Ampicillin plus probenecid compared with procaine penicillin plus probenecid in the treatment of gonorrhoea.

396 male patients with gonococcal urethritis were treated by one of three treatment schedules. Of 132 patients treated with 2.4 m.u. procaine penicillin plus 2 g. probenecid, 109 were followed. There were three (2.8 per cent) recurrences in the first week and none in the second. Of 132 patients treated with 2 g. ampicillin plus 2 g. probenecid, 112 were followed. There were four (3.6 per cent.) recurrences in the first week and three (2.6 per cent.) in the second (total of 6.2 per cent.). Of 132 patients treated with 3 g. ampicillin plus 2 g. probenecid, 115 were followed. There was one (0.8 per cent.) recurrence in the first week and five (4.4 per cent.) in the second (total of 5.2 per cent.). A close correlation was found between the sensitivities of gonococcal strains to ampicillin and to penicillin. The overall sensitivity pattern of N. gonorrhoeae to penicillin had not changed at The London Hospital since the last report in 1972, but there was further evidence of cross-resistance between penicillin and cotrimoxazole.