Antidepressant drug interactions in the elderly. Understanding the P-450 system is half the battle in reducing risks.

Antidepressant treatment in patients 65 years of age or older carries increased risks of adverse drug events because of age-related physiologic changes, polypharmacy, and individual variability in drug metabolism (due to genetic factors, concurrent disease, diet, and consumption habits). Reduction of total drug burden, adjustment of dose levels, and careful selection of an appropriate agent are important steps toward avoiding adverse drug interactions, In addition, the documented and potential drug interactions of the various classes of antidepressants, and specific agents within each class, should be considered. Each elderly patient should be treated individually and monitored carefully during the initiation and maintenance of antidepressant therapy.