Double-blind randomized study of prophylactic trimethoprim/sulfamethoxazole in granulocytopenic patients with...

In a double blind study, oral prophylactic trimethoprim/sulfamethoxazole was evaluated for its utility in preventing serious infections in patients with hematologic malignancy. Of 58 evaluated granulocytopenic episodes in 47 patients, acute leukemia was the underlying malignancy in 46 episodes. Trimethoprim/sulfamethoxazole prophylaxis resulted in fewer microbiologically documented infections (seven versus 15; p = 0.029). This was primarily the result of a reduction in episodes of bacteremia in the trimethoprim/sulfamethoxazole-treated group as compared with the placebo-treated group (three versus nine episodes; p = 0.05). The combined frequency of disseminated candidiasis, candidemia, and esophagitis of presumed fungal etiology was greater in the trimethoprim/sulfamethoxazole-treated group (six) than in the placebo-treated group (two) but not significantly so (p = 0.13). Similarly, there were no significant differences between groups in the overall incidence of infectious complications, number of febrile days, use of parenteral antibiotics, or number of days following randomization to first infectious episode. Throat and rectal surveillance cultures more frequently revealed trimethoprim/sulfamethoxazole-resistant gram-negative bacilli and yeasts in the trimethoprim/sulfamethoxazole-treated group. More frequent emergence of yeast isolates from previously culture-negative patients was documented (p = 0.033). Thus, in this study, trimethoprim/sulfamethoxazole prophylaxis during granulocytopenia reduced the incidence of microbiologically documented infections. However, the emergence of resistant bacteria and of fungi may limit the potential usefulness of this approach.