EXAM #5: GERIATRIC PHARMACOLOGY Flashcards Preview

Pharmacology > EXAM #5: GERIATRIC PHARMACOLOGY > Flashcards

Flashcards in EXAM #5: GERIATRIC PHARMACOLOGY Deck (33):
1

What are four methods to achieve successful pharmacotherapy in the geriatric population/ prevent the prescribing cascade.

1) Avoid prescribing new drugs until tests confirm diagnosis
2) Start low and titrate up
3) Avoid starting or changing multiple medications at once
4) Reach TD before switching or adding new agents

2

What are the tools used to evaluate appropriate medication use in the elderly?

1) Beers List
2) STOPP
3) START

- STOPP= Screening Tool of Older Persons' potentially inappropriate Prescriptions
- START= Screening Tool to Alter doctors to Right Treatment

3

What body composition changes in the elderly can result in altered pharmacokinetics?

1) Decreased TBW
2) Decreased lean body mass
3) Increased body fat

4

What cardiovascular changes in the elderly can result in altered pharmacokinetics?

1) Decreased sensitivity to B-adrenergic stimulation
2) Decreased baroreceptor activity
3) Decreased CO
4) Increased TPR

5

What liver changes in the elderly can result in altered pharmacokinetics?

1) Decreased hepatic size
2) Decreased hepatic blood flow

6

What renal changes in the elderly can result in altered pharmacokinetics?

1) Decreased GFR
2) Decreased RBF
3) Decreased filtration fraction
4) Decreased tubular secretory function
5) Decreased renal mass

7

What happens to first pass metabolism with aging?

Less first pass metabolism

8

What happens to drug distribution with aging?

Differences in body composition lead to altered distribution

9

What happens to drug metabolism and clearance with aging?

Reduced liver and kidney function/ blood flow impairs metabolism and clearance

10

What are the implications of less first pass metabolism in the geriatric population?

1) LOWER dose requirements for drugs INACTIVATED by first pass metabolism
2) HIGHER dose requirements for PRODRUGS that require first pass metabolism for activation

11

What does a large Vd indicate?

Most of the drugs DISTRUBUTES to the extravascular compartment

12

How is Vd altered in the elderly? What will happen with the adminstration of a lipophilic drug?

High fat mass and low lean body mass INCREASE the Vd

Thus, there is an increased Vd in the elderly--especially with lipophillic drugs

13

What is the effect of lower TBW in the elderly in regards to water soluble drugs?

Less TBW= lower Vd (more drug stays intravascular)

14

How does a large Vd affect the half-life of a lipid-soluble drug? Give an example of a drug that follows this pattern.

A large Vd INCREASES the half-life

*Digoxin

15

How does a low Vd of a water soluble drug alter the loading dose? Give an example of a drug that follows this pattern.

Loading dose would be DECREASED to prevent toxicity

*Genatmicin

16

What is drug clearance? What is the equations for clearance?

Rate of elimination of a drug

CL= Q (flow) x E(extraction)

17

What are the two major organs are involved in drug clearance?

Liver
Kidneys

18

How is hepatic clearance altered in elderly patients?

1) Decreased flow to liver
2) Decreased liver metabolism/ extraction
- Phase I enzymes have REDUCED activity (CYP p450)


Thus, reduced drug clearance

19

Which phase of liver metabolism is most affected by aging?

Phase I i.e. CYP p450

20

What is a capacity-limited drug? What are the implications in the elderly?

Rate-limiting step in clearance is liver enzymes (vs. flow)

*There will be decreased clearance of a capacity-limited drug if metabolized by Phase I enzymes*

21

What is a flow-rate limited drug? What are the implications in the elderly?

Rate-limiting step in clearance is hepatic blood flow

*All drugs that are flow limited will have decreased clearance in the elderly*

22

What are the implications of less drug clearance on maintenance dosing the the elderly?

Generally, less maintenance doses are needed to maintain a steady state drug concentration

23

What is the exception to changes in maintenance doses seen in the elderly?

No change seen in capacity-limited, phase II metabolized drugs

24

Why is renal excretion decreased in the elderly?

1) Decreased GFR
2) Polypharmacy causes competition at tubular transporters

25

Generally, what is the marker used to determine GFR?

Creatinine

26

What is creatinine directly proportional to?

Lean muscle mass

27

How does creatinine change in elderly patients?

Less lean body mass= less creatinine

28

What is the Cockcroft and Gault equation?

Equation that accounts for decreased muscle mass in elderly when calculating GFR based on creatinine

29

How do decreased hepatic and renal drug clearance in elderly patients alter the T1/2? What type of drug will see the largest change?

- Decreased clearance INCREASES half-life
- Lipophilic drugs have further increases in half-life b/c of increased Vd

30

What do you need to keep in mind about NSAIDs in the elderly?

Elderly patients are highly susceptible to toxicity of NSAIDs

31

Explain how NSAIDs can lead to renal damage in the elderly.

- RBF is reduced in elderly
- PGs are secreted to maintain blood flow/GFR
- NSAIDs BLOCK PGs

32

What can the effects of anticholinergic drugs lead to in the elderly?

Overall functional decline from:
1) Falls
2) Impaired congnition

33

What drug classes have anticholinergic activity that may lead to functional decline in the elderly?

Anticonvulsants
Antidepressants
Antihistamines
Antipsychotics
CV
GI/GU antispasmodics
H2 antagonists
Muscle relaxants
PD drugs
Vertigo

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