erythromycin should be used with caution in patients with hepatic disease as it is primarily excreted in the liver. Hepatotoxicity, including elevated liver enzymes, and hepatocellular and/or cholestatic hepatitis, with or without jaundice, has been reported in patients receiving oral erythromycin formulations, although the occurrence in children is rare. Monitor hepatic function in patients receiving prolonged treatment with erythromycin.

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 erythromycin, 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.

Use erythromycin with caution in patients with hearing impairment. Erythromycin can rarely cause reversible loss of hearing and patients with preexisting hearing impairment may be at greater risk. Patients with renal or hepatic impairment may be at increased risk for developing hearing loss, particularly when high doses of erythromycin lactobionate are given (4 g/day or higher). However, cases of ototoxicity have not been reported in children (1 case in an adolescent).

Systemic erythromycin (primarily IV administration) has been reported to cause QT prolongation resulting in ventricular arrhythmias of the torsade de pointes type; fatalities have been reported. Cases of cardiac toxicity, some resulting in death, have been reported in neonates following IV administration of erythromycin. Erythromycin should be avoided in patients with known QT prolongation or in patients with ongoing proarrhythmic conditions such as uncorrected electrolyte imbalance (hypokalemia, hypomagnesemia), clinically significant bradycardia, and in patients receiving Class 1A or Class III antiarrhythmic agents. Ventricular tachyarrhythmias have also been reported in adults with idiopathic long QT syndrome. It has been recommended that patients who may be predisposed to torsade de pointes and require IV erythromycin should have erythromycin infused at a rate of less than 15 mg/min (at least 20 minutes). To minimize the risk of cardiotoxicity in neonates and children, an infusion rate of at least 60 minutes has been suggested. Risk factors for torsade de pointes, such as electrolyte abnormalities, should also be eliminated prior to erythromycin therapy.

Erythromycin should be used cautiously in patients with a seizure disorder. There have been rare reports of seizures during erythromycin therapy.

Use erythromycin with caution in patients with myasthenia gravis. Exacerbation of condition and new onset of symptoms of myasthenic syndrome have been reported with erythromycin therapy.

Description: Erythromycin is a macrolide antibiotic produced by Streptomyces erythraeus and was the first of several macrolide antibiotics now on the market. Although erythromycin is active against many microbes, its clinical applications are relatively few. Erythromycin has poor GI tolerability and needs more frequent dosing than newer macrolides, such as azithromycin and clarithromycin, making it less favorable for many indications. Erythromycin is primarily used for respiratory infections, such as community-acquired pneumonia due to atypical pathogens (e.g., M. pneumoniae and C. trachomatis), as an alternative to azithromycin. It is a preferred agent for the treatment of pertussis (whooping cough) in non-neonatal pediatric patients. Erythromycin has been associated with infantile hypertrophic pyloric stenosis (IHPS) in neonates, particularly during the first 2 weeks of age. Due to this risk, azithromycin is the preferred agent for pertussis treatment and prophylaxis in neonates. Ophthalmic erythromycin is used in all neonates at birth for the prophylaxis of ophthalmia neonatorum due to N. gonorrheae or C. trachomatis. Erythromycin can also be used as a prokinetic agent in children with gastrointestinal motility disorders. Significant drug interactions have been associated with erythromycin as a result of its inhibition of the CYP3A4 enzyme system. Oral and ophthalmic formulations of erythromycin are FDA-approved for use in pediatric patients as young as neonates; the IV formulation is FDA-approved for use in pediatric patients as young as infants.

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: Bordetella pertussis, Chlamydia sp., Chlamydia trachomatis, Corynebacterium diphtheriae, Corynebacterium minutissimum, Corynebacterium sp., Cutibacterium acnes, Entamoeba histolytica, Haemophilus influenzae (beta-lactamase negative), Haemophilus influenzae (beta-lactamase positive), Helicobacter pylori, Legionella pneumophila, Listeria monocytogenes, Moraxella catarrhalis, Mycobacterium kansasii, Mycobacterium scrofulaceum, Mycoplasma pneumoniae, Neisseria gonorrhoeae, Staphylococcus aureus (MSSA), Staphylococcus sp., Streptococcus agalactiae (group B streptococci), Streptococcus pneumoniae, Streptococcus pyogenes (group A beta-hemolytic streptococci), Streptococcus sp., Treponema pallidum, Ureaplasma urealyticum, Viridans streptococci
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.

