wk6 metabolsim and excretion

Question 1

phase 1 metabolsim

Answer 1

addition of polar groups through oxidation, reduction or hydrolysis, makes the drug more polar and prepares it for phase 2

Question 2

phase 2 metabolism

Answer 2

conjugation with ionic groups. glutathione, acetyl, methyl. makes drug more water soluble

Question 3

metabolsim of morphine

Answer 3

primary pathway is phase 2 metabolism. udp glucuronosyl transferase (ugt) is the enzyyme responsible. it conjugates glucuronic acid and makes glucuronide morphine metabolites.

Question 4

metabolsim of praracetamol

Answer 4

primary pathway phase 2. and metabolites are paracetamol glucuronide/sulfate. however, in overdose, the metabolism shifts to phase 1 and produces the toxic metablite napqi by enzyme cyp2e1.. risks liver damage

Question 5

what are prodrugs

Answer 5

drugs that need to be metabolized to become active like codeine to morphine by cyp2d6

Question 6

two main routes of excretion

Answer 6

renal excretion (the major route) - glomerular filtration > active tubular secretion > tubular reabsorption

biliary - large polar molecules reabsorbed from intestine and reenter bloodstream