Pyrimethamine

Pyrimethamine is an antifolate drug used to prevent and treat a variety of protozoal infections, including malaria and the toxoplasmosis infection that can cause severe birth defects. It works by blocking the production of an enzyme called dihydrofolate reductase, which is necessary for the synthesis of nucleic acids, an essential process for the life of these parasites. Pyrimethamine is also used in combination with other drugs, like sulfonamides, to further prevent or treat infections. As such, it is an important tool in preventing and treating diseases in humans and animals caused by these parasites.