Some aspects of the pharmacology of pyrantel in the dog

Abstract

Extract

Acetylcholine and cholinesterase occur in many different species of unicellular and multicellular animals and their presence is oftenrelated to nerve and muscle activity and to movement. The substances occur in parasitic helminths and several modern anthelmintics appear to act by disrupting cholinergic mechanisms. One such group, the organophosphorous compounds, inactivate cholinesterase allowing preservation of endogenous acetylcholine and consequent interference with normal motor activity. A second group owes its basic mode of action to chemical and biological features shared with acetylcholine and acts, essentially, by mimicking the effects of excessive amounts of the natural neurotransmitter. Examples are, bephenium and thenium, both of which possess the configuration (Broome, 1962) and methvridine, which has a -CH₂-CH₂-O-CH₃ grouping.