Recommended Dosage of Augmentin for Uncomplicated UTI
For uncomplicated urinary tract infections (UTIs), Augmentin (amoxicillin-clavulanate) should be used at a dose of 875/125 mg orally every 12 hours for 3-7 days, though it is considered a second-line option after first-line agents due to its inferior efficacy and higher risk of adverse effects. 1, 2
Treatment Algorithm for UTIs with Augmentin
First-Line vs. Second-Line Therapy
- Augmentin is considered a second-line agent for uncomplicated UTIs
- First-line options (when local resistance rates are favorable) include:
- Trimethoprim-sulfamethoxazole (if resistance <20%)
- Nitrofurantoin
- Fosfomycin
- Fluoroquinolones (reserved due to collateral damage concerns)
Dosing Recommendations
- Uncomplicated UTI:
- 875/125 mg orally every 12 hours for 3-7 days
- Complicated UTI/Pyelonephritis:
- 875/125 mg orally every 12 hours for 10-14 days
- Consider an initial IV dose of ceftriaxone 1g or aminoglycoside when using β-lactams for pyelonephritis 2
Efficacy and Limitations
The Infectious Diseases Society of America (IDSA) guidelines note that β-lactam agents, including amoxicillin-clavulanate, generally have:
- Inferior efficacy compared to other UTI antimicrobials
- More adverse effects than first-line agents
- Should be used with caution for uncomplicated cystitis 1
Clinical trials have shown varying success rates with Augmentin for UTIs:
- Approximately 70% success rate for amoxicillin-resistant organisms 3
- 83% cure rate in one comparative study (vs. 100% for co-trimoxazole) 4
- 84% microbiological cure rate one week after treatment in patients with recurrent UTIs 5
Important Considerations and Caveats
When to Use Augmentin
- When first-line agents cannot be used due to allergies or resistance
- For treatment of amoxicillin-resistant bacterial infections
- When local antibiogram data supports its use
Side Effects to Monitor
- Gastrointestinal effects (diarrhea, abdominal pain) occur in approximately 10-20% of patients 4, 5, 6
- Hypersensitivity reactions
Duration of Treatment
- Shorter durations (3 days) may be appropriate for uncomplicated cystitis in women
- Longer durations (10-14 days) are recommended for pyelonephritis or complicated UTIs 1, 2
Resistance Considerations
- Amoxicillin alone should not be used due to high resistance rates
- The addition of clavulanic acid helps overcome some β-lactamase-mediated resistance
- Local resistance patterns should guide empiric therapy decisions
Augmentin remains a useful alternative when first-line agents cannot be used, particularly for amoxicillin-resistant organisms, but should be prescribed judiciously given its broader spectrum and higher side effect profile compared to more targeted first-line UTI therapies.