Advances in opioid therapy and formulations.

Newly developed opioid analgesics and drug delivery systems may provide pain relief for patients intolerant of morphine. Long-acting oral opioids supply satisfactory analgesia at more convenient dosing intervals. Implantable pumps can provide full analgesic doses of opioids both subcutaneously and intrathecally over extended time periods. Optimal opioid use should rely on individualized dose-finding approaches to enhance pain relief while limiting drug-related side effects and avoiding the common problems associated with opioid prescription in clinical practice.