What is the dose of azithromycin (AZI)?

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Last updated: April 2, 2025 • View editorial policy

From the Guidelines

Azithromycin should be administered at a dose of 1 g orally, single dose, for the treatment of Chlamydia in adults, as recommended by the most recent guidelines 1. The dosing of azithromycin varies depending on the condition being treated and the patient population.

  • For adults with Chlamydia, the recommended dose is 1 g orally, single dose 1.
  • For children who weigh >45 kg but are aged <8 years, the recommended dose is 1 g orally, single dose 1.
  • For children ≥8 years, the recommended dose is 1 g orally, single dose, or 100 mg orally, twice a day for 7 days 1. It is essential to note that azithromycin should be taken at least 1 hour before or 2 hours after meals, as food can reduce absorption. The medication works by binding to bacterial ribosomes, preventing protein synthesis and inhibiting bacterial growth. Common side effects include nausea, diarrhea, and abdominal pain. Patients with liver or kidney disease may require dose adjustments, and azithromycin can interact with certain medications like antacids containing aluminum or magnesium, which should be taken at least 2 hours apart from azithromycin. The guidelines from 2024 1 provide the most up-to-date recommendations for azithromycin dosing, and it is essential to follow these guidelines to ensure optimal treatment outcomes. In contrast to the 2019 guidelines 2, the 2024 guidelines provide more specific recommendations for azithromycin dosing in different patient populations. Therefore, the 1 g orally, single dose, recommendation for azithromycin in adults with Chlamydia should be followed, as it is based on the most recent and highest quality evidence 1.

From the FDA Drug Label

The recommended dose of azithromycin for oral suspension for the treatment of pediatric patients with acute otitis media is 30 mg/kg given as a single dose or 10 mg/kg once daily for 3 days or 10 mg/kg as a single dose on the first day followed by 5 mg/kg/day on Days 2 through 5. The recommended dose of azithromycin for oral suspension for the treatment of pediatric patients with acute bacterial sinusitis is 10 mg/kg once daily for 3 days. The recommended dose of azithromycin for oral suspension for the treatment of pediatric patients with community-acquired pneumonia is 10 mg/kg as a single dose on the first day followed by 5 mg/kg on Days 2 through 5. The recommended dose of azithromycin for children with pharyngitis/tonsillitis is 12 mg/kg once daily for 5 days.

The dose of azithromycin varies depending on the condition being treated.

  • Acute Otitis Media: 30 mg/kg as a single dose or 10 mg/kg once daily for 3 days or 10 mg/kg as a single dose on the first day followed by 5 mg/kg/day on Days 2 through 5.
  • Acute Bacterial Sinusitis: 10 mg/kg once daily for 3 days.
  • Community-Acquired Pneumonia: 10 mg/kg as a single dose on the first day followed by 5 mg/kg on Days 2 through 5.
  • Pharyngitis/Tonsillitis: 12 mg/kg once daily for 5 days 3.

From the Research

Azithromycin Dosage

  • The dosage of azithromycin varies depending on the infection being treated.
  • For the treatment of atypical pneumonia, a 5-day regimen consisting of 500 mg in a single dose on the first day followed by 250 mg once daily for 4 consecutive days was compared with that of a 3-day course of azithromycin given in single daily doses of 500 mg 4.
  • Azithromycin has been shown to be effective for the treatment of sexually transmitted diseases caused by Chlamydia trachomatis, with a single dose of 1-g 5.
  • The pharmacokinetic profiles of azithromycin are characterized by good oral bioavailability, excellent tissue penetration and persistence, and long elimination half-lives, which allow for once-daily or twice-daily dosing 6.

Comparison with Other Antibiotics

  • Azithromycin has increased gram-negative activity compared with erythromycin, including activity against Haemophilus influenzae, while maintaining activity against gram-positive organisms 6.
  • Compared with erythromycin, azithromycin offers improved tolerability, with fewer gastrointestinal side effects 7.
  • Azithromycin has been compared with doxycycline for the treatment of rectal chlamydia, with doxycycline showing a higher microbiological cure rate 5, 8.

Specific Infections

  • For the treatment of anorectal Chlamydia trachomatis infection, a single dose of azithromycin (1-g) was compared with a 7-day course of doxycycline (100 mg twice daily) 5.
  • For the treatment of atypical pneumonia, azithromycin was given in single daily doses of 500 mg for 3 or 5 days 4.

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Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.