Prevention of subsequent urinary tract infections in women by the use of anti-adherence antimicrobial agents: a double-blind comparison of enoxacin with co-trimoxazole.

A prospective, double-blinded crossover study was carried out to test whether a brief course of antibiotic therapy could eliminate bacteria adherent to uroepithelial cells and thus prolong the interval between urinary tract infections (UTIs). Thirty-two women with frequent Gram-negative urinary tract infections were randomized to receive either co-trimoxazole or enoxacin twice a day for 10 days to treat their UTI. Their urines were collected for 30 days after the onset of their UTI and quantitatively analyzed for bacteria, antibiotics, and bacteria adherent to uroepithelial cells (UECs). A subsequent infection caused the patient to be treated with the alternative antibiotic. A third infection terminated the study. Both regimens were indistinguishable in the rate of elimination of bacteria and in their inhibition of bacterial adherence to UECs for up to five days after stopping treatment. The interval between infections was inversely correlated with the number of adherent bacteria per UEC 30 days after the onset of the first UTI. Both regimens were equally effective in preventing subsequent UTI and the effect of 10 days therapy on the inhibition of bacterial adherence to UEC's did not extend beyond five days after stopping treatment.