Usefulness of transdermal fentanyl in the management of nonmalignant chronic pain: A prospective, observational, multicenter study

Tricyclic antidepressants and carbamazepine have become the mainstay in the treatment of neuropathic pain. Within the last decade, controlled trials have shown that numerous other drugs relieve such pain. We identified all placebo-controlled trials and calculated numbers needed to treat (NNT) to obtain one patient with more than 50% pain relief in order to compare the efficacy with the current treatments, and to search for relations between mechanism of pain and drug action. In diabetic neuropathy, NNT was 1.4 in a study with optimal doses of the tricyclic antidepressant imipramine as compared to 2.4 in other studies on tricyclics. The NNT was 6.7 for selective serotonin reuptake inhibitors, 3.3 for carbamazepine, 10.0 for mexiletine, 3.7 for gabapentin, 1.9 for dextromethorphan, 3.4 for tramadol and levodopa and 5.9 for capsaicin. In postherpetic neuralgia, the NNT was 2.3 for tricyclics, 3.2 for gabapentin, 2.5 for oxycodone and 5.3 for capsaicin, whereas dextromethorphan was inactive. In peripheral nerve injury, NNT was 2.5 for tricyclics and 3.5 for capsaicin. In central pain, NNT was 2.5 for tricyclics and 3. 4 for carbamazepine, whereas selective serotonin reuptake inhibitors, mexiletine and dextromethorphan were inactive. There were no clear relations between mechanism of action of the drugs and the effect in distinct pain conditions or for single drug classes and different pain conditions. It is concluded that tricyclic antidepressants in optimal doses appear to be the most efficient treatment of neuropathic pain, but some of the other treatments may be important due to their better tolerability. Relations between drug and pain mechanisms may be elucidated by studies focusing on specific neuropathic pain phenomena such as pain paroxysms and touch-evoked pain.

Opioids are our most powerful analgesics, but politics, prejudice, and our continuing ignorance still impede optimum prescribing. Just over 100 years ago, opium poppies were still grown on the Cambridgeshire fens in the UK to provide oblivion for the working man and his family, but the brewing lobby argued on thin evidence that their potions were less dangerous. The restriction of opioid availability to protect society and the individual continues in many countries. In this review I focus on chronic and cancer pain, but many of the principles apply in acute pain. The justification for this focus is that patients with chronic pain may suffer longer and unnecessarily if we prescribe and legislate badly.

We report the transfer into Spanish of a multi-dimensional measure of perceived health originally developed in Great Britain, the Nottingham Health Profile (NHP), and an assessment of the preliminary validity of the version is presented. Translation of the questionnaire was obtained from experts and from a Spanish monolingual lay group. Construct validity of the version was assessed in two studies: testing relationship of NHP scores to other self-reported measures of health in a general population survey; and comparing NHP scores for a group of frequent users and for a group of non-users of primary health services. Mean scores of NHP dimensions were higher for people with poorer self-reported health and higher for the frequent health services users than for the non-users. Findings suggest that the Spanish version of the NHP is culturally equivalent to the original questionnaire, and has a similar level of construct validity. Nevertheless, further research on reliability and on the weighting system is required to establish the equivalence of the Spanish version definitively.