Drug Metabolism - Exam 2

inactivation of drug action def

metabolism prevents binding to its target

Prodrug activation def

parent drug is inactive, must be metabolized to produce effect

no effect on drug action -

metabolite has similar or inc binding to target

No metabolism on drug action

some very polar drugs (tetracycline) require no metabolism and are excreted

Richard T williams

father of drug metabolism (toxicology) science

Phase 1 and 2 metabolic pathways

Organic pesticides and drugs of abuse

what are the 2 major routes metabolites are eliminated from body?

Urine (primary) and Bile

Urine (primary route of elimination)

kidneys function to filter out molecules w/ MW < 70,000 not large proteins

lipophilic compounds → reabsorbed into blood stream by passive diffusion

polar drugs are secreted from blood stream into proximal tubule

Urinary excrection equation

excrection = filtration - (reabsorption + secrection)

Bile (secondary route of drug elimination)

excretion by liver into bile in phase 2 metabolism

molecules have a polar group (anionic or uncharged) and minimum mw of 500-600

diclofenac example

40% bile → MW 500 and - charge

60% urine → MW 300