Oral Liquid Augmentin Equivalent for 875/125 mg Tablet Twice Daily
The oral liquid suspension equivalent of Augmentin 875/125 mg tablet twice daily is NOT straightforward because liquid formulations contain different ratios of amoxicillin to clavulanate, and direct conversion is not recommended due to excessive clavulanate exposure.
Critical Dosing Principle
You cannot simply substitute liquid suspension for the 875/125 mg tablet on a milligram-per-milligram basis. The Infectious Diseases Society of America explicitly warns that substituting two 250 mg tablets for one 500 mg tablet results in excessive clavulanate dosing, and the same principle applies to liquid formulations 1.
Why Direct Conversion Is Problematic
- Augmentin tablets maintain a fixed 7:1 ratio of amoxicillin to clavulanate (875 mg amoxicillin with 125 mg clavulanate) 1
- Liquid suspensions typically come in different ratios (commonly 200/28.5 mg per 5 mL, 400/57 mg per 5 mL, or 600/42.9 mg per 5 mL for high-dose formulations) 2, 3
- Attempting to match the 875 mg amoxicillin dose using standard liquid formulations would deliver excessive clavulanate, increasing gastrointestinal side effects 1
Clinical Decision Algorithm
If the patient MUST use liquid formulation:
Option 1 (Preferred for most infections): Use the high-dose pediatric formulation approach
- Augmentin ES-600 suspension (600 mg amoxicillin/42.9 mg clavulanate per 5 mL) was specifically designed to provide high amoxicillin doses with lower clavulanate exposure 2, 3
- For an adult requiring 875 mg amoxicillin twice daily, this would require approximately 7.3 mL twice daily
- This provides comparable amoxicillin dosing with reduced clavulanate-related diarrhea 1
Option 2 (Alternative): Switch to three-times-daily dosing with standard suspension
- Use 500 mg amoxicillin three times daily instead of 875 mg twice daily 1
- This is explicitly recommended by the Infectious Diseases Society of America when three-times-daily dosing is clinically indicated 1
- Standard suspension (400/57 mg per 5 mL) would require 6.25 mL three times daily
- The European Position Paper on Rhinosinusitis supports 500 mg three times daily for 10 days for respiratory infections 1
Option 3 (Last resort): Consider alternative antibiotic
- If liquid formulation is essential and the above options are not feasible, consider switching to an alternative antibiotic available in appropriate liquid formulation
- This avoids the complications of excessive clavulanate dosing
Common Pitfall to Avoid
Never calculate liquid dose by simply dividing 875 mg by the concentration per mL of standard suspension. This mathematical approach ignores the clavulanate component and will result in excessive clavulanate exposure, leading to significantly increased diarrhea (up to 2% vs 1% with appropriate dosing) 1.
Clinical Context Matters
- The 875/125 mg twice-daily formulation is specifically recommended for respiratory infections including acute bacterial rhinosinusitis, community-acquired pneumonia, and acute exacerbations of chronic bronchitis 1
- Clinical success rates with 875/125 mg twice daily range from 91.5-93% for respiratory infections 1
- If switching to liquid is necessary, ensure the total daily amoxicillin dose remains adequate (1750 mg/day for twice-daily or 1500 mg/day for three-times-daily dosing) 1, 4