Medication Management in the Elderly

Question 1

What is pharmacokinetics?

Answer 1

• “What the body does with the drug”
• Absorption
• Distribution
• Metabolism
• Excretion

Question 2

What is pharmacodynamics?

Answer 2

• “What the drug does to the body”

- Receptors (blocked or stimulated)

Question 3

What are some age related changes that changes medication management in the elderly?

Answer 3

• Drug-receptor interactions (brain receptors more sensitive)
• Liver mass shrinks
• Hepatic blood flow and enzyme activity decline (prolonging drug half-life)
• Dropped metabolism
• Gastric emptying rate and motility slow
• Absorption capacity of active transport mechanisms decline
• Vascular nerve control less stable
• Decline in kidney function d/t decreased renal blood flow, decreased GFR, decreased # of nephrons
• Blood flow and waste removal slow
• Lengthened half-life for renal excreted drugs
• Increased adipose tissue, lean body mass falls
• Total body water declines, raising concentration of water-soluble drugs
• Plasma protein diminishes, raises blood levels of free drug
• Drugs can overshoot (e.g. anti-hypertensives drop BP too low, digoxin slowing HR too much)

Question 4

What drug interactions slow absorption?

Answer 4

• Combinations of drugs wherein one drug affects absorption of the other (i.e. antacids, Ca, Mg, Al ions bind to object drug decreasing effect of same
• Free fraction effect: drugs binding ++ to protein
• Decreased albumin production and aging liver = rise in free fraction in blood, leading to increase in toxic side effects (e.g. malnutrition, uremia, DM, acute nephrotic syndrome, etc.)

Question 5

How does slowed liver metabolism impact drugs in the elderly?

Answer 5

• Aging causes liver function to diminish (e.g. drug catabolization declines)
• Active drug or metabolites remain in body longer (e.g. long acting benzos)
• May result in excessive sedation

Question 6

Describe renal function decline in the elderly:

Answer 6

• Renal function declines with age (e.g. creatinine clearance declines 10% q decade after 40 years)
• Creatinine clearance 30 ml/min or below = risk of accumulation of drug/metabolites nephrotoxic to kidney functioning (e.g. gentamycin)
• Initial renal function level and ongoing peak and trough level monitoring essential to prevent irreversible kidney damage/hearing loss/balance disturbances
• Drugs like antibiotics **, NSAID’s, and ACE inhibitors hard on kidneys
• Elderly dehydrate easily, which can further affect creatinine levels and eGFR

Question 7

What is the difference between rational vs. irrational polypharmacy?

Answer 7

RATIONAL: conscientious, minimal use of multiple drugs, diligent pt follow up

IRRATIONAL: inappropriate use of multiple drugs (e.g. going to walk in clinics with no thorough assessment of other meds), risks outweigh the benefits

Question 8

What are the roots of irrational polypharmacy?

Answer 8

• Prescriber hesitates to d/c meds patient has been taking for a long time, so list grows as more meds are added
• Prescriber orders meds to alleviate adverse reactions to other meds
• Pt influenced by anecdotal reports re: benefits of certain meds

Question 9

Describe alternative pharmacotherapy:

Answer 9

• 40%+ use alt. pharmacotherapy (e.g. herbal remedies unbeknownst to HC providers)
• Many people believe natural/alternative medications are reputable and safe
• Ex. Gingseng, ginko biloba, garlic, St John’s wort, etc.

Question 10

Describe potentially inappropriate medication use in older adults:

Answer 10

• Beers Criteria, updated in 2015 by American Geriatrics Society
• Intended for:
• Use in all ambulatory, acute, institutionalized settings
• Adults 65+ of age
• Palliative and hospice settings excluded
• Improve care of older adults by reducing exposure to PIM’s (potentially inappropriate medications)

Question 11

What are some potentially inappropriate medications and drug-drug interactions in the elderly?

Answer 11

• Anticoagulants
• Anticholinergics
• Cardiac glycosides
• Antihypertensive agents
• Antimicrobials
• Antipsychotics, anxiolytics, antidepressants, benzodiazepines
• NSAID’s
• Laxatives
• Antacids
• Long acting oral hypoglycemics
• Opioid analgesics
• Diuretics

Question 12

What is the nurses role in managing medications in the elderly?

Answer 12

• Complete a thorough history including drug/alcohol consumption
• Ensure medication reconciliation complete on admission, transfer, and discharge (herbs, OTC, vitamins)
• Know the therapeutic aim of the drug and how it will be measured
• When is the outcome to be reviewed?
• What adverse effects might be expected and their significance?
• How will the drug be monitored? (i.e lab values)
• Teach about medication hazards
• Institute non pharmacological approaches prn
• Individualize patient education to patient/family (oral/written)

Question 13

What are principles of geriatric prescribing?

Answer 13

• Titrate dosage with pt. response (e,g, “start low and go slow’)
• Simplify therapeutic regimen
• Encourage regular pharmacy med reviews
• Encourage use of one pharmacy only
• Consider safest dispensing (e.g. med machine, blister packs)
• Monitor compliance
• Avoid pharmacology whenever possible try non-pharmacological approaches