Prospective comparison of amoxicillin-clavulanic acid and cefaclor in treatment of uncomplicated urinary tract infections.

Patients with acute, uncomplicated urinary tract infections were treated with either amoxicillin-clavulanic acid (A-C) in fixed combination or cefaclor for 10 days in a prospective randomized comparison. The A-C group included 29 women and 1 man (mean age, 25.5 years), and the cefaclor group included 35 women and 1 man (mean age, 24.9 years). The cure rates were 26 (87%) of 30 with A-C and 26 (72%) of 36 with cefaclor (P greater than 0.20). There was one failure in each group, each caused by an isolate resistant to ampicillin. There were one relapse and two reinfections in the A-C group, compared with seven relapses and two reinfections in the cefaclor group. Side effects, including patients started on antibiotics but whose cultures did not confirm urinary tract infections, were diarrhea in 7 (16%) and rash in 1 (2%) of 44 A-C patients, compared with diarrhea in 1 (2%) and yeast vaginitis in 3 (6%) of 48 cefaclor patients. Although the A-C group had a greater proportion of antibody-coated bacterium-positive infections (22 versus 18 with cefaclor), there was a lower recurrence rate with fewer relapses in patients treated with A-C.