On the schistosomicidal effect of triclabendazole an experimental study.

Mice were infected with S. mansoni cercariae and divided to three groups: one as control, the others were treated with a single oral dose of PZQ or TCBZ. The efficacy of the drugs was evaluated on the basis of egg excretion, number, sex and distribution of worms, oogram changes and tissue egg load. Results demonstrated that eggs disappeared from the stools in both treated groups, all worms died in the PZQ treated group while in the TCBZ group, worm production amounted to 84%. Male worms were more susceptible to the two drugs, they died earlier. On the fourth week after TCBZ, the few surviving worms returned back from their hepatic shift to the mesenteric veins. By studying the oogram pattern, it was found that PZQ had a direct lethal effect on the mature eggs; TCBZ had a lower effect on egg viability but the oogram findings indicated cessation of egg laying.