Antiprotozoal agents are medications used to treat infections caused by protozoa, which are single-celled organisms. These agents target various types of protozoal infections, including those caused by Plasmodium (malaria), Giardia (giardiasis), and Entamoeba (amoebic dysentery). They work by disrupting the life cycle of the protozoa, preventing them from multiplying and causing disease. Common classes of antiprotozoal agents include antimalarials, metronidazole, and nitazoxanide. Each class has specific mechanisms of action and is effective against different protozoal species. Proper diagnosis and treatment are essential for effective management of protozoal infections, as resistance to these agents can develop over time.