pharm 3: geriatrics

greatest factor that increases risk of AE of meds in older adults

polypharmacy - risk increases sharply with >4 meds

other risk factors for AE in older adults

Greater disease severity

Small body size

Hepatic or renal insufficiency

Use of high-risk drug classes (e.g., long-acting benzodiazepines, antihypertensives)

Altered PK/PD responses

aging itself is not usually an

independent risk factor for most AE

which pharmacokinetic factor is least affected by aging

absorption ; only minamally changed

how is absorption affected?

Slower gastric emptying

Reduced gastric acidity

Possible reduced splanchnic blood flow

distribution changes w/ aging with lipophilic drugs

↑ Body fat → ↑ volume of distribution of lipophilic drugs (e.g., benzos) → prolonged half-life

distribution changes with aging on water soluble drugs

↓ Total body water due to decreased lean body mass → ↑ concentration of water-soluble drugs (e.g., ethanol)

distribution changes with protein bound drugs

↓ Plasma albumin → ↑ free fraction of protein-bound drugs

which phase of metabolism is most affected by aging

Phase 1 oxidative metabolism

other changes in metabolism due to aging

↓ Liver mass

↓ Hepatic blood flow

↓ Phase I oxidative metabolism (CYP-dependent)

as phase 1 declines, drugs requiring _____ have _____

drugs requiring CYP oxidation have prolonged effects.

what are some examples of drugs that use CYP oxidation and will have prolonged effect?

Long-acting benzodiazepines (diazepam, chlordiazepoxide) → prolonged sedation

Antihypertensives processed via hepatic oxidation

Other Phase I–heavy drugs: warfarin, theophylline, phenytoin

____ metabolism is usually preserved

phase II (conjugation) usually preserved ; drugs using phase 2 are preferred.

renal elimination changes associated with aging include -

↓ GFR

↓ Renal blood flow

↓ Tubular secretion

renal changes will result in ______ of renally cleared meds

↑ Half-life of renally cleared meds (high clinical significance)

as pts age, they will have altered _____ and ____ leading to changes in drug _____ or _____

altered receptor number and sensitivity, leading to changes in drug sensitivity or responsivness

aging will cause patients to be more sensitive to what kind of drugs?

↑ Sensitivity to CNS depressants (opioids, benzodiazepines)

↑ Sensitivity to anticoagulants

patients will have decrease responsiveness to

β-agonists & β-blockers

↓ Homeostatic reserve → ↑ risk of

orthostatic hypotension, bradycardia

changes in baroreceptor reflex -->

↑ fall risk

age will especially effect activity of what kind of drugs?

anti-muscarinic drugs

common drugs/classes causing problems in elderly

Antimuscarinic/anticholinergic drugs – bladder meds (oxybutynin), 1st gen antihistamines, TCAs

Psychotropics – antipsychotics, benzodiazepines, sedative hypnotics

Opioids

NSAIDs

Antihypertensives (esp. alpha blockers → orthostasis)

Hypoglycemics (sulfonylureas → hypoglycemia risk)

what are some common drugs that CAUSE constipation?

Opioids

Anticholinergics

Calcium channel blockers (esp. verapamil)

Iron supplements

Antacids w/ aluminum or calcium

Antipsychotics

Diuretics (dehydration-related)

for constipation drugs - see constipation quizlet from GI module.

drugs used to improve cognition in alzheimer's disease

acetylcholinesterase inhibitors (AChEIs)

NMDA receptor antagonist

monoclonal antibody (new)

acetylcholinesterase inhibitors (AChEIs) include

Donepezil (aricept)

Rivastigmine (exelon)

Galantamine (razadyne)

AChEIs benefits -

modest improvement in cognition ; slow progression

AEs of AChEIs

N/V/D, bradycardia, syncope, ↑ hip fracture risk

drug interactions of AchEIs

anticholinergic drugs decrease effect

NMDA receptor antagonists include

memantine

memantine is used for

moderate - severe AD

memantine is commonly combined with

AChEIs

what are the AE of memantine

dizziness, confusion, insomnia, hallucinations, and delusions

monoclonal antibodies (new) include

aducanumab (aduhelm)

aducanumab (aduhelm) reduces

amyloid plaque

AE of aducanumab (aduhelm) include

cerebral edema, microhemorrhage

Anti-psychotics are ONLY used in older adults when there is

Schizophrenia

Schizoaffective disorder

Bipolar disorder (mania)

Parkinson's disease psychosis (pimavanserin)

anti-psychotics can be used for severe behavioral disturbances in dementia ONLY WHEN

danger to self/others or severe distress.

reasons for non-compliance in the elderly

Cognitive impairment

Visual/hearing impairment

Polypharmacy

Cost

Adverse effects

Physical limitations (arthritis → pill bottle difficulty)

Misunderstanding instructions

Depression

Lack of social support

with prescribing in elderly, start

low and titrate slowly

anti-cholingergics can worsen

worsen dementia, glaucoma, constipation, urinary retention

NSAIDS can worsen

worsen HTN, renal disease, CHF

benzodiazepines can worsen

worsen fall risk, cognitive impairment

alpha blockers can worsen

orthostatic hypotension

steroids can worsen

diabetes, osteoporosis