Azithromycin
General
- Type: Antibiotic, Macrolide
- Dosage Forms: powder for solution, suspension reconstituted, packet, tablet
- Dosage Strengths: powder for solution: 500mg, 2.5g; suspension reconstituted: 100, 200mg/5mL; packet: 1g; tablet: 250, 500, 600mg
- Routes of Administration: PO, IV
- Common Trade Names: Zithromax, Z-Pak, Zmax
Adult Dosing
- Babesiosis (In combination with Atovaquone) [Mild/Moderate 500mg PO x1 on day 1, then 250mg PO q24h x7-10 days. Severe 500mg IV q24hr for 7 to 10 days]
- Bacterial Infections [500mg PO x1 on day 1, then 250mg PO q24h x4 days]
- Strep Pharyngitis/tonsillitis [500mg PO x1 on day 1, then 250mg PO q24h x4 days] Alt: 500mg PO q24h x3 days
- COPD exacerbation [500mg PO x1 on day 1, then 250mg PO q24h x4 days] Alt: 500mg PO q24h x3 days
- Community-acquired pneumonia [500mg PO x1 on day 1, then 250mg PO q24h x4 days] Alt: 500mg IV q24h x2 or more days, then 500mg PO q24h to complete 7-10 day course
- Chlamydia: 1 g PO x1; (for uncomplicated urethritis, cervicitis, oropharygeal)
- Gonorrhea (initial or recurrent) [1 g PO x1]
- Gonorrhea (persistent) [2 g PO x1]
- PID [500mg IV q24h x1-2 days, then 250mg PO q24h x5-6 days]
- Urethritis, non-gonococcal initial infection [1 g PO x1]
- Chancroid [1 g PO x1]
- MAC (disseminated) [500-600mg PO q24h] (not 1st-line agent; use with ethambutol)
- MAC (primary prophylaxis) [1200mg PO qwk] Alt: 600mg PO 2x/wk
- MAC (secondary prophylaxis) [500-600mg PO q24h] (not 1st-line agent; use with ethambutol)
- Endocarditis prophylaxis (dental) [500mg PO x1] (Start: 30-60min before procedure)
- Pertussis [500mg PO on day 1, followed by 250mg q24hr for days 2-5]
- Presumptive cervicitis [1 g PO x1]
- Salmonella [1 g PO q24h x1 day, then 500mg PO q24h x2-6 days]
- Typhoid fever [10mg/kg PO q24h x1wk]
Pediatric Dosing
- Pneumonia (peds)
- 10mg/kg/day PO in a once daily dose on day 1 (max 500mg)
- Followed by 5mg/kg/day PO once daily on days 2-5
- 10mg/kg/day PO in a once daily dose on day 1 (max 500mg)
- Bacterial sinusitis: Children ≥6 months: Oral: 10mg/kg PO once daily for 3 days (maximum: 500mg daily)
- Otitis media: Children ≥6 months: Oral:
- 1-day regimen: 30mg/kg as a single dose (maximum dose: 1,500mg)
- 3-day regimen: 10mg/kg once daily for 3 days (maximum: 500mg daily)
- 5-day regimen: 10mg/kg on day 1 (maximum: 500mg daily) followed by 5mg/kg/day once daily on days 2 to 5 (maximum: 250mg daily)
- Pharyngitis (as an alternative agent in penicillin allergic patients):
- Children ≥2 years and Adolescents: Oral: 12mg/kg/dose once daily for 5 days (maximum: 500mg daily)
Special Populations
- Pregnancy Rating: B
- Lactation risk: Excreted in low amounts of breast milk and may lead to rash, somnolence, and diarrhea in nursing infants
- Renal Dosing: Caution in patients with GFR <10 mL/minute, though primarily elimated through hepatic metabolism
- Hepatic Dosing: Caution is indicated for potential hepatotoxicity though it is rare, and there are no specific dosage adjustments indicated for patients with liver failure
Contraindications
- Hypersensitivity to azithromycin or other macrolides or any component of the formulation
- History of cholestatic jaundice/hepatic dysfunction with prior Azithromycin use
Adverse Reactions
Serious
Prolonged QT, torsades, hepatic necrosis, Eaton-Lambert, Myasthenia gravis, corneal erosion
Common
Vomiting, diarrhea, abdominal pain, headache, vision changes
Pharmacology
- Half-life: 68 hrs
- Metabolism: Hepatic
- Excretion: Biliary
- Mechanism of Action:Binds 50S ribosomal subunit interfering with microbial protein synthesis
Antibiotic Sensitivities[1]
Key
- S susceptible/sensitive (usually)
- I intermediate (variably susceptible/resistant)
- R resistant (or not effective clinically)
- S+ synergistic with cell wall antibiotics
- U sensitive for UTI only (non systemic infection)
- X1 no data
- X2 active in vitro, but not used clinically
- X3 active in vitro, but not clinically effective for Group A strep pharyngitis or infections due to E. faecalis
- X4 active in vitro, but not clinically effective for strep pneumonia
See Also
References
- ↑ Sanford Guide to Antimicrobial Therapy 2014
- Epocrates
- Micromedex