Drug Characteristics
  • Formulation

    Capsules: 250 mg

    Suspension: 200 mg/5ml        

  • Dose

    Atypical mycobacterial infections (MAI) or Mycobacterium Avium Complex (MAC): 500 mg orally once a day (as part of a combination regimen)

    MAC prophylaxis: 1250 mg once a week.

    Cryptosporidium: 500 mg orally once a day with paromomycin        

  • Side Effects

    Gastrointestinal disturbances (abdominal pain, nausea, diarrhoea), rash, LFT elevations, hearing impairment (with high or prolonged doses)

  • Interactions

    Azithromycin is an inhibitor of cytochrome P450 isoenzymes (but much less so than other macrolides and used in preference to clarithromycin). There may be increased plasma levels of co-administered drugs metabolized by the same pathway e.g. theophylline, warfarin. Terfenadine and astemizole are contraindicated due to risk of cardiac arrhythmias

    Antacids or medicines containing iron or zinc may impair absorption: azithromycin needs to be taken at least 2 hours before or 2 hours after antacids        

  • Renal

    Dose as in normal renal function

  • Hepatic

    Azithromycin is metabolized by the liver and excreted in the bile. There are no current data on the dosage adjustment in patients with moderate to severe hepatic dysfunction. LFTs should be monitored closely in patients with hepatic dysfunction

  • Pregnancy

    Limited Human Data – Animal Data Suggest Low Risk

  • Other Information

    Bioavailability of the capsule is increased if taken on an empty stomach i.e. 1 hour before or 2 hours after food. The generic tablet formulation of azithromycin can be taken with food

    Azithromycin has been used as a last-line treatment for cryptosporidiosis and toxoplasmosis, but these are not routine indications