Azithromycin (Intravenous)

Generic name:

Azithromycin

Drug class:

Macrolide antibiotic

Dosage form:

Intravenous infusion solution

Route of administration:

Intravenous (IV)

Dose:

Typical adult dose: 500 mg IV once daily; for some infections a loading dose of 500 mg on day 1 followed by 250 mg once daily on days 2–5. Dose ranges: 250–500 mg IV daily; infusion over at least 1 hour. Pediatric dose: loading dose 10 mg/kg IV once, then maintenance 5 mg/kg IV once daily. Adjustments vary by indication; consult label.

Mechanism of action:

Azithromycin binds to the 50S ribosomal subunit of susceptible bacteria, inhibiting translocation and protein synthesis.

Drug usage cases:

• Community-acquired pneumonia
• Acute bacterial sinusitis
• Skin and soft tissue infections
• Pharyngitis/tonsillitis
• Exacerbations of chronic obstructive pulmonary disease (COPD)
• Nongonococcal urethritis and cervicitis (Chlamydia trachomatis)
• Gonorrhea (Neisseria gonorrhoeae)
• Chancroid (Haemophilus ducreyi)
• Traveler’s diarrhea
• Prophylaxis of Mycobacterium avium complex in HIV patients
• Off-label: reduction of exacerbations in cystic fibrosis

Drug contraindications:

• Hypersensitivity to azithromycin, erythromycin, or any macrolide antibiotic
• History of cholestatic jaundice or hepatic dysfunction associated with prior macrolide use

Side effects:

• Gastrointestinal: diarrhea, nausea, abdominal pain, vomiting
• Injection site reactions: phlebitis, pain, inflammation
• Hepatotoxicity: elevated liver enzymes, hepatitis
• QT interval prolongation, torsades de pointes
• Headache, dizziness
• Hearing impairment (transient)
• Clostridioides difficile–associated diarrhea
• Hematologic: neutropenia, thrombocytopenia
• Hypersensitivity reactions: rash, urticaria, anaphylaxis

Warnings:

• QT prolongation: use with caution in patients with known risk factors
• Hepatic impairment: monitor liver function tests
• Clostridioides difficile–associated diarrhea risk; monitor for severe diarrhea
• Potential for resistant organisms; use appropriate culture data
• Infusion rate: administer over at least 1 hour to reduce phlebitis
• Caution in renal impairment; dosage adjustment may be necessary

Use during pregnancy or breastfeeding:

Pregnancy: Category B. Animal studies show no teratogenic effects; limited human data do not indicate increased risk of fetal harm. Use only if clearly needed. Breastfeeding: Azithromycin is excreted in breast milk; may cause diarrhea or candidiasis in nursing infants. Evaluate benefits versus potential risk; monitor infant for gastrointestinal symptoms.