04 Elderly

Question 1

Absorption

Answer 1

Decrease in small bowel SA
Slowed gastric emptying
Increase in gastric pH
Decreased calcium carbonate absorption
Increased levodopa absorption

Question 2

Distribution

Answer 2

Increase in body fat mass (inc Vd for lipophilic drugs)
Decrease total body water (dec Vd for hyrophilic drugs)
Dec albumin = inc ADRs
(acute illness) inc a-1 glycoprotein = dec drug effect

Question 3

Metabolism

Answer 3

Dec hepatic blood floow
Dec liver volume
Prolonged phase I rxns
Dec CYP450 metabolism
Dec first pass met = inc drug conc

Question 4

Elimination

Answer 4

Dec GFR = dec elimination
Normal creatinine (actually decreased but with sarcopenia)

Question 5

Pharmacodynamic changes

Answer 5

Drug-receptor interaction
Post-receptor events
Adaptive homeostatic responses
Pathologic organ change
Inc sensitivity (psychoactive drugs, antihypertensives, oral hypoglycemic agents)
Dec sensitivity (vasodilators, diuretics, bronchodilators): Furosemide, B-agonists, B blocker

Question 6

Anticholinergic effects

Answer 6

Central and peripheral effects

TCAs, sedating antihistamines, urinary antimuscarinics for OAB, antipsychotics, antiparkinsons

Question 7

Drug related problems in elderly

Answer 7

Drug ineffectiveness (under dosing or poor adherence)
ADRs
Drug-disease interaction (prescribing cascade)
Drug-drug interaction
Drug-food interaction
Inadequate monitoring of drug therapy (risk for ADR and ineffective therapy)
Inappropriate drug selection
Lack of pt adherence
Overdose
Under treatment

Question 8

ADR types

Answer 8

Type A: dose-related, predictable, avoidable

Type B: bizzare

Question 9

Drugs most commonly associated with ADRs

Answer 9

Warfarin
Antiplatelet agents
Hypoglycemic drugs
Insulin
Antipsychotics
Antidepressants
Sedative-hypnotics

Question 10

Drug-disease interaction

Answer 10

Dementia = amitriptyline = delirium
Peptic ulcer disease = aspirin = upper GI bleed
Diabetic nephropathy = ibuprofen = renal failure
Gout = hydrochlorothiazide = gout flares
Seizure = imipramine = lower seizure threshold

Question 11

Drug-drug interactions

Answer 11

Elanapril-mefenamic acid = hyperkalemia
Digoxin-furosemide = hypokalemia
Nitroglycerin-sildenaful = hypotension
Verapamil-atenolol = bradycardia, hypotension
Warfarin-aspirin = bleeding

Question 12

Drug-food interactions

Answer 12

Warfarin-kale/spinach = thrombotic events (inc vitamin K)
Insulin-beer = hypoglycemia (rise in plasma insulin)
Simvastatin-grapefruit: myopathy, inc transaminase (inhibit CYP3A4)
Digoxin-fiber = rapid HR
Ciprofloxacin-milk = dec antibiotic effect

Question 13

Most common class of potentially inappropriate medications (PIM)

Answer 13

NSAIDs

Question 14

PIM with highest rate of hospitalization

Answer 14

Ketorolac (non-selective for COX2)

Question 15

Factors to consider on using high risk drugs

Answer 15

Remaining life expectancy
Goals of care
Potential benefits of medications

Question 16

Steps in medication review

Answer 16

Verification (list of current medications)
Clarification and evaluation
Reconciliation (compare old and new drugs and changes)
Transmission