CROSSOVER OF HUMAN IMMUNODEFICIENCY VIRUS-INFECTED PATIENTS FROM AEROSOLIZED PENTAMIDINE TO TRIMETHOPRIM-SULFAMETHOXAZOLE - LACK OF HEMATOLOGIC TOXICITY AND RELATIONSHIP OF SIDE-EFFECTS TO CD4+ LYMPHOCYTE COUNT

Trimethoprim-sulfamethoxazole (TMP/SMZ) was given in a crossover study to 130 human immunodeficiency virus-infected patients who had been receiving aerosolized pentamidine; 86 (66%) successfully crossed over to TMP/SMZ without hypersensitivity reactions or hematologic toxicity. No significant changes occurred in mean hemoglobin concentration, leukocyte count, or platelet count between study enrollment and 12-month follow-up. Predominant side-effects, in 41 patients (33.8%), were fever and maculopapular rashes, which resolved promptly with discontinuation of TMP/SMZ. The mean time to first side effect was 12.3 days, and 86% of side effects developed within 30 days. Three patients experienced toxicity serious enough to warrant hospitalization. Of patients with less-than-or-equal-to 200 CD4+ lymphocytes/mm3 57% developed rashes after the crossover compared with only 27% of patients with higher CD4+ cell counts. Many patients currently receiving aerosolized pentamidine can be safely crossed over without hematologic toxicity or hypersensitivity reactions.