Effect of metacycline treatment on non-acute prostatitis.

Sixty-nine patients with symptoms of non-acute prostatitis were treated with metacycline and placebo according to the double-blind crossover technique. The patients reported improvement significantly more often after metacycline than after placebo treatment. But no difference was found between metacycline and placebo in respect of the palpatory findings or the number, morphology and motility of spermatozoa, the number of white blood cells in expressed prostatitic fluid, the zinc, magnesium or fructose content or antibacterial activity of seminal fluid. The lysozyme level in seminal fluid was significantly more often reduced after treatment with metacycline than after placebo. "Therapeutic" concentrations of metacycline were demonstrable in expressed prostatitic fluid specimens collected three hours after intake of the dose prescribed. The majority of patients harbouring Neisseria gonorrhoeae or Mycoplasma hominis were improved after the antibiotic treatment and the organism was no longer demonstrable. No undesirable effects of the treatment with metacycline were observed.