Pyrimethamine is an antiparasitic drug used against
Toxoplasma gondii (
Toxoplasmosis),
Atoxoplasma, and
Sarcocystis (
Sarcocystosis). It may be effective for
Leucocytozoon.
Pyrimethamine is a thiamine (vitamin B1) antagonist, meaning that the side effect of taking this drug, is that similar to amprolium, it reduces the amount of thiamine in the body.
Warning: Overdose may cause liver damage.