Antiparasitics are medications used to treat infections caused by parasites, which are organisms that live on or inside a host and can cause harm. These drugs target various types of parasites, including protozoa, helminths (worms), and ectoparasites (like lice and fleas). They work by disrupting the life cycle of the parasites, ultimately leading to their elimination from the host's body. Common antiparasitic medications include metronidazole for protozoan infections and ivermectin for certain worm and ectoparasite infections. The choice of antiparasitic depends on the type of parasite involved and the severity of the infection. Proper diagnosis and treatment are essential for effective management of parasitic diseases.