Nursing Pharmacology Chapter 2:  General Principles:  Pharmacokinetics

 

Phase II Metabolism

 

Some Phase II Reactions

Type of Conjugation

Endogenous Reactant

Transferase (Location)

Types of Substrates

Examples

Glucuronidation

UDP glucuronic acid

UDP glucuronosyl transferase (microsomal)

phenols, alcohols, carboxylic acids, hydroxylamines, sulfonamides

morphine, acetaminophen, diazepam, digitoxin, digoxin, meprobamate

Acetylation

Acetyl-CoA

N-Acetyl transferase (cytosol)

Amines

sulfonamides, isoniazid, clonazepam, dapsone, mescaline

Glutathione conjugation

glutathione

GSH-S-transferase (cytosolic, microsomes)

epoxides, nitro groups, hydroxylamines

ethycrinic acid, bromobenzene

Sulfate conjugation

Phosphoadenosyl phosphosulfate

Sulfotransferase (cytosol)

phenols, alcohols, aromatic amines

estrone, 3-hydroxy coumarin, acetaminophen, methyldopa

Methylation

S-Adenosyl-methionine

transmethylases (cytosol)

catecholamines, phenols, amines, histamine

dopamine, epinephrine, histamine, thiouracil, pyridine

Adapted from Table 4-3, Correia, M.A., Drug Biotransformation. in Basic and Clinical Pharmacology, (Katzung, B. G., ed) Appleton-Lange, 1998, p 57.

  1. Stoelting, R.K., "Pharmacokinetics and Pharmacodynamics of Injected and Inhaled Drugs", in Pharmacology and Physiology in Anesthetic Practice, Lippincott-Raven Publishers, 1999, 1-17.

  2. Benet, Leslie Z, Kroetz, Deanna L. and Sheiner, Lewis B The Dynamics of Drug Absorption, Distribution and Elimination. In, Goodman and Gillman's The Pharmacologial Basis of Therapeutics,(Hardman, J.G, Limbird, L.E, Molinoff, P.B., Ruddon, R.W, and Gilman, A.G.,eds) TheMcGraw-Hill Companies, Inc.,1996, pp. 3-27

  3. Correia, M.A., Drug Biotransformation. in Basic and Clinical Pharmacology, (Katzung, B. G., ed) Appleton-Lange, 1998, pp 50-61