Reviews properties and pharmacological effects of medications for pain, including peripherally acting analgesics, centrally acting narcotics, and adjuvant analgesics including antidepressants. Discusses the role of the endogenous opioid system in pain and depression. Explores clinical management issues in both inpatient and outpatient settings, with emphasis on the need to address the psychosocial context in which medications are prescribed. (Author/NB)