Co-Amoxiclav Dosage for UTI
For uncomplicated lower urinary tract infections (cystitis) in adults, use amoxicillin-clavulanate 875 mg/125 mg orally every 12 hours for 5-7 days. 1
Standard Dosing by UTI Type
Uncomplicated Cystitis (Lower UTI)
- 875 mg/125 mg orally twice daily for 5-7 days is the recommended regimen 1
- This dosing demonstrates comparable efficacy to the older 500 mg/125 mg three times daily regimen, with significantly lower rates of severe diarrhea (1.0% vs 2.5%) 2
- E. coli shows high susceptibility to this combination, making it a first-choice option despite 75% median resistance to plain amoxicillin 1
Complicated UTIs and Pyelonephritis
- 875 mg/125 mg orally twice daily for 5-10 days, individualized based on clinical response 1
- FDA clinical trial data in 308 patients with pyelonephritis or complicated UTI showed bacteriological success rates of 81% at 2-4 days post-therapy and 52.5% at 2-4 weeks follow-up 2
- Treatment duration should extend to 7-14 days for patients with bacteremia associated with complicated UTI 3
Catheter-Associated UTIs
- 875 mg/125 mg orally twice daily for 7-14 days for most patients, regardless of whether the catheter remains in place 1
- Remove the catheter as soon as clinically appropriate 1
- A 3-day regimen may be considered for younger women with mild CA-UTI after catheter removal 1
Pediatric Dosing
- 20-40 mg/kg/day divided into 3 doses for pediatric UTIs 1
- One study using approximately 22 mg/kg/day for 10 days achieved 94% cure rates in children aged 1 month to 14 years 4
Treatment Monitoring and Failure
When to Reassess
- If no clinical response with defervescence by 72 hours, treatment may need extension and urologic evaluation 1
- Consider alternative diagnosis or resistant organism if no improvement is seen 1
Resistance Considerations
- Do not use for ESBL-producing organisms in standard doses - these require alternative agents or high-dose protocols 1, 3
- For multidrug-resistant organisms (ESBL, carbapenem-resistant), carbapenems or novel agents are typically required 5, 3
- However, emerging evidence suggests very high doses (2875 mg amoxicillin twice daily with 125 mg clavulanic acid) may break ESBL K. pneumoniae resistance in select outpatient cases, though this is not yet standard practice 6
Important Clinical Caveats
Local Resistance Patterns
- Always consider local antimicrobial resistance patterns when selecting empiric therapy 1
- Perform susceptibility testing when possible to adjust therapy accordingly 1
Not Recommended For
- Asymptomatic bacteriuria - treatment is not indicated 1
- Severe pyelonephritis or prostatitis - ceftriaxone/cefotaxime or ciprofloxacin may be preferred as first-line treatment 1
Adverse Effects
- Gastrointestinal disturbances are most common (14.9% diarrhea rate with 875 mg twice daily dosing) 2
- The twice-daily 875 mg regimen has significantly less severe diarrhea than three-times-daily 500 mg dosing 2
- Overall, 10-20% of patients experience mild gastrointestinal side effects, rarely requiring discontinuation 7, 4
Penicillin Allergy
- For patients with penicillin allergies, alternative agents should be considered 5