Lecture 23: Drug Therapy in Geriatrics

Question 1

Why is geriatrics a unique specialty?

Answer 1

changes associated with primary aging
secondary aging
multimorbidity
geriatric syndromes
multiple medications
setting of care
policy decisions
psychosocial issues
ethics (and advocacy)

Question 2

What is the definition of life span?

Answer 2

greatest age reached by any member of a species

Question 3

What is the definition of life expectancy?

Answer 3

greatest age reached by members of a population

Question 4

What are the age categories within older adults?

Answer 4

young-old (65-74)

middle-old (75-84)

old-old (85+)

Question 5

What is a centenarian?

Answer 5

someone who has lived to be 100 years

Question 6

What is a super centenarian?

Answer 6

someone who has lived to be 110 years

Question 7

What is a semi-supercentenarian?

Answer 7

someone aged 105-109 years

Question 8

What are the heath care considerations for geriatrics?

Answer 8

chronic conditions

76% of seniors have at least 1 chronic condition

Question 9

What is multimorbidity?

Answer 9

associated with age

linear associated with number of medications

Question 10

What is frailty?

Answer 10

a state of increased vulnerability from age-associated decline in reserve and function resulting in reduced ability to cope with everyday or acute stressors

no universally agreed upon definition

Question 11

What is the pathophysiology of frailty?

Answer 11

a gradual decrease in physiological reserve occurs with aging

in frailty, this decrease is accelerated and homeostatic mechanisms start to fail

Question 12

What is the definition of geriatric syndrome?

Answer 12

a multifactorial condition that involves the interaction between identifiable situation-specific stressors and underlying age-related risk factors, resulting in damage across multiple organ systems

Question 13

What are key features of geriatric syndrome?

Answer 13

clinical and multifactorial conditions in older persons

associated with poor heath outcomes

do not fit into disease categories (comorbidities)

require a multidimensional treatment approach

Question 14

What are the risks of geriatric syndromes?

Answer 14

clinical conditions that do not fit a disease category

multi-factorial, multi-system

Question 15

What are potentially inappropriate medications?

Answer 15

also identified as “PIM”

a medication or medication class where harm outweighs the benefit, and there are safer alternatives available

the Beers Criteria are explicit

the Beers Criteria are used by CIHI to identify PIM

Question 16

What is the goal of medication safety?

Answer 16

reduce severe, avoidable medication-related harm by 50% over 5 years

Question 17

What are the priority actions of medication safety?

Answer 17

high risk situations; includes children, older adults

polypharmacy

transitions in care

Question 18

Who is at risk for adverse drug reactions?

Answer 18

people with multiple chronic conditions

women

people over the age of 65

Question 19

What is the definition of polypharmacy?

Answer 19

literal definition: 2 or more medications

most commonly accepted definition in practice: 5 or more medications (Rx or OTC)

the use of 2 or more drugs without indications or for the same purpose

the use of a drug to treat the adverse reactions of another drug

the use of 2 or more drugs from the same class to treat different indications

clinically meaningful: when a medication is not needed

Question 20

What are prescribing cascades?

Answer 20

use of one drug to treat the adverse effects of another

Question 21

What are potential prescribing omissions (PPO)?

Answer 21

undertreatment

not prescribing medications to patients who would benefit

often seen in patients with polypharmacy

Question 22

What are examples of potential prescribing omissions?

Answer 22

statins for lipid management

anticoagulation for AF

LMWH for venous thromboprophylaxis

osteoporosis treatment

recent studies of hospitalized patients show 83% admitted had a PPO per START criteria

Question 23

What are different forms of aging?

Answer 23

chronological aging
physiologic aging
social age
legal age
functional age

Question 24

What is aging?

Answer 24

is NOT synonymous with disease

changes are experienced by all human beings

some changes may be due to lifestyle choices, social determinants of health, exposure to particular chemicals, etc.

Question 25

What is physiological aging?

Answer 25

each organ system has changes associated with aging, which often start in the 5th decade

implications of these changes include:
reduced tissue/organ function
functional decline
increased susceptibility to disease
change in behavior
differences in PK and PD

Question 26

What are physiological changes associated with aging?

Answer 26

body composition: increased fat

CV: decreased cardiac output, decreased beta sensitivity

Renal: decreased GFR, decreased nephrons

GI: decreased H+, increased gastric emptying time

Hepatic: decreased size, decreased blood flow

Nervous: decreased blood flow to CNS

Pulmonary: decreased cilia

Endocrine: decreased hormonal secretions

Question 27

What are the effects on body composition that occur when aging?

