Hycanthone dose-response in Schistosoma mansoni infection in Kenya.

The recommended doses of the drugs now used to cure schistosomiasis mansoni may be associated with toxic side-effects. Since Schistosoma mansoni does not multiply in the human host and the disease seems to be closely associated with the intensity of infection, it may not be necessary to use 100% lethal antischistosomal doses, particularly in endemic areas. A dose-response to the antischistosomal drug, hycanthone was established for three different doses in 169 patients with heavy S. mansoni infections in the Machakos district of Kenya. The highest dose used (1.5 mg/kg or half the recommended package-insert dose) resulted in a 96% decrease in egg output (equivalent ot death of the worms); 0.75 mg/kg in an 85% decrease; and 0.375 mg/kg in an 11% decrease one month after treatment. In contrast to the vomiting common with the package-insert dose (3.0 mg/kg), there were no side-effects with any of the lower doses.