What are substrates of CYP450?
Emily Wilson
Updated on June 02, 2026
Some Common Substrates, Inhibitors and Inducers of CYP450 Isoenzymes
| Substrates | Inhibitors | Inducers |
|---|---|---|
| Clomipramine | Cimetidine | Broccoli |
| Clozapine | Ciprofloxacin | Brussels sprouts |
| Imipramine | Fluvoxamine | Cigarette Smoking |
| Theophylline |
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.
What is the difference between inducer and substrate?
Substrates bind with the active site of the enzyme and form the substrate-enzyme complex. In contrast, enzyme inducer increases the activity of the enzyme by binding or by enhancing the expression of the gene that is coding the enzyme.
What are substrates in drugs?
Substrates are drugs that bind to the active site of an enzyme and are transformed into metabolites while being present in this active site. The biotransformation process of a drug may involve multiple enzymes leading to various metabolites; each metabolic route relies on specific characteristics.
What is cytochrome P450 isoenzymes?
Cytochrome P450 represents a family of isozymes responsible for biotransformation of many drugs via oxidation. The enzymes are heme-containing membrane proteins, which are located in the smooth endoplasmic reticulum of several tissues.
How do you memorize CYP450 inducers and 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.
How do you remember cytochrome P450 inducers?
What is the difference between a substrate and an inhibitor?
An enzyme inhibitor is a molecule that binds to an enzyme and decreases its activity. Not all molecules that bind to enzymes are inhibitors; enzyme activators bind to enzymes and increase their enzymatic activity, while enzyme substrates bind and are converted to products in the normal catalytic cycle of the enzyme.
Why is cyp450 important?
Cytochrome P450 enzymes are essential for the metabolism of many medications. Knowledge of the most important drugs metabolized by cytochrome P450 enzymes, as well as the most potent inhibiting and inducing drugs, can help minimize the possibility of adverse drug reactions and interactions.
Where are cyp450 enzymes 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.
