Randomized controlled trial of pyrimethamine plus sulfadiazine versus trimethoprim plus sulfamethoxazole for treatment of toxoplasmic encephalitis in AIDS patients.

BACKGROUND

Toxoplasmic encephalitis (TE), caused by Toxoplasma gondii, is common in AIDS patients. TE can result in tissue destruction via massive inflammation and brain abscess formation.

METHODS

Randomized controlled trials were performed in AIDS patients to assess which drug regimen was optimally effective for the treatment of TE. AIDS patients with TE were randomly divided into 3 groups that received a 6-week course of either pyrimethamine (50 mg/day or 100 mg/day) plus sulfadiazine (4 g/day) and folinic acid (25 mg/day) or trimethoprim (10 mg/kg/day) plus sulfamethoxazole (50 mg/kg/day) (TMP-SMX), and results were evaluated with respect to clinical response, mortality, morbidity, and serious adverse events. The primary outcome was defined as death in the first 6-week period. The secondary outcome was successful treatment within 6 weeks without severe adverse events, bone marrow suppression, drug-induced rash, or any other event that caused a change in the treatment regimen.

RESULTS

The results from this study showed that in AIDS patients, TE was most successfully treated with the combination of pyrimethamine (50 mg/day) plus sulfadiazidine (4 g/day) and folinic acid (25 mg/day); failure rates were not significantly different among the 3 treatment groups.

CONCLUSIONS

Available data suggest that of the currently available options, treatment of TE with pyrimethamine at 50 mg/day plus sulfadiazidine at 4 g/day provides the best primary outcome for AIDS patients with TE; however, because this study was terminated prematurely, we suggest that treatment with intravenous TMP-SMX be further evaluated to determine its efficacy.