Issue 9 March 2007
How can NeuPSIG advance research on neuropathic pain?
In past issues of this newsletter, I have shared with the members of NeuPSIG a number of proposals and issues that the management committee has been discussing. One very important goal that NeuPSIG has set for itself involves advancing research on neuropathic pain. Specifically, our Constitution and Bylaws include the following aims and objectives that are relevant to research: (1) collaboration for basic and clinical research; (2) the study of the underlying mechanisms of neuropathic pain; and (3) the identification and implementation of programs to prevent the development of neuropathic pain.
One way in which NeuPSIG has addressed these research objectives has been by sponsoring or co-sponsoring quite a few conferences in various locations around the world. It is likely that these meetings have stimulated participants to think of new research questions and methods, and that they have also provided opportunities to initiate research collaborations. This approach to advancing research is somewhat indirect, however, and the NeuPSIG management committee has been considering more direct methods for advancing “the understanding of mechanisms, assessment, prevention, and treatment of neuropathic pain” (NeuPSIG’s mission).
In preliminary discussions, several possibilities have been considered. These include sponsorship for (1) pilot clinical trials involving a small number of sites that would provide a basis for designing larger international efforts that would be funded by government, private foundations, or industry; (2) meetings to advance important research areas, for example, by developing recommendations for “identifying novel treatments using animal models of neuropathic pain,” “optimizing research designs for proof-of-concept studies of neuropathic pain treatments in normal volunteers and in patients;” and “identifying pain mechanisms in patients with neuropathic pain;” (3) research grants for junior investigators; and (4) research grants for highly innovative projects that are unlikely to succeed in obtaining funding from traditional sources.
This list of possible research initiatives was generated from discussions by the management committee, and we would very much like to hear your thoughts about whether these are worthwhile initiatives for NeuPSIG to undertake. Of course, these are only a few examples of how NeuPSIG could advance research on neuropathic pain, and we would also very much value your input and ideas for additional activities that should be considered by the management committee to accomplish this very important objective.
NeuPSIG Management committee met in Guatemala
The NeuPSIG management committee met in Guatemala City on Dec 6-7, 2006. The committee discussed future meetings including a possible meeting in Asia in 2009 in conjunction with a local regional pain meeting and also a 3rd International Congress on Neuropathic Pain in 2010. The committee talked about the impact on NeuPSIG’s meetings of the recent IASP decision to hold the world congress every two years. Reports from the various NeuPSIG subcommittees were also discussed and some of the main points are summarized below. The next management committee meeting will take place in Berlin in June 2007 prior to the 2nd International Neuropathic Pain congress,
The 2nd International Neuropathic Pain congress will take place in Berlin June 7-10, 2007.
The congress will take place at the InterContinental Berlin which is located in the heart of Berlin (please see conference website http://www.kenes.com/neuropathic/ for further details).
The Main topics of the meeting are:
• Postherpetic neuralgia
• Diabetic neuropathy
• Complex regional pain syndromes
• Central pain syndromes
• Animal models in neuropathic pain
• Mechanism-based classification and therapy
• Clinical assessment in neuropathic pain
• Quantitative sensory testing in neuropathic pain
• Genetics of neuropathic pain
• Design of clinical trials in neuropathic pain
• Novel molecular drug targets in neuropathic pain
Greatly reduced and subsidized registration fees will be available to trainees and a limited number of travel grants for trainees presenting posters and for physicians from developing countries will be awarded. Please note that the deadline for submission of Travel Grant application forms is Friday, April 13, 2007 (see NeuPSIG website for further details and forms)
The U Rochester/NeuPSIG annual International Conference on the Mechanisms and Treatment of Neuropathic Pain
Last year’s meeting took place in Bermuda at the beginning of November. This year’s meeting will take place at Snowbird Mountain Conference Center, Salt Lake City, Utah, November 1 - 3, 2007. Further details and registration at: http://www.neuropathicpain.org/
NeuPSIG Satellite meeting in London in 2008
The SIG organized satellite meeting to the 12th IASP World Congress on Pain “Recent developments in neuropathic pain” has now been approved by IASP and will take place at the Royal Society of Medicine in London August 13th - 15th 2008 immediately preceding the congress. The Scientific Program Committee under the chair of Andrew Rice has planned an exciting meeting including plenary sessions and posters covering basic neuroscience and clinical topics. See www.kenes.com/neuropathic2008/ for list of invited speakers.
