What happens in Phase 1 of drug metabolism?

What happens in Phase 1 of drug metabolism?

Phase I reactions of drug metabolism involve oxidation, reduction, or hydrolysis of the parent drug, resulting in its conversion to a more polar molecule. Phase II reactions involve conjugation by coupling the drug or its metabolites to another molecule, such as glucuronidation, acylation, sulfate, or glicine.

Which of the following is an example of phase 1 reaction?

These reactions include hydrolysis, reduction, and oxidation. Hydrolysis. In a reaction with water, a bond in the compound is broken, resulting in two compounds.

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

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.

What are phase 1 enzymes?

Phase I enzymes are responsible for reactions involving oxidation, reduction, and hydrolysis. Oxidation involves the enzymatic addition of oxygen or removal of hydrogen, carried out by mixed function oxidases, often in the liver.

Do all drugs undergo phase 1 metabolism?

Some drugs undergo either phase 1 or phase 2 metabolism, but most undergo phase 1 metabolism followed by phase 2 metabolism. Aspirin (2-ethanoyloxybenzoic acid) hydrolyses to produce 2-hydroxybenzoic acid and ethanoic acid.

Which steps involved in Phase 1 reaction?

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. These reactions include conjugation reactions, glucuronidation, acetylation, and sulfation.

Is hydroxylation a Phase 1 reaction?

Hydroxylation is the most common reaction type in phase I metabolism and usually produces a chemically stable and more polar hydroxylated metabolite than the drug.

What happens when a drug is metabolized?

In most cases, when a drug is metabolized it becomes inactivated. However, the metabolites of some drugs are pharmacologically active and exert an effect on the body. In fact, the active metabolite of some medications is responsible for the principal action of the drug.

Why do I metabolize drugs so quickly?

Some drugs are chemically altered by the body (metabolized)… read more ) drugs slowly. As a result, a drug may accumulate in the body, causing toxicity. Other people metabolize drugs so quickly that after they take a usual dose, drug levels in the blood never become high enough for the drug to be effective.

What are Phase II reactions in pharmacology?

phase II reactions convert a parent drug to more polar (water soluble) inactive metabolites by conjugation of subgroups to -OH, -SH, -NH2 functional groups on drug drugs metabolized via phase II reactions are renally excreted

What is a Phase 1 reaction in chemistry?

Phase I reactions involve hydrolysis, reduction and oxidation, exposing or introducing a functional group (-OH, -NH 2, -SH or –COOH) to increase reactivity and slightly increase hydrophilicity. 1

What is Phase 1 metabolism in pharmacology?

Phase I metabolism oxidation (via cytochrome P450), reduction, and hydrolysis reactions phase I reactions convert a parent drug to more polar (water soluble) active metabolites by unmasking or inserting a polar functional group (-OH, -SH, -NH2) geriatric patients have decreased phase I metabolism

What are the Phase 2 reactions of hydrophobic reactions?

2. Phase II reactions include glucuronidation, sulfation, acetylation, methylation, conjugation with glutathione, and conjugation with amino acids (glycine, taurine and glutamic acid) that strongly increase hydrophilicity. R1R2R1R2 OH