PHAR 430 Lecture Notes - Lecture 4: Epoxide Hydrolase, Rifampicin, Amprenavir
Document Summary
Enzyme activation = when an xenobiotic increases the activity of an enzyme does not involve transcriptional/translational changes. Rifampicin induces cyp3a4 that metabolizes warfarin = reduced benefit of warfarin. This effect is dose- dependent (the receptors get saturated) and time dependent (when rifampicin is taken away, still takes a few days to go back to normal because the enzymes have to regenerate) benzpyrene = combustion product, carcinogenic. Causes auto- induction (the substrate induces the enzyme that metabolizes it). This is dose- dependent (the more compound (cid:455)ou"re e(cid:454)posed to, the more induction, but only until the enzyme is saturated) and time-dependent (the enzymes have to regenerate). Enzyme induction is dose dependent (the (cid:373)ore (cid:272)o(cid:373)pou(cid:374)d (cid:455)ou"re e(cid:454)posed to the (cid:373)ore i(cid:374)du(cid:272)tio(cid:374), (cid:271)ut o(cid:374)l(cid:455) u(cid:374)til the enzyme is saturated), time dependent (the enzymes have to regenerate), and reversible. Bolded drugs = reported to cause drug-drug interactions.
