Changes in Pharmacodynamics
Pharmacodynamic considerations include receptor number and affinity, signal transduction mechanisms, cellular responses, and homeostatic regulation. Sensitivity to certain drugs may be either increased or decreased in the elderly, e.g., sensitivity to benzodiazepines is greater in older patients, as is the response to some opioids and anticoagulants.
Conversely, the elderly seem to be less responsive to certain β-adrenoceptor agonists and antagonists. Simons, et al. studied H1-receptor sensitivity to hydroxyzine by measuring changes in suppression of histamine-induced wheal and flare and suggested an enhanced suppression of H1-receptor activity in the elderly. Printer- Friendly Email This