Antiparasitics are medications used to treat infections caused by parasites, which are organisms that live on or in a host and benefit at the host's expense. These drugs target various types of parasites, including protozoa, helminths (worms), and ectoparasites like fleas and ticks. 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 infestations. The choice of antiparasitic depends on the type of infection and the specific parasite involved. Proper diagnosis and treatment are essential for effective management of parasitic diseases.