Augmentin 600/5 Dosing for an 80-lb Child
No, 7.5 mL twice daily of Augmentin 600/5 suspension is significantly underdosed for an 80-lb (36 kg) child and should not be prescribed.
Correct Dosing Calculation
For an 80-lb (36 kg) child, the appropriate dose depends on the indication:
For Respiratory Tract Infections (Pneumonia, Sinusitis)
- The recommended regimen is 90 mg/kg/day of the amoxicillin component, divided into two doses, for presumed bacterial community-acquired pneumonia or severe respiratory infections 1, 2.
- For a 36 kg child: 90 mg/kg/day × 36 kg = 3,240 mg/day total, or 1,620 mg per dose twice daily 2.
- Using Augmentin 600 mg/5 mL suspension: 1,620 mg ÷ 120 mg/mL = 13.5 mL per dose, twice daily 3.
For Less Severe Infections
- The standard-dose regimen is 45 mg/kg/day divided twice daily 1, 2, 3.
- For a 36 kg child: 45 mg/kg/day × 36 kg = 1,620 mg/day total, or 810 mg per dose twice daily 2.
- Using Augmentin 600 mg/5 mL suspension: 810 mg ÷ 120 mg/mL = 6.75 mL per dose, twice daily 3.
Why 7.5 mL BID Is Incorrect
- 7.5 mL of Augmentin 600/5 delivers only 900 mg per dose (1,800 mg/day), which equals 50 mg/kg/day for this 36 kg child 3.
- This falls below both the standard 45 mg/kg/day regimen (which would be 6.75 mL BID for mild infections) and far below the high-dose 90 mg/kg/day regimen (13.5 mL BID) needed for pneumonia or severe infections 2, 3.
- The prescribed dose provides inadequate coverage for penicillin-resistant Streptococcus pneumoniae and β-lactamase-producing organisms such as Haemophilus influenzae and Moraxella catarrhalis 1, 2, 4.
Indication-Specific Dosing Algorithm
High-Dose Regimen (90 mg/kg/day) Indications
Use 13.5 mL twice daily when any of the following apply 2:
- Community-acquired pneumonia
- Age < 2 years
- Daycare attendance
- Recent antibiotic use (within 30 days)
- Geographic area with > 10% penicillin-resistant S. pneumoniae
- Moderate-to-severe illness presentation
Standard-Dose Regimen (45 mg/kg/day) Indications
Use 6.75 mL twice daily for 2, 3:
- Mild-to-moderate respiratory infections in children ≥ 2 years
- No recent antibiotic exposure
- No daycare attendance
- Low local resistance patterns
Treatment Duration
- Complete a full 10-day course for respiratory tract infections, particularly pneumonia 1, 2, 5.
- Continue therapy for at least 48–72 hours after complete symptom resolution 2.
- Clinical improvement should occur within 48–72 hours; if not, reevaluate for treatment failure or atypical pathogens 1, 2.
Critical Pitfalls to Avoid
- Never substitute two 250 mg tablets for one 500 mg tablet in adult formulations, as this doubles the clavulanate dose and increases diarrhea risk 5, 3.
- Do not use outdated lower-dose recommendations from older guidelines; current resistance patterns mandate higher dosing 2.
- Ensure the correct suspension concentration is dispensed—Augmentin 600/5 contains 600 mg amoxicillin per 5 mL, not the older 400/5 or 200/5 formulations 3, 4.
- For children weighing ≥ 40 kg, use adult dosing regimens rather than pediatric weight-based calculations 2, 3.