The 3rd International Neuropathic Pain Congress.
The NeuPSIG management committee decided to go ahead with plans for a 3rd congress which will take place in Europe in May or June 2010.
For summary of upcoming NeuPSIG meetings see box below.
Classification and taxonomy
This committee, chaired by Rolf-Detlef Treede has now completed a manuscript “Redefinition of neuropathic pain and a grading system for clinical use, which has recently been submitted for publication. The recommendations of this manuscript will be submitted to the IASP task force on taxonomy.
Comments and discussion regarding these recommendations will be posted on the NeuPSIG website. Please email your comments to the NeuPSIG secretary (firstname.lastname@example.org).
Maija Haanpaa, the committee chair, reported that the committee met recently in Istanbul and a manuscript is almost ready for submission. The committee plans to hold an additional two day meeting within the next few months.
This committee which is chaired by Bob Dworkin reported that the first NeupSIG sponsored guidelines have been published (Recommendations for the management of herpes zoster, Clin Infect Dis 44, supp 1, S1-S26, 2007). Plans are to have this article available on the NeuPSIG website.
The committee has also prepared a manuscript on guidelines for the pharmacologic management of neuropathic pain which has recently been submitted for publication. The committee is now working on developing guidelines for interventional treatments for neuropathic pain based on a successful workshop on this topic that was held as part of the recent University of Rochester/NeuPSIG meeting in Bermuda. The committee plans to meet in Snowbird Utah in November immediately after the next International Conference on the Mechanisms and Treatment of Neuropathic Pain. A future project of the committee is to produce guidelines for
non-pharmacological and complementary therapies for the treatment of neuropathic pain (e.g., TENS, psychological treatment, acupuncture, physical therapy and rehabilitation).
Gary Strichartz, chair of this committee, reported on some possible activities for the committee. It was decided to look into the feasibility of holding a meeting on animal and human surrogate models of neuropathic pain. The committee was also considering developing a database on neuropathic pain treatment trials and performing a survey on the efficacy of lidocaine in the treating various types of neuropathic pain.
This issue of the NeuPSIG newsletter includes a review by Dr. Chris Wells on the use of opioids in the treatment of neuropathic pain, which is based on his recent lecture at the NeuPSIG Neuropathic Pain Symposium in Guatemala City. Other submissions are welcome
OPIOIDS FOR NEUROPATHIC PAIN
J C D Wells, UK
As neuropathic pain became recognised as an entity, several authorities suggested that opioids were not useful for its management (Bowsher, Arner). One of the reasons for this was its unsuitability for some acute, intermittent, episodic pains such as trigeminal neuralgia, and it was also felt that burning pain was better treated with drugs such as Amitriptyline than with opioids. Arner's paper was often quoted as showing that neuropathic pain was not treatable with opioids, but this looked at just 12 patients with neuropathic pain who had not responded to any treatment, and 4 were actually still on opioids when they entered the trial. Intravenous opioids were used, but mainly Buprenorphine, with negative benefit. Arner himself never meant this to be a reason not to consider investigating the use of all opioids for different types of neuropathic pain.
However, Max in 1988 and then authors such as Kalso, Rowbotham and Jadad over the next 5 years showed that opioids could and did work for neuropathic pain. In the last 5 years, there have been 100 papers or more regarding efficacy of opioids for neuropathic pain, most of which were more-or-less positive with a few dissenting voices (Raja, Rowbotham, Watson, Gimbel, Morley, Boreau and Gilron). And yet, Eisenberg in the Journal of the American Medical Association, and later, in a Cochrane review, argues that the use of opioids is controversial and describes mixed results in short-term usage, whilst accepting intermediate studies demonstrating significant efficacy of opioids over placebo, which is likely to be clinically important. He does, however, insist that further randomized controlled trials (RCTs) are needed to establish their long-term efficacy, safety and effects on quality of life.