Answer 27

loss of muscle mass: start ~age 40, accelerates in 6th decade (i.e. 50’s), by age 90, a person has half their muscle mass, some changes may be due to inactivity vs. physiologic aging

function and quality of muscle changes, along with neural stimulation, which slows

fat mass increases

Question 28

What are the physiological changes to absorption in the GI tract?

Answer 28

increased gastric pH

decreased gastric acid secretion

decreased GI blood flow

decreased gastric surface area

decreased GI motility

Question 29

What are the PK implications of the physiological changes to absorption in the GI tract?

Answer 29

potential for delay in absorption

minimal impact on extent of absorption of passively absorbed drugs

active transport (e.g. B12, iron, calcium) may be reduced

Question 30

What are the physiological changes to absorption in the IM, topical?

Answer 30

decreased blood flow

decreased skin hydration

Question 31

What are the PK implications of the physiological changes to absorption in the IM, topical?

Answer 31

slower, erratic, or lower absorption (e.g. antibiotics)

NB in immobile patients

higher absorption of topical steroids

NB if occlusive dressings

Question 32

What is absorption of drugs in older adults?

Answer 32

most drugs are well absorbed in older adults

rate of absorption may be delayed in some patients

this is relevant for some treatments, e.g. immediate release levodopa, analgesia

drug absorption can also be affected by other conditions or medications

Question 33

What is distribution of drugs in older adults?

Answer 33

distribution can be altered by aging or other disease states

lipid soluble drugs show an increase in Vd

protein changes with aging are insignificant and rarely have an impact on drug therapy

protein changes often occur with concurrent illness, not aging

Question 34

What is metabolism of drugs in older adults?

Answer 34

drugs metabolized by Phase 2 are preferred in older adults

for medications oxidatively metabolized, reduce dose

multiple medications can have more dramatic drug interactions if impacting CYP P450

metabolism can be dramatically affected by illness, particularly acute illness

other factors affecting metabolism include chronic illness, genetics, diet, smoking, EtOH use

Question 35

What is the elimination of drugs in older adults?

Answer 35

decreased renal elimination of drugs is the single most clinically significant change in PK due to aging

the majority of drug dosage adjustments in older adults are due to renal function

note: decreased muscle mass in frail older adults

CrCl is an estimate

Question 36

What are changes to pharmacodynamics in older adults?

Answer 36

altered homeostatic balance manifested in a stress environment

change in homeostatic regulation

change in receptor responsiveness: change in receptor density, change in receptor affinity, post-receptor changes, change in negative feedback

implications: increased sensitivity to drugs

Question 37

What are changes to the CNS in older adults?

Answer 37

higher cognitive function

mechanism: neuronal loss, receptor downregulation

examples: central anticholinergics, stimulants

Question 38

What are changes to postural in older adults?

Answer 38

mechanism: fewer dopamine (D2) receptors in striatum

examples: antipsychotics, metaclopramide

Question 39

What are changes to movement in older adults?

Answer 39

tardive dyskinesia

mechanism: impaired or decreased dopamine synthesizing neurons

examples: dopamine blockers, antipsychotics, anti-emetics (metoclopramide)

Question 40

What are changes to blood pressure in older adults?

Answer 40

orthostasis

mechanism: blunting of beta response, receptor down-regulation, changes in vascular tree and autonomic nervous system

examples: BP meds, TCA, antipsychotics, diuretics

Question 41

What are changes to CV in older adults?

Answer 41

arrhythmias

mechanism: cardiac hypersensitivity

examples: antiarrhythmic medication

Question 42

What are changes to coagulation in older adults?

Answer 42

anticoagulation

mechanism: poor hepatic production of coagulation factors, dietary intake

examples: anticoagulants, thrombolytics

Question 43

What are changes to visceral muscle in older adults?

Answer 43

mechanism: visual disturbances (pupillary autonomic responses)

bladder instability (detrusor contractions)

intestinal motility decreased

examples: anticholinergics

Question 44

What are changes to temperature in older adults?

Answer 44

thermoregulation

mechanism: poor temperature regulating mechanisms

examples: meds affecting awareness, mobility, muscular activity, vasoconstrictor mechanisms; CNS meds