Azithromycin

What it is and how it works

Mechanism of Action Azithromycin is a macrolide antibacterial drug.

Indications

Azithromycin tablet is a macrolide antibacterial drug indicated for treatment of patients with mild to moderate infections caused by susceptible strains of the designated microorganisms in the specific conditions listed below: Acute bacterial exacerbations of chronic bronchitis in adults Acute bacterial sinusitis in adults Uncomplicated skin and skin structure infections in adults Urethritis and cervicitis in adults Genital ulcer disease in men Acute otitis media in pediatric patients (6 months of age and older) Community-acquired pneumonia in adults and pediatric patients (6 months of age and older) ( 1.1 , 1.2 ) Pharyngitis/tonsillitis in adults and pediatric patients (2 years of age and older) ( 1.1 , 1.2 ) Limitation of Use: Azithromycin is not recommended in patients with pneumonia who are judged to be inappropriate for oral therapy because of moderate to severe illness or risk factors.

Dosage and administration (summary)

Recommended Dosage for Adult Patients Infection Recommended Dose/Duration of Therapy Community-acquired pneumonia (mild severity) Pharyngitis/tonsillitis (second-line therapy) Skin/skin structure (uncomplicated) 500 mg as a single dose on Day 1, followed by 250 mg once daily on Days 2 through 5. Acute bacterial exacerbations of chronic bronchitis (mild to moderate) 500 mg as a single dose on Day 1, followed by 250 mg once daily on Days 2 through 5 or 500 mg once daily for 3 days. Acute bacterial sinusitis 500 mg once daily for 3 days. Genital ulcer disease (chancroid) Non-gonococcal urethritis and cervicitis One single 1 gram dose.

Contraindications

Patients with known hypersensitivity to azithromycin, erythromycin, any macrolide or ketolide drug. Patients with a history of cholestatic jaundice/hepatic dysfunction associated with prior use of azithromycin. Hypersensitivity Azithromycin is contraindicated in patients with known hypersensitivity to azithromycin, erythromycin, any macrolide or ketolide drug.

Warnings and precautions

Serious (including fatal) allergic and skin reactions: Discontinue azithromycin if reaction occurs. Hepatotoxicity: Severe, and sometimes fatal, hepatotoxicity has been reported. Discontinue azithromycin immediately if signs and symptoms of hepatitis occur. Infantile Hypertrophic Pyloric Stenosis (IHPS): Following the use of azithromycin in neonates (treatment up to 42 days of life), IHPS has been reported. Direct parents and caregivers to contact their physician if vomiting or irritability with feeding occurs. Prolongation of QT interval and cases of torsades de pointes have been reported.

Pregnancy

Pregnancy Risk Summary Available data from published literature and postmarketing experience over several decades with azithromycin use in pregnant women have not identified any drug-associated risks for major birth defects, miscarriage, or adverse maternal or fetal outcomes (see Data) .

Storage and supply

How Supplied Azithromycin tablets USP are supplied in the following strengths and package configurations: Azithromycin tablets USP, 250 mg are supplied as pink, modified capsule shaped, film-coated tablets, engraved with 'LU' on one side and 'L04' on the other side containing azithromycin dihydrate equivalent to 250 mg of azithromycin USP.

Source: Azithromycin (Azithromycin) — US FDA prescribing information, 2026-08-20, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.