Comparative Pharmacology
Head-to-head clinical analysis: E MYCIN E versus E E S 400.
Peer-Reviewed Evidence
Head-to-head clinical analysis: E MYCIN E versus E E S 400.
E-MYCIN E vs E.E.S. 400
Head-to-head clinical comparison of therapeutic indices and safety profiles.
Erythromycin binds to the 50S ribosomal subunit of susceptible bacteria, inhibiting protein synthesis by blocking the translocation of peptide chains.
Erythromycin, a macrolide antibiotic, binds to the 50S ribosomal subunit of susceptible bacteria, inhibiting protein synthesis. At high concentrations, it may also inhibit RNA synthesis.
Treatment of infections caused by susceptible strains of microorganisms (e.g., respiratory tract infections, skin infections, pertussis, diphtheria, intestinal amebiasis)Prophylaxis of rheumatic feverOphthalmic neonatal conjunctivitis due to Chlamydia trachomatis
Treatment of infections caused by susceptible strains of microorganisms: respiratory tract infections (including Legionnaires disease, pertussis), skin and soft tissue infections, diphtheria, syphilis, chlamydial infections, and ocular infections in neonates.Prophylaxis of recurrent rheumatic fever.Off-label: gastrointestinal motility disorder (as a motilin agonist).
250-500 mg orally every 6 hours or 333-500 mg every 8 hours; maximum 4 g/day.
Erythromycin ethylsuccinate 400 mg orally every 6 hours. For severe infections, up to 4 g/day in divided doses.
None Documented
None Documented
Terminal elimination half-life is 1.5-3 hours in adults; prolonged to 4-6 hours in neonates and patients with hepatic impairment.
1.5-2.0 hours in adults with normal renal function; may be prolonged in hepatic impairment (up to 5-6 hours) but not significantly changed in renal disease.
Erythromycin is primarily metabolized by the hepatic cytochrome P450 enzyme system (CYP3A4) via demethylation.
Primarily metabolized in the liver via demethylation by CYP3A4; undergoes N-demethylation and hydroxylation.
Primarily excreted unchanged in urine (70-80%) via glomerular filtration and tubular secretion; 15-20% excreted in feces via biliary elimination.
Primarily hepatic (biliary) excretion of unchanged drug and metabolites; approximately 2-5% renal excretion of unchanged drug; 5-15% fecal elimination.
70-80% bound, primarily to albumin.
70-80% bound to albumin; binding is reversible and saturable at high concentrations.
0.6-0.9 L/kg; indicates extensive tissue penetration, including lung, tonsils, and middle ear fluid.
Approximately 0.7 L/kg (range 0.5-0.9 L/kg); indicates extensive tissue penetration including intracellular and inflammatory fluids.
Oral: 30-40% (erythromycin base is acid-labile); enteric-coated formulations: 40-60%.
Oral (as erythromycin ethylsuccinate): approximately 30-65% (variable, reduced by food); intravenous: 100%.
No dose adjustment required for mild to moderate renal impairment. For severe renal impairment (eGFR < 10 mL/min), reduce dose by 50% or extend interval to every 12-18 hours.
No specific dose adjustment required for renal impairment; caution with high doses in severe renal failure (CrCl <10 mL/min) due to potential ototoxicity.
Child-Pugh Class A: no adjustment. Class B: reduce dose by 50% or extend interval. Class C: avoid use or reduce dose by 75% and monitor closely.
In hepatic impairment, reduce dose by 50-75% depending on severity. Child-Pugh Class A: no adjustment; Class B: reduce to 50% of normal dose; Class C: avoid or use with extreme caution, maximum 1 g per day.
30-50 mg/kg/day orally divided every 6-8 hours; maximum 2 g/day. For severe infections, up to 75 mg/kg/day divided every 6 hours.
30-50 mg/kg/day in 4 divided doses. For severe infections, up to 60-100 mg/kg/day. Maximum 2 g/day.
Consider reduced renal function; monitor for QT prolongation and ototoxicity. Initiate at lower end of dosing range (250 mg every 6 hours) and titrate based on response and tolerance.
No specific dose adjustment; monitor for QT prolongation and hearing loss. Consider lower end of dosing range due to age-related decline in hepatic function.
Erythromycin has been associated with prolongation of the QT interval and rare cases of ventricular arrhythmias, including torsades de pointes, which can be fatal. Avoid use in patients with known QT prolongation, electrolyte abnormalities, or concurrent use of other QT-prolonging drugs.
Increased risk of infantile hypertrophic pyloric stenosis (IHPS) when given to neonates. Erythromycin has also been associated with prolongation of the QT interval and risk of cardiac arrhythmias, including torsades de pointes.
["QT interval prolongation and risk of cardiac arrhythmias","Hepatic dysfunction and hepatitis","Exacerbation of myasthenia gravis","Clostridium difficile-associated diarrhea","Allergic reactions including anaphylaxis","Superinfection with prolonged use"]
Hepatic dysfunction, QT prolongation (risk of arrhythmia), exacerbation of myasthenia gravis, Clostridioides difficile-associated diarrhea, ototoxicity (especially with high doses or renal impairment), potential for drug interactions (CYP3A4 inhibitors/inducers).