This drug may also have activity against the following microorganisms: Actinomyces sp., Bacillus anthracis, Borrelia burgdorferi, Brucella sp., Campylobacter jejuni, Clostridium perfringens, Clostridium sp., Erysipelothrix sp., Haemophilus ducreyi, Klebsiella granulomatis, Neisseria meningitidis, Neisseria sp., Nocardia asteroides, Pasteurella sp., Peptococcus sp., Peptostreptococcus sp., Rickettsia sp., Vibrio cholerae
NOTE: Some organisms may not have been adequately studied during clinical trials; therefore, exclusion from this list does not necessarily negate the drug's activity against the organism.

For the treatment of mild to moderately severe lower respiratory tract infections (LRTIs), including community-acquired pneumonia (CAP):
-for the treatment of nonspecific lower respiratory tract infections (LRTIs):
Oral dosage:
Neonates*: 10 mg/kg/dose PO every 6 hours.
Infants, Children, and Adolescents: 30 to 50 mg/kg/day (Usual Max: 2 g/day) PO in 3 to 4 divided doses. The FDA-approved dosage is up to 100 mg/kg/day (Max: 4 g/day) for more severe infections. However, this is rarely done in clinical practice.
Intravenous dosage:
Neonates*: 10 mg/kg/dose IV every 6 hours.
Infants, Children, and Adolescents: 15 to 20 mg/kg/day (Max: 4 g/day) IV divided every 6 hours.
-for the treatment of community-acquired pneumonia (CAP):
Oral dosage:
Infants, Children, and Adolescents: 40 mg/kg/day (Usual Max: 2 g/day) PO in 4 divided doses for 5 to 7 days in patients with presumed/confirmed atypical pathogens as an alternative therapy to azithromycin.
Intravenous dosage:
Infants, Children, and Adolescents: 20 mg/kg/day (Max: 4 g/day) IV divided every 6 hours for 5 to 7 days in patients with presumed/confirmed atypical pathogens as an alternative therapy to azithromycin.

For the treatment of pertussis (whooping cough):
Oral dosage:
Neonates: 40 to 50 mg/kg/day PO in 4 divided doses for 14 days.
Infants, Children, and Adolescents: 40 to 50 mg/kg/day (Max: 2 g/day) PO in 4 divided doses for 14 days.

For the treatment of mild to moderately severe upper respiratory tract infections, including group A beta-hemolytic streptococcal (GAS) pharyngitis (primary rheumatic fever prophylaxis) and tonsillitis:
-for the treatment of nonspecific upper respiratory tract infections:
Oral dosage:
Neonates*: 10 mg/kg/dose PO every 6 hours.
Infants, Children, and Adolescents: 30 to 50 mg/kg/day PO in 3 to 4 divided doses. Up to 100 mg/kg/day (Max: 4 g/day) may be used.
Intravenous dosage:
Neonates*: 10 mg/kg/dose IV every 6 hours.
Infants, Children, and Adolescents: 15 to 20 mg/kg/day IV divided every 6 hours (Max: 4 g/day).
-for the treatment of streptococcal pharyngitis and tonsillitis, including group A beta-hemolytic streptococcal (GAS) pharyngitis (primary rheumatic fever prophylaxis):
Oral dosage (erythromycin base or stearate):
Neonates*: 10 mg/kg/dose PO every 6 hours for 10 days.
Infants, Children, and Adolescents: 30 to 50 mg/kg/day PO in 3 to 4 divided doses (Max: 1 g/day) for 10 days. For the treatment of group A streptococcal pharyngitis, guidelines recommend erythromycin as an alternative for patients allergic to penicillin.
Oral dosage (erythromycin ethylsuccinate):
Neonates*: 10 mg/kg/dose PO every 6 hours for 10 days.
Infants, Children, and Adolescents: 30 to 50 mg/kg/day PO in 3 to 4 divided doses (Max: 1.6 g/day) for 10 days. For the treatment of group A streptococcal pharyngitis, guidelines recommend erythromycin as an alternative for patients allergic to penicillin.
-for secondary rheumatic fever prophylaxis:
Oral dosage (erythromycin base or stearate):
Infants, Children, and Adolescents: 30 to 50 mg/kg/day PO in 3 to 4 divided doses (Max: 500 mg/day). A macrolide is recommended for secondary prevention of rheumatic fever in patients allergic to both penicillin and sulfisoxazole. Guidelines recommend secondary prophylaxis for 10 years or until age 40 years (whichever is longer) for patients who have experienced rheumatic fever with carditis and have residual heart disease (persistent valvular disease). For patients who have experienced rheumatic fever with carditis but have no residual heart disease, prophylaxis is recommended for 10 years or until age 21 years (whichever is longer). For patients who have experienced rheumatic fever without carditis, prophylaxis is recommended for 5 years or until age 21 years (whichever is longer).
Oral dosage (erythromycin ethylsuccinate):
Infants, Children, and Adolescents: 30 to 50 mg/kg/day PO in 2 to 4 divided doses (Max: 800 mg/day). A macrolide is recommended for secondary prevention of rheumatic fever in patients allergic to both penicillin and sulfisoxazole. Guidelines recommend secondary prophylaxis for 10 years or until age 40 years (whichever is longer) for patients who have experienced rheumatic fever with carditis and have residual heart disease (persistent valvular disease). For patients who have experienced rheumatic fever with carditis but have no residual heart disease, prophylaxis is recommended for 10 years or until age 21 years (whichever is longer). For patients who have experienced rheumatic fever without carditis, prophylaxis is recommended for 5 years or until age 21 years (whichever is longer).

