What are the 2 phases of drug metabolism?

Drug metabolism reactions comprise of two phases: Phase I (functionalization) reactions such as oxidation, hydrolysis; and Phase II (conjugation) reactions such as glucuronidation, sulphate conjugation.

What are different phases of metabolism What are different pathways?

The metabolism of xenobiotics is often divided into three phases:- modification, conjugation, and excretion. These reactions act in concert to detoxify xenobiotics and remove them from cells.

What happens in Phase 1 drug metabolism?

Phase I metabolism consists of reduction, oxidation, or hydrolysis reactions. These reactions serve to convert lipophilic drugs into more polar molecules by adding or exposing a polar functional group such as -NH2 or -OH.

Do all drugs go through 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.

Is first pass metabolism the same as Phase 1?

Phase 1 reactions are often oxidations or hydrolysis reactions, although reductions also occur. In terms of first-pass metabolism in the liver – hydrolysis of pharmacologically inactive esters (prodrugs) to active drugs are important phase 1 reactions.

Do all drugs undergo Phase 1 and Phase 2 metabolism?

What is the main purpose of Phase I metabolism?

Phase I biotransformation reactions introduce or expose functional groups on the drug with the goal of increasing the polarity of the compound. Although Phase I drug metabolism occurs in most tissues, the primary and first pass site of metabolism occurs during hepatic circulation.

Do all drugs go through Phase 2 metabolism?

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.

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

Moreover, a further difference between phase I and phase II metabolism is that the reactions involving in phase I metabolism are oxidation, reduction and hydrolysis while the reactions involving in phase II metabolism are Methylation, glucuronidation, acetylation and sulfation.

When do drugs go from Phase I to Phase II?

Once drugs have undergone Phase I metabolism, they become more polar and are easier to eliminate. Metabolites of many drugs undergo Phase II metabolism subsequent to phase I metabolism. Of course, some drugs undergo only Phase I or only Phase II metabolism.

What are the three phases of drug metabolism?

It occurs through enzymatic reactions. Furthermore, drug metabolism is of three phases; Phase I (modification), Phase II (conjugation) and Phase III (further modification and excretion) and all three phases actively involve to detoxify and remove xenobiotics from the cells.

How are Phase I and Phase II reactions carried out?

Biotransformation is carried out by two distinct groups of enzymatic reactions that are known as Phase-I and Phase-II. Most of the time drugs undergo Phase-I reactions first and then Phase-II reactions, but it is possible that a drug undergoes either only Phase I or