pyrimethamine

pharmacology

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July 13, 2026

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Pyrimethamine is a folic acid antagonist with the chemical formula C₁₂H₁₃ClN₄. It is used in the prevention and treatment of malaria and for treating toxoplasmosis. Pyrimethamine works by inhibiting folic acid synthesis in protozoans. It is one of several antiprotozoal drugs used to combat diseases caused by protozoans, which are eukaryotic organisms distinct from bacteria.12

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antiprotozoal drug
… sulfate, often in combination with pyrimethamine and sulfadoxine, or with artemisinin, in combination with agents such as mefloquine or amodiaquine. A high level of quinine in the plasma frequently is associated with cinchonism, a mild adverse reaction associated with such symptoms as a ringing noise in the ears (tinnitus), headache,…
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… sulfate, often in combination with pyrimethamine and sulfadoxine, or with artemisinin, in combination with agents such as mefloquine or amodiaquine. A high level of quinine in the plasma frequently is associated with cinchonism, a mild adverse reaction associated with such symptoms as a ringing noise in the ears (tinnitus), headache,…
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malaria
Treatment
…are chloroquine, a combination of pyrimethamine and sulfadoxine, mefloquine, primaquine, and artemisinin—the latter a derivative of Artemisia annua, a type of wormwood whose dried leaves have been used against malarial fevers since ancient times in China. All of these drugs destroy the
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…are chloroquine, a combination of pyrimethamine and sulfadoxine, mefloquine, primaquine, and artemisinin—the latter a derivative of Artemisia annua, a type of wormwood whose dried leaves have been used against malarial fevers since ancient times in China. All of these drugs destroy the
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