For the treatment of chlamydial conjunctivitis or ophthalmia neonatorum caused by C. trachomatis:
Oral dosage (ethylsuccinate):
Neonates: 50 mg/kg/day PO in 4 divided doses for 14 days. A second course of treatment may be necessary.

For postexposure pertussis prophylaxis:
Oral dosage:
Neonates: 40 to 50 mg/kg/day PO in 4 divided doses for 14 days. Administer to close contacts within 3 weeks of exposure.
Infants, Children, and Adolescents: 40 to 50 mg/kg/day (Max: 2 g/day) PO in 4 divided doses for 14 days. Administer to close contacts within 3 weeks of exposure.

For the treatment of skin and skin structure infections, including impetigo, secondary bacterial infection of eczema, cellulitis, and erysipelas:
-for the treatment of unspecified skin and skin structure infections:
Oral dosage:
Neonates*: 10 mg/kg/dose PO every 6 hours.
Infants, Children, and Adolescents: 30 to 50 mg/kg/day PO in 3 to 4 divided doses. Up to 100 mg/kg/day (Max: 4 g/day) may be used.
Intravenous dosage:
Neonates*: 10 mg/kg/dose IV every 6 hours.
Infants, Children, and Adolescents: 15 to 20 mg/kg/day IV divided every 6 hours (Max: 4 g/day).
-for the treatment of impetigo or secondary bacterial infection of eczema:
Oral dosage:
Neonates*: 10 mg/kg/dose PO every 6 hours for 5 to 7 days.
Infants, Children, and Adolescents: 40 mg/kg/day PO in 3 to 4 divided doses (Max: 2 g/day) for 5 to 7 days.
-for the treatment of cellulitis and erysipelas:
Oral dosage (erythromycin base or stearate):
Neonates*: 10 mg/kg/dose PO every 6 hours for 5 to 14 days.
Infants, Children, and Adolescents: 30 to 50 mg/kg/day PO in 3 to 4 divided doses (Max: 2 g/day) for 5 to 14 days.

For the treatment of ophthalmic infection, including bacterial conjunctivitis or corneal abrasion*:
-for the treatment of bacterial conjunctivitis:
Ophthalmic dosage:
Infants, Children, and Adolescents: 1 centimeter ribbon in the affected eye(s) up to 6 times daily.
-for the treatment of corneal abrasion*:
Ophthalmic dosage:
Infants, Children, and Adolescents: 0.5 inch ribbon in the affected eye(s) 4 times daily for 3 to 5 days.

