Adult Dosing of Augmentin 400-57/5 Suspension
Critical Formulation Clarification
The Augmentin 400-57/5 suspension (400 mg amoxicillin/57 mg clavulanate per 5 mL) is NOT a standard adult formulation and should generally be avoided in adults. 1
FDA-Approved Adult Dosing Strategy
Adults who have difficulty swallowing tablets may use the 400 mg/57 mg per 5 mL suspension in place of the 875 mg/125 mg tablet. 1 This means:
- For respiratory tract infections or more severe infections: Use 10.9 mL (approximately 11 mL) of the 400-57/5 suspension twice daily to replace one 875/125 mg tablet 1
- For mild-to-moderate infections: Use 6.25 mL of the 400-57/5 suspension twice daily to replace one 500/125 mg tablet 1
Preferred Adult Formulations
The standard adult dosing should prioritize tablets whenever possible 1:
- Mild-to-moderate infections: 500 mg/125 mg tablet every 12 hours 1
- Respiratory tract infections and more severe infections: 875 mg/125 mg tablet every 12 hours 1
- Alternative for respiratory infections: 500 mg/125 mg tablet every 8 hours 1
Clinical Decision Algorithm
- First choice: Use adult tablet formulations (500/125 mg or 875/125 mg) 1
- If swallowing difficulty exists: Calculate equivalent suspension volume based on the 400-57/5 formulation 1
- Duration: 5-10 days depending on infection type, with respiratory infections typically requiring 7-10 days 2
Critical Dosing Warnings
- Never substitute two 250/125 mg tablets for one 500/125 mg tablet due to excessive clavulanate exposure 1
- The 400-57/5 suspension is primarily designed for pediatric patients weighing ≥40 kg as an alternative to adult tablets 1
- Take at the start of meals to enhance clavulanate absorption and minimize gastrointestinal intolerance 1
Common Pitfalls to Avoid
- Using pediatric weight-based dosing formulas for adults—this formulation should only be used as a direct tablet replacement 1
- Underdosing by using standard pediatric volumes instead of the calculated adult-equivalent volumes 1
- Prescribing this suspension as first-line for adults when tablets are appropriate 1