Adult-Gerontology Clinical Nurse Specialist (CNS) Practice Exam

What physiological aspect is crucial for understanding the effects of aging on drug absorption?

1. Reduced gastrointestinal blood flow

2. Increased liver volume

3. Enhanced renal function

4. Higher metabolic rate

The correct answer is: Reduced gastrointestinal blood flow

Understanding the physiological changes that occur with aging is essential for comprehending how these changes affect pharmacokinetics, particularly drug absorption. Aging often leads to reduced gastrointestinal blood flow, which is a significant factor in drug absorption. As individuals age, there can be a decline in cardiovascular health, which may manifest as decreased blood flow to the gastrointestinal tract. This reduction in blood supply can ultimately impact the rate and extent of drug absorption from the gastrointestinal system into the systemic circulation. When blood flow is diminished, it can result in slower and sometimes incomplete absorption of oral medications. This is particularly important for drugs that rely on rapid absorption to achieve their therapeutic effects. In contrast, other factors such as increased liver volume, enhanced renal function, and a higher metabolic rate are not typically associated with aging. In fact, aging often results in decreased liver size and function, along with compromised renal function, which affects drug clearance rather than absorption directly. Furthermore, metabolic rates generally decline with age, influencing the overall pharmacokinetics but not specifically focusing on the absorption phase. Thus, the understanding of reduced gastrointestinal blood flow is vital for clinicians managing medication regimens in older adults.