For the facilitation of gastric emptying in patients with feeding intolerance* and gastrointestinal motility disorders (e.g., gastroparesis*, dysmotility of prematurity*, post-operative intestinal dysmotility*):
Oral dosage:
Neonates: 10-12.5 mg/kg/dose PO every 6 hours given 30 minutes before feedings; however optimal dose has not been established and efficacy outcomes have differed in various studies. Most studies have used a treatment duration of 10-14 days. Studies of erythromycin for 'rescue therapy' (treatment of gastrointestinal dysmotility) in neonates (mainly premature neonates) have shown that high-dose erythromycin (50 mg/kg/day) is necessary to achieve significant prokinetic effects from erythromycin. In clinical studies, high-dose erythromycin has improved feeding tolerance, shortened the time that parenteral nutrition is required, and decreased the incidence of parenteral nutrition-associated cholestasis. Prophylactic therapy with erythromycin has not shown clinical efficacy in most studies. Intermediate-dose erythromycin (20 mg/kg/day PO divided every 6 hours) was also shown to improve feeding tolerance, and shorten parenteral nutrition duration and time to achieve body weight of >= 2500 g compared with placebo in a study of 45 very low birthweight infants. Low-dose erythromycin (< 15 mg/kg/day) has been used in studies, but conflicting results have been reported. Some studies have shown a benefit while others have not. There have also been conflicting results with regards to efficacy for gestational age (GA) in studies that stratified results by GA. Some studies have only seen benefit in neonates > 32 weeks , while others have reported benefit only in infants < 32 weeks.
Infants, Children, and Adolescents: 3 mg/kg/dose PO 4 times daily, up to 10 mg/kg/dose (Max: 250 mg/dose) PO 4 times daily, has been used; however, data are limited. Guidelines for the treatment of gastroparesis state that oral erythromycin improves gastric emptying; however, long-term use (e.g., > 4 weeks) is limited by tachyphylaxis.
Intravenous dosage:
Infants, Children, and Adolescents: 3 mg/kg/dose (Max: 250 mg/dose) IV every 6-8 hours; however, data are limited in children. 3 mg/kg/dose every 8 hours is recommended by clinical guidelines if an IV prokinetic agent is needed. However, metoclopramide is considered the first-line agent.

For surgical infection prophylaxis* as a bowel preparation* in combination with neomycin:
Oral dosage:
Infants, Children, and Adolescents: 20 mg/kg/dose (Max: 1 g/dose) PO in combination with neomycin 15 mg/kg/dose (Max: 1 g/dose) PO. This is given as 3 doses starting approximately 10 hours the afternoon and evening prior to surgery (i.e., at 1 PM, 2 PM, and 11 PM on the day before 8 AM surgery). Data for antimicrobial prophylaxis in colorectal surgery in pediatric patients are lacking; however, it is suggested that prophylactic regimens that have been studied in adults would have similar efficacy in children.

For the treatment of infectious diarrhea and gastroenteritis, including amebiasis and cholera*:

-for the treatment of intestinal amebiasis:
Oral dosage (erythromycin base or stearate):
Infants, Children, and Adolescents: 30 to 50 mg/kg/day (Max: 1 g/day) PO in 3 to 4 divided doses for 10 to 14 days.
Oral dosage (erythromycin ethylsuccinate):
Infants, Children, and Adolescents: 30 to 50 mg/kg/day (Max: 1.6 g/day) PO in 3 to 4 divided doses for 10 to 14 days.
-for the treatment of cholera*:
Oral dosage:
Infants, Children, and Adolescents: 12.5 mg/kg/dose (Max: 500 mg/dose) PO every 6 hours for 3 days.

For the treatment of listeriosis:
Oral dosage:
Infants, Children, and Adolescents: 30 to 50 mg/kg/day (Usual Max: 2 g/day) PO in 3 to 4 divided doses. The FDA-approved labeling states that up to 100 mg/kg/day (Max: 4 g/day) may be given for more severe infections; however, this is rarely done in clinical practice.

For the adjunctive treatment of diphtheria and to prevent establishment of carrier state:
Oral dosage:
Infants, Children, and Adolescents: 30 to 50 mg/kg/day (Max: 2 g/day) PO divided every 6 to 8 hours for 14 days as an adjunct to diphtheria antitoxin.
Intravenous dosage:
Infants, Children, and Adolescents: 20 to 50 mg/kg/day (Max: 2 g/day) IV divided every 6 hours for 14 days as an adjunct to diphtheria antitoxin.

