Treatment protocol determines the efficacy of clindamycin in acute murine toxoplasmosis

To determine the contribution to the efficacy of clindamycin in acute murin e toxoplasmosis of treatment protocol variables, groups of Swiss Webster mi ce inoculated intraperitoneally with 10(2) RH strain Toxoplasma gondii tach yzoites were treated with peroral clindamycin at 25, 50 and 400 mg/kgBM per day for 1, 2 and 3 weeks. While the lowest drug dose applied for a single week prolonged survival time as compared to untreated animals, not even the highest dose applied for 1 or 2 weeks completely prevented mortality. Conv ersely, 100% protection was achieved with 3-week treatment courses at both 50 and 400 mg/kg per day. While both survival rates and survival times incr eased in parallel with the drug dose and treatment duration, the latter was shown to be critical to the outcome, suggesting the use of clindamycin as an antitoxoplasmic agent should be as a prolonged course. (C) 1999 Elsevier Science B.V. and International Society of Chemotherapy. All rights reserve d.