Postcoital antimicrobial prophylaxis for recurrent urinary tract infection. A randomized, double-blind, placebo-controlled trial
A. Stapleton, R. H. Latham, C. Johnson and W. E. Stamm
Department of Medicine, University of Washington, Seattle.
We conducted a randomized, double-blind, placebo-controlled study to
determine the efficacy of postcoital antibiotic prophylaxis in healthy
young women prone to recurrent urinary tract infections. Sixteen patients
were randomized to receive postcoital administration of a combination
product of trimethoprim and sulfamethoxazole, while 11 received postcoital
placebo. The treatment groups were similar with respect to age, parity,
diaphragm use, history of lifetime urinary tract infections, frequency of
intercourse, and number of lifetime sexual partners. In over 6 months of
observation, postcoital administration of trimethoprim-sulfamethoxazole was
highly effective in preventing recurrent urinary tract infections. Nine of
11 patients who took the placebo developed urinary tract infections
(infection rate, 3.6 per patient-year), compared with only two of 16
patients who received postcoital trimethoprim-sulfamethoxazole (infection
rate, 0.3 per patient-year). Postcoital administration of
trimethoprim-sulfamethoxazole was effective in patients with both low (two
or fewer times per week) and high (three or more times per week)
intercourse frequencies. Side effects were few and compliance was
excellent. We conclude that postcoital trimethoprim-sulfamethoxazole is a
safe, effective, and inexpensive approach to management of recurrent
urinary tract infections in young women.
