What is the recommended dose and frequency of Augmentin (amoxicillin-clavulanate) for an uncomplicated urinary tract infection (UTI)?

Augmentin Dosing for Uncomplicated UTI

For uncomplicated urinary tract infections, amoxicillin-clavulanate (Augmentin) should be used as a second-line agent at a dose of 875/125 mg twice daily for 3-5 days. 1

Recommended Dosing Regimen

• Dose: 875/125 mg
• Frequency: Twice daily (every 12 hours)
• Duration: 3-5 days for uncomplicated cystitis

Position in Treatment Algorithm

Amoxicillin-clavulanate is not considered a first-line agent for uncomplicated UTIs according to current guidelines. The European Association of Urology (2024) and Infectious Diseases Society of America (2011) both classify β-lactams, including amoxicillin-clavulanate, as alternative or second-line agents 1.

First-line options that should be considered before Augmentin:

• Fosfomycin trometamol (3g single dose)
• Nitrofurantoin (100mg twice daily for 5 days)
• Pivmecillinam (400mg three times daily for 3-5 days)

Clinical Evidence Supporting This Regimen

The FDA label for amoxicillin-clavulanate supports the 875/125 mg twice daily dosing regimen for urinary tract infections. Clinical trials have demonstrated that this regimen is as effective as 500/125 mg three times daily, with comparable bacteriological success rates 2. Importantly, the twice-daily regimen showed a statistically significant reduction in severe diarrhea compared to the three-times-daily regimen (1% vs 2%) 2.

Important Considerations

Efficacy Concerns

β-lactams, including amoxicillin-clavulanate, generally have inferior efficacy and more adverse effects compared with other UTI antimicrobials 1. They should be used with caution and only when first-line agents cannot be used.

Resistance Patterns

• Local resistance patterns should be considered before prescribing
• Amoxicillin-clavulanate may be useful for ESBL-producing E. coli but less effective against ESBL-producing Klebsiella pneumoniae 3

Duration of Therapy

While traditional courses were longer, current evidence supports shorter durations (3-5 days) for uncomplicated cystitis 1. Longer courses increase costs and adverse effects without improving efficacy 4.

Monitoring and Follow-up

• Clinical response should be assessed within 48-72 hours
• If symptoms persist or recur within 2 weeks, perform a repeat urine culture and select a different antibiotic class 1
• Routine post-treatment urinalysis or urine cultures are not indicated for asymptomatic patients 1

Cautions and Adverse Effects

The most common adverse effect is diarrhea (14-15% of patients), with severe diarrhea occurring in approximately 1% of patients on the twice-daily regimen 2. Other potential adverse effects include:

• Gastrointestinal disturbances
• Skin rash
• Candidal infections

When to Consider Alternative Therapy

Consider alternative therapy when:

1. Patient has allergy to β-lactams
2. Local resistance patterns show high resistance to amoxicillin-clavulanate
3. Previous treatment failure with amoxicillin-clavulanate
4. Presence of risk factors for resistant organisms

Remember that fluoroquinolones should be reserved for important uses other than acute cystitis due to their propensity for collateral damage, despite their high efficacy 1.