MedicinePOMEssential

Pyrimethamine

A tablet used together with a sulfonamide to treat toxoplasmosis.

Clinical information

Common uses

toxoplasmosis, combined with a sulfonamide

Common side effects

loss of appetite
vomiting — taking it with meals helps

Cautions

can cause folate deficiency and low blood counts
narrow dosing margin — folinic acid may be needed
keep away from children — accidental overdose can be fatal
severe skin reactions possible, especially with sulfonamides

Interactions

sulfonamides — severe hypersensitivity reactions can occur

Reference information, not medical advice — always follow your doctor or pharmacist. Source: DailyMed, dailymed.nlm.nih.gov, pyrimethamine label, setid fdeff3ed-e783-411a-8317-57e8b0e931e0 (accessed 2026-08-16)

Approved brands & formulations1

Brand name	Dosage form	Strength	Importer	Category
Pyrimethamine	Tablet	25 mg	—	POM