Abstract
Triclabendazole was tested in vitro and in vivo against a range of helminths. Although in vitro activity was found against Hymenolepis diminuta (0.5 .mu.g/ml). Fasciola hepatica (2.5 .mu.g/ml), Taenia crassiceps and Schistosoma mansoni (50 .mu.g/ml), in vivo activity was only found against F. hepatica, a single oral dose of 40 mg/kg killing 99% of adult flukes in the rat. This spectrum of activity suggests a mechanism of action unlike that of other benzimidazole anthelmintics.