A comparison of trimethorprim-sulfamethoxazole with sulfamethoxazole alone in infections localized to the kidneys.

Ninety patients with urinary tract infections were treated in a randomized double-blind study with either a combination of trimethoprim and sulfamethoxazole (TMP-SMX) or sulfamethoxazole alone (SMX). Thirty of 42 patients treated with TMP-SMX were cured by the time of follow-up compared with 26 of 48 treated with SMX alone. Of the 29 patients infected with SMX-resistent organisms, the combination TMP-SMX cured 12 of 17, whereas SMX alone cured 2 of 12. Of the 61 patients infected with SMX-sensitive organisms, TMP-SMX cured 18 of 25; SMX alone cured 24 of 36. In 50 women the infection was found localized to The upper urinary tract by the use of the Fairley bladder washout technique. TMPsmx cured 16 or 24 of these patients with proved upper tract infections and SMX alone cured 11 of 26. Although none of these differences were significant, TMP-SMX appears to be an effective drug combination for the therapy of proved upper tract infection and is also effective in eradicating sulfonamide-resistant organisms.