L6: pharmacokinetics 2

name and describe the first stage of metabolism

catabolic reactions: can produce more reactive compound

name and describe the second phase of metabolism

synthetic/anabolic reactions involving conjugation to produce inactive compounds

describe metabolism in the liver

microsomal IC enzymes (like cytochrome P450, alcohol dehydrogenase, MAO).

describe the elimination of aspirin

phase 1: hydroxylation via hydrolytic reactions to creates derivative salicylic acid while

phase 2; adds sugar in conjugation to create conjugate glucuronide

how many genes code for the P450 enzyme

74 (3 main ones to metabolise drugs found in liver)

name some inducers of P450: CYP1A2

Brussel sprouts, broccoli, tobacco

name the 3 routes for excretion

renal, GI, lung

name the mechanisms of renal excretion

glomerular filtration, active tubular secretion, and passive diffusion

describe the time course of clearance graph

follows mono-expinential decay determined by rate of metabolism and excretion. IV dosing regimes cause steady increases while injections cause spikes

describe saturation kinetics

disproportional increase in the steady state plasma concentrations leading to clinical side effects + toxicity. e.g. alcohol saturation of alcohol dehydrogenase