What is the recommended dosing for Augmentin (amoxicillin-clavulanate) in treating urinary tract infections (UTIs)?

Augmentin (Amoxicillin-Clavulanate) Dosing for UTIs

For urinary tract infections (UTIs), amoxicillin-clavulanate (Augmentin) should be dosed at 500 mg every 8 hours or 875 mg every 12 hours for 7-14 days, depending on infection severity.

Dosing Recommendations Based on UTI Classification

Uncomplicated UTIs

• Standard dosing: 500 mg every 8 hours OR 875 mg every 12 hours for 7 days 1, 2
• Duration should be at least 5-7 days to ensure complete bacterial eradication

Complicated UTIs

• Standard dosing: 875 mg every 12 hours OR 500 mg every 8 hours for 10-14 days 3, 1
• For severe infections, consider initial parenteral therapy before transitioning to oral therapy

Special Populations

Renal Impairment

• For GFR 10-30 mL/min: 500 mg or 250 mg every 12 hours (depending on infection severity) 2
• For GFR <10 mL/min: 500 mg or 250 mg every 24 hours (depending on infection severity) 2
• Patients on hemodialysis: 500 mg or 250 mg every 24 hours with additional dose during and after dialysis 2
• Note: 875 mg dose should NOT be used in patients with GFR <30 mL/min 2

Pediatric Patients (≥3 months, <40 kg)

• For genitourinary tract infections:
  • Mild/moderate: 25 mg/kg/day divided every 12 hours OR 20 mg/kg/day divided every 8 hours 2
  • Severe: 45 mg/kg/day divided every 12 hours OR 40 mg/kg/day divided every 8 hours 2

Administration Guidelines

• Take at the start of a meal to minimize gastrointestinal intolerance 2
• Continue treatment for at least 48-72 hours after patient becomes asymptomatic 2
• For infections caused by Streptococcus pyogenes, treatment should continue for at least 10 days 2

Clinical Considerations

Efficacy and Resistance

• Amoxicillin-clavulanate is particularly effective for UTIs caused by amoxicillin-resistant organisms due to the beta-lactamase inhibitory effect of clavulanic acid 4
• Historical studies have shown approximately 70% success rates for amoxicillin-resistant organisms 4
• For Enterococcus faecalis UTIs, amoxicillin-clavulanate 500/125 mg three times daily for 7 days is recommended 1

Alternative Treatments

• First-line agents for uncomplicated UTIs typically include:
  • Nitrofurantoin 100 mg twice daily for 5-7 days
  • Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days
  • Fosfomycin 3g single dose 1
• For pyelonephritis, fluoroquinolones or cephalosporins are preferred due to better tissue penetration 3, 1

Common Pitfalls and Caveats

1. Avoid using amoxicillin-clavulanate as first-line for uncomplicated UTIs when narrower-spectrum options are available
2. Always obtain urine culture before starting therapy to guide definitive treatment
3. Assess for clinical response within 48-72 hours of starting treatment
4. For ESBL-producing organisms, consider alternative agents as amoxicillin-clavulanate may not be effective
5. Adjust dosing in renal impairment to avoid toxicity while maintaining efficacy

Treatment Algorithm

1. Obtain urine culture before starting therapy
2. Assess for complicated vs. uncomplicated UTI
3. For uncomplicated UTI: 500 mg every 8 hours OR 875 mg every 12 hours for 7 days
4. For complicated UTI: 875 mg every 12 hours OR 500 mg every 8 hours for 10-14 days
5. Adjust dose for renal impairment according to guidelines
6. Reassess in 48-72 hours and adjust therapy based on culture results and clinical response
7. Complete full course of therapy even if symptoms resolve earlier