Pyrimethamine
Last updated: 17/08/2023
(Also known as: daraprim; ethylpyrimidine)
The following alerts are based on the data in the tables below. An absence of an alert does not imply the substance has no implications for human health, biodiversity or the environment but just that we do not have the data to form a judgement.
Environmental fate
Ecotoxicity
Human health
 
 
A drug used to treat protozoal infections
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Dogs, Cats, Horses, Sheep, Birds
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C₁₂H₁₃ClN₄
CCC1=C(C(=NC(=N1)N)N)C2=CC=C(C=C2)Cl
No data
WKSAUQYGYAYLPV-UHFFFAOYSA-N
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)
Yes
Cambridge Crystallographic Data Centre diagrams
Common Name
Relationship
Link
pyrimethamine
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Antiparasitic, Antiprotozoic, Medicinal drug
Unclassified substance
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Synthetic
Interferes with tetrahydrofolic acid synthesis from folic acid by inhibiting the enzyme dihydrofolate reductase (DHFR)
[Dihydrofolate reductase, inhibitor], [Bifunctional dihydrofolate reductase-thymidylate synthase, inhibitor]
58-14-0
200-364-2
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Not listed
Not available
No
No data
248.71
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5-(4-chlorophenyl)-6-ethyl- 2,4-pyrimidinediamine
2,4-diamino-5-p-chlorophenyl-6-ethylpyrimidine
Evidence of use in third world countries
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White solid
None identified
None identified
No UK authorisation for use with animals
Not applicable
Usually supplied in tablet form
100
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
Moderate
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233
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4.90 X 1002
Calculated
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2.69
Low
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7.34
R3 R = Peer reviewed scientific publications 3 = Unverified data of known source
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Weak base
8.29 X 10-03
Low volatility
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Soil adsorption and mobility
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Low risk
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
Based on LogP < 3
Low risk
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None
Terrestrial ecotoxicology
440
Rat
Moderate
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5.06
R4 R = Peer reviewed scientific publications 4 = Verified data
Selenastrum capricornutum
Moderate
0.752
R4 R = Peer reviewed scientific publications 4 = Verified data
Selenastrum capricornutum
Moderate
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HUMAN HEALTH AND PROTECTION
High (class III)
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440
Rat
Moderate
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Intraperitoneal LD₅₀ = 70 mg kg⁻¹
Rat
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Subcutaneous LDLo = 160 mg kg⁻¹
Rat
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Principally lost via the urine as metabolites
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
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Carcinogen
Endocrine disruptor
No data found
A0 A = Chromosome aberration (EFSA database) 0 = No data
; B0 B = DNA damage/repair (EFSA database) 0 = No data
; C0 C = Gene mutation (EFSA database) 0 = No data
; D0 D = Genome mutation (EFSA database) 0 = No data
; E1 E = Unspecified genotoxicity type (miscellaneous data source) 1 = Positive
No data found
Reproduction / development effects
Acetyl cholinesterase inhibitor
Neurotoxicant
✓Yes, known to cause a problem
No data found
No data found
Respiratory tract irritant
Skin irritant
Skin sensitiser
XNo, known not to cause a problem
XNo, known not to cause a problem
No data found
Eye irritant
Phototoxicant
 
XNo, known not to cause a problem
No data found
 
May cause hypersensitivity, megaloblastic anemia & thrombocytopenia May cause gastrointestinal problems
IMDG Transport Hazard Class 6.1
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Not listed (Not listed)
UN3249
Packaging Group III (minor danger)
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pyrimethamine
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pirimetamina
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Record last updated:
17/08/2023
Contact:
aeru@herts.ac.uk
Please cite as:
Lewis, K.A., Tzilivakis, J., Warner, D. and Green, A. (2016) An international database for pesticide risk assessments and management. Human and Ecological Risk Assessment: An International Journal , 22 (4), 1050-1064. DOI: 10.1080/10807039.2015.1133242