Adverse events associated with trimethoprim-sulfamethoxazole and atovaquone during the treatment of AIDS-related Pneumocystis carinii pneumonia.

Atovaquone was compared to trimethoprim-sulfamethoxazole (TMP-SMZ) for the relationship of time receiving therapy, plasma drug concentrations, and incidence of adverse reactions in patients with AIDS-associated Pneumocystis carinii pneumonia. Treatment-limiting adverse events occurred in 9% of atovaquone-treated patients and 24% of TMP-SMZ-treated patients. Adverse events usually did not occur before day 7 for either treatment. Only the incidence of rash increased with increasing plasma concentrations of atovaquone. The incidence of anemia, neutropenia, and azotemia increased with increasing trimethoprim plasma concentration, while other adverse events (gastrointestinal disorders, rash, fever, and liver function abnormalities) were independent of plasma drug concentration.