Objective: The World Health Organization (WHO) published guidelines to improve cancer pain control which allow to relieve noceptive cancer pain in 80% of adult patients. Nevertheless WHO recommendations do not include: various ways to start morphine treatment, how to manage opioids adverse effects, severe cancer pain management, postoperative pain and procedure-relatived pain. The goal of this review is to discuss these issues.
Data sources: The data were retrieved from PubMed years 2001 to 2006 (keywords used alone or in combination were: opioids, cancer, pain, pain killers, rotation, intraspinal, ketamine, side effects), the "Standard, Options and Recommendations on cancer nociceptive pain treatments for adult patients" published by the French Union of Comprehensive Cancer Centers (FNCLCC; Fédération nationale des centres de lutte contre le cancer) and the European Association for Palliative Care (EAPC) recommendations on morphine and alternative opioids in cancer pain. Data also include an analysis of studies before 2001 which give information about the pharmacokinetic data of transdermal and transmucosal fentanyl.
Study selection: Studies written in English or French related to the medical treatments (commercialized in France) for nociceptive cancer pain for adult patients were analyzed. Analyzed articles were clinical or experimental studies or metaanalyses. Studies on neuropathic cancer pain, editorials and letters to the editor were discarded.
Results: Nociceptive cancer pain is characterized by its frequent instability. More than 50% of patients have paroxystic painful accesses (PPA), either spontaneous or induced by care or mobilizations. Morphine is the main treatment but the prescription of controlled-release morphine must be associated with the prescription of immediate-release morphine to treat the PPA or to transmucosal fentanyl which has a faster onset of action than immediate-release morphine. Morphine treatment can be introduced either by immediate-release morphine or by controlled-release morphine. The introduction of immediate-release morphine is recommended for old or fragile patients, patients with denutrition, hepatic or renal failure. For patients suffering unbearable side effects under morphine or morphine resistant pain, opioid rotation or intravenous morphine or fentanyl are recommended. Spinal opioids administration (by epidural or intrathecal routes) is most often indicated in patients with very severe and resistant pain in terminal disease. In the postoperative period, previous pain treatment must be maintained or increased. Pain bounded to care procedures must be prevented with various and associated treatments: for example, mixed topics lidocaïne-prilocaine for venous or arterial punctures; infiltration of local anaesthetics and inhalation of an oxygen - nitrous oxide mixture for medullary biopsies.
Conclusion: Oral immediate or controlled release morphine is the most common and effective pain treatment for most patients with nociceptive cancer pain but rotation with other opioids or alternative routes of administration must be discussed quickly if pain persits or if adverse effects occur.