Pyrimethamine is an antiparasitic drug used in the prevention and treatment of toxoplasmosis and malaria. One of the folic acid antagonists that is used as an antimalarial or with a sulfonamide to treat toxoplasmosis.
- Mechanism
- Curator reviewed
Pyrimethamine inhibits the dihydrofolate reductase of plasmodia and thereby blocks the biosynthesis of purines and pyrimidines, which are essential for DNA synthesis and cell multiplication. This leads to failure of nuclear division at the time of schizont formation in erythrocytes and liver.
- Primary indication
- For the treatment of toxoplasmosis and acute malaria; For the prevention of malaria in areas non-resistant to pyrimethamineCurator reviewed · 1 structured indication
- Formula / weight
- C12H13ClN4 · 248.711 g/mol (avg)
- First approval
- Canada, 2012 · United States, 1953
- Also known as
- Chloridine · Chloridyn · Diaminopyritamin · Ethylpyrimidine · Primethamine
- Code names
- NSC-3061 · RP-4753 · WR-2978
- Brand names
Resolves to
Clinical / RWD
Structure
InChIKey
WKSAUQYGYAYLPV-UHFFFAOYSA-NSMILESCCC1=C(C(N)=NC(N)=N1)C1=CC=C(Cl)C=C1Targets
Transporters
What you can answer from here — as of September 23, 2026
4Protein targetsEach mapped to UniProt, with action and pharmacological actionListed above
2TransportersSubstrate / inhibitor direction, not just membershipListed above
Which drugs share a target with Pyrimethamine, and which of those have an active Phase 3 trial?
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