Antiparasitic medications are drugs designed to treat infections caused by parasites, which are organisms that live on or in a host and benefit at the host's expense. These medications target various types of parasites, including protozoa, helminths (worms), and ectoparasites (like lice and mites). Common antiparasitic medications include metronidazole for protozoan infections, albendazole for worm infections, and permethrin for treating lice. These drugs work by disrupting the life cycle of the parasites, ultimately leading to their elimination from the host's body. Proper diagnosis and treatment are essential for effective management of parasitic infections.