HTHSCI 2H03 Lecture Notes - Lecture 2: Cyp3A4, Hepatocyte, Rifampicin

• School: McMaster University
• Department: Health Sciences
• Course: HTHSCI 2H03
• Professor: kirsten

Document Summary

Drug structure, absorption and distribution: absorption: must be free and unbound - off the excipient, off plasma proteins, etc, 20% of the drug is in a fat-soluble state. Warfarin binds very well but other drugs bind more readily/ tightly than warfarin, like aspirin. Drug- drug interaction: if a patient on warfarin takes aspirin, aspirin binds more readily than and displaces. Absorption: drugs that are non-polar diffuse across plasma membranes and are absorbed. Iv drugs are (cid:374)ot (cid:862)te(cid:272)h(cid:374)i(cid:272)all(cid:455)(cid:863) a(cid:271)sor(cid:271)ed: drugs with this characteristic are also easily distributed through (cid:271)od(cid:455) tissues, (cid:271)ut o(cid:374)l(cid:455) (cid:862)free(cid:863) drug molecules can be distributed. Distribution: only free (unbound) drug molecules can be distributed into body tissues, drug-drug & drug-food interactions, blood flow (vascularity), organ size, and physical properties (eg. a fat soluble drug will distribute into more fat tissue) Metabolism: drugs are bio transformed into water-soluble compounds that are easily excreted by the kidneys (facilitate elimination and excretion) when a drug is metabolized it is inactive.