Hooton TM et al. (2005) Amoxicillin-clavulanate vs ciprofloxacin for the treatment of uncomplicated cystitis in women: a randomized trial. 949–955

Current standard therapy for acute uncomplicated cystitis in women comprises trimethoprim-sulfamethoxazole for 3 days. As the prevalence of resistance to this combination grows in some areas, increasing reliance on fluoroquinolones as an alternative strategy for this and other infections, such as respiratory tract infections, is raising concerns about the future usefulness of this drug class. Although increasing emphasis is being placed on the use of fluoroquinolone-sparing regimes, no published studies have evaluated the efficacy of amoxicillin-clavulanate in the current climate of high-level amoxicillin resistance.

Hooton et al. compared the efficacy of 3-day regimens of amoxicillin-clavulanate and ciprofloxacin in a randomized, single-blind trial in 370 women aged 18–45 years with symptoms of acute uncomplicated cystitis. Patients were recruited between July 1998 and May 2002 from a university student health center and a health maintenance organization and were followed up for 4 months.

The rate of clinical cure (defined as lack of symptomatic persistent or recurrent urinary tract infection) was significantly lower in the group receiving amoxicillin-clavulanate (58%) compared with the group given ciprofloxacin (77%). The difference remained significant even when women with strains of Escherichia coli susceptible to amoxicillin-clavulanate were analyzed separately. The difference in clinical cure rates was most marked during the first 2 weeks of therapy.

The authors conclude that trimethoprim-sulfamethoxazole should remain first-line treatment for acute cystitis in women with no history of allergy to the combination and where the risk of resistance is low. Use of a fluoroquinolone or other alternative, such as nitrofurantoin, is appropriate in situations where trimethoprim-sulfamethoxazole resistance is likely. Amoxicillin-clavulanate is not an appropriate first-line agent for empiric therapy of acute cystitis.