LESSONS FROM RECENT PAPERS
Raja (2002) looked at 76 patients with post-herpetic neuralgia in a RCT crossover trial. There were 3 groups - opioids versus tricyclics versus placebo - with titration to relief or unacceptable side-effects. Average dosaging at titration was 91 mg of morphine per day, 15 mg of Methadone per day, 89 mg of Nortriptyline per day and 63 mg of Desipramine per day. All reduced pain, with no appreciable effect on cognitive function, and the reduction was said to be 20 to 30 per cent. Fifty four per cent preferred the opioid, with 30 per cent preferring the tricyclics. Adverse events occurred in both groups, with constipation, nausea and drowsiness greater in the opioid group than in the other groups.
Rowbotham (2003) reported on 2 doses of Levorphanol in central and peripheral neuropathic pain. The low dose showed a 21 per cent reduction in pain, the high dose a 36 per cent reduction. There was some improvement in function and sleep, not reaching statistical significance. Better results were obtained in peripheral than in central. neuropathy
Watson (2003) looked at 36 patients with diabetic neuropathy in a RCT. An active placebo of Benztropine was used, versus up to 80 mg of Oxycontin. This produced a 50 per cent better reduction of pain than the placebo and disability was lessened in the active group. There was also benefit in the SF36 and in sleep, and adverse events were similar. However, 7 withdrew in the Oxycontin group and only one in the placebo group. Main side-effects were nausea, constipation and sweating, with both groups reporting sleepiness in 50 per cent of patients.
Gimbel (2003) also reported on diabetic neuropathy, from a RCT of 59 patients. Titration took place up to 120 mg of controlled-release Oxycodone, with an average of 37 mg. Pain reduction was 40 per cent, which was statistically superior to a placebo response of 20 per cent. There was an improvement in sleep, but minimal effect on disability. Ninety six per cent of the Oxycodone group reported adverse events, versus 68 per cent of the placebo group. Main adverse events were 42 per cent with constipation, 40 per cent with somnolence, 36 per cent with nausea, 32 per cent with drowsiness and 24 per cent with pruritis.
Gilron (2003) looked at 154 patients with diabetic neuropathy, 41 per cent opioid-naive. Ten per cent received opioids by the clock, but 25 per cent received opioids prn. He reported that barriers included both physicians, patient fear of addiction, adverse events and administrative.
Morley et al (2003) described the treatment of 18 patients with neuropathic pain with Methadone versus placebo, and found that 20 mg of Methadone daily gave a significant reduction of pain, however, with adverse events including nausea, vomiting, dizziness and headache. Seven of the patients withdrew because of adverse events.
Boreau (2003) reported on 127 patients with post-herpetic neuralgia. Tramadol was given, up to 400 mg per day, with a significant reduction of pain versus placebo, but only a 9 per cent reduction on average. Adverse events were infrequent but included nausea and constipation.
Several papers over the last 6 years have reviewed the results of treatment of neuropathic pain, and produced league tables of useful drugs (eg, Argoff 2004).
Sindrup and Jensen (2000) reported NNTs for tricyclics of 2.6, Carbamazepine of 2.5, Gabapentin of 4.1, Tramadol of 3.4 and SSRIs of 6.7. Capsaicin came in at 5.9 and Mexiletine is 38! At that time, opioids were not mentioned.
Hemptonstall et al (2004) reported the following NNTs for post-herpetic neuralgia: tricyclics 2.64, opioids 2.67, Pregabalin 3.42, Gabapentin 4.39, Tramadol 4.76 and Capsaicin 3.26; Lidoderm patch 2.0. They recommended tricyclics and anticonvulsants as first line treatments, with opioids as second line.
