Trimethoprim-sulfamethoxazole vs ampicillin in chronic urinary tract infections. A double-blind multicenter cooperative controlled study.

A multicenter, prospective, double-blind, controlled study was performed to compare the efficacy of trimethoprim-sulfamethoxazole with that of ampicillin in the treatment of chronic urinary tract infections. The incidence of adverse clinical signs and symptoms as well as abnormal laboratory values were comparable in the two treatment groups. This study appears to establish the fact that trimethoprim-sulfamethoxazole is an acceptable alternative to ampicillin for the treatment of chronic urinary tract infections caused by susceptible Escherichia coli.