For the treatment of early Lyme disease* (erythema migrans*), including solitary and multiple erythema migrans* as second line therapy:
Oral dosage:
Infants, Children, and Adolescents: 12.5 mg/kg/dose (Max: 500 mg/dose) PO every 6 hours for 14 days. Due to lower efficacy, reserve macrolides for patients in whom other antibiotic classes are contraindicated.

For pneumococcal prophylaxis* in penicillin-allergic patients with sickle cell disease:
Oral dosage:
Infants and Children 1 month to 2 years: 10 mg/kg/dose (Max: 125 mg/dose) PO twice daily. Continue prophylaxis until at least age 5 years.
Children 3 to 5 years: 10 mg/kg/dose (Max: 250 mg/dose) PO twice daily until at least age 5 years.

For the treatment of bartonellosis*, including cat scratch disease*, bacillary angiomatosis*, bacillary peliosis* (peliosis hepatis*), bacteremia*, osteomyelitis*, and chronic verruga peruana*:
-for the treatment of bacillary angiomatosis in immunocompetent patients*:
Oral dosage:
Infants, Children, and Adolescents: 40 mg/kg/day PO in 4 divided doses (Max: 2 g/day) for 2 weeks to 3 months for uncomplicated infections. Add rifampin and treat complicated infections for 3 months. Treat relapses for 4 to 6 months.
Intravenous dosage:
Infants, Children, and Adolescents: 20 mg/kg/day IV in 4 divided doses (Max: 2 g/day) for 2 weeks to 3 months for uncomplicated infections. Add rifampin and treat complicated infections for 3 months. Treat relapses for 4 to 6 months.
-for the treatment of bacillary peliosis (peliosis hepatis) in immunocompetent patients*:
Oral dosage:
Infants, Children, and Adolescents: 40 mg/kg/day PO in 4 divided doses (Max: 2 g/day) for 3 to 4 months. Add rifampin for complicated infections. Treat relapses for 4 to 6 months.
Intravenous dosage:
Infants, Children, and Adolescents: 20 mg/kg/day IV in 4 divided doses (Max: 2 g/day) for 3 to 4 months. Add rifampin for complicated infections. Treat relapses for 4 to 6 months.
-for the treatment of Bartonella infections, including cat scratch disease, bacillary angiomatosis, bacillary peliosis (peliosis hepatitis), bacteremia, and osteomyelitis, in immunocompromised patients*:
Oral dosage:
Infants, Children, and Adolescents: 40 mg/kg/day PO in 4 divided doses (Max: 2 g/day) for at least 3 months.
Intravenous dosage:
Infants, Children, and Adolescents: 20 mg/kg/day IV in 4 divided doses (Max: 2 g/day) for at least 3 months.
-for the treatment of severe Bartonella infections, including multifocal disease or with clinical decompensation, in immunocompromised patients*:
Oral dosage:
Adolescents: 500 mg PO every 6 hours for at least 3 months plus rifampin.
Intravenous dosage:
Adolescents: 500 mg IV every 6 hours for at least 3 months plus rifampin.
-for the treatment of chronic verruga peruana*:
Oral dosage:
Infants, Chldren, and Adolescents: 7.5 to 12.5 mg/kg/dose (Max: 500 mg/dose) PO every 6 hours for 14 days as second-line therapy.

For the treatment of granuloma inguinale* (Donovanosis):
Oral dosage (erythromycin base):
Adolescents: 500 mg PO 4 times daily as an alternative for at least 3 weeks and until all lesions have completely healed. Consider adding a second antibiotic if lesions do not respond within the first few days of therapy.

For the treatment of chlamydia infection*, including infant pneumonia:
-for the treatment of chlamydial infection*:
Oral dosage:
Infants and Children weighing less than 45 kg: 50 mg/kg/day (base or ethylsuccinate) PO in 4 divided doses (Max: 2 g/day) for 14 days.
-for the treatment of pneumonia caused by C. trachomatis in neonates and infants:
Oral dosage (ethylsuccinate):
Neonates: 50 mg/kg/day PO in 4 divided doses for 14 days; a second course may be required. The FDA-approved duration is for at least 3 weeks.
Infants: 50 mg/kg/day PO in 4 divided doses for 14 days; a second course may be required. The FDA-approved duration is for at least 3 weeks.

