From the Guidelines
Augmentin (amoxicillin-clavulanate) achieves good urinary concentrations, making it a viable option for urinary tract infections, as supported by the most recent evidence from 1.
Key Points to Consider
- The European Association of Urology guidelines suggest using a combination of amoxicillin plus an aminoglycoside for complicated UTIs, indicating the potential effectiveness of amoxicillin in urinary tract infections 1.
- Both amoxicillin and clavulanic acid are primarily eliminated through the kidneys, resulting in high concentrations of the active drug in the urinary tract, which can exceed the minimum inhibitory concentration needed to treat common uropathogens like E. coli.
- The typical adult dosing for uncomplicated UTIs is 500 mg/125 mg twice daily or 875 mg/125 mg twice daily for 5-7 days, though duration may vary based on infection severity.
- For complicated UTIs, higher doses or longer treatment courses may be necessary, and Augmentin's effectiveness against beta-lactamase producing bacteria is particularly valuable in urinary infections.
Important Considerations
- Patients should take Augmentin with food to minimize gastrointestinal side effects and complete the full prescribed course even if symptoms improve before finishing the medication.
- Local patterns of susceptibility of coliforms to antimicrobial agents should be considered during selection of an antimicrobial agent before sensitivity results are available, as there is substantial geographic variability 1.
- The choice of antimicrobial agent should be based on the most recent and highest quality evidence available, taking into account the potential for resistance and the effectiveness of the agent in achieving good urinary concentrations.
From the FDA Drug Label
Approximately 60% of an orally administered dose of amoxicillin is excreted in the urine within 6 to 8 hours.
The urinary concentration of Augmentin (amoxicillin-clavulanate) is expected to be significant, as a substantial portion of the amoxicillin dose is excreted in the urine. Amoxicillin achieves good urinary concentrations, with approximately 60% of the dose being excreted in the urine within 6 to 8 hours 2.
From the Research
Urinary Concentration of Augmentin
- Augmentin (amoxicillin-clavulanate) has been found to be effective in the treatment of urinary tract infections, including uncomplicated and complicated, recurrent, and nosocomial infections, and bacteriuria 3.
- The combination of amoxycillin and clavulanic acid in Augmentin reduces the level of resistance in most Gram-negative urinary pathogens, making them sensitive to urinary levels of amoxycillin achieved on standard dosage 4.
Efficacy in Treating Urinary Tract Infections
- Clinical trials have shown a success rate of about 70 per cent for amoxycillin-resistant organisms when treated with Augmentin 4.
- A study comparing Augmentin with co-trimoxazole for the treatment of uncomplicated urinary tract infections found that 83% of patients treated with Augmentin were cured, although the cure rate with co-trimoxazole was significantly greater 5.
- Another study found that Augmentin was effective in treating urinary tract infections in patients with spinal injuries, with a bacteriological success rate of 100% 24 hours after therapy and 69% 8 days after therapy 6.
Urinary Concentration and Resistance
- The potentiation of amoxycillin by clavulanic acid in Augmentin reduces the level of resistance in most Gram-negative urinary pathogens, allowing for effective treatment of urinary tract infections caused by multiply resistant bacteria 4.
- However, some studies have found that Augmentin may not be effective against all types of bacteria, and that resistance to Augmentin can occur 5, 6.