Azithromycin Dosing for Pediatric Streptococcal Infections
For pediatric patients with streptococcal pharyngitis, the recommended dose of azithromycin is 12 mg/kg once daily for 5 days (maximum 500 mg per day). 1
Dosing Recommendations by Infection Type
Group A Streptococcal Pharyngitis/Tonsillitis
- 12 mg/kg once daily for 5 days (maximum 500 mg per day) 1
- Note: The higher dose of 12 mg/kg is specifically recommended for streptococcal pharyngitis to prevent recurrence of infection 2
- Studies have shown that lower doses (10 mg/kg) may result in inferior bacterial eradication compared to penicillin V 3
Other Streptococcal Infections (including pneumonia)
- For infants and children aged >6 months: 10 mg/kg (maximum: 500 mg) on day 1, followed by 5 mg/kg per day (maximum: 250 mg) on days 2-5 1, 4
- For infants aged <6 months: 10 mg/kg per day for 5 days 1
Administration Guidelines
- Azithromycin oral suspension can be taken with or without food 4
- Administer as a single daily dose 4
- Avoid simultaneous administration with aluminum or magnesium-containing antacids as they reduce absorption 1
Weight-Based Dosing Chart for Streptococcal Pharyngitis
| Weight (kg) | Weight (lbs) | Daily Dose (12 mg/kg) |
|---|---|---|
| 10 kg | 22 lbs | 120 mg once daily |
| 20 kg | 44 lbs | 240 mg once daily |
| 30 kg | 66 lbs | 360 mg once daily |
| 40 kg | 88 lbs | 480 mg once daily |
| ≥42 kg | ≥92 lbs | 500 mg once daily (max) |
Clinical Efficacy
- Higher-dose azithromycin (20 mg/kg/day for 3 days) has shown superior bacterial eradication compared to lower-dose regimens (10 mg/kg/day) for streptococcal pharyngitis 5
- The 5-day regimen with 12 mg/kg daily is preferred over shorter courses for streptococcal pharyngitis to ensure adequate bacterial eradication 1, 2
- Azithromycin achieves clinically relevant concentrations at infection sites and has a prolonged half-life, allowing once-daily dosing 6
Important Considerations
- Azithromycin is an alternative for patients with penicillin allergy 1
- Penicillin or amoxicillin remains first-line therapy for Group A streptococcal pharyngitis due to narrow spectrum and low cost 1
- Monitor for gastrointestinal side effects (abdominal discomfort, diarrhea, nausea, vomiting), which are generally mild to moderate 1, 7
- Resistance of Group A streptococcus to macrolides varies geographically and should be considered when selecting therapy 1
Special Populations
- No dosage adjustment is needed based on gender 4
- Use with caution in patients with impaired hepatic function 1
- No dosage adjustment is recommended for patients with renal impairment (GFR ≤80 mL/min), but use caution in severe renal impairment 4
Remember that while azithromycin offers the convenience of shorter treatment duration and once-daily dosing, local resistance patterns should be considered when selecting antimicrobial therapy for streptococcal infections.