M in ADME

Question 1

what is drug metabolism?

Answer 1

drug clearance

forming one or more new chemical entities (metabolites)

Question 2

what may the drug metabolite be?

Answer 2

1. equal/increased pharmacological activity
2. cause toxic effects
3. no/reduced activity
4. interact with drugs

Question 3

what are the sites of drug metabolism?

Answer 3

-small intestine
-skin
-lungs
-kidney
-liver

Question 4

what are the types of metabolic reactions?

Answer 4

phase 1
phase 2

Question 5

what do phase 1 metabolic reactions catalyse?

Answer 5

drugs become more hydrophilic and polar

Question 6

what do phase 2 metabolic reactions catalyse?

Answer 6

drugs conjugated to allow easy excretion

Question 7

what are types of phase 1 reactions?

Answer 7

Question 8

what are cytochrome P450 (CYP450) enzymes?

Answer 8

Question 9

what is the most common subtype of CYP450?

Answer 9

CYP3A

Question 10

what do phase 2 reactions occur to?

Answer 10

carboxyl/hydroxyl/amino/sulfhydryl groups

Question 11

what phase 2 conjugations do they form with?

Answer 11

glucuronic acid, glutathione, amino acid

Question 12

what are the common enzymes of phase 1&2?

Answer 12

Question 13

what are the factors affecting drug metabolism?

Answer 13

-age
-genetics

Question 14

how does age affect drug metabolism?

Answer 14

metabolic pathways mature at different rates
-liver mass and blood flow decreases with age = decreased hepatic metabolism

Question 15

how does genetic factors affect drug metabolism?

Answer 15

1. CYP metaboliser effects - poor/intermediate/extensive/ ultrarapid
2. genetic polymorphisms of CYP
3. CYP expressions between individuals/ethnic groups