Geriatrics: Pharmacology & Polypharmacy

How does the ratio of body fat to lean muscle mass typically change in geriatric patients, and how does this affect lipophilic drugs?

Body fat increases while lean muscle mass decreases; this increases the volume of distribution (Vd) for lipophilic drugs, prolonging their half-life.

What is the most common clinical definition of polypharmacy?

The concurrent use of five or more medications by a single patient.

Which physiological change in the aging kidney most significantly impacts the clearance of water-soluble drugs?

A decrease in the Glomerular Filtration Rate (GFR).

What is the primary purpose of the Beers Criteria published by the American Geriatrics Society?

To identify potentially inappropriate medications (PIMs) that should generally be avoided or used with caution in older adults.

How does a decrease in serum albumin levels affect the pharmacokinetics of highly protein-bound drugs like warfarin?

It increases the free (active) fraction of the drug in the plasma, which can lead to increased drug effects and toxicity.

Why are long-acting benzodiazepines (e.g., diazepam) specifically listed as high-risk in the Beers Criteria?

They have a prolonged half-life in the elderly, significantly increasing the risk of falls, fractures, and prolonged sedation.

List three common clinical manifestations of high anticholinergic burden in a geriatric patient.

Common manifestations include dry mouth, constipation, urinary retention, blurred vision, and acute confusion or delirium.

What is the functional difference between the STOPP and START criteria in geriatric medication review?

STOPP identifies potentially inappropriate medications that should be discontinued, while START identifies indicated medications that are often omitted.

Why are NSAIDs particularly risky for geriatric patients with a history of heart failure or chronic kidney disease?

They inhibit prostaglandins, leading to sodium/water retention and reduced renal blood flow, which can exacerbate both conditions.

According to the modified WHO pain ladder for geriatrics, what is the preferred first-line agent for mild chronic musculoskeletal pain?

Acetaminophen (Paracetamol), typically limited to a maximum of 3 grams per 24 hours to avoid hepatotoxicity.