Abstract
Eighty-nine men with gonococcal urethritis were randomly treated with trimethoprim-sulfamethoxazole, 4 tablets (trimethoprim, 320 mg and sulfamethoxazole, 1600 mg) twice daily for 2 days, or ampicillin (3.5 g) plus probenecid (1 g) in a single dose. Forty-one (95.3%) of 43 patients who received trimethoprim-sulfamethoxazole and 41 (97.6%) of 42 given ampicillin were cured. Neither drug caused major side effects. All isolates of Neisseria gonorrhoeae were susceptible in vitro to trimethoprim-sulfamethoxazole, and all but 1 were inhibited by ampicillin. The ampicillin-resistant strain (minimum inhibitory concentration, 4 .mu.g/ml) produced penicillinase and was recovered from a patient who responded to treatment with trimethoprim-sulfamethoxazole. There was no significant correlation between the minimum inhibitory concentrations of trimethoprim-sulfamethoxazole and ampicillin. Trimethoprim-sulfamethoxazole is as efficacious and safe as ampicillin in the therapy of gonococcal urethritis.