Lecture 44: Prescribing in geriatrics

What age-related GI changes can affect drug absorption in older adults?

Delayed gastric emptying and altered GI pH can change the onset of action for certain medications

How does delayed gastric emptying impact medications?

It slows the onset of action and may increase stomach exposure to irritant drugs

How does increased body fat in older adults affect drug distribution?

It increases the volume of distribution for lipophilic drugs, prolonging their half-lives

What age-related metabolic change most affects drug metabolism?

Reduced hepatic metabolism due to decreased liver size and blood flow

This decreases clearance of hepatically-metabolized drugs, often requiring dosage adjustments

What major excretory change occurs with aging and why is this significant?

Renal function declines, leading to reduced glomerular filtration rate (GFR)

Drugs eliminated renally may accumulate, requiring monitoring and dose adjustments

What is tissue sensitivity, and why is it relevant in older adults?

Older adults may have heightened sensitivity to certain drugs, such as benzodiazepines, increasing adverse effects

What is a prescribing cascade?

A situation where side effects from one medication lead to prescribing additional medications, increasing ADE risk

How does delayed gastric emptying affect naproxen in older adults?

Naproxen stays in the stomach longer, increasing risk of irritation, ulcers, and upper GI bleeding

Why does naproxen have increased effects and toxicity risk in older adults?

Lower serum albumin results in more unbound (active) naproxen, enhancing effects and side-effects at normal doses

How does reduced renal function affect naproxen elimination?

It slows clearance, prolongs half-life, and increases risk of toxicity

What adverse effects of naproxen become more likely in older adults?

GI bleeding, renal injury, hypertension, and cardiovascular complications

What alternatives exist for safer benzodiazepine use in older adults?

Either prolong time between doses, switch to temazepam, oxazepam, or lorazepam, or deprescribing entirely

What is the purpose of the Beers Criteria?

It identifies potentially inappropriate medications for older adults based on updated evidence

What are the START/STOPP criteria used for?

To guide clinicians on which medications to start or stop, improving prescribing safety in older adults