For the treatment of chancroid* due to Haemophilus ducreyi:
Oral dosage (erythromycin base):
Children weighing 45 kg or more and Adolescents: 500 mg PO 3 times daily for 7 days as an alternative. A longer course of therapy may be required in HIV-infected patients and uncircumcised males.

For the treatment of acne vulgaris*:
Oral dosage:
Children and Adolescents 7 to 17 years: 250 to 500 mg PO twice daily initially, then 250 to 500 mg once daily. The use of erythromycin for acne has decreased due to the high rates of resistance to C. acnes.
Topical dosage:
Children and Adolescents 7 to 17 years: Apply a thin layer topically to the affected skin area(s) twice daily. Topical antibiotic monotherapy is not recommended due to increased bacterial resistance; if topical monotherapy is continued for longer than a few weeks, the addition of topical benzoyl peroxide is recommended.

For the treatment of infantile acne*:
-for the oral treatment of infantile acne:
Oral dosage:
Infants and Children younger than 2 years: 125 to 375 mg PO twice daily (approximately 30 to 40 mg/kg/day PO in 2 divided doses). 125 mg PO twice daily was successfully used in patients with moderate acne (n = 18) in a case series of 29 infants and children 6 to 16 months of age with infantile acne. Higher doses (250 or 375 mg PO twice daily) were necessary in patients with severe acne.
-for the topical treatment of infantile acne:
Topical dosage:
Infants and Children younger than 2 years: Apply a thin layer of a 2% topical preparation to the affected area twice daily. Due to a slow onset of action and the increased risk of the development of bacterial resistance, topical antibiotic monotherapy is not recommended. If topical antibiotic therapy is continued longer than a few weeks, the addition of topical benzoyl peroxide is recommended.

For the treatment of lymphogranuloma venereum* caused by C. trachomatis:
Oral dosage (erythromycin base):
Adolescents: 500 mg PO 4 times daily for 21 days is recommended as an alternative.

For the prevention of ophthalmia neonatorum (i.e., ophthalmia neonatorum prophylaxis) due to N. gonorrhoeae or C. trachomatis:
Ophthalmic dosage:
Neonates: Apply a ribbon (approximately 1 cm) of 0.5% ophthalmic ointment into each lower conjunctival sac immediately after birth (i.e., within 1 hour). Do not flush eyes after instillation.

For the post-exposure diphtheria prophylaxis* of close contacts of persons with diphtheria:
Oral dosage:
Infants, Children, and Adolescents: 30 to 50 mg/kg/day (Max: 1 g/day) PO divided every 6 to 8 hours for 7 to 10 days.

For diphtheria carriage eradication:
Oral dosage:
Infants, Children, and Adolescents: 30 to 50 mg/kg/day (Max: 1 g/day) PO divided every 6 hours for 7 to 14 days.
Intravenous dosage:
Infants, Children, and Adolescents: 15 to 20 mg/kg/day IV divided every 6 hours for 7 to 14 days.

For the treatment of peritoneal dialysis catheter-related infection*:
Oral dosage (Erythromycin base):
Infants, Children, and Adolescents: 30 to 50 mg/kg/day PO divided every 6 to 8 hours (Max: 500 mg/dose) for at least 14 to 28 days.

For secondary bartonellosis prophylaxis* (i.e., long-term suppressive therapy*) in immunosuppressed patients:
Oral dosage:
Adolescents: 500 mg PO every 6 hours if a relapse occurs after at least 3 months of treatment. For persons living with HIV, discontinuation may be considered after 3 to 4 months of treatment and CD4 count more than 200 cells/mm3 for at least 6 months. Some experts suggest that Bartonella titers also decrease by 4-fold before discontinuing suppressive therapy.

