Azithromycin Dosing for Acute Otitis Media in a 36.5 kg Child
Azithromycin is NOT a first-line antibiotic for acute otitis media in children, and high-dose amoxicillin (80-90 mg/kg/day) should be used instead unless there is a documented penicillin allergy or recent amoxicillin exposure. 1
First-Line Treatment Recommendation
High-dose amoxicillin at 80-90 mg/kg/day divided into two doses is the recommended first-line therapy for uncomplicated acute otitis media in children, which would be approximately 1460-1645 mg twice daily for a 36.5 kg child 1, 2
Amoxicillin-clavulanate (high-dose formulation with 14:1 ratio) is indicated when the child has received amoxicillin in the previous 30 days, has concurrent purulent conjunctivitis, or presents with severe illness 1, 2
Azithromycin Dosing (If Indicated)
If azithromycin must be used due to penicillin allergy or other contraindications, the FDA-approved dosing regimens are:
Three-Day Regimen (Preferred for AOM)
- 10 mg/kg once daily for 3 days 3
- For a 36.5 kg child: 365 mg once daily for 3 days 3
- Total course: 1095 mg over 3 days 3
Alternative Regimens
Five-day regimen: 10 mg/kg on Day 1, then 5 mg/kg once daily on Days 2-5 3
- Day 1: 365 mg, Days 2-5: 182.5 mg daily 3
Single-dose regimen: 30 mg/kg as a single dose 3
- For 36.5 kg child: 1095 mg as a single dose 3
Important Clinical Caveats
Why Azithromycin is Not First-Line
Macrolide resistance in Streptococcus pneumoniae is substantial, with studies showing 26-38% of pneumococcal isolates being macrolide-resistant 4
International guidelines consistently recommend amoxicillin or amoxicillin-clavulanate as first-line therapy, with macrolides not mentioned as preferred agents 1
The 2013 American Academy of Pediatrics guidelines do not list azithromycin as a first-line option for acute otitis media 1
When Azithromycin May Be Considered
Non-type I penicillin allergy where cephalosporins are also contraindicated 1
Research studies demonstrate that azithromycin achieves clinical cure rates of 74-93% at end of therapy, which is comparable to amoxicillin-clavulanate 5, 4, 6, 7
The 3-day regimen shows better compliance (100%) compared to 10-day amoxicillin regimens (90%) and fewer gastrointestinal side effects 5, 4, 7
Monitoring and Follow-Up
Clinical improvement should be evident within 48-72 hours regardless of antibiotic choice 1
If symptoms persist or worsen after 48-72 hours, consider treatment failure and switch to amoxicillin-clavulanate or ceftriaxone 1
The single-dose 30 mg/kg regimen has not been adequately studied for re-dosing if the child vomits within 30 minutes 3
Practical Administration
Azithromycin can be taken with or without food 3
For a 36.5 kg child using the 3-day regimen with 200 mg/5 mL suspension: administer approximately 9 mL (just under 2 teaspoons) once daily for 3 days 3
Treatment-related adverse events occur in approximately 11-20% of azithromycin-treated children, primarily gastrointestinal symptoms 5, 4