What are cytochrome P450 inducers and inhibitors?
Cytochrome P-450 enzyme inducers (e.g., rifampin, phenytoin, phenobarbital) decrease the bioavailability and increase the clearance of verapamil and diltiazem. Conversely, the enzyme inhibitor cimetidine increases the bioavailability and decreases the clearance of calcium antagonists.
How do you remember CYP450 inhibitors?
Cytochrome P450 (CYP450) enzymes can be inhibited or induced by some drugs, resulting in significant drug interactions that can cause unanticipated adverse reactions or therapeutic failures. An easy way to remember the mnemonic is; CRAP GPs spend all day on SICKFACES.com.
What are strong CYP3A inhibitors?
Strong inhibitors of CYP3A4 include: Clarithromycin, telithromycin, nefazodone, itraconazole, ketoconazole, atazanavir, darunavir, indinavir, lopinavir, nelfinavir, ritonavir, saquinavir, tipranavir. It is important to note that not all drugs within a class of medications are known to be inhibitors of CYP3A4.
Is Phenobarbital a CYP inducer?
Phenobarbital is a potent cytochrome P450 enzyme inducer, leading to interactions with other drugs by increasing their clearance.
Is grapefruit a CYP450 inhibitor or inducer?
Grapefruit juice is associated with the inhibition of Cytochrome P450 enzyme system, particularly the CYP3A4 enzyme7.
Is amiodarone an enzyme inhibitor?
Amiodarone is a substrate of CYP3A4 and CYP2C8 and an inhibitor of CYP2C9, CYP2D6, CYP3A4, and p-glycoprotein.
What drugs are metabolized by CYP3A?
| Sensitive index substrates unless otherwise noted | |
|---|---|
| CYP2C9 | tolbutamide(c), S-warfarin(c) |
| CYP2C19 | lansoprazole (c,d), omeprazole |
| CYP2D6 | desipramine, dextromethorphan, nebivolol |
| CYP3A | midazolam, triazolam |
What are CYP3A drugs?
CYP3A inducers include the glucocorticoids, rifampin, carbamazepine, phenobarbital, and phenytoin. Among the many significant CYP3A inhibitors are grapefruit juice, erythromycin, ketoconazole, clarithromycin, and verapamil.
Is azithromycin a CYP3A4 inhibitor?
Azithromycin has been shown to be a weak substrate for CYP3A4, to be minimally metabolized by the enzyme, and to neither induce nor inhibit CYP3A4 activity [16].
Is Prozac a CYP3A4 inhibitor?
Fluoxetine is an example of a CYP3A4 inhibitor in common use, and has been associated with elevated serum concentrations of antipsychotics and warfarin, but has no prior documenta- tion of effecting metabolism of glucocorticoids [1].
Is St John’s wort a CYP450 inducer?
John’s wort (SJW) to cause drug interactions. At that time, SJW had been identified as an inducer of cytochrome P450 3A4 (CYP3A4) and P-glycoprotein (P-gp). SJW has been determined to be an inducer of several CYP450 enzymes, including CYP3A4, CYP2C9, and CYP2C19.
Does pomelo interact with drugs?
Medicines can interact with whole fruit, fruit pulp or fruit extracts. Fruit of concern include orange, pomelo, pomegranate, cranberry, red/purple grape, apple, and grapefruit. Patients should be informed about the risk of interactions from consuming fruit.
What are Isoenzymes in cytochrome P-450?
The cytochrome P450 isoenzymes are a superfamily of haemoprotein enzymes that catalyse the metabolism of a large number of endogenous and exogenous compounds. Recently, the cytochrome isoenzymes have been shown to be important in the synthesis of steroid hormones and bile acids, the arachidonic acid cascade and in central nervous function.
What does cytochrome P-450 CYP27A1 mean?
Cytochrome P450 27A1 (CYP27A1) is a ubiquitous enzyme that hydroxylates cholesterol and other sterols. Complete CYP27A1 deficiency owing to genetic mutations is detrimental to human health, whereas 50% of activity retention is not and does not affect the whole body cholesterol levels.
What are P450 drugs?
P450 refers to a family of metabolic proteins called the cytochrome P450 enzymes; they are responsible for breaking down drugs inside the body. P450 inhibitors slow or stop the chemical action of a cytochrome P450 enzyme usually by binding with the enzyme before it can do its job.
What is the cytochrome enzyme system?
6.1.3.1 Cytochrome P450 system. Cytochrome P450 (CYP) enzymes are a group of enzymes encoded by P450 genes and are expressed as membrane bound proteins mostly found in the endoplasmic reticulum of the liver. CYP enzymes function as monoxygenases and effect oxidation by transfer of one oxygen atom through a number of steps.