Use of trimethoprim-sulfamethoxazole for treatment of infections in patients with cancer.

Trimethoprim-sulfamethoxazole (TMP-SMZ) was used alone and in combination with other antimicrobial agents as treatment for infections in patients with cancer. Patients who did not respond to previous treatment with combinations of antibiotics received TMP-SMZ orally or parenterally during a total of 127 episodes of infection. The combined response rate for these two routes of administration was 49%, and the individual rates were similar for both routes. Twenty-eight infections were treated with TMP-SMZ plus tobramycin, and 75% responded after treatment with other drugs had failed. Ticarcillin plus TMP-SMZ was used as initial therapy for presumed or proved infection during 276 episodes of fever. Of 102 documented infections, 77% responded. Toxicity from TMP-SMZ was minimal.