 | Editorial BMJ 2005;330:156-157 (22 January),
http://bmj.bmjjournals.com/cgi/content/full/330/7484/156
Opioids for persistent non-cancer pain
A team approach and individualisation of treatment are needed
Epidemiological studies from Australia and Denmark indicate that about
19% of the population is afflicted by chronic pain that is not caused
by cancer.1 2 The prevalence of chronic pain that interferes with daily
activities is 12.6%.1 In most Western countries, opioids are
established in treating pain due to cancer, and they are increasingly
used to manage chronic pain not due to cancer. Opioids are effective
analgesics, but they also have a strong reinforcing potential-fear of
addiction and diversion restrict their medicinal use. Good clinical
trials, guidelines, and responsible prescription are needed to ensure
the availability of opioids for those patients who may benefit.3 4
A recent systematic review included 11 randomised and controlled trials
on oral opioids in non-cancer pain.5 The review showed that opioids
provided pain relief for both neuropathic (postherpetic neuralgia,
diabetic neuropathy) and musculoskeletal pain (osteoarthritis). Large
differences between individuals in the response to opioids in all
conditions implied that the effectiveness of the treatment should be
tested in each individual. Adverse effects were common and included
constipation, nausea, vomiting, somnolence, sedation, dizziness,
itching, dry mouth, and headache. The studies were of short duration
(four days to eight weeks in each treatment arm). Some studies included
an open label phase for up to two years, but only a few patients
continued to use opioids.
When treating pain due to cancer, alleviating symptoms is the main
goal, whereas in the management of chronic non-cancer pain the goal is
to keep the patient functional, both physically and mentally, with
improved quality of life. Relief of pain may be an essential factor in
this and opioids are only one aspect of the overall rehabilitative
strategy for the patient. In a few instances, such as when an elderly
patient is waiting for a hip replacement, opioids can be regarded as a
fairly straightforward means of alleviating pain for a limited period.
The more chronic and complex the problem and the younger the patient,
the lesser is the role opioids have in the rehabilitation plan. A
multidisciplinary pain clinic will try other analgesics (including
antidepressants and anticonvulsants), non-steroidal anti-inflammatory
drugs, weak analgesics, transcutaneous nerve stimulation, cognitive
behaviour therapy, and exercise programmes.
Opioids are not effective in every patient with pain. Randomised
controlled trials indicate that no criteria have been identified that
predict good response to opioids in any particular condition. Also,
these trials were of short duration and included a selected group of
patients. Many questions regarding safety, such as long term effects on
hormonal and immune function, development of tolerance and increased
pain sensitivity, addiction and diversion of drugs were not answered by
these trials.6 Therefore, each patient who is considered for treatment
with opioids needs to be assessed for both efficacy and safety. Good
monitoring serves the individual patient and provides valuable
information from areas that cannot be studied in randomised and placebo
controlled studies, such as tolerance, addiction, and diversion of
drugs.
Patients need to be informed of the possible benefits and risks of
opioid treatment, and they need to be monitored carefully. This takes
time. Treatment of young patients and patients with psychosocial
problems or addictive behaviour should be initiated in
multidisciplinary pain clinics that have the resources and expertise to
assess these problems. However, primary care doctors should always be
involved in the decision making as they will usually take
responsibility for the patients in the long term. Multidisciplinary
pain clinics should be available for consultation if problems occur.
These clinics should also follow and audit to ensure that information
gained over the years is used to reassess the appropriateness of the
treatment.
Opinions regarding the medicinal use of opioids have always been
polarised. History shows how too liberal use has led to heightened
regulatory control, reluctance of doctors to prescribe opioids, and
under-treatment of pain. Guidelines are needed to prevent history
repeating itself. The British Pain Society published its
recommendations for the appropriate use of opioids for persistent
non-cancer pain in March 2004.4 The document includes information for
the patient, who is an important partner in the treatment plan. The
recommendations were carefully worked out with consultations of the
royal colleges of anaesthetists, general practitioners, and
psychiatrists. They are based on what is known about the effectiveness
of opioids in the treatment of chronic non-cancer pain. The
recommendations acknowledge the lack of data in many important areas of
clinical research; in these areas they are based on clinical
experience. The recommendations provide an excellent balanced
framework. Individual pain specialists and primary care doctors now
need to work within this framework and collect data through good
monitoring. Such data will be valuable when the recommendations are
reviewed in March 2007.
Eija Kalso, professor of pain research and management
University of Helsinki and Pain Clinic, Department of Anaesthesia and
Intensive Care Medicine, Helsinki University Central Hospital, PO Box
340, FIN-00029 HUS, Finland (eija.kalso@helsinki.fi)
Competing interests: EK has consulted, lectured, and participated in
studies sponsored by Johnson & Johnson, Pfizer, and Mundipharma.
References
1=2E Eriksen J, Jensen MK, Sj=F8gren P, Ekholm O, Rasmussen NK.
Epidemiology of chronic non-malignant pain in Denmark. Pain 2003;106:
221-8.[CrossRef][ISI][Medline]
2=2E Blyth FM, March LM, Brnabic AJM, Cousins MJ. Chronic pain and
frequent use of health care. Pain 2004;111:
51-58.[CrossRef][ISI][Medline]
3=2E Kalso E, Allan L, Dellemijn PLI, Faura CC, Ilias WK, Jensen TS,
et al. Recommendations for using opioids in chronic non-cancer pain.
Eur J Pain 2003;7: 381-6.[CrossRef][Medline]
4=2E The Pain Society. Recommendations for the appropriate use of
opioids for persistent non-cancer pain. A consensus statement prepared
on behalf of the Pain Society, the Royal College of Anaesthetists, the
Royal College of General Practitioners and the Royal College of
Psychiatrists. March 2004.
www.britishpainsociety.org/pdf/opioids_doc_2004.pdf (accessed 14 Dec
2004).
5=2E Kalso E, Edwards JE, Moore RA, McQuay HJ. Opioids in chronic
non-cancer pain: a systematic review of efficacy and safety. Pain
2004;112: 372-80.[CrossRef][ISI][Medline]
6=2E Ballantyne JC, Mao J. Opioid therapy for chronic pain. N Engl J
Med 2003;349: 1943-53.[Free Full Text]
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