Pharmacology of Older Adults

Question 1

As we age how does absorption

Answer 1

Divalent cations (calcium, magnesium, iron) can affect absorption of many fluoroquinolones (e.g., ciprofloxacin)

Enteral feedings interfere with absorption of some drugs (e.g., phenytoin) - many patients are on PPIs which increase the stomach pH so they cannot be absorbed as readily

Increased gastric pH may increase or decrease absorption of some drugs–> C. diff

Drugs that affect GI motility can affect absorption - metochlopromide affects motility

Question 2

Effects of aging on Volume of Distribution

Answer 2

decreased body water leads to lower VD for hydrophilic drugs

decrease lean body mass leads to lower VD for drugs that bind to muscle

increased fat stores leads to higher VD for lipophilic drugs

decreased plasma protein (albumin) leads to higher percentage of drug that is unbound (active)

Question 3

Effects of aging on Metabolism

Answer 3

Metabolic clearance of a drug by the liver
may be reduced because aging decreases liver blood flow, size, and mass the liver is the most common site of drug metabolism

Question 4

Stay away from

Answer 4

*Benzodiazepines (Diazepam/Valium) - they remain more delirious

Question 5

Effects of aging on Elimination - what do you avoid?

Answer 5

older people have renal dysfunction - avoid NSAIDs because they impair the prostanglandin pathway that keeps the renal vessels open -decreased renal blood flow

Question 6

False normal serum creatinine number

Answer 6

Older people are leaner so their creatinine is lower but appears normal, masking the change int he serum creatinine
–>use Cockroft-Gault Equation or check their serum creatinine a

Question 7

Benzodiazepines

Answer 7

may cause more sedation and poorer psychomotor performance/ FALLS in older adults. Likely caused by reduced clearance of the drug and resultant higher plasma level
–changes from independent to Dependent

Question 8

Morphine

Answer 8

patients may experience higher levels of morphine with longer pain relief–> more delirious
–>start low, you can always increase

Question 9

Biggest problem category of drugs

Answer 9

Anticholinergics (Benadryl, Antipsychotics: Amytryptilline)

- cholinergic nerves decline as we age, as you give them anticholinergics you are adding on to the problem of Alzheimers --> delirium/confusion     * muscle relaxants are overused---> makes them      confused and more likely to fall

Question 10

Most common drug-drug interactions

Answer 10

cardiovascular
psychotropic drugs

leads to more confusion Confusion, Cognitive impairment, Arterial hypotension, Acute renal failure

Question 11

Drug Drug interaction: ACE inhibitor + diuretic/potassium leads to

Answer 11

Hypotension and hyperkalemia

*DO NOT give potassium supplements because they have decrease in GFR–don’t give them until it is necessary.

Question 12

Drug Drug Interaction: Benzodiazepine + antidepressant, antipsychotic, or benzodiazepine

Answer 12

Confusion, sedation, falls

Question 13

Which drugs should you not give to older people?

Answer 13

Benzos- falls, stroke
Magestrol - for CHF
Metochlopromide (gastroparesis in Diabetes–> Parkinson’s like tremors
Non-COX NSAIDs,
Anti-psychotics (Anticholinergics that reduced brain function) –> orthostasis
Insulin-sliding scale/ oral hypoglycemics –> hypoglycemia

Question 14

Furosemide and NSAID make people

Answer 14

Hypotensive - orthostatic hypotension
NSAID could also be causing gastritis, also affects his kidneys
Hyperkalemic

Question 15

ACE inhibitor + potassium

Answer 15

risk of Hyperkalemia