What is the dosing regimen for Augmentin (amoxicillin-clavulanate) for a urinary tract infection (UTI)?

Augmentin Dosing for Urinary Tract Infections

For urinary tract infections, Augmentin (amoxicillin-clavulanate) should be dosed at 875 mg/125 mg orally every 12 hours for 7-14 days, with 7 days sufficient for patients with prompt symptom resolution and 10-14 days for those with delayed response. 1

Dosing Recommendations Based on UTI Type

Uncomplicated UTIs

• For uncomplicated cystitis, Augmentin is not considered a first-line agent but can be used when other recommended agents cannot be used 2
• When used for uncomplicated cystitis, the recommended dose is 500 mg/125 mg every 12 hours or 250 mg/125 mg every 8 hours for 3-7 days 3
• β-lactams like Augmentin generally have inferior efficacy and more adverse effects compared with other UTI antimicrobials, so they should be used with caution for uncomplicated cystitis 2

Complicated UTIs

• For complicated UTIs, including pyelonephritis, the recommended dose is 875 mg/125 mg every 12 hours for 7-14 days 1, 3
• In clinical trials for complicated UTIs, the 875 mg/125 mg every 12 hours regimen was comparable in efficacy to 500 mg/125 mg every 8 hours dosing 3
• Urine culture and susceptibility testing should always be performed before initiating therapy for complicated UTIs 2

Catheter-Associated UTIs

• For catheter-associated UTIs, 7 days of treatment is recommended for patients with prompt symptom resolution 2
• For patients with delayed response to treatment, 10-14 days of therapy is recommended 2
• If the catheter has been in place for ≥2 weeks, it should be replaced before starting antibiotics to improve outcomes 1

Administration Guidelines

• Augmentin should be taken at the start of a meal to minimize gastrointestinal intolerance and enhance absorption of clavulanate potassium 3
• The 875 mg/125 mg every 12 hours regimen is associated with significantly less diarrhea compared to the 500 mg/125 mg every 8 hours regimen (1% vs 2% for severe diarrhea) 3
• Two 250 mg/125 mg tablets should not be substituted for one 500 mg/125 mg tablet, as they contain different amounts of clavulanic acid 3

Special Populations

• Pediatric patients weighing 40 kg or more should be dosed according to adult recommendations 3
• For patients with renal insufficiency, dose adjustment may be necessary 4

Clinical Considerations

• Obtaining urine culture before starting antibiotics is crucial due to the wide spectrum of potential infecting organisms and increased likelihood of antimicrobial resistance 1
• Consider local resistance patterns when selecting empiric therapy 1
• The primary goals of therapy are prompt resolution of symptoms and eradication of bacteriuria, using the shortest effective duration of antibiotics to limit development of resistance 1

Common Pitfalls and Caveats

• β-lactams like Augmentin generally have inferior efficacy compared to fluoroquinolones for UTIs, with one study showing clinical cure rates of 58% for amoxicillin-clavulanate vs 77% for ciprofloxacin 2
• Diarrhea is the most common adverse effect, occurring in approximately 14-15% of patients 3
• For recurrent UTIs, a 7-day course of Augmentin (250 mg/125 mg every 8 hours) has shown microbiological cure rates of 84% one week after treatment and 67% one month later 5