Antiparasitic drugs are medications designed to treat infections caused by parasites, which are organisms that live on or inside a host and can cause various diseases. These drugs target different types of parasites, including protozoa, helminths (worms), and ectoparasites like lice and ticks. By disrupting the life cycle of these parasites, antiparasitic drugs help eliminate infections and alleviate symptoms. Common examples of antiparasitic drugs include metronidazole for protozoan infections and ivermectin for treating certain worm and ectoparasite infections. These medications are essential in both human and veterinary medicine, helping to improve health and prevent the spread of parasitic diseases in communities.