Maximum Dosage Limits:
-Neonates
50 mg/kg/day PO; safety and efficacy of IV use have not been established, however, doses up to 40 mg/kg/day IV have been used off-label.
-Infants
50 mg/kg/day PO is the common maximum dose used in clinical practice; however, up to 100 mg/kg/day PO is FDA-approved for the treatment of severe infections. 20 mg/kg/day is the FDA-approved maximum IV dose; however, doses up to 40 mg/kg/day IV have been used off-label.
-Children
50 mg/kg/day (Max: 2 g/day) PO is the common maximum dose used in clinical practice; however, up to 100 mg/kg/day PO (Max: 4 g/day) is FDA-approved for the treatment of severe infections. 20 mg/kg/day (Max: 4 g/day) is the FDA-approved IV maximum dose; however, doses up to 40 mg/kg/day (Max: 4 g/day) IV have been used off-label.
-Adolescents
50 mg/kg/day (Max: 2 g/day) PO is the common maximum dose used in clinical practice; however, up to 100 mg/kg/day PO (Max: 4 g/day) is FDA-approved for the treatment of severe infections. 20 mg/kg/day (Max: 4 g/day) is the FDA-approved IV maximum dose; however, doses up to 40 mg/kg/day (Max: 4 g/day) IV have been used off-label.

Patients with Hepatic Impairment Dosing
Erythromycin should be used with caution in patients with impaired hepatic function. Although specific dosage guidelines are not available, a reduced dosage may be necessary.

Patients with Renal Impairment Dosing
No dosage adjustment needed.

*non-FDA-approved indication

Monograph content under development

Mechanism of Action: Erythromycin binds to the 50S ribosomal subunit, inhibiting bacterial protein synthesis. It is effective against a wide range of microorganisms, and like other antibiotics that inhibit protein synthesis, erythromycin is mainly bacteriostatic. Activity of erythromycin against gram-positive organisms generally is greater than against gram-negative organisms due to its superior penetration into gram-positive organisms.

Erythromycin has actions that make it useful outside of the infectious disease field. Erythromycin mimics the effect of the gastrointestinal polypeptide motilin on gastrointestinal motility. This action is probably due to agonism at the motilin receptors. Motilin receptors are found mainly in the gastric antrum and proximal duodenum. The physiologic action produced is increased motility during the interdigestive (between-meal) period, without affecting postprandial motility. Erythromycin does not affect either dopamine receptors or increase acetylcholine concentrations in the gut. Tachyphylaxis can result from motilin receptor down regulation. Low-dose erythromycin (1 to 3 mg/kg/dose) has been shown to stimulate the neural motilin receptors, augmenting phase III migrating motor complexes, and thus peristalsis, whereas higher doses act on smooth muscle motilin receptors, producing sustained antral and antroduodenal contractions. With respect to feeding intolerance in neonates, erythromycin's prokinetic actions are likely to be both dose and gestational age-dependent, with better efficacy noted with higher doses and more mature neonates.

The susceptibility interpretive criteria for erythromycin are delineated by pathogen. The MICs are defined for Staphylococcus sp., Enterococcus sp., Micrococcus sp., R. mucilaginosa, Lactobacillus sp., Lactococcus sp., and Bacillus sp. (excluding B. anthracis) as susceptible at 0.5 mcg/mL or less, intermediate at 1 to 4 mcg/mL, and resistant at 8 mcg/mL or more. The MICs are defined for C. jejuni/coli as susceptible at 8 mcg/mL or less, intermediate at 16 mcg/mL, and resistant at 32 mcg/mL or more. The MICs are defined for Corynebacterium sp. and Pasteurella sp. as susceptible at 0.5 mcg/mL or less, intermediate at 1 mcg/mL, and resistant at 2 mcg/mL or more. The MICs are defined for S. pneumoniae, beta-hemolytic Streptococcus sp., Streptococcus sp. Viridans group, E. rhusiopathiae, Gemella sp., Abiotrophia sp., and Granulicatella sp. as susceptible at 0.25 mcg/mL or less, intermediate at 0.5 mcg/mL, and resistant at 1 mcg/mL or more. The MICs are defined for M. catarrhalis as susceptible at 2 mcg/mL or more.

The primary mechanisms for bacterial resistance to erythromycin include a modification of the 23S rRNA in the 50S ribosomal subunit to alter binding and active drug efflux.

Pharmacokinetics: Erythromycin is administered orally, intravenously, topically, and ophthalmically. Distribution of erythromycin is extensive following either oral or intravenous administration. Protein binding is extensive at 75% to 90%. Erythromycin is widely distributed into most body tissues except the brain and cerebrospinal fluid (CSF); in the presence of meningitis, penetration into the CSF increases. Tissue concentrations persist longer than do serum concentrations. Erythromycin concentrates in the bile and liver in patients with normal hepatic function. Because of erythromycin's relatively poor oral absorption, significant concentrations are achieved in the large intestine. Excretion of erythromycin is mainly via the bile, with some reabsorption. Only small amounts are found in the urine, with less than 5% excreted as unchanged drug. In adult patients with normal renal function, the serum half-life is about 1.5 hours.

