BIOM1060 Lecture Notes - Fall 2018 Lecture 13 - Therapeutic index, C Max, Portal vein
Document Summary
Process by which drug molecule chemically changed into another species (metabolite) Converts toxic drug into non-toxic metabolite or change physicochemical properties of drug to allow to be more efficiently excreted: sometimes used to activate a drug (prodrug) Can occur anywhere in body (but mostly in liver) Occurs via action of enzymes on the drug. Phase i: catabolic reactions - reactions that break down structure or change chemical functional groups (eg. oxidation, reduction and hydrolysis reactions: often mediated by cytochrome p450 enzymes (located inside vesicles in hepatocytes - aka main liver cells) Phase ii: anabolic or conjugation reactions - attachment of substituent group to make metabolite more polar (facilitates more efficient urinary excretion) Factors affecting metabolism: liver fibrosis/damage (eg. reduced metabolic capacity, blood flow, albumin synthesis, drugs that compete with same drug metabolising enzymes, exercise: can reduce hepatic blood flow by 70% Infections: change plasma albumin concentration: patient characteristics (eg. gender, age)
