How does age affect drug metabolism?

Age plays a significant role in drug metabolism, primarily through its effects on liver and kidney function. As individuals age, there can be physiological changes that affect how drugs are processed in the body. For instance, liver function can decline with age, leading to reduced enzyme activity responsible for metabolizing many drugs. This can result in slower metabolism and longer half-lives for certain medications, potentially necessitating dosage adjustments to avoid toxicity.

Similarly, kidney function often decreases with age, which can impair the excretion of renally-cleared drugs. Impaired renal function can accumulate drugs or their metabolites in the system, increasing the risk of adverse effects. These variations in liver and kidney function in older adults underscore the need for careful consideration of pharmacotherapy in this population.

The other options do not address the physiological changes that occur with age that directly influence drug metabolism, making option C the most accurate in reflecting the impact of age on how drugs are processed in the body.