Affected cytochrome P450 isoenzymes and drug transporters: CYP3A4 and P-glycoprotein (P-gp)
Erythromycin is an inhibitor of the CYP3A4 enzyme system as well as a substrate and inhibitor of P-glycoprotein (P-gp). As a result, concurrent administration of erythromycin and drugs primarily metabolized by CYP3A4 may result in elevated serum concentrations of the concomitant drug and potentially significant drug interactions.


-Route-Specific Pharmacokinetics
Oral Route
Bioavailability
Oral erythromycin is rapidly and reliably absorbed. However, significant interpatient variability has been reported and some patients do not attain optimal serum levels. Absorption is better with salt forms. Peak concentrations of erythromycin ethylsuccinate suspension are reached approximately 1 hour after administration in infants and children. For enteric-coated formulations (erythromycin base), peak concentrations have been reported to occur between 2-3 hours after administration in children.

Effect of food
Effect of food is dependent on which form (base vs. salt) and which preparation (delayed release tablets vs. enteric-coated pellets in tablets or capsules) is given. Optimal absorption for most forms is achieved in the fasting state. For the base (delayed-release tablets; Ery-Tab) and the ethylsuccinate salt, the FDA-approved labeling states that food does not significantly affect the absorption. However, studies have found greater absorption when erythromycin ethylsuccinate suspension is given with milk or food in infants and children.

Intravenous Route
In a study in 14 premature neonates (mean gestational age 25.5 weeks; mean birthweight 770 g; mean postnatal age 6.7 days) treated with either 40 mg/kg/day or 25 mg/kg/day of IV erythromycin divided every 6 hours, peak concentrations measured 0.5 hour after infusion completion ranged from 3.05-3.69 and 1.92-2.9 mcg/ml, respectively. Administration of 500 mg IV over 1 hour in adults produced mean concentrations of 7 mcg/ml, 10 mcg/ml, 2.6 mcg/ml, and 1 mcg/ml at 20 minutes, 1 hour, 2.5 hours, and 6 hours, respectively.


-Special Populations
Pediatrics
Neonates
The clearance of erythromycin is slightly lower in neonates compared with adults due to the expected immature renal and hepatic function in neonates. In a pharmacokinetic study in 14 premature neonates (mean gestational age (GA) 25.5 weeks) with birthweight <= 1500 g (mean 770 g) and postnatal age <= 15 days (mean 6.7 days), the mean clearance, volume of distribution, and elimination half-life after IV erythromycin (25 or 40 mg/kg/day divided every 6 hours) were approximately 0.75 L/kg/hr, 2 L/kg, and 2 hours, respectively. In another pharmacokinetic study in 12 infants < 4 months of age (29-49 days) who received oral erythromycin ethylsuccinate suspension, a mean elimination half-life of approximately 2.2-2.4 hours was reported. This compares with an elimination half-life of approximately 1.5 hours in adults.

Infants and Children
In a pharmacokinetic study in 29 infants and children (2-46 months) who received oral erythromycin ethylsuccinate suspension, mean elimination half-lives of 1.4 and 1.7 hours were observed in the fasting and fed states, respectively. This is similar to what has been reported in adults. In another study in 12 infants < 4 months of age (29-49 days) who received oral erythromycin ethylsuccinate suspension, a mean elimination half-life of approximately 2.2-2.4 hours was reported, which is slightly longer than that observed in adults (approximately 1.5 hours).

Hepatic Impairment
The pharmacokinetics of erythromycin have not been studied in pediatric patients with hepatic impairment. However, erythromycin is significantly metabolized in the liver and eliminated in the bile and patients with hepatic dysfunction may have reduced elimination of erythromycin.

Renal Impairment
The pharmacokinetics of erythromycin have not been studied in pediatric patients with renal impairment; however, erythromycin is not significantly excreted in the kidneys and renal impairment would not be expected to alter the pharmacokinetics. Erythromycin is not removed by hemodialysis or peritoneal dialysis.