New strategies in opioid therapy for cancer pain.

BACKGROUND: The last decade has seen a great increase in the range of opioid agents and formulations available for the treatment of chronic pain, raising new clinical questions and options.

METHODS: The author conducted an extensive review of the existing medical literature on opioid agents and formulations currently available.

RESULTS: Opioids remain the cornerstone of pharmacotherapy for cancer pain. In addition to severity of pain, coexisting disease, response to previous therapy, the drug's pharmacokinetics and available formulations influence the choice of an opioid agent. Short-half-life drugs, such as morphine, hydromorphone, fentanyl, oxycodone, and oxymorphone, are generally favored initially because they are easier to titrate than long-half-life agents. Long-acting controlled-release opioid preparations can lessen the inconvenience of around-the-clock administration of drugs with a short duration of action. In recent years several new formulations have been developed, including controlled-release morphine suppositories and suspensions; controlled-release tablets of oxycodone, hydromorphone, and codeine; and transdermal fentanyl, a patch that allows 3-day dosing and avoids the first-pass effect of the liver. Most patients who receive controlled-release opioids should be provided with a rescue dose of an immediate-release opioid to treat pain that may break through the controlled-release schedule.

CONCLUSIONS: Among the important advances in the last decade in the treatment of chronic pain is the realization that the goals of care and the best means of achieving them differ not only among individuals but often for a single patient throughout a long course of care. Physicians must not only be knowledgeable but also flexible in their approach to managing cancer pain. An understanding of the range of opioid agents and the formulations available can allow physicians to maintain the best possible quality of life for their patients with chronic pain.