Oral trimethoprim/sulfamethoxazole for prevention of bacterial infection during the induction phase of cancer chemotherapy in children.

We conducted a randomized, double-blind, placebo-controlled study to evaluate the efficacy of oral trimethoprim/sulfamethoxazole (TMP/SMX) in the prevention of bacterial infections in children with cancer. Sixty-three patients with acute leukemia were studied during the induction phase of chemotherapy; 28 patients with solid tumors who were starting intensive chemotherapy were also enrolled and treated for 2 months. There was no significant difference in the frequency of febrile episodes between the 43 children receiving trimethoprim/sulfamethoxazole and the 48 receiving placebo. However, when the group of 74 children who experienced granulocytopenia (absolute granulocyte count less than 500/microL) was analyzed separately, significant reductions in the frequencies of confirmed bacteremia (2.6% v 20.0%, P = .02) and febrile episodes (35.9% v 65.7%, P = .01) were observed in the trimethoprim/sulfamethoxazole group. Furthermore, life table analysis showed that children with leukemia receiving trimethoprim/sulfamethoxazole had significantly more days without fever and without bacteremia. No benefits from prophylaxis were recognized in the subgroup with solid tumors. Although the frequency of oral thrush was greater (P = .02) in the trimethoprim/sulfamethoxazole group (25.6%) than in the placebo group (6.3%), invasive fungal infection did not occur. Although the mean duration of granulocytopenia was greater among those receiving trimethoprim/sulfamethoxazole (13.7 v 9.0 days, P = .05), this did not appear to increase the overall risk for bacterial infection. These data suggest that trimethoprim/sulfamethoxazole reduces the frequency of bacteremia and febrile episodes in granulocytopenic children undergoing induction chemotherapy for acute leukemia.