Closantel is a halogenated salicylanilide anthelmintic widely used in veterinary medicine for the control of parasitic infections. It is particularly effective against blood-feeding parasites such as Fasciola species, Haemonchus contortus, and certain ectoparasites. Closantel works by uncoupling oxidative phosphorylation in parasite mitochondria, leading to energy depletion and parasite death. The drug shows high plasma protein binding, which contributes to its prolonged activity and sustained therapeutic effect. It is mainly administered to sheep, cattle, and goats for the treatment of liver flukes and gastrointestinal nematodes. Closantel has limited activity against non-blood-feeding parasites, making it a targeted antiparasitic agent. Its long half-life allows for extended protection after a single dose. Proper dosing is essential, as overdose may result in toxic effects, particularly ocular toxicity. Due to its efficacy and persistence, closantel plays an important role in parasite control programs. Overall, it remains a valuable veterinary drug when used responsibly and according to recommended guidelines.
