CYP3A4


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CYP3A4

A gene on chromosome 7q21.1 that encodes a member of the cytochrome P450 superfamily of monooxygenases, which catalyse reactions in drug metabolism and synthesis of cholesterol, steroids and other lipids. CYP3A4 localises to the endoplasmic reticulum; its expression is induced by glucocorticoids and drugs. It metabolises roughly half of the drugs in current use today—e.g., paracetamol (acetaminophen), codeine, cyclosporin A, diazepam and erythromycin—as well as steroids and carcinogens.

CYP3A4

One isoenzyme form of the cytochrome P450 system involved in the metabolism of many drugs. Drugs that alter this enzyme system can influence the metabolism of other agents taken by patients and cause unanticipated toxic effects.
References in periodicals archive ?
Quercetin, kaempferol and myricetin inhibit CYP3A4 in vitro.
Genetic factors are known to make a great contribution to the variability in the CYP3A4 activity.[8],[9],[10] Among CYP3A4 alleles identified, CYP3A4*1G (CYP3A4 SNP, rs2242480 [G/A]) is a well-known single-nucleotide polymorphism site with a high mutation frequency in Chinese population.[11],[12],[13],[14] A synonymous G-A transition in exon 10 has been confirmed to be associated with CYP3A4 enzyme activity, leading to change in drug metabolism and distinct response to treatment among different patients.
Vladimir Maletic, MD, MS, explains: "Concomitant use of LATUDA with strong CYP3A4 inhibitors such as ketoconazole may increase the exposure of lurasidone compared to the use of LATUDA alone."
Suppose that a drug, X, is predominantly metabolized through CYP3A4 in humans and that it is concomitantly administered with another drug, Y, that is a strong inhibitor of CYP3A4.
It is metabolized in the liver through CYP3A4 and CYP2D6 enzymes where it undergoes O-desmethylation and N-desmethylation as well as conjugation of O-desmethylated glucuronide derivatives.
The authors reported that significant pharmacokinetic interactions were more likely with drugs that were substrates for CYP3A4 and/or p-glycoprotein (ABCB1) and were less likely in studies that investigated SJW products with low-hyperforin content.
-- Consider the potential effects of increased plasma concentrations of midazolam or other benzodiazepines metabolized via CYP3A4 (alprazolam, triazolam) when administering with AKYNZEO.
Grapefruit inhibits cytochrome P450 3A4 (CYP3A4), a key enzyme that breaks down many drugs in the small intestine and the liver.
As is known to all, CYP2C9 and CYP3A4 play an important role in the drug metabolism.
The risk of bleeding with rivaroxaban can be accentuated by the concomitant use of medications such as amiodarone [3] which compete for metabolism via the CYP3A4 hepatic pathway [4].
Both the systemic and pre-systemic drug dispositions are affected because of the location of CYP3A4 in the liver and small bowel.