Effective postcoital quinolone prophylaxis of recurrent urinary tract infections in women.

A total of 33 sexually active, premenopausal and postmenopausal women, suffering from recurrent urinary tract infections was randomized to receive postcoital prophylaxis with a dose of either 100 mg. ofloxacin (12), 200 mg. norfloxacin (11) or 125 mg. ciprofloxacin (10). While 130 urinary tract infections occurred in these patients during a mean of 8 months before postcoital quinolone prophylaxis, only 1 occurred during a mean of 15 months following prophylaxis. This difference was statistically highly significant. Each of these patients ingested a mean of 117 quinolone doses per year of postcoital prophylaxis. Before prophylaxis 74% of the introital cultures yielded gram-negative enterobacteria (mainly Escherichia coli), whereas only 11% yielded the same bacteria following prophylaxis. Postcoital oral prophylaxis with minimal quinolone doses is highly effective in the prevention of recurrent urinary tract infections in women, because it achieves high urinary bactericidal concentrations, and clears the majority of the introital and urethral Enterobacteriaceae without inducing resistance to the quinolones despite long-term treatment. This prophylaxis is highly recommended because of its ease of compliance, preservation of drug efficacy, lack of toxicity and cost-effectiveness. Postcoital quinolone prophylaxis is as good as or better than daily quinolone prophylaxis and uses only a third of the amount of drug consumed in daily prophylaxis.