Augmentin (Amoxicillin-Clavulanic Acid) for Urinary Tract Infections
Amoxicillin-clavulanic acid is recommended as a first-choice treatment option for lower urinary tract infections, with high effectiveness against most common uropathogens. 1
Effectiveness in UTIs
- Amoxicillin-clavulanic acid is officially recognized by the WHO as a first-line treatment for lower urinary tract infections (UTIs) 1
- The combination extends amoxicillin's spectrum by protecting it from degradation by β-lactamase enzymes produced by resistant bacteria 2
- Clinical studies have shown microbiological cure rates of 84% one week after treatment and 67% one month later in patients with recurrent UTIs 3
Indications and Positioning in Treatment Guidelines
- Amoxicillin-clavulanic acid is classified as an "Access" antibiotic in the WHO AWaRe classification, indicating it's appropriate for first-line empiric therapy 1
- It's particularly valuable for treating UTIs caused by amoxicillin-resistant organisms, with success rates of approximately 70% for such infections 4
- In randomized trials comparing amoxicillin alone versus amoxicillin-clavulanic acid for UTIs caused by penicillin-resistant bacteria, the combination achieved 85% cure rates versus only 25% with amoxicillin alone 5
Treatment Recommendations by UTI Type
Lower UTIs (Cystitis)
- Recommended as first-line therapy alongside nitrofurantoin and sulfamethoxazole-trimethoprim 1
- Standard dosing is typically 375 mg three times daily for uncomplicated lower UTIs 4
- Treatment duration of 7 days is generally recommended, extending to 14 days for men when prostatitis cannot be excluded 1
Complicated UTIs
- For complicated UTIs with systemic symptoms, amoxicillin plus an aminoglycoside is recommended as one of the first-line combination options 1
- In patients with spinal cord injury, amoxicillin-clavulanic acid is recognized as an appropriate treatment option for symptomatic UTIs 1
Special Considerations
- Amoxicillin-clavulanic acid maintains good activity against E. coli in urinary isolates, unlike amoxicillin alone which has high resistance rates (median 75% resistance) 1
- For patients with multidrug-resistant organisms, particularly those with extended-spectrum β-lactamase (ESBL) producing bacteria, amoxicillin-clavulanic acid may be considered for non-severe infections 1
- Side effects occur in approximately 20% of patients but are generally mild and rarely require discontinuation of treatment 3
Limitations and Caveats
- Some studies have shown slightly lower cure rates compared to other agents; one study found 83% cure with augmentin versus 100% with co-trimoxazole 6
- Resistance patterns vary geographically, so local antibiotic susceptibility patterns should guide empiric therapy 1
- Not recommended for upper UTIs (pyelonephritis) as first-line therapy, where fluoroquinolones or third-generation cephalosporins are preferred 1
- Should not be used for asymptomatic bacteriuria, which generally should not be treated with antibiotics 1
Pediatric Considerations
- Amoxicillin-clavulanic acid is recommended for empiric treatment of UTIs in children 1
- Pharmacokinetic studies show good penetration into tissues and appropriate urinary concentrations in pediatric patients 2
- Dosing should be adjusted based on the child's weight, typically 20-40 mg/kg per day divided in 3 doses 1