Pediatric Residents

Drug Name: Azithromycin

Click on the titles below for drug details

  • Macrolide antibiotic.
  • Inhibits bacterial protein production by binding to the 50S Ribosome subunit.
  • Bacteriostatic
  • Typically enteral, but can also be used IV (Do not give IM)
  • Usually 10 mg/kg x1 dose on Day 1 of treatment, then an additional 4 days of 5mg/kg/dose q24 hours
    • Day 1 maximum dose 500 mg, Days 2-5 maximum dose is 250 mg/dose.
  • Suspension can be administered with or without food. Tablet may be administered with food to reduce GI side effects.
  • Dosage forms:
    • 100mg/5mL and 200mg/5mL suspension
    • 250mg and 500mg tablet; Z-Pak (250mg tablets with 5 day dosing cards for Day 1-Day 5)
  • Spectrum
    • Gram positives: Corynebacterium diphtheriae
    • Gram-Negative: Bordetella pertussis, H. influenzae, Legionella pneumophilia, and Neisseria gonorrhoeae
    • Covers many intracellular and atypical organisms.
      • Bartonella henselae, Babesia
      • Bordetella pertussis
        • Note, in infants <6 months should prescribe 10 mg/kg/dose qD for 5 days
      • Mycoplasma pneumoniae
      • Mycoplasma-Induced Rash and Mucositis (MIRM) - limited evidence but may reduce disease progression/speed up resolution.
      • Mycobacterial infections
  • Indications:
    • STIs
      • Chancroid, Chlamydia trachomatis, Gonorrhea (if ceftriaxone not available)
    • Bacterial enteritis (although there is growing resistance) - Shigellosis, Campylobacter, Cholera, Typhoid fever
    • Prophylaxis for meningococcal disease (10 mg/kg single dose, maximum 500 mg)
    • GAS - alternative agent with severe penicillin allergy
    • Sometimes used in more typical sinus/respiratory disease when first line agents (e.g., Beta-lactams) are not available or contraindicated.
    • Also used for anti-inflammatory effects in patients with Cystic Fibrosis, Pseudomonas colonization, and asthma.
      • For this indication, it is usually dosed 3x/week.
  • Hypersensitivity to macrolide antibiotics
  • While this is more common with Erythromycin, may be associated with hypertrophic pyloric stenosis if used in neonates.
  • QT Prolongation and risk of ventricular tachycardia
    • May occur within minutes of first dose and up to 7 days after initiation
    • Higher risk in female patients, those with heart disease, congenital long QT, coadministration of other QT-prolonging medications, hypokalemia, hypomagnesemia
  • Ototoxicity - typically reversible
  • Diarrhea, including risk of C. diff colitis
  • Penetrates well into the skin, lung, tonsils, and cervix.
  • Does NOT cross the CSF, even with inflamed meninges.
  • Predominantly eliminated hepatically; however there is no dosage adjustment required.
  • Diarrhea is quite common with azithromycin administration
  • High degree of Streptococcal resistance - if prescribed for AOM, CAP, or GAS pharyngitis, would consider close follow up to ensure symptom improvement.