What type of enzyme is CYP3A4?
Function. CYP3A4 is a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases that catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids, and other lipids components.
What drugs are CYP3A inhibitors?
CYP3A inducers include the glucocorticoids, rifampin, carbamazepine, phenobarbital, and phenytoin. Among the many significant CYP3A inhibitors are grapefruit juice, erythromycin, ketoconazole, clarithromycin, and verapamil.
What is the function of CYP2C9?
The CYP2C9 enzyme breaks down (metabolizes) compounds including steroid hormones and fatty acids. The CYP2C9 enzyme also plays a major role in breaking down the drug warfarin, which thins the blood and prevents blood clots from forming.
What are CYP450 inhibitors?
The cytochrome P450 (CYP450) enzymes are essential to produce numerous agents, including cholesterol and steroids. CYP450 inhibitors are used to minimize or prevent such reactions. Drugs are metabolized in many sites of our body; however, the liver is the primary organ for drug metabolism.
What induces CYP3A4?
Induction. CYP3A4 activity is induced via the pregnane X receptor (PXR), the constitutive androstane receptor (CAR), peroxisome proliferator-activated receptor (PPARα) and probably the glucocorticoid receptor (GR)3, 11.
What does inducer of CYP3A4 mean?
CYP3A4 inducers are drugs that increase the activity of CYP3A4. Note that the CYP3A4 enzyme is particularly susceptible to enzyme inducers, and marked reductions in the plasma concentrations of CYP3A4 substrates may occur.
What are CYP3A inhibitors used for?
A CYP3A inhibitor used to increase the systemic exposure of atazanavir or darunavir in combination with other antiretroviral agents in the treatment of HIV-1 infection. A viral protease inhibitor used in the treatment of HIV infection.
What foods affect cytochrome P450?
| Drug | Food | Increase Drug Effect |
|---|---|---|
| Some statins (eg, Lipitor, Zocor, Mevacor, Advicor) | Grapefruit, pomegranate, and cranberry juices | † |
| Antidepressants (MAO inhibitors) | Chocolate and other foods containing tyramine | † |
| Allergy medications (eg, Allegra) | Black pepper | † |
| Potentially all drugs metabolized by P450 liver enzymes | Black tea | † |
What is CYP2C9 genotype?
CYP2C9 Genotyping Of special interest are those drugs with narrow therapeutic index, such as warfarin (Coumadin®), tolbutamide, and phenytoin (Dilantin®), where impairment in CYP2C9 metabolic activity might cause difficulties in dose adjustment as well as toxicity. VKORC1 is the site of action of warfarin.
What is CYP2C9 inhibitor?
Drugs and compounds which inhibit or antagonize the biosynthesis or actions of CYTOCHROME P-450 CYP2C9. Drug. Drug Description. Miconazole.
What is the function of CYP450?
Background: The cytochrome P450 (CYP) enzymes are membrane-bound hemoproteins that play a pivotal role in the detoxification of xenobiotics, cellular metabolism and homeostasis. Induction or inhibition of CYP enzymes is a major mechanism that underlies drug-drug interactions.
What drugs inhibit CYP450?
Medicines that are potent CYP3A4 inhibitors include (but are not limited to) clarithromycin, diltiazem, erythromycin, itraconazole, ketoconazole, ritonavir, and verapamil9.
What are strong CYP3A inhibitors?
“Strong CYP3A inhibitors include antiviral, antibiotic, antifungal, and antidepressant medications from which many patients taking Korlym could benefit,” he added. “Korlym’s label instructs doctors how to do this safely.”.
What is a CYP3A4 inducer?
CYP3A4 Inducers. CYP3A4 inducers are drugs that increase the activity of CYP3A4. Note that the CYP3A4 enzyme is particularly susceptible to enzyme inducers, and marked reductions in the plasma concentrations of CYP3A4 substrates may occur.
What are examples of competitive inhibitors?
Competitive inhibitor drug usage is extensive. Examples include Tamiflu: Flu, tetrahydrofolate: (anticancer drug), para-aminobenzoic acid: antibiotic. Tamiflu works by competitively inhibiting the enzyme ‘neuraminidase’.
What is a CYP3A4 substrate?
CYP3A4 Substrates. Cytochrome P450 (CYP) proteins are heme-thiolate monooxygenases that mediate NADPH -dependent electron transport and function to oxidize a variety of structurally unrelated compounds, including steroids, fatty acids and xenobiotics.