Pharmacotherapeutic group: Anthelmintics, praziquantel combinations.
ATCvet code: QP52AA51.
The product is an anthelmintic containing as active substances the tetrahydropyrimidine derivative pyrantel (as the embonate salt), the pro-benzimidazole febantel and praziquantel, a partly hydrogenated pyrazinoisoquinoline derivative. It is effective against certain roundworms and tapeworms.
In this fixed combination pyrantel and febantel act synergistically against roundworms (ascarids, hookworms and whipworms) in dogs. In particular, the action spectrum covers Toxocara canis, Toxascaris leonina, Uncinaria stenocephala, Ancylostoma caninum, and Trichuris vulpis.
The spectrum of activity of praziquantel covers tapeworm species in dogs. In particular, it includes all Taenia species, as well as Multiceps multiceps, Dipylidium caninum, Echinococcus granulosus and Echinococcus multilocularis. Praziquantel acts against all intestinal stage of these parasites.
Pyrantel acts as a nicotinic agonist at acetylcholine receptors, causing spastic paralysis of roundworms via a depolarising neuromuscular block.
The anthelmintic efficacy of febantel is due to its ability to inhibit the polymerisation of tubuline to microtubuli. The resulting structural and functional metabolic disturbances exhaust the parasite’s energy reserves and kill it in 2-3 days.
Praziquantel is absorbed very rapidly through the parasite’s surfaces and is evenly distributed throughout their bodies. It causes severe damage of their integument, leading to disruption of metabolism and subsequently to death.
Praziquantel is absorbed almost completely in the small intestine following oral administration to dogs. Absorption is very rapid reaching maximum serum levels within 0.5 to 2 hours. After absorption, the drug is widely distributed through the body. Plasma protein binding is high. Praziquantel is rapidly metabolised in the liver leading to inactive metabolites. In dogs, metabolites are eliminated by urine (66 % of an oral dose) and via the bile (15%) in the faeces. Elimination half-life in dogs is about 3 hours.
Pyrantel (as embonate), being a low water-soluble compound, is poorly absorbed in the gastrointestinal tract, reaching the final parts of the intestine. The absorbed drug is extensively metabolised and the parent compound/metabolites are excreted by urine.
Febantel is a pro-drug that after oral administration and oral absorption is metabolised to fenbendazole and oxfendazole, the chemical entities exerting the anthelmintic effect. The active metabolites are excreted via faeces.