Drugs metabolized mainly by CYP2B6 include artemisinin, bupropion, cyclophosphamide, efavirenz, ketamine, and methadone. CYP2B6 is one of the most polymorphic CYP genes in humans and variants have been shown to affect transcriptional regulation, splicing, mRNA and protein expression, and catalytic activity.
What does CYP1A2 metabolize?
CYP1A2 metabolizes endogenous compounds such as retinols, melatonin, steroids, uroporphyrinogen and arachidonic acids and plays a major role in procarcinogen activation and DDIs, due to induction and inhibition by several therapeutic drugs.
What drugs are metabolized by CYP450?
Drugs may be metabolized by only one CYP450 enzyme (e.g., metoprolol by CYP2D6) or by multiple enzymes (e.g., warfarin [Coumadin] by CYP1A2, CYP2D6, and CYP3A4). 13 Drugs that cause CYP450 metabolic drug interactions are referred to as either inhibitors or inducers (Table 110,14–16).
What drugs are CYP3A4 inhibitors?
Potent inhibitors of CYP3A4 include clarithromycin, erythromycin, diltiazem, itraconazole, ketoconazole, ritonavir, verapamil, goldenseal and grapefruit. Inducers of CYP3A4 include phenobarbital, phenytoin, rifampicin, St. John’s Wort and glucocorticoids.
What is Gene CYP2B6?
CYP2B6 (Cytochrome P450 Family 2 Subfamily B Member 6) is a Protein Coding gene. Diseases associated with CYP2B6 include Efavirenz, Poor Metabolism Of and Acute Frontal Sinusitis. Among its related pathways are Drug metabolism – cytochrome P450 and Cytochrome P450 – arranged by substrate type.
Why do I metabolize caffeine so fast?
And he zeroed in on one gene in particular, CYP1A2, which controls an enzyme – also called CYP1A2 – that determines how quickly our bodies break down caffeine. One variant of the gene causes the liver to metabolize caffeine very quickly.
What happens when CYP1A2 is inhibited?
Drugs that inhibit CYP1A2 will predictablyincrease the plasma concentrationsof the medications listed inTable 1, and in some cases adverseoutcomes will occur. Of particular noteis fluvoxamine, which is a potentCYP1A2 inhibitor and also inhibitsother CYP450 enzymes, such asCYP2C19, CYP3A4, and to some extentCYP2C9.
What is the cytochrome P450 system in the liver?
Cytochrome P450 enzymes also function to metabolize potentially toxic compounds, including drugs and products of endogenous metabolism such as bilirubin, principally in the liver. The Human Genome Project has identified 57 human genes coding for the various cytochrome P450 enzymes.
Where is cytochrome P450 found?
Cytochrome P450 enzymes are primarily found in liver cells but are also located in cells throughout the body. While a large body of knowledge exists on the role of CYP450s in xenobiotic metabolism, recent studies have begun to reveal the endogenous functions carried out by this important superfamily of enzymes.
Is grapefruit a CYP450 inhibitor or inducer?
A number of studies have shown that a single glass of grapefruit juice produced an individual-dependent, variable increase in the systemic bioavailability of cisapride by inhibition of intestinal cytochrome P450 3A4 (CYP3A4) activity.
Which drugs are inhibitors?
Examples of ACE inhibitors include:
- Benazepril (Lotensin)
- Enalapril (Vasotec)
- Lisinopril (Prinivil, Zestril)
- Quinapril (Accupril)
What are inhibitors?
: one that inhibits: such as. a : an agent that slows or interferes with a chemical action. b : a substance that reduces or suppresses the activity of another substance (such as an enzyme)
What are CYP2C19 inhibitors?
CYP2C19 catalyzes the metabolism of more than 12 clinically important drugs, such as omeprazole (antiulcerative), (S)-mephenytoin (anticonvulsant), and diazepam (anxiolytic), etc. (Lee, 2012). It plays an important role in the proton pump–inhibitor therapy for peptic ulcer and gastroesophageal reflux diseases.
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.
How does CYP2C19 affect metabolism?
Most often, changes in the CYP2C19 gene lead to impaired metabolism of these drugs, which reduces their effectiveness. One change in the CYP2C19 gene (known as CYP2C19*17) increases the enzyme’s ability to metabolize drugs.
What is CYP2B6 * 6?
Methadone. Methadone is primarily cleared by hepatic CYP2B6 to its inactive metabolite. Of the many variants of the very polymorphic gene CYP2B6, one of the most common and clinically significant variant allele is CYP2B6*6 (516G>T, Q172H; 785A>G, K262R), which markedly reduces CYP2B6 expression and activity.