CYP2C19
cytochrome P450 family 2 subfamily C member 19
Gene summary
A protein-coding gene on chromosome 10 (drug metabolism (phase i)). Encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids.
Source: NCBI Gene, accessed 2026-10-07.
Protein reference (UniProt)
- Protein
Cytochrome P450 2C19
- Function
A cytochrome P450 monooxygenase involved in the metabolism of polyunsaturated fatty acids (PUFA). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate, and reducing the second into a water molecule, with two electrons provided by NADPH via cytochrome P450 reductase (NADPH--hemoprotein reductase). Catalyzes the hydroxylation of carbon-hydrogen bonds. Hydroxylates PUFA specifically at the omega-1 position. Catalyzes the epoxidation of double bonds of PUFA. Also metabolizes plant monoterpenes such as limonene. Oxygenates (R)- and (S)-limonene to produce carveol and perillyl alcohol. Responsible for the metabolism of a number of therapeutic agents such as the anticonvulsant drug S-mephenytoin, omeprazole, proguanil, certain barbiturates, diazepam, propranolol, citalopram and imipramine. Hydroxylates fenbendazole at the 4' position.
- Pathway
Lipid metabolism; fatty acid metabolism. Terpene metabolism; (4R)-limonene degradation.
- Subcellular location
Endoplasmic reticulum membrane; Microsome membrane.
Source: UniProtKB/Swiss-Prot P33261, release 2026_03, licensed CC BY 4.0. This is the protein’s normal biology, not evidence about post-drug syndromes; associated conditions are inherited disorders of the gene, not PFS, PSSD or PRSD.
Why its pathway is in the library
Phase I enzymes determine exposure to finasteride, SSRIs, and other implicated drugs; variation here shapes the likelihood and persistence of adverse effects.
Written for the whole drug metabolism family, not for CYP2C19 specifically.
Mentioned in 1 corpus record
- Peer-reviewed paper
Influence of CYP2C19, CYP2D6, and ABCB1 Gene Variants and Serum Levels of Escitalopram and Aripiprazole on Treatment-Emergent Sexual Dysfunction: A Canadian Biomarker Integration Network in Depression 1 (CAN-BIND 1) Study
Farhana Islam, Leen Magarbeh, Samar S. M. Elsheikh, Stefan M. Kloiber, Caroline Wanderley Espinola, Venkat Bhat, Benicio Noronha Frey… · The Canadian Journal of Psychiatry
In 178 adults with major depressive disorder treated with escitalopram (weeks 0-8), nonresponders were augmented with aripiprazole while responders continued escitalopram alone (weeks 8-16), with sexual function and satisfaction tracked on the SexFX scale…
ABCB1CYP2C19CYP2D6MECH-0352023 (epub Oct 2023)PSSDSystems review · Oct 2026
Also in drug metabolism (phase i)
All 23 genes- CYP2D6
cytochrome P450 family 2 subfamily D member 6 (gene/pseudogene)
chr 22· Drug metabolism· 6 records - COMT
catechol-O-methyltransferase
chr 22· Drug metabolism· 4 records - CYP3A4
cytochrome P450 family 3 subfamily A member 4
chr 7· Drug metabolism· 2 records - CYP3A5
cytochrome P450 family 3 subfamily A member 5
chr 7· Drug metabolism· 1 record - MAOA
monoamine oxidase A
chr X· Drug metabolism· 1 record - AKR1B1
aldo-keto reductase family 1 member B
chr 7· Drug metabolism· Pathway candidate - AKR1B10
aldo-keto reductase family 1 member B10
chr 7· Drug metabolism· Pathway candidate - ALDH1A1
aldehyde dehydrogenase 1 family member A1
chr 9· Drug metabolism· Pathway candidate
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