Oxycodone. Pharmacological profile and clinical data in chronic pain management.

Opioids are widely used as effective analgesic therapy for cancer pain. Despite years of controversy, their use has been also accepted in chronic non-cancer pain. Oxycodone alone and in combination has been used for over 80 years in the treatment of a variety of pain syndromes. As single agent, the controlled release (CR) oxycodone's market in the USA grew from 10% in 1996 to 53% in 2000 and it has become a leading opioid in the United States. Recent data showed that the fixed-combination oxycodone/acetaminophen (5 mg/325 mg) is the most often prescribed opioid across all the different chronic pain diagnoses. Compared with morphine, oxycodone has a higher oral bioavailability and is about twice as potent. Pharmacokinetic-pharmacodynamic data support oxycodone as a pharmacologically active opiod that does not require conversion to oxymoprhone for pharmacological activity. Seven studies addressed the safety and efficacy of oxycodone for the treatment of non-cancer pain (low back pain, osteoarthritis pain, and painful diabetic neuropathy). Both immediate release (IR) and CR oxycodone are equally effective and safe. Along these trials, mean daily dosage of oxycodone was approximately 40 mg, with a low incidence of intolerable typical opiate side effects. In cancer pain, oxycodone can be considered a valid alternative to oral morphine to be used for opioid rotation. No difference in analgesic efficacy between CR oxycodone and CR morphine was found. Controlled-release preparations, with a long duration of action, are attractive because they offer the advantage of longer dosing intervals and sustained analgesic effect.