Block I - Geriatric

Question 1

Young old

Answer 1

65-75

Question 2

Middle old

Answer 2

75-85

Question 3

Old old

Answer 3

85+

Question 4

Pharmacokinetic changes in geris: absorption

Answer 4

Decreased gastic acidity, motility (usually doesn’t effect bioavailability)

Question 5

Pharmacokinetic changes in geris: distribution

Answer 5

Decrease TBW, lean body mass, plasma albumin, increase in adipose (increase in conc of free hydrophilic drugs, delayed clearance of lipophilic drugs, drugs stays in body longer)

Question 6

Pharmacokinetic changes in geris: metabolism

Answer 6

Decrease first pass metabolism and minor changes in phase I, phase II not affected (increased bioavailability of drugs, increased half-life of drugs, inducers/inhibitors/CYP450 system dynamics altered

Question 7

Pharmacokinetic changes in geris: elimination

Answer 7

Decreased renal blood flow and GFR (increased drug half-life when renal elimination is required); CrCl not reliable in geris because reduced lean muscle mass

Question 8

Pharmacodynamic changes in geris

Answer 8

Less sensitive to beta receptors, baroreceptors, insulin receptors, more sensitive to centrally activing drugs = adjust accordingly.

Question 9

How to avoid adverse effects in geris

Answer 9

Pt education (review meds), use resources (Beers, STOPP, etc) to evaluate appropriate use, avoid certain drugs (benzos, AChE, skeletal muscle relaxants = falls)

Question 10

Normal physiologic changes that affect: absorption

Answer 10

Gastric acidity and motility decrease = drugs take longer to absorbed, but bioavailability unchanged.

Question 11

Normal physiologic changes that affect: distribution

Answer 11

Less albumin = more free drug = start at low dose. Less lean body mass/lower TBW = increase in hydrophilic drugs in conc. Increase in adipose tissue = lipophilic drugs better absorbed = take longer to clear = pt’s age is half-life.

Question 12

Normal physiologic changes that affect: metabolism

Answer 12

First pass and phase 1 reactions slowed = not as much metabolized. Phase 2 unchanged.

Question 13

Normal physiologic changes that affect: excretion

Answer 13

Decreased renal blood flow and GFR = increased half-life = use Cockroft-Gault equation to calculate clearance

Question 14

Risks causing ADR in geris

Answer 14

Polypharmacy, drug dose (more than they can clear), duration of therapy (long period at high dose), pt conditions (dehydration, acute illness, renal function), changing pharmacodynamics/kinetics, narrow therapeutic index. Three check points: prescribe (clinician), dispense (pharmacist), administer (caregiver).

Question 15

Drugs to avoid in geris

Answer 15

Always: dronedarone, digoxin (>0.125mg), non-benzos, insulin sliding scale, glyburide, megestrol; Certain conditions: AChE inhibitors in syncope, nonbenzos in falls/fx; Use with caution: aspirin in primary prevention; Meds with strong AChE properties: antihistamines, TCA, first gen antipsychotics, antimuscarinics, antispasmodics, anti-Parkinson’s, skeltal muscle relaxants.

Question 16

Big drugs to avoid

Answer 16

Anticholinergic drugs, benzos, warfarin, digoxin (at high dose), lithium, skeletal muscle relaxants