drug metabolism

Metabolic Changes of Drugs Babylon university college of pharmacy drug metabolism 3rd class – second semester Dr. Abdulhussien Aljebory 2015
Books: 1. Wilson and Gisvold’s Textbook of Organic Medicinal and Pharmaceutical Chemistry 11th ed. Lippincott, Williams & Wilkins ed.
2. Foye’s Principles of Medicinal Chemistry
METABOLISM OR BIOTRANSFORMATION
Metabolism: It is a general term used for chemical transformation of xenobiotics and endogenous nutrients (e.g., proteins, carbohydrates and fats) within or outside the body.
?It is an essential pharmacokinetic process, which renders lipid soluble and non-polar compounds to water soluble and polar compounds so that they are excreted by various processes.
? This is because only water-soluble substances undergo excretion, whereas lipid soluble substances are passively reabsorbed from renal or extra renal excretory sites into the blood by virtue of their lipophilicity.
?The term metabolism is commonly used probably because products of drug transformation are called metabolites.
?Metabolism is a necessary biological process that limits the life of a substance in the body.
?Biotransformation: It is a specific term used for chemical transformation of xenobiotics in the body/living organism.
a series of enzyme-catalyzed processes—that alters the physiochemical properties of foreign chemicals (drug/xenobiotics) from those that favor absorption across biological membranes (lipophilicity) to those favoring elimination in urine or bile (hydrophilicity )
?Xenobiotics :These are all chemical substances that are not nutrient for body (foreign to body) and which enter the body through ingestion, inhalation or dermal exposure.
?They include :
? drugs, industrial chemicals, pesticides, pollutants, plant and animal toxins, etc.