An older client is likely to have medications adjusted based on which pharmacokinetic process?

For older clients, the pharmacokinetic process that is most often adjusted relates to distribution. As people age, their body composition changes, which affects how drugs are distributed throughout the body. Specifically, older adults typically have a higher percentage of body fat and a lower percentage of lean body mass and total body water. This shift impacts the volume of distribution for both hydrophilic (water-soluble) and lipophilic (fat-soluble) medications.

For example, lipophilic drugs may have a prolonged half-life in older adults due to their increased fat stores, leading to a buildup of the drug in the body and a greater risk for side effects. Conversely, the distribution of hydrophilic drugs may be reduced due to lower lean body mass and total body water, potentially necessitating dose adjustments to avoid toxicity.

Metabolism and elimination processes are also critical in older adults but are often more influenced by hepatic and renal function respectively, which can vary significantly with comorbidities and medication regimen. Absorption may be altered as well, but this is less frequently the focus when managing medication therapy in the elderly compared to distribution-related adjustments. Understanding the changes in drug distribution in elderly patients is crucial for optimizing pharmacotherapy and minimizing adverse effects.