Extended-release morphine sulfate in treatment of severe acute and chronic pain.

Morphine is the archetypal opioid analgesic. Because it is a short-acting opioid, its use has been limited to the management of acute pain. The development of extended-release formulations have resulted in the increased utilization of morphine in chronic pain conditions. This review documents the history of morphine use in pain treatment, and describes the metabolism, pharmacodynamics, formulations, and efficacy of the currently available extended-release morphine medications.