BIO200H5 Lecture Notes - Lecture 10: Vasoconstriction, Adme, Enalapril
Document Summary
Drug life = the time that the drug stays in the bloodstream and works. Drug accumulation = build up of the drug in the blood plasma over time and over. Depends on the volume of distribution, its half life and the clearance rates. Bioavailability is how much of the drug goes into the body and does its work and how multiple doses it is used. It is the fraction of the drug that reaches the blood after administration. Drug dose administered through i. v. fraction = 1 (100% bioavailable) Drug dose administered orally; fraction < 100% Different routes of administration cause different amount of bioavailability. Extent of absorption across gut wall (ex. / hydrophilic drugs = incomplete absorption, low bioavailability; p-glycoprotein) First-pass elimination (initial metabolism of drug by liver) Concentration of drug in blood is tracked over time. Max concentration absorbed (cmax) occurs at tmax. Area under curve(auc); total exposure over time; correlates to total absorption.
