[New Level III opioids of the World Health Organization]

The new opioids and the new galenic forms, now available in France, require an update in practitioners' knowledge. The purpose of the present study is to help those prescribing select the appropriate opioid and its galenic form for pain relief.

Presentation of pharmacological properties of opioids (mechanisms, pharmacokinetics and pharmacovigilance). Presentation of indications, modes of prescription and use of main opioids for pain (especially cancer pain). Examples for calculating required drug dosage depending on the clinical situation and the route of administration. Symptomatic treatments of the main undesirable side effects of the opioids, and actions to be taken in the event of accidental overdose.

Oral morphine is the treatment first recommended for nociceptive pain insufficiently relieved by WHO level I and II analgesics. The new immediate-release galenic forms allow morphine titration and the treatment of breakthrough pain. Transmucosal fentanyl, soon available in France, is recommended for breakthrough pain in patients already under opioid treatment: it gives more rapid relied starting after only 5 minutes and it only acts for a short time. Transdermal fentanyl is indicated for stable cancer pain. It is particularly suitable when oral and injectable morphine routes are not available, or for patients with severe constipation. Hydromorphone is the first opioid recommended in France for severe cancer pain when morphine resistance exists or uncontrolled side effects are present (opioid rotation). The new opioids and the new galenic forms widen the range of therapeutic possibilities. Their use is well codified for cancer pain and must still undergo clinical trials for chronic non-cancer pain. When correctly indicated, opioid selection provides a considerable advance in pain management.