Lack of activity of artemether for prophylaxis and treatment of Toxoplasma gondii and Pneumocystis carinii infections in rat.

Artemisinin and its derivatives have been found effective in vivo against Plasmodium and in vitro against Toxoplasma gondii and Pneumocystis carinii. We tested the activity of artemether for prophylaxis and treatment in the rat model of concurrent T. gondii and P. carinii infection. Artemether at doses of 18 and 100 mg/kg administered (s.c.) in prophylaxis did not prevent toxoplasmosis or pneumocystosis, while trimethoprimsulfamethoxazole (reference treatment) was effective for prevention of both infections. Similar results were obtained in curative studies. These results do not support the use of artemether for prevention or treatment of toxoplasmosis or pneumocystosis.