Psychotropic medications present special problems in the elderly because of altered pharmacokinetics and pharmacodynamics. Aging is associated with changes in absorption, distribution, and elimination of medications. Pharmacodynamic changes refer to alterations in end-organ responsiveness occurring with aging. Common problems that further complicate psychotropic drug use in the elderly include polypharmacy, compliance, lack of specific diagnosis, and concomitant physical illness. The treating physician must be aware of these issues when prescribing psychotropic medications for the elderly.