Geriatric PK/PD: Metabolism

Question 1

Major site of metabolism

Answer 1

Liver

Question 2

Liver and prodrugs

Answer 2

liver metabolizes them to the active form (ex: ACEis)

Question 3

Variability in metabolism at the liver

Answer 3

depends on blood flow, enzyme activity, size, number of hepatocytes, damage

Question 4

Metabolism in general for elderly patients

Answer 4

In general, metabolism may be decreased in older patients; decrease in metabolism → less of active med in the system

Question 5

3A4 activity in older patients

Answer 5

Reduced

Question 6

2D6 activity in older patients

Answer 6

Not affected

Question 7

Drugs metabolized by 2D6

Answer 7

Desipramine, metoprolol, mexiletine, timolol

Question 8

Phase I metabolism: what processes are decreased?

Answer 8

Hydroxylation, methylation

Question 9

Drugs that get metabolized via hydroxylation

Answer 9

alprazolam, midazolam, quinidine, propranolol, triazolam, r-warfarin

Question 10

Drugs that get metabolized via demethylation

Answer 10

imipramine, sertraline, verapamil, theophylline

Question 11

Phase II metabolism: processes that are unchanged

Answer 11

Glucuronidation, acetylation

Question 12

Drugs metabolized via glucuronidation

Answer 12

oxazepam, lorazepam, temazepam

Question 13

Drugs metabolized via demethylation

Answer 13

isoniazid

Question 14

Drug classes that the elderly may not metabolize well

Answer 14

BZDs, CCBs, NSAIDs, fentanyl, imipramine, labetalol

Question 15

What happens to liver mass and volume as you age?

Answer 15

Decreases

Question 16

Slow metabolizers and ADRs

Answer 16

More susceptible to ADRs b/c meds aren’t eliminated as quickly

Question 17

Induction in the elderly

Answer 17

No generalizations, some shows that the effect is reduced in the elderly

Question 18

Inhibition in the elderly

Answer 18

No apparent change of effect with age

Question 19

Frality effects

Answer 19

Clearance is reduced