Dworkin et al (2003) stated that there was good evidence for opioid efficacy, and recommended Oxycodone, up to 120 mg per day, morphine up to 240 mg per day, with 300 mg in phantom pain. They reported that there was a decrease in disability and improvement in sleep. Adverse events included constipation, sedation and nausea, with cognitive impairment and decreased mobility reported in the elderly. They felt that tolerance might occur, but dependence was probably low.
Dworkin, however, reported that "we hold diverse opinions regarding the algorithm for administering opioids". Nevertheless, in general, the authors recommended short-acting morphine in a dose of 5 to 15 mg, given 4-hourly or equivalent, to titrate the required dosage, once steady state had been reached conversion could be made to long-acting opioids such as controlled-release morphine or Oxycontin, transdermal Fentanyl, Levorphanol or Methadone Hydrochloride.
Finnerup et al in Pain 2005 recommended Lidoderm patches for allodynia, with Gabapentin and tricyclics for this and other pain as first line drugs, with opioids and Tramadol only used after these had been tried, either singly or in combination.
Breivik in 2005 pointed out that there were no long-term double-blind RCTs, whilst accepting that these might be difficult. He commented on the Denmark experience, where there has been liberal use of opioids for more than 15 years. Erikkson in 2003, in Pain in Europe, described Pain Clinics seeing patients with opioid abuse problems and stated that three-quarters of patients referred to Pain Clinics were already on an opioid from their family practitioner, with an average dose of 70 mg of morphine per day. Erikkson estimated that 40 per cent of these were problem users and that up to 19 per cent of chronic pain patients were suffering from an addictive disorder.
Watson, in 2004, described long-term experience of 102 patients with chronic, non-cancer pain, having been on medication for more than a year with a median of 8 years. Forty four per cent were satisfied with pain relief, despite side-effects, and 54 per cent were less disabled. Thirty four per cent had intolerable side-effects, and overall the reduction in pain was modest. He did report using opioids in a few patients with dependency, with successful results due to very careful management.
COMBINATIONS OF OPIOIDS AND ANTICONVULSANTS
Gilron's trial in 2005 was a RCT on 57 patients with post-herpetic neuralgia or diabetic neuropathy. There were 4 groups, one placebo group, one on Gabapentin, one on morphine and one on a combination of morphine and Gabapentin. There was a titration to tolerance, with a maximum dose of 120 mg of morphine and 3200 mg of Gabapentin. Mean dosages of the morphine group were 45 mg, the Gabapentin group 2207 mg and in the combined group 34 mg morphine and 1705 mg of Gabapentin.
The best results were obtained in the combined group, with 45 per cent, compared with 35 per cent relief in the morphine group and 30 per cent from the Gabapentin group. Pain relief, mood, sleep and activity were all assessed, and results were better than with placebo.
A trial by Peramo (2003), an open trial on 60 patients with neuropathic pain, showed a better result in a Gabapentin and Fentanyl group over 72 hours than Gabapentin alone. There was similar nausea and vomiting, and constipation, in both groups, but a greater problem with pruritis in the Fentanyl group.
Whilst opioids have good efficacy, there is no doubt that significant side-effects occur. The most common are constipation, nausea, drowsiness, dizziness, pruritis, with some patients reporting vomiting, headache, dry mouth and sweating. Respiratory depression, always cited as a potential risk, has never really been noted in clinical practice in patients who have pain, with the use of sensible dosaging.
Physical addiction is physiological and manageable. Psychological dependence, a behavioural pattern of drug abuse where medication is taken for psychic and mental effects, is always a fear. However, it is clear that most patients exposed to opioids do not become drug abusers.
McQuay wrote (BMJ 2001) that "opioids are our most powerful analgesics, but politics, prejudice and our continuing ignorance still impede optimum prescribing. What happens when opioids are given to someone in pain is different to what happens when they are given to someone not in pain. The medical use of opioids does not create drug addicts, and restrictions on its use hurts patients".
