CYTOCHROME P-450 BASED DRUG INTERACTION.pptx

Cytochrome P450 (CYP) enzymes are a large family of heme-containing enzymes found primarily in the liver. They play a critical role in the metabolism of a wide variety of substances, including drugs, toxins, and endogenous compounds such as hormones and fatty acids. The name "P450" comes from the absorption peak at 450 nm when the enzyme is bound to carbon monoxide. These enzymes facilitate oxidation reactions, which often make substances more water-soluble and easier to excrete from the body.

CYP enzymes are involved in numerous drug interactions due to their ability to metabolize medications. These interactions can lead to altered drug levels, resulting in either reduced efficacy or increased toxicity. Key CYP enzymes include CYP3A4, CYP2D6, CYP2C9, CYP2C19, and CYP1A2, each responsible for the metabolism of different drugs.

But in this slide share, we only study the drug interaction of the cytochrome P450 enzyme.

Understanding the function and interactions of CYP enzymes is essential in pharmacology to ensure safe and effective drug therapy.

It also includes the mechanisms of drug interaction, i.e., enzyme inhibition and enzyme induction, with proper examples and explained in easy language.

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1. Topic : - CYTOCHROME P-450 BASED DRUG INTERACTION UTTARANCHAL UNIVERSITY UTTARANCHAL UNIVERSITY OF PHARMACEUTICAL SCIENCES Prem Nagar , Dehradun, 248001 Uttarakhand . MADE BY :- PRAMESH PANWAR

2. INTRODUCTION ABOUT CYTOCHROME P-450. Cytochrome P450 (CYP) enzymes are a large family of heme-thiolate monooxygenases found primarily in the liver, but also present in other tissues such as the intestines, lungs, and kidneys. They play a crucial role in the metabolism of drugs and other xenobiotics, as well as in the biosynthesis of cholesterol, steroids, and other lipids. Drug interactions involving CYP enzymes are a significant concern in clinical pharmacology, as they can lead to altered drug efficacy or increased toxicity . These enzyme are responsible for breakdown of wide range of substances including medications, toxins, even Hormones. i.e .., endogenous compound. They need NADPH and O2 for their work or action. This cause rise or decline i.e., alternation in the blood level and efficacy of the affected drug, potentially leading to the ADR effect or therapeutic failure. Many drug interaction are result in Drug inhibition or induction of CYP enzyme . Drug interaction, involving Cytochrome P-450 enzyme occurs, when one drug affect the metabolisms of another drug by inducing or inhibiting the activity of specific Cytochrome P-450 enzyme.

3. MECHANISMS OF DRUG INTERACTIONS Drug interactions involving CYP enzymes can occur via two main mechanisms: enzyme inhibition and enzyme induction

4. ENZYME INHIBITION Inhibition of CYP-450 by different drug or diff-diff drug interaction is called Inhibition . If two drug are substrate for same CYP is-enzyme then metabolism of one or both the drugs may be delayed . Example :- Erythromycin and midazolam both are substrate of 3A4 isoenzyme. So there is competition for binding site and at last metabolisms of midazolam in inhibition. Cimitidine and Ketoconazole binds to Cytochrome P-450 and completely inhibit the metabolism of Testosterone.

5. TYPES OF ENZYME INHIBITION

6. DRUG INDUCTION Induction of CYP-450 enzyme by drugs and pollutants Some certain drugs can induce the activity of specific CYP-450 enzymes, resulting in increased metabolisms of other drugs that are substrate for those enzymes. Example:- Phenobarbitone, Rifampicin (CYP3A4 inducer), Smoking (IA2 inducer i.e.., Theophylline), DDT, Alcohol, Phenytoin (CYP2C9 Inducer)

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