Description

Simple

An antibiotic medication used to treat a variety of infections caused by bacteria.

Clinical

A macrolide antibiotic used to treat a variety of bacterial infections.

Overview

Azithromycin is a broad-spectrum macrolide antibiotic with a long half-life and a high degree of tissue penetration [3]. It was initially approved by the FDA in 1991 [4].

It is primarily used for the treatment of respiratory, enteric and genitourinary infections and may be used instead of other macrolides for some sexually transmitted and enteric infections. It is structurally related to erythromycin [2].

Azithromycin [9-deoxo-9a-aza-9a-methyl-9a-homoerythromycin] is a part of the _azalide_ subclass of macrolides, and contains a 15-membered ring, with a methyl-substituted nitrogen instead of a carbonyl group at the 9a position on the aglycone ring, which allows for the prevention of its metabolism. This differentiates azithromycin from other types of macrolides [Read more

Pharmacology

Indication

Azithromycin should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria in order to prevent the development antimicrobial resistance and maintain the efficacy of azithromycin [FDA label].

Azithromycin is indicated for the treatmen... Read more

Pharmacodynamic

Macrolides stop bacterial growth by inhibiting protein synthesis and translation, treating bacterial infections [ Read more

Mechanism of action

In order to replicate, bacteria require a specific process of protein synthesis, enabled by ribosomal proteins [ Read more

Absorption

Bioavailability of azithromycin is 37% following oral administration. Absorption is not affected by food. Macrolide absorption in the intestines is believed to be mediated by P-glycoprotein (ABCB1) efflux transporters, which are known to be encoded by the _ABCB1_ gene [ Read more

Protein binding

The serum protein binding of azithromycin varies in humans, decreasing from 51% at 0.02 g/mL to 7% at 2 g/mL [FDA label].

Volume of distribution

After oral administration, azithromycin is widely distributed in tissues with an apparent steady-state volume of distribution of 31.1 L/kg [FDA label]. Significantly greater azithromycin concentrations have been measured in the tissues rather than in plasma or serum [FDA label], [ Read more

Clearance

Mean apparent plasma cl=630 mL/min (following single 500 mg oral and i.v. dose) [FDA label]

Half life

Terminal elimination half-life: 68 hours [FDA label]

Route of elimination

Biliary excretion of azithromycin, primarily as unchanged drug, is a major route of elimination. Over a 1 week period, approximately 6% of the administered dose is found as unchanged drug in urine [FDA label].

Toxicity

**Rat Oral LD50**: >2000 mk/kg [MSDS]

Possible major adverse effects include cardiovascular arrhythmias and hearing loss. Macrolide resistance is also an ongoing issue [ Read more

Adverse Effects

Effect Regions Age Groups Incidences Evidence Type
Pain at injection site US
  • Kind: experimental
    • Percent: 7%
  • Clinical Trial
    Diarrhea US
  • Kind: experimental
    • Percent: 4-6%
  • Clinical Trial
    Loose stools US
  • Kind: experimental
    • Percent: 4-6%
  • Clinical Trial
    Vomiting US
  • Kind: experimental
    • Percent: 1-6%
  • Clinical Trial
    Local inflammation at injection site US
  • Kind: experimental
    • Percent: 3%
  • Clinical Trial
    Nausea US
  • Kind: experimental
    • Percent: <3%
  • Clinical Trial
    Abdominal Pain US
  • Kind: experimental
    • Percent: 2-3%
  • Clinical Trial
    Increase in serum phosphate US
  • Kind: experimental
    • Percent: <1
  • Clinical Trial
    Increased bilirubin US
  • Kind: experimental
    • Percent: <1
  • Clinical Trial
    Increased serum alkaline phosphatase US
  • Kind: experimental
    • Percent: <1
  • Clinical Trial
    Increased bicarbonate US
  • Kind: experimental
    • Percent: <1
  • Clinical Trial
    Increased basophils US
  • Kind: experimental
    • Percent: <1
  • Clinical Trial
    Allergic Reactions US
  • Kind: experimental
    • Percent: <1
  • Hyperkinesia US
  • Kind: experimental
    • Percent: <1
  • Clinical Trial
    Constipation US
  • Kind: experimental
    • Percent: <1
  • Pruritis US
  • Kind: experimental
    • Percent: <1
  • Heart palpitations US
  • Kind: experimental
    • Percent: <1
  • Clinical Trial
    Conjunctivitis US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Vesiculobullous rash US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Urticaria US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Sweating US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Fungal dermatitis US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Eczema US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Rhinitis US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Pleural Effusion US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Cough US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Pharyngitis US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Pain US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Malaise US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Face edema US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Fungal Infection US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Fever US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Nervousness US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Anemia US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Oral moniliasis US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Leukopenia US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Headache US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Agitation US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Hyperkinesia US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Taste perversion US
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Anorexia US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Chest Pain US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Enteritis US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Jaundice US
    • pediatric
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Rash US
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Pruritus US
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Photosensitivity US
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Angioedema US
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Bronchospasm US
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial
    Gastritis US
  • Kind: experimental
    • Percent: ≤1%
  • Clinical Trial

    Contraindications

    • Route:
      • Oral
    • Hypersensitivity:
      • true
      • Ketolides
    • Regions: US
    • Hypersensitivity:
      • true
      • Macrolides
    • Regions: US
    • Route:
      • Oral
    • Hypersensitivity:
      • true
      • erythromycin
    • Regions: US
    • Route:
      • Oral
    • Regions: US
    • Patient Conditions:
        • Name: Hepatic dysfunction
        • Drugbank Id: DBCOND0094733
    • Patient Conditions Associated With:
        • Name: Prior azithromycin use
        • Drugbank Id: DBCOND0117160
    • Route:
      • Oral
    • Regions: US
    • Patient Conditions:
        • Name: Cholestatic jaundice
        • Drugbank Id: DBCOND0094562
    • Patient Conditions Associated With:
        • Name: Prior azithromycin use
        • Drugbank Id: DBCOND0117160
    • Route:
      • Ophthalmic
      • Oral
    • Hypersensitivity:
      • true
    • Regions: US

    Food Interactions

    Take on an empty stomach. Take at least 1 hour before or 2 hours after meals.