New results on the effect of praziquantel in experimental cysticercosis.

14C-praziquantel penetrates the cyst wall of Cysticercus fasciolaris and kills the cysticercus within the cyst, although the uptake of praziquantel by the encysted larva was slower than by an isolated one. This fact is in good agreement with earlier in vitro chemotherapeutic studies. Scanning and transmission electron microscopic studies have shown that praziquantel causes a marked destruction of the tegument along the whole pseudostrobila and the scolex of C. fasciolaris. The type of tegumental damage is identical to that produced in adult tapeworms and trematodes.