Single-dose minocycline in the treatment of gonococcal urethritis. Clinical efficacy in relation to bacterial resistance and its effects on associated Chlamydia trachomatis infections.

Seventy-two men with gonococcal urethritis were given a single 300-mg dose of minocycline. The failure rate was 13% and the trial was terminated at an early stage. Failure was correlated with increased resistance of Neisseria gonorrhoeae to minocycline. The activity of penicillin, spectinomycin, erythromycin, tetracycline, sulphamethoxazole, cefuroxime, cefotaxime, rosamicin, thiamphenicol, and piperacillin against N. gonorrhoeae were examined in vitro. With the exception of spectinomycin, parallel patterns of resistance to the other antibiotics and minocycline were found. Resistance to spectinomycin was not found, confirming the usefulness of this antibiotic in the treatment of gonorrhoea. The incidence of PGU was significantly lower after a single dose of minocycline than in previous studies.