Questions and answers

What are the 2 phases of drug metabolism?

What are the 2 phases of drug metabolism?

There are often two phases of drug metabolism. Phase I: Non-synthetic reactions such as cleavage (e.g. oxidation, reduction, hydrolysis), formation or modification of a function group. Phase II: Synthetic reactions such as conjugation with an endogenous substance (e.g. sulfate, glycine, glucuronic acid).

What are the phases of drug metabolism?

Drugs can be metabolized by oxidation, reduction, hydrolysis, hydration, conjugation, condensation, or isomerization; whatever the process, the goal is to make the drug easier to excrete. The enzymes involved in metabolism are present in many tissues but generally are more concentrated in the liver.

Where does Phase 2 of drug metabolism occur?

Conjugation. Glucuronidation, the most common phase II reaction, is the only one that occurs in the liver microsomal enzyme system. Glucuronides are secreted in bile and eliminated in urine. Thus, conjugation makes most drugs more soluble and easily excreted by the kidneys.

Which of the following is Phase 2 metabolism reaction?

Phase II metabolic reactions are characterized as conjugation reactions and are catalyzed by enzymes known as transferases. Glutathione conjugation with reactive metabolic products by glutathione S- transferases. Amino acid conjugation by acyl-CoA synthetase and N-acetyltransferase.

What are the three phases of metabolism?

The metabolism of xenobiotics is often divided into three phases:- modification, conjugation, and excretion.

What is the difference between Phase 1 and Phase 2 metabolism?

The key difference between phase I and phase II metabolism is that the phase I metabolism converts a parent drug to polar active metabolites while phase II metabolism converts a parent drug to polar inactive metabolites. Metabolism (drug metabolism) is the anabolic and catabolic breakdown of drugs by living organisms.

Where does Phase 1 and 2 metabolism occur?

The liver is the primary site for metabolism. Liver contains the necessary enzymes for metabolism of drugs and other xenobiotics. These enzymes induce two metabolism pathways: Phase I (functionalization reactions) and Phase II (biosynthetic reactions) metabolism.

Do all drugs undergo Phase 1 and Phase 2 metabolism?

This is called conjugation and the product is called a conjugate. Metabolites formed in phase 2 are unlikely to be pharmacologically active. Some drugs undergo either phase 1 or phase 2 metabolism, but most undergo phase 1 metabolism followed by phase 2 metabolism.