Azitgro (azithromycin)

# Azitgro (azithromycin) ## Overview Azithromycin is an azalide antibiotic (a subclass of macrolides) that inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit. It is characterized by a long half-life (approximately 68 hours) and high tissue penetration. ## Primary Indications * Community-acquired pneumonia (CAP). * Acute bacterial exacerbations of COPD. * Acute bacterial sinusitis. * Pharyngitis/tonsillitis (due to *S. pyogenes*). * Uncomplicated skin and skin structure infections. * Urethritis/cervicitis (*Chlamydia trachomatis*). * Prevention/treatment of *Mycobacterium avium* complex (MAC) in HIV. ## Adult Dosing * **Respiratory/Skin Infections:** 500 mg orally on Day 1, followed by 250 mg once daily on Days 2–5. * **Chlamydial Urethritis/Cervicitis:** 1 g orally as a single dose. * **MAC Prophylaxis:** 1,200 mg orally once weekly. * **Note:** Dosing may vary based on local susceptibility patterns and specific institutional guidelines. ## Pediatric Dosing * **General Infections (≥6 months):** 10 mg/kg (max 500 mg) on Day 1, followed by 5 mg/kg (max 250 mg) once daily on Days 2–5. * **Pharyngitis/Tonsillitis:** 12 mg/kg/day (max 500 mg) once daily for 5 days. * **Acute Otitis Media:** 30 mg/kg as a single dose OR 10 mg/kg once daily for 3 days. ## Dose Adjustments * **Renal Impairment:** No dosage adjustment necessary for mild-to-moderate impairment. Use with caution in severe impairment (GFR <10 mL/min). * **Hepatic Impairment:** Use with caution; azithromycin is primarily eliminated via the liver. Avoid in severe hepatic disease. ## Contraindications * Hypersensitivity to azithromycin, erythromycin, or any macrolide/ketolide antibiotic. * History of cholestatic jaundice/hepatic dysfunction associated with prior use of azithromycin. ## Adverse Effects * **Common:** Diarrhea, nausea, abdominal pain, vomiting. * **Serious:** QTc interval prolongation (risk of Torsades de Pointes), hepatotoxicity, *Clostridioides difficile*-associated diarrhea (CDAD), hypersensitivity reactions (SJS/TEN), and infantile hypertrophic pyloric stenosis (in neonates). ## Key Drug Interactions * **QTc-Prolonging Agents:** Increased risk of cardiac arrhythmias (e.g., amiodarone, ondansetron, antipsychotics). * **Warfarin:** May potentiate the anticoagulant effect; monitor INR. * **Digoxin:** May increase digoxin serum concentrations; monitor levels. * **Nelfinavir:** May increase azithromycin serum concentrations. ## Monitoring * **Cardiac:** Monitor ECG in high-risk patients (pre-existing arrhythmias or electrolyte imbalances). * **Hepatic:** Monitor for signs of jaundice or elevated LFTs if therapy is prolonged. * **GI:** Monitor for symptoms of severe or persistent diarrhea. ## Clinical Pearls * Azithromycin has a long tissue half-life; clinical effect often persists beyond the end of the short 3- to 5-day course. * It is generally well-tolerated with fewer GI side effects compared to erythromycin. * Due to rising resistance patterns in *S. pneumoniae*, utilize local antibiograms to guide empirical therapy for respiratory infections. *** **Educational Disclaimer:** This information is for educational purposes only. Always consult the most current official prescribing information (package insert) or a clinical pharmacist at your institution to verify doses, contraindications, and drug interactions before prescribing or administering medication.