["Hypersensitivity to erythromycin or any macrolide antibiotic","Concurrent use with terfenadine, astemizole, or cisapride due to risk of cardiotoxicity","Preexisting QT prolongation or history of ventricular arrhythmias"]
Hypersensitivity to erythromycin or any macrolide antibiotic, concomitant use with terfenadine, astemizole, cisapride, pimozide, ergotamine, or dihydroergotamine (risk of cardiac arrhythmias).
Data Pending Review
Data Pending Review
Take on an empty stomach: 1 hour before or 2 hours after meals. Avoid grapefruit juice as it can increase erythromycin serum concentrations and risk of QT prolongation. Avoid alcohol as it may increase hepatotoxicity risk. High-fat meals may delay absorption.
Take with food to minimize gastrointestinal upset. Avoid grapefruit juice as it can increase erythromycin concentrations via CYP3A4 inhibition. No other significant food interactions.
E-MYCIN E (erythromycin) is classified as FDA Pregnancy Category B. No teratogenic effects have been demonstrated in animal studies, and adequate well-controlled studies in pregnant women have not shown fetal risk. However, data are limited; use during pregnancy only if clearly needed. First trimester: No evidence of increased risk of major malformations. Second and third trimesters: Considered safe; erythromycin is a first-line agent for Group B Streptococcus prophylaxis during labor.
FDA Pregnancy Category B. No evidence of teratogenicity in animal studies; inadequate human studies in first trimester. No known risk of major birth defects or miscarriage. Avoid in maternal myasthenia gravis due to potential neonatal hypotonia.
Erythromycin is excreted into breast milk in small amounts (M/P ratio approximately 0.5-1.0). Breastfeeding is considered safe as concentrations are low and unlikely to cause adverse effects in the infant. However, caution is advised due to potential for gastrointestinal disturbances or sensitization. The AAP classifies erythromycin as compatible with breastfeeding.
Compatible with breastfeeding. Erythromycin is excreted into breast milk in small amounts (M/P ratio approximately 0.5). No adverse effects reported in infants. Monitor infant for gastrointestinal disturbances or rash.
No specific dosage adjustments are recommended during pregnancy. Pharmacokinetic changes (increased volume of distribution, altered clearance) are not clinically significant for erythromycin. Standard dosing (e.g., 250-500 mg PO QID) is used. For IV therapy, no adjustment needed.
No dose adjustment required. Physiologic changes in pregnancy (increased volume of distribution, renal clearance) do not necessitate dose changes for erythromycin. Standard adult dosing applies.
Category C
Category C
E-MYCIN E (erythromycin ethylsuccinate) is a macrolide antibiotic with bacteriostatic activity against gram-positive cocci and atypical pathogens. It is a prodrug that is hydrolyzed to active erythromycin. Administer on an empty stomach for optimal absorption. It may prolong QT interval; use with caution in patients with electrolyte disturbances or concurrent QT-prolonging drugs. Monitor for hepatotoxicity, especially in patients with pre-existing liver disease. It is a strong inhibitor of CYP3A4, increasing levels of statins, warfarin, and other drugs.
E.E.S. 400 (erythromycin ethylsuccinate) is a macrolide antibiotic with bacteriostatic activity. It is a prodrug hydrolyzed to erythromycin base. Use with caution in patients with hepatic impairment or preexisting hearing loss. Monitor for QT prolongation, especially with concurrent use of other QT-prolonging drugs. Commonly used as an alternative in penicillin-allergic patients for respiratory tract infections. It also has prokinetic effects on the GI tract, which can be utilized in gastroparesis but may cause abdominal cramping.
Take this medication exactly as prescribed, usually every 6 to 8 hours, on an empty stomach (1 hour before or 2 hours after meals).Do not crush or chew the tablets; swallow them whole with a full glass of water.Complete the full course of therapy even if you feel better to prevent antibiotic resistance.Avoid grapefruit juice as it may increase the effects and side effects of this medication.Contact your doctor immediately if you experience jaundice, dark urine, severe abdominal pain, or signs of liver problems.Inform your doctor about all medications you are taking, especially statins, warfarin, or other drugs metabolized by CYP3A4.Use effective contraception if you are of childbearing age; this medication may reduce the effectiveness of hormonal contraceptives.If you miss a dose, take it as soon as you remember. If it is almost time for the next dose, skip the missed dose and continue your regular schedule. Do not double the dose.
Take this medication exactly as prescribed, usually every 6 hours or as directed.Complete the full course even if you feel better to prevent resistance.May cause stomach upset; taking with food can reduce GI irritation.Avoid grapefruit juice as it may affect drug levels.Report symptoms of liver problems (yellowing skin/eyes, dark urine) or hearing loss immediately.Do not take with certain medications like statins or warfarin without consulting your doctor.Use effective contraception if applicable, as erythromycin may reduce birth control pill efficacy.