ABSTRACT
An anthelmintic must be selectively toxic to the parasite. This is usually achieved by either the inherent pharmacokinetic properties of the compound itself, or by inhibition of metabolic processes vital to the parasite. Life support mechanisms of parasites are based mainly on maintaining an advantageous feeding site, and using the acquired foodstuff to generate chemical energy. Parasitic helminths must maintain an appropriate feeding site, and nematodes and trematodes must actively ingest and move food through their digestive tracts to maintain an appropriate energy state. Interference with neuromuscular coordination in the parasite may occur by inhibiting the breakdown of excitatory neurotransmitters, or by mimicking the action of the excitatory transmitter, resulting in spastic paralysis of the parasite. Benzimidazole parasiticides comprise the largest chemical family of veterinary drugs used for the treatment of endoparasitic diseases in domestic animals.
