Pharmacology

Question 1

What are guidelines used in prescribing for older people?

Answer 1

1. Problem oriented prescribing
2. Keep drug regimen simple
3. Start low and go slow
4. Avoid polypharmacy
5. Consider potential drug interactions
6. Provide patients with clear instructions
7. Review regularly

Question 2

What are some physiologic effects of aging that will impact pharmacological intervention?

Answer 2

1. Vision - may not see what you are showing them
2. Hearing - may not hear what you are telling them
3. GI - Xerostomia = dry mouth: contributes to tooth decay, impaired taste, impaired ability to chew & swallow

Question 3

Pharmacokinetics = ADME

What factors of older adults affect Absorption?

Answer 3

1. Decreased gastric acidity
2. Increased GI transit time
3. Decreased blood flow to muscle
4. Decreased skin hydration and increased keratinized cells

Question 4

Pharmacokinetics = ADME

What factors of older adults affect Distribution?

Answer 4

Altered levels of plasma proteins (Albumin)

- Less protein bound drug results in increased levels of “free” or “active” drug

Question 5

Pharmacokinetics = ADME

What factors of older adults affect Metabolism?

Answer 5

1. Decreased liver mass and blood flow

2. Decreased enzyme activity

Question 6

Pharmacokinetics = ADME

What factors of older adults affect [Renal] Elimination?

Answer 6

1. Decreased renal mass
2. Decreased glomerular filtration and tubular secretion
3. Decreased renal blood flow
   - Beginning in the 4th decade, a 6-10% decrease in GFR and renal plasma flow occurs every 10 years
   - By age 70, a 40-50% decrease in renal function may have occurred even in the absence of renal disease

Question 7

What are the characteristics of high risk drugs in the elderly?

Answer 7

1. Drugs excreted primarily by the kidney
2. Drugs metabolized in the liver (not as much of a worry as kidneys)
3. Drugs with a narrow
   therapeutic window
4. Drugs which act on the CNS
5. Drugs with pharmacologic effects that over-burden the body’s homeostatic mechanisms

Question 8

What are factors predisposing the elderly to ADRs?

Answer 8

1. Multiple and more frequent drug use
2. Multiple drug affects
3. Physiologic changes associated with aging

Question 9

What are common ADRs experienced by the elderly?

Answer 9

1. Hyperkalemia
2. Cardiac arrhythmias
3. Hypokalemia
4. GI complaints
5. Dehydration–>Dizziness
6. Urinary retention
7. Orthostatic hypotension
8. Cognitive impairment
   - other ADRs: Diarrhea, Constipation, Incontinence, Sexual dysfunction, Falls, CNS changes
   - Often over-looked as age-related changes occur; Attributed to “old age”

Question 10

What drug classes commonly cause ADRs in elderly?

Answer 10

1. Psychotropic drugs: antipsychotics, anxiolytics, sedatives, antidepressants
2. Cardiovascular: antihypertensives, antiarrhythmics, diuretics
3. Hypoglycemic agents
4. Analgesics
5. Antimicrobials

Question 11

Symptoms include dizziness, light-headedness, faintness and feelings of weakness or unsteadiness; Drugs may be the single most important contributing factor

Answer 11

postural hypotension

Question 12

What are the peripheral effects of anticholinergics?

Answer 12

1. dry mouth
2. constipation
3. blurred vision
4. urinary retention
   - peripheral effects are more common

Question 13

What are the central effects of anticholinergics?

Answer 13

1. labile mood
2. confusion
3. psychosis
4. disorientation
5. insomnia
6. ataxia
7. agitation
8. restlessness
9. impaired memory

Question 14

What factors lead to polypharmacy?

Answer 14

1. Determinants of polypharmacy
2. Concurrent, chronic medical conditions
3. Attitudes of health care professionals
4. Patient attitudes

Question 15

What are the consequences of polypharmacy?

Answer 15

1. Unnecessary drugs
2. Non-compliance
3. Medication errors
4. ADRs/side effects
5. Drug Interactions
6. Physiological vulnerability
7. Increased health care costs