Chapter 7: Drug Therapy & Safety in Older Adults

As the population of older adults grows, healthcare professionals must address the prevalence of chronic conditions that often result in polypharmacy, typically defined as the simultaneous use of five or more prescription medications. The text details how physiological changes significantly impact the four stages of pharmacokinetics: drug absorption is slowed by diminished gastric acidity and blood flow; distribution is altered by a decrease in lean muscle and total body water alongside an increase in body fat; metabolism is hindered by reduced liver size and hepatic blood flow; and excretion is compromised by a natural decline in renal mass and glomerular filtration rates. These shifts often lead to prolonged drug half-lives and an increased risk of toxicity, making the "start low and go slow" dosing strategy a clinical necessity. Furthermore, pharmacodynamic changes, such as reduced receptor sensitivity and a more permeable blood-brain barrier, increase vulnerability to central nervous system side effects and adverse events like orthostatic hypotension. To improve patient safety, the chapter highlights the Beers Criteria for identifying potentially inappropriate medications and the BANDD CAMP mnemonic for monitoring drugs requiring renal dosage adjustments. Nursing professionals are identified as critical advocates who improve medication adherence by addressing barriers such as cognitive impairment, sensory deficits, and financial constraints through clear communication, simplified dosing schedules, and collaborative care coordination.