How does age impact pharmacokinetics?

Age significantly impacts pharmacokinetics primarily through changes in organ function and body composition. As individuals age, their physiological characteristics evolve, resulting in alterations that influence how drugs are absorbed, distributed, metabolized, and excreted.

For instance, age-related changes often include a decline in renal and hepatic function, which affects the clearance of drugs from the body. Older adults may exhibit decreased glomerular filtration rate (GFR) and liver size, leading to reduced metabolic capacity. Additionally, body composition shifts, such as increased body fat and decreased lean body mass and total body water, alter the volume of distribution for both hydrophilic and lipophilic drugs. This can lead to prolonged half-lives for certain medications and changes in drug concentrations, which necessitates careful adjustment of dosages.

Understanding these age-related pharmacokinetic changes is critical for healthcare providers to manage medication therapy safely and effectively in older patients, ensuring optimal therapeutic outcomes while minimizing the risk of adverse effects.