What is Erythromycin (antibiotic) base and how is it used?

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From the Guidelines

Erythromycin base is a macrolide antibiotic used to treat various bacterial infections, with a typical adult dosage of 500 mg taken orally four times a day for 21 days, as recommended by the Centers for Disease Control and Prevention 1.

Key Points

  • Erythromycin base works by inhibiting bacterial protein synthesis, preventing bacteria from growing and multiplying.
  • It is typically prescribed for respiratory tract infections, skin infections, whooping cough, and certain sexually transmitted infections.
  • The medication should be taken on an empty stomach, 1 hour before or 2 hours after meals, as food can reduce absorption.
  • Common side effects include gastrointestinal disturbances like nausea, vomiting, and abdominal pain.
  • Erythromycin can interact with several medications by affecting liver enzymes, so it's essential to inform your healthcare provider about all medications you're taking.

Important Considerations

  • Erythromycin base should be used cautiously in patients with liver disease, and pregnant women should consult their doctor before use.
  • Completing the full course of antibiotics is crucial, even if symptoms improve, to prevent antibiotic resistance and ensure the infection is completely eliminated.
  • According to the guidelines, erythromycin base is an effective treatment option for certain bacterial infections, with a recommended dosage and treatment duration 1.

From the FDA Drug Label

Erythromycin tablets are available in two strengths containing either 250 mg or 500 mg of erythromycin base Erythromycin is produced by a strain of Saccharopolyspora erythraea (formerly Streptomyces erythraeus) and belongs to the macrolide group of antibiotics.

Erythromycin base refers to the active ingredient in erythromycin tablets, which contains either 250 mg or 500 mg of the base. It is a macrolide antibiotic used to treat various infections caused by susceptible bacteria.

  • The erythromycin base is used orally, as an alternative drug in treatment of certain infections, such as acute pelvic inflammatory disease caused by N. gonorrhoeae in female patients with a history of sensitivity to penicillin 2.
  • Key points about erythromycin base include its production by a strain of Saccharopolyspora erythraea and its classification as a macrolide antibiotic 2.

From the Research

Definition of Erythromycin Base

  • Erythromycin is a macrolide antibiotic that acts by inhibiting the translocation reaction during protein synthesis 3.
  • It is active against most gram-positive bacteria, some gram-negative bacteria, and other microorganisms such as Treponema, Chlamydia, and Mycoplasma 3.

Mechanism of Action

  • Erythromycin inhibits protein synthesis in susceptible organisms by binding to the 50S ribosomal subunit 4.
  • Alteration in this binding site confers simultaneous resistance to all macrolide antibiotics 4.

Uses of Erythromycin

  • Erythromycin is used to treat various infections caused by susceptible organisms, including respiratory tract and soft tissue infections 5.
  • It is also used to treat infections caused by atypical respiratory pathogens, such as Legionella 6.
  • Erythromycin is one of the safest antibiotics available and is effective when used against susceptible organisms and in indicated clinical situations 5.

Comparison with Other Macrolides

  • Azithromycin and clarithromycin are erythromycin analogues that have recently been approved by the FDA 4.
  • Clarithromycin is several-fold more active in vitro than erythromycin against gram-positive organisms, while azithromycin is 2- to 4-fold less potent 4.
  • Azithromycin and clarithromycin have pharmacokinetics that allow shorter dosing schedules because of prolonged tissue levels 6.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Azithromycin and clarithromycin: overview and comparison with erythromycin.

Infection control and hospital epidemiology, 1992

Research

Erythromycin.

The Medical clinics of North America, 1987

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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