Different opioids cost different amounts in different countries. Methadone is usually inexpensive, whilst slow-release Oxycontin and Fentanyl can be four times the price and therapeutic dosages can mean a cost of $3,000 to $4,000 a year per patient.
Tramadol. This drug, with a complex action including opioid receptor affinity, is also a potent inhibitor of serotonin re-uptake and blocks noradrenaline uptake. There is significant trial evidence for its usage in neuropathic pain and the generic formulation is inexpensive. Comparison should take place with pure opioids to assess its place.
WHAT CONDITIONS MIGHT RESPOND TO OPIOIDS?
In intermittent shooting pain, such as trigeminal neuralgia, there is no evidence of them being useful. In brachial avulsion injuries, only a paper on Tramadol by Waikukul has shown benefit. In central pain syndromes, such as central post-stroke pain and even phantom limb pain, trials are limited with small numbers of patients, and generally a small response. However, post-herpetic neuralgia and diabetic neuropathy, as well as polyneuropathy, have been studied in ever-increasing numbers with good benefit.
Results in patients with allodynia in experimental trials show mixed results, but intravenous titrations have been useful and there are certainly sub-groups with allodynia who do respond. Lidoderm patches are clearly the first line treatment in allodynia.
Opioids work, especially in post-herpetic neuralgia and diabetic neuropathy. Expect a 30 per cent reduction in pain only, less with Tramadol. Significant adverse events can be a major problem and often lead to patients discontinuing medication in spite of pain relief. Most trial work is short-term or intermediate-term, and it is clear that the majority of patients withdraw from opioid treatment after a year or so, although some have been shown to be on this long-term with benefit.
There are possibly significant differences between the various drugs, which have slightly different properties. There are also barriers of various types, including physician, patient and administrative. There are potential benefits and drawbacks to its use in the elderly (Ahmad 2002). There is no evidence that increasing the dose above 200 mg of morphine, or equivalent, per day produces benefit, and average doses in trials are around 100 mg of morphine daily or its equivalent. If the dose needs to be increased above 200 mg this may well lead to problems.
In the future, we need to examine the reason why some patients do become addicted, which may well be because they did not have true neuropathic (or nociceptive) pain in the first place. We need to consider potential rotation of opioids if tolerance occurs. Side-effects need to be managed aggressively and it appears to be clear that the combination of opioids with anticonvulsants is beneficial.
We may be able to reduce the total dose of opioid given by the use of Devazepide. Cholecystokynin has been found to affect neuropathic pain and reduce opioid efficacy. This drug is a cholecystokynin antagonist, and both pre-clinical and pilot studies have suggested an enhancement of opioid benefit with consequent reduced doses and less toxicity.
