ATCvet code : QP52AA51.
Pharmacodynamics
Pyrantel acts as a cholinergic agonist. Its mode of action is to stimulate nicotinic cholinergic receptors of the parasite, induce spastic paralysis and thereby allow expulsion from the gastro-intestinal (GI) system by peristalsis.
Praziquantel is very rapidly absorbed and distributed throughout the parasite. Both in vivo and in vitro studies have shown that praziquantel causes severe damage to the parasite integument, resulting in contraction and paralysis. There is an almost instantaneous tetanic contraction of the parasite musculature and a rapid vacuolisation of the syncytial tegument. This rapid contraction has been explained by changes in divalent cation fluxes, especially calcium.
In this fixed combination product the pyrantel is active against the following ascarids: Toxocara cati and Toxascaris leonina. The praziquantel is effective against tapeworms, in particular Dipylidium caninum and Taenia taeniaeformis.
The veterinary medicinal product has also been shown to be efficacious in the control of hookworms, Ancylostoma tubaeforme and A. braziliense and the tapeworm Joyeuxiella pasqualei, none of which occur naturally in the UK or Ireland, but may occasionally be found in imported animals. Praziquantel is effective against Echinococcus multilocularis. E. multilocularis does not occur in the UK or Ireland but is becoming more common in some European countries.