Symposium on geriatrics--Part I: Drug prescribing for elderly patients

To describe the pharmacokinetic and pharmacodynamic changes that occur with aging and to discuss common problems noted with the use of medications often prescribed for elderly patients.

We searched the medical literature, reviewed pertinent articles, and summarized drug-related information applicable to geriatric patients.

Use of medications is common in the elderly population; most elderly persons take two or more different medications each day. Aging is associated with anatomic and physiologic changes that can have an effect on how medications are handled. Such changes include alterations in various volumes of drug distribution and in drug absorption, metabolism, and clearance. Elderly patients may also have increased or decreased drug effects because of alteration in receptor response. These changes in pharmacokinetics and pharmacodynamics may result in a prolonged drug half-life, an increased potential for drug toxicity, and a greater likelihood for adverse drug reactions.

Medications for elderly patients should be prescribed only after the anatomic and physiologic changes of aging are understood and with increased surveillance for potential drug toxicity or adverse drug reactions.