Ahmad M, Goucke CR (2002) Management Strategies for the Treatment of neuropathic Pain in the Elderly. Drugs Aging 19: 929-945
Argoff CE, Katz N, Backonja M (2004) Treatment of post-herpetic Neuralgia: A Review of therapeutic Options. J Pain Symptom Manage 28 (4): 396-411
Arner S, Meyerson BA (1988) Lack of analgesic Effect of Opioids on neuropathic and idiopathic Forms of Pain. Pain 39 (2): 243-246
Benedetti, F et al (1998) Dose-responsive Relationship of Opioids in nociceptive and neuropathic post-operative Pain. Pain 74: 205-211
Boureau F, Legallicier P, Kabir-Ahmadi M (2003) Tramadol in post-herpetic Neuralgia: A randomized, double-blind, Placebo-controlled Trial. Pain 104: 323-331
Breivik H (2005) Opioids in chronic non-cancer Pain, Indications and Controversies. European Journal of Pain 9: 127-130
Cunningham AL, Dworkin RH (2000) The Management of post-herpetic Neuralgia. British Medical Journal 321: 778-779
Dellemijn PLI et al (1997) Randomised double-blind active-placebo-controlled Crossover Trial of intravenous Fentanyl in neuropathic Pain. Lancet 349: 753-758
Dellemijn PLI (1999) Are Opioids effective in relieving neuropathic Pain? Pain 80: 453-462
Dickenson AH and Suzuki R (2005) Opioids in neuropathic Pain: Clues from Animal Studies. European Journal of Pain 9: 113-116
Duhmke RM, Cornblath DD, Hollingshead JRF (2004) Tramadol for neuropathic Pain (Cochrane Review) In: The Cochrane Library 3, Chichester, UK
Dworkin RH, Backonja M, Rowbotham MC et al (2003) Advances in neuropathic Pain. Arch Neurol 60: 1524-1534
Eisenberg, E et al (2005) Systematic Review and meta-Analysis of randomized controlled Trials. JAMA 293: 3043-3052
Finnerup, NB et al (2005) Algorithm for neuropathic Pain Treatment: An Evidence-based Proposal. Pain, 118: 289-305
Foley KM (2003) Opioids and chronic neuropathic Pain (Editorial). N Eng J Med 348 (13):1279-1281
Gilron I, Bailey JM (2003) Trends in Opioid Use for chronic neuropathic Pain: A Survey of Patients pursuing Enrolment in clinical Trials. Can J Anesth 50: 42-47
Gilron I, Bailey JM, Dongsheng Tu ME et al (2005) Morphine, Gabapentin or their Combination for neuropathic Pain. New Engl J Med 352 (13): 1324-1334
Gimbel JS, Richards P, Portenoy RK (2003) Controlled-release Oxycodone for Pain in diabetic Neuropathy: A randomized controlled Trial. Neurology 60: 927-934
Gourlay, G (1991) Different Opioids - same Actions? In: Kalso E, McQuay HJ and Wiesenfeld-Hallin Z (Eds) Opioid Sensitivity of chronic non-cancer Pain. Progress in Pain Research and Management Vol 14: 97-115
Harati Y et al (1998) Double-blind randomized Trial of Tramadol for the Treatment of the Pain of diabetic Neuropathy. Neurology 50: 1842-1846
Hemptenstall K et al (2004) Analgesic Therapy in post-herpetic Neuralgia: A quantitative systematic Review. The Pain Society ASM 30 Mar-2 Apr, Manchester, UK
Kalso E, Edwards JE, Moore RA et al (2004) Opioids in chronic non-cancer Pain: Systematic Review of Efficacy and Safety. Pain 112: 372-380
McCleane G (2003) Pharmacological Management of neuropathic Pain. CNS Drugs 17: 10311043
McQuay H (2001) Opioids in chronic non-malignant Pain. BMJ 322: 1134-1135
Maier C et al (2002) Morphine Responsiveness, Efficacy and Tolerability in Patients with chronic, non-tumour-associated Pain - Results of a double-blind placebo-controlled Trial. Pain 97: 223-233
Makin MK et al (1998) Methadone in the Management of Cancer related neuropathic Pain. The Pain Clinic Vol 10;4:275-280
Morley JS, Bridson J, Miles JB et al (2003) Low-dose Methadone has an analgesic Effect in neuropathic Pain: A double-blind randomized controlled Crossover Trial. Palliat Med 17: 576-587
Moulin DE, Palma D, Watling C et al (2003) Methadone in the Management of intractable neuropathic Pain (Abstract) 55th Annual American Academy of Neurology Meeting, 29 Mar-5 Apr, London, Canada
