Pyrimethamine
Pyrimethamine is a diaminopyrimidine antiparasitic agent that selectively inhibits plasmodial and toxoplasmal dihydrofolate reductase (DHFR) with much greater affinity than the mammalian enzyme, thereby blocking folate metabolism and inhibiting nucleic acid synthesis in the parasite. It is used in combination with sulfadiazine or dapsone for the treatment and secondary prophylaxis of toxoplasmosis, and with sulfadoxine as the combination Fansidar for treatment of chloroquine-resistant malaria.
Molecular Weight
248.7100 g/mol
LogP
2.70
TPSA
77.80 Ų
Lipinski RO5
Pass
Therapeutic Areas
Mechanism of Action
Disrupts essential metabolic pathways or structural components of parasitic organisms, leading to paralysis, starvation, or death of the parasite.
Pharmacokinetics (PK)
Pharmacodynamics (PD)
Disrupts essential metabolic pathways or structural components of parasitic organisms, leading to paralysis, starvation, or death of the parasite.
2D Structure
Cite this structure
Embed this structure
SMILES
CCc1nc(N)nc(N)c1-c1ccc(Cl)cc1
InChI
InChI=1S/C12H13ClN4/c1-2-9-10(11(14)17-12(15)16-9)7-3-5-8(13)6-4-7/h3-6H,2H2,1H3,(H4,14,15,16,17)
Molecular Formula
C12H13ClN4
HBD / HBA
2 / 4
Rotatable Bonds
2
Heavy Atoms
17
No targets recorded
Target interaction data is not yet available for this drug.
No interactions recorded
Drug interaction data is not yet available for this compound.
No side effects recorded
Side effect data is not yet available for this drug.
Frequently Asked Questions
Pyrimethamine is a diaminopyrimidine antiparasitic agent that selectively inhibits plasmodial and toxoplasmal dihydrofolate reductase (DHFR) with much greater affinity than the mammalian enzyme, thereby blocking folate metabolism and inhibiting nucleic acid synthesis in the parasite. It is used in combination with sulfadiazine or dapsone for the treatment and secondary prophylaxis of toxoplasmosis, and with sulfadoxine as the combination Fansidar for treatment of chloroquine-resistant malaria.
Disrupts essential metabolic pathways or structural components of parasitic organisms, leading to paralysis, starvation, or death of the parasite.
Yes, Pyrimethamine is an approved drug. It has reached clinical phase 4. It is classified as a Small molecule.
References & Data Sources
- ChEMBL — European Bioinformatics Institute (EBI). CHEMBL36. Open-access bioactivity database.
- PubChem — National Center for Biotechnology Information (NCBI). CID 4993. Chemical information database.
Data aggregated from publicly available pharmacological databases. Last updated 2026-03-28.
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