Augmentin Dosing for 38 kg Girl with Acute Pharyngitis
For a 38 kg girl with acute pharyngitis, Augmentin is NOT the first-line treatment—amoxicillin alone at 50 mg/kg once daily (1900 mg, rounded to 2000 mg maximum) or 25 mg/kg twice daily (950 mg per dose) for 10 days is the preferred regimen. 1, 2
Why Augmentin is Not First-Line
Amoxicillin alone (without clavulanate) is the guideline-recommended first-line therapy for uncomplicated Group A Streptococcal (GAS) pharyngitis, with a "Strong, high" evidence rating 1, 3
Augmentin should be reserved for specific situations: recurrent pharyngitis, suspected bacterial resistance, or chronic GAS carriers with recurrent symptoms 2, 3
The addition of clavulanate is unnecessary for typical GAS pharyngitis because GAS does not produce beta-lactamases, making the clavulanate component redundant 4
If Augmentin Must Be Used
If there is a specific clinical indication for Augmentin (such as recurrent infection or carrier state), the dose would be 40 mg/kg/day of the amoxicillin component divided into 3 equal doses for 10 days. 2, 3
Calculation for 38 kg patient:
- Total daily amoxicillin dose: 40 mg/kg/day × 38 kg = 1520 mg/day
- Divided into 3 doses: approximately 507 mg per dose, three times daily
- Practical dosing: 500 mg three times daily for 10 days 2
Critical Dosing Warning:
- Two 250 mg tablets of Augmentin are NOT equivalent to one 500 mg tablet because both contain 125 mg of clavulanate, which would result in excessive clavulanate exposure 2
- Use the appropriate strength formulation to avoid this error
Essential Treatment Principles
Complete the full 10-day course even if symptoms resolve earlier, to prevent acute rheumatic fever and other complications 1, 2, 3
Patient becomes non-contagious after 24 hours of appropriate antibiotic therapy 2, 3
If using standard amoxicillin instead (which is preferred): 50 mg/kg once daily = 1900 mg (round to maximum 1000 mg per guidelines) OR 25 mg/kg twice daily = 950 mg per dose (round to 1000 mg twice daily for this weight) 1, 3
Common Pitfall to Avoid
The most important pitfall is using Augmentin when simple amoxicillin would suffice. Augmentin increases cost, gastrointestinal side effects, and unnecessary antibiotic exposure without added benefit in uncomplicated GAS pharyngitis. 2, 4 Reserve it for the specific indications mentioned above.