Nash T, Makin M et al (2002) Methadone in the Treatment of neuropathic non-cancer Pain. Poster Abstract, The Pain Society ASM, 9-12 April, Bournemouth UK
Nelson KA et al (1997) High-dose oral Dextromethorphan versus Placebo in painful diabetic Neuropathy and post-herpetic Neuralgia. Neurology 48:1212-1218
Omote K et al (1995) Intrathecal Buprenorphine in the Treatment of Phantom Limb Pain. Anesth Analg 80:1030-1032
Peramo F, Caballero J, Gonzalez-Fernandez R, Montero V et al (2003) Transdermic Fentanyl in neuropathic Pain (Abstract) Jt Meeting European Society of Anaesthesiologists and European Academy of Anaesthesiology Confederation of European National Societies of Anaesthesiology Association of Anaesthetists of Great Britain & Ireland, 31 May- 3 Jun, Glasgow, Scotland
Raja SN, Haythornwaite JA, Pappagallo M, Clark MR, Travison TG et al (2002) Opioids versus Antidepressants in post-herpetic Neuralgia. Neurology 59: 1015-1021
Rowbotham DJ et al (2001) Safety and Tolerability of oral Devazepide in Cancer-related Opioid-resistant Pain. Pilot Study, 2nd World Congress of the World Institute of Pain, 27-30 June, Turkey
Rowbotham MC (1999) The Debate over Opioids and neuropathic Pain, In: Kalso E, McQuay HJ and Wiesenfeld-Hallin Z (Eds) Opioid Sensitivity of chronic non-cancer Pain. Progress in Pain Research and Management Vol 14: 307-317
Rowbotham MC, Twilling L, Davies PS, Reisner L, Taylor K Mohr D (2003) Oral Opioid Therapy for chronic peripheral and central neuropathic Pain. N Engl J Med 348: 1223-1232
Simpson KH et al (2001) The CCK-A Antagonist Devazepide (Devacade) as an Adjunct to strong Opioids in the Management of Patients with neuropathic Pain. Pain Society ASM 27-30 March, York, UK
Sindrup SH et al (1999) Tramadol relieves Pain and Allodynia in Polyneuropathy: A randomized, double-blind controlled Trial. Pain 83:85-90
Sohn W, Bornhovd K (2004) Transdermal Fentanyl (DurogesicR) relieves chronic neuropathic Pain due to diabetic Polyneuropathy - Results of a 3 Month, Multicentre Pilot Study (Abstract) 3rd World Congress of the World Institute of Pain, 21-25 Sept, Barcelona, Spain
The British Pain Society (2004) Recommendations for the appropriate Use of Opioids for persistent non-cancer Pain. The British Pain Society, London. www.britishpainsociety.org
Van den Eynden, Louis (2004) Matrix Project: Transdermal Buprenorphine in daily Practice (Abstract) 3rd World Congress of the World Institute of Pain, 21-25 Sept, Barcelona, Spain
Waikukul S et al (1998) Comparison of Analgesics for Pain after brachial Plexus Injury: Tramadol versus Paracetamol with Codeine. The Pain Clinic Vol 11; 2:119-124
Watson CP et al (2000) Randomised, double-blind Crossover Comparison of the Efficacy and Safety of oral controlled-Release Oxycodone and active Placebo in Patients with painful diabetic Neuropathy. Poster
Watson CPN, Watt-Watson RN, Chipman ML (2004) Chronic non-cancer Pain and the long Term Utility of Opioids. Pain Res Manage Vol 9, 1: 19-24
Watson CPN, Chipman ML (2005) Comparative Efficacy and Safety of different Analgesics for neuropathic Pain (Abstract) 24th ASM of the American Pain Society 30 Mar-2 Apr, Boston USA
Xu XJ et al (1999) Opioid Sensitivity in experimental central Pain after spinal Cord Injury in Rats, In: Kalso E, McQuay HJ and Wiesenfeld-Hallin Z (Eds) Opioid Sensitivity of chronic non-cancer Pain. Progress in Pain Research and Management Vol 14: 183-200
Zochodne DW, Max MB (2003) An old Acquaintance: Opioids in neuropathic Pain (Editorial). Neurology 60: 894-895
MARK YOUR CALENDARS! June 7-10, 2007, Berlin
As of March 3, 2007, the NeuP SIG has xxx members in 55 countries representing 37 specialties.
NeuPSIG committee meeting in Guatemala City