Azithromycin Use in Pediatric Patients by Age
Azithromycin can be safely used in pediatric patients from birth (including neonates under 1 month of age), though dosing regimens vary by age and indication. 1, 2
Age-Specific Recommendations
Infants Under 1 Month
- Azithromycin is the preferred macrolide for treatment and post-exposure prophylaxis of pertussis in infants under 1 month of age 1
- Dosage: 10 mg/kg once daily for 5 days 1
- Infants in this age group should be monitored for infantile hypertrophic pyloric stenosis (IHPS) and other serious adverse events, although azithromycin has not been associated with IHPS in this population 1
Infants 1-5 Months
- Azithromycin is recommended as a first-line agent for pertussis treatment and prophylaxis based on in vitro effectiveness, safety, and convenient dosing schedule 1
- Safety data from surveillance studies show azithromycin appears to be safe in this age group with no reported cases of IHPS 3
Infants Under 6 Months
- Dosage: 10 mg/kg once daily for 5 days 1, 2
- While the FDA has not specifically licensed macrolides for use in infants under 6 months, clinical data support the use of azithromycin in this population 1, 3
Children 6 Months and Older
- Dosage for most indications: 10 mg/kg (maximum 500 mg) on day 1, followed by 5 mg/kg (maximum 250 mg) daily for days 2-5 1, 2
- For community-acquired pneumonia, particularly atypical pneumonia caused by Mycoplasma or Chlamydia, this 5-day regimen is recommended by the Infectious Diseases Society of America 1
Weight-Based Dosing Guidelines
- 15-25 kg: 200 mg once daily 2
- 26-35 kg: 300 mg once daily 2
- 36-45 kg: 400 mg once daily 2
- ≥46 kg: 500 mg once daily 2
Pharmacokinetics in Pediatric Patients
- Studies in children aged 6-15 years show sustained systemic exposure with once-daily dosing 4
- Mean elimination half-life is approximately 65 hours in pediatric patients between 0.5 and 16 years of age 5
- Pharmacokinetic parameters in children aged 5-15 years include Cmax of 0.383 mcg/mL and AUC0-24 of 3.109 mcg·hr/mL 6
Safety Considerations
- Azithromycin has fewer gastrointestinal side effects compared to other macrolides such as erythromycin 1, 7
- Common side effects include abdominal discomfort, diarrhea, nausea, vomiting, headache, and dizziness 1, 6
- Azithromycin should not be taken simultaneously with aluminum or magnesium-containing antacids as they reduce absorption 1, 6
- Monitor for potential drug interactions, particularly with medications that prolong QT interval 2, 6
- Azithromycin is classified as an FDA Pregnancy Category B drug 1
Specific Indications in Pediatrics
- Acute otitis media: Safety and effectiveness established for children 6 months and older 6
- Acute bacterial sinusitis: Safety and effectiveness established for children 6 months and older 6
- Community-acquired pneumonia: Safety and effectiveness established for children 6 months and older 6
- Pharyngitis/tonsillitis: Safety and effectiveness established for children 2 years and older 6
Clinical Pearls
- Azithromycin has been shown to have similar efficacy but significantly fewer side effects compared to amoxicillin/clavulanate or erythromycin in the treatment of community-acquired pneumonia in children 7
- For pertussis treatment and prophylaxis, azithromycin is preferred over erythromycin due to better safety profile, especially in young infants 1
- In infants under 1 month, the risk of severe pertussis complications outweighs the potential risks of azithromycin treatment 1