New perspectives in the use of opioids for the management of pain

Opioid drugs are the main Therapeut. option for the Mgmt. of severe acute/Chron. pain. This option is supported by the deep knowledge of their Pharmacol. properties, their proven analgesic effectiveness/their well-known side effect profile. This situation has resulted in the use of morphine for many years as the firstline analgesic for the management of acute pain and cancer-related pain. The development of new drugs with other mechanisms of action upon opioid receptors has not meant the substitution of pure antagonists, but a greater availability of therapeutic options. Furthermore, the availability of new dosage forms has increased the use of opioids, particularly with extended release oral formulations (morphine, dihydrocodeine, tramadol), transdermal formulations (fentanyl, tramadol, buprenorphine) and, more recently, an oral transmucosal dosage form of fentanyl. Additionally, opioid turnover can allow an optimal use of the available drugs, while the identification and adequate management of breakthrough or irruptive pain will significantly improve the quality of life of patients with chronic pain. However, the more frequent use of opioid analgesics will probably involve their combined administration, with potential interactions that must be known. This paper reviews the pharmacodynamics of opioids and recalls the basic concepts that underlie the current use of these analgesics. © 2003 Sociedad Española del Dolor. Published by Arán Ediciones, S.L.