Coordinated multicenter study of norfloxacin versus trimethoprim-sulfamethoxazole treatment of symptomatic urinary tract infections. The Urinary Tract Infection Study Group.

In a coordinated, double-blind multicenter trial among general practitioners, 2,255 consecutive patients with symptoms suggesting urinary tract infection were screened; 886 were randomized to receive 200 mg of norfloxacin (333 patients), 400 mg of norfloxacin (335), or 160 mg/800 mg of trimethoprim-sulfamethoxazole (TMP-SMZ; 218) twice daily for seven days. We analyzed bacteriologic efficacy for 252, 240, and 141 of the patients receiving 200 mg of norfloxacin, 400 mg of norfloxacin, or TMP-SMZ, respectively. The short-term efficacy was 97.5%-98.6%, and the accumulated efficacy was 87.9%-88.8%. In patients with complicated infections and in men, the efficacy for the group receiving 200 mg of norfloxacin was lower than that for the other groups. In patients with recurrent infection, bacterial elimination was greater for those receiving TMP-SMZ. Significantly fewer adverse reactions occurred in patients receiving norfloxacin than in those treated with TMP-SMZ. The 200-mg dosage of norfloxacin seemed to cause fewer side effects than the 400-mg dosage.