Pharmacodynamics in Older Adults

ByJ. Mark Ruscin, PharmD, FCCP, BCPS, Southern Illinois University Edwardsville School of Pharmacy;
Sunny A. Linnebur, PharmD, BCPS, BCGP, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado
Reviewed/Revised Jul 2021
View Patient Education

    In contrast to pharmacokinetic effects, pharmacodynamics is defined as what the drug does to the body or the response of the body to the drug; it is affected by receptor binding, postreceptor effects, and chemical interactions (see Drug–Receptor Interactions). In older adults, the effects of similar drug concentrations at the site of action (sensitivity) may be greater or smaller than those in younger people (see table Effect of Aging on Drug Response). Differences may be due to changes in drug-receptor interaction, postreceptor events, or adaptive homeostatic responses and, among frail patients, are often due to pathologic changes in organs. However, clinical differentiation between pharmacodynamic and pharmacokinetic effects can sometimes be difficult.

    Table
    Table
    quizzes_lightbulb_red
    Test your KnowledgeTake a Quiz!
    Download the free MSD Manual App iOS ANDROID
    Download the free MSD Manual App iOS ANDROID
    Download the free MSD Manual App iOS ANDROID