Opioid formulations: tailoring to the needs in chronic pain.

Opioids are one of the standard therapies used in the management of chronic pain. They were first widely adopted for the treatment of chronic pain associated with cancer and are now considered important in the alleviation of non-cancer and neuropathic pain. Around-the-clock (ATC) medication has been found to be an effective approach in treating chronic pain. Guidelines issued by the American Pain Society (1999) note that in most cases the preferred route of administering opioids is oral, because of convenience, flexibility, and relative steadiness of the opioid concentrations in the blood. The advantages of ATC therapy and oral medication are some of the reasons for the development of controlled-release, oral formulations of opioids (e.g. morphine, oxycodone, hydromorphone, and hydrocodone). The reduced dosing frequency makes the oral medication more convenient for patients, making it easier for them to comply with the dosing regimen. ATC therapeutic coverage and the possible increased compliance afforded by controlled-release formulations can make opioids even more effective in managing chronic pain.