Trimethoprim-Sulfamethoxazole in the Treatment of Gonococcal Urethritis: Clinical and Laboratory Correlates

Abstract

In a multicenter study, 326 men with gonococcal urethritis were randomly assigned to one of four treatment groups: (1) aqueous procaine penicillin G, 4.8 million units, plus 1.0 g of probenecid; (2) tetracycline HCL, 9 g over four days; (3) trimethoprim-sulfamethoxazole (TMP-SMZ), six tablets once daily for three days; (4) TMP-SMZ three tablets twice daily for three days. They were reexamined at six to eight days and 13–15 days after completion of treatment. Among men in group 2 the failure rate was 15.9% at one week and 20.0% within two weeks. These results were less successful (P < .05) than those obtained with the other regimens. There was no significant difference among the results of the other regimens. Gonococci from TMP-SMZ therapeutic failures who denied reexposure were more resistant to SMZ than the total sample of isolates, and regional differences in susceptibility to SMZ and TMP explained regional differences in clinical efficacy of TMP-SMZ for gonorrhea.