What is the typical dose of amoxicillin (amoxicillin)-clavulanate for a urinary tract infection (UTI)?

Amoxicillin-Clavulanate Dosing for Urinary Tract Infections

For urinary tract infections, amoxicillin-clavulanate should be dosed at 20-40 mg/kg per day in 3 divided doses for children, or 500/125 mg every 8 hours for adults for 7-14 days. 1

Adult Dosing

Standard Dosing Regimen

• Uncomplicated UTI: 500 mg amoxicillin/125 mg clavulanate every 8 hours for 7-14 days 1, 2
• More severe infections: 875 mg amoxicillin/125 mg clavulanate every 12 hours or 500 mg amoxicillin/125 mg clavulanate every 8 hours 2
• Take at the start of a meal to enhance absorption and minimize gastrointestinal intolerance 2

Administration Considerations

• For patients with difficulty swallowing, the 125 mg/5 mL or 250 mg/5 mL suspension may be used in place of tablets 2
• The 200 mg/5 mL or 400 mg/5 mL suspension may be used in place of the 875 mg tablet 2

Pediatric Dosing

Age-Based Recommendations

• Neonates and infants <12 weeks: 30 mg/kg/day divided every 12 hours (based on amoxicillin component) 2
• Children ≥12 weeks:
  • Less severe infections: 25 mg/kg/day every 12 hours or 20 mg/kg/day every 8 hours 2
  • More severe infections: 45 mg/kg/day every 12 hours or 40 mg/kg/day every 8 hours 2
• Children weighing ≥40 kg: Use adult dosing recommendations 2

Treatment Duration

• 7-14 days is the recommended duration for UTI treatment 1
• The 12-hour regimen is associated with significantly less diarrhea in children 2

Clinical Considerations

Efficacy and Resistance

• Amoxicillin-clavulanate is effective against beta-lactamase-producing organisms that may be resistant to amoxicillin alone 3
• Microbiological cure rates of 84% one week after treatment have been reported for recurrent UTIs 4
• Local antimicrobial sensitivity patterns should guide therapy selection 1

Potential Side Effects

• Gastrointestinal intolerance is common, particularly with higher doses of clavulanic acid 5
• Taking medication with food can help minimize GI side effects 2

Special Populations

• For patients with renal impairment, dose adjustment may be necessary
• The 250 mg tablet of amoxicillin-clavulanate should not be used until a child weighs at least 40 kg due to different amoxicillin to clavulanic acid ratios 2

Treatment Pitfalls to Avoid

1. Inadequate duration: Three-day treatment courses have shown insufficient efficacy (55% success rate) compared to 10-day courses (82% success rate) 6
2. Failure to consider resistance patterns: Local resistance patterns should guide empiric therapy
3. Inappropriate formulation substitution: Different formulations have different amoxicillin-to-clavulanate ratios and are not interchangeable 2
4. Ignoring bacterial virulence factors: Treatment success may be influenced by bacterial adhesins and host factors 6

Remember to adjust therapy based on culture and sensitivity results when available, as this significantly improves treatment outcomes.