Chronic Pain



No national or international guidelines available. 

Cochrane Reviews

Opioid switching to improve pain relief and drug tolerability.

Quigley C. Cochrane Database of Systematic Reviews 2004, Issue 3.


Opioid switching is the term given to the clinical practice of substituting one strong opioid with another, in an attempt to achieve a better balance between pain relief and side effects. This is an established clinical practice for patients with cancer pain, but the evidence is based on case reports and uncontrolled studies, and no randomised trials met the inclusion criteria for this review. In addition, the case reports and uncontrolled studies are inconsistent in their reporting of the reasons for opioid switching (whether the change was made because of intolerable side effects, inadequate pain relief, or both). It is also unclear whether the initial opioid was being given at a high enough, but tolerable, dose to achieve maximum pain relief. Opioids are increasingly used for non-cancer pain, but the practice of opioid switching does not yet appear to be established in this group of patients. 

Opioid therapy for treating rheumatoid arthritis pain.

Whittle SL, Richards BL, Husni E, Buchbinder R. Cochrane Database of Systematic Reviews 2011, Issue 11.


Best estimate of what happens to people with rheumatoid arthritis who take opioids. Patient-reported global impression of change: 

  • 18 more people out of 100 reported a 'good' or 'very good' improvement in the symptoms of their rheumatoid arthritis after treatment with opioids for between one and six weeks (18% absolute improvement)
  • 57 people out of 100 reported a 'good' or 'very good' improvement in symptoms
  • 40 people out of 100 who took a placebo reported a 'good' or 'very good' improvement in symptoms


  • 30 more people out of 100 experienced at least one side-effect during treatment with opioids for between one and six weeks (30% absolute difference)
  • 51 people out of 100 had at least one side-effect
  • 21 people out of 100 who took a placebo had at least one side-effect

Topical NSAIDs for acute pain in adults.

Massey T, Derry S, Moore RA, McQuay HJ. Cochrane Database of Systematic Reviews 2010, Issue 6.


The evidence from a large number of studies is that topical NSAIDs work well, though evidence for good effect is available only for topical diclofenac, ibuprofen, ketoprofen, and piroxicam. About 6 or 7 out of 10 patients will have successful pain controlover seven days with topical NSAID, compared with 4 out of 10 with placebo; the high response with placebo is because conditions like sprained ankles tend to get better on their own eventually. For every four or five participants treated with one of these topical NSAIDs, one would experience good pain relief (equivalent to at least 50% reduction) after about one week, who would not have done if treated with placebo.

Local adverse events at the site of application are no worse with topical NSAID than with topical placebo; they are mild and transient, and occur in about 6% of participants. Systemic adverse events (nausea, stomach upset, for example) and adverse event withdrawals were uncommon, occurring no more frequently with topical NSAID than topical placebo. No serious adverse events were reported in these studies.

Acetaminophen for osteoarthritis.

Towheed T,Maxwell L, JuddM, CattonM, HochbergMC,WellsGA. Cochrane Database of Systematic Reviews 2006, Issue 1.


The studies show that people who took acetaminophen has less pain (when resting, moving, sleeping and overall) and felt better overall than people who took a placebo. Pain (when measured on a different scale), physical function and stiffness were about the same.
 Pain decreased by 4 more points on a scale of 0-100 for people who took acetaminophen instead of a placebo.

Topical NSAIDs for chronic musculoskeletal pain in adults.

Derry S, Moore RA, Rabbie R. Cochrane Database of Systematic Reviews 2012, Issue 9.


Topical (applied to the skin) non-steroidal anti-inflammatory drugs (NSAIDs) provide significantly more participants with osteoarthritis of the knee or hand with good levels of pain relief than placebo (sham). There is no evidence for other chronic painful conditions. The best data were for topical diclofenac, where there were large, good quality studies. The way the product is made may influence how well it works, with diclofenac in a substance called DMSO giving better results than a diclofenac gel in this review. For every six participants treated with diclofenac solution, one will experience a good level of pain relief over 8 to 12 weeks; with diclofenac gel, 11 participants need to be treated for one to benefit.

Skin reactions (mostly mild) were more common with topical NSAIDs than placebo or NSAIDs taken by mouth, but there was a reduction in gastrointestinal adverse events compared with NSAIDs taken by mouth. For every 16 participants treated with topical diclofenac, one is likely to experience a local skin reaction, and for every 50 treated, one will withdraw due to unacceptable problems. Serious adverse events were uncommon.

Long-term opioid management for chronic non cancer pain.

Noble M, Treadwell JR, Tregear SJ, Coates VH, Wiffen PJ, Akafomo C, Schoelles KM. Cochrane Database of Systematic Reviews 2010, Issue 1.


The findings of this systematic review suggest that proper management of a type of strong painkiller (opioids) in well-selected patients with no history of substance addiction or abuse can lead to long-term pain relief for some patients with a very small (though not zero) risk of developing addiction, abuse, or other serious sideeffects. However, the evidence supporting these conclusions is weak, and longer-term studies are needed to identify the patients who are most likely to benefit from treatment. 

Vitamin D for the treatment of chronic painful conditions in adults.

Straube S, Derry S, Moore RA, McQuay HJ Cochrane Database of Systematic Reviews 2010, Issue 1.


Vitamin D has a variety of roles in the body. It is made in the skin through the action of sunlight and can also be obtained from food. A lack of vitamin D has been implicated in a number of diseases, including chronic painful conditions. Additionally, associations of such diverse types of pain as headache, abdominal pain, knee pain, and back pain with season of the year and latitude provide indirect support for a role for vitamin D. The possibility of a link between vitamin D and chronic pain has attracted interest because - if it was true - vitamin D would be a cheap and relatively safe treatment for chronic pain. There is some evidence supporting this link but it is not of high quality and is at risk of bias. This review sought out high quality evidence from Randomised Controlled Trials on the treatment of chronic pain with vitamin D. There were few high quality studies of which only one reported a beneficial effect. At present, therefore, there is insufficient evidence for an effect of vitamin D in chronic pain conditions. More research is needed to determine if vitamin D is a useful pain treatment at all and if so, whether the effect is restricted to those who are vitamin D deficient, how much vitamin D is useful, in which conditions, and for how long.



No national or international guidelines available. 

Cochrane Reviews

Psychological therapies for the management of chronic pain (excluding headache) in adults.

Williams ACDC, Eccleston C, Morley S. Cochrane Database of Systematic Reviews 2012, Issue 11.


Small to moderate benefits, more for disability, mood and catastrophic thinking than for pain, were found in trials which compared CBT with no treatment. Some of these were still positive six months later. Behaviour therapy showed few and only brief benefits. Psychological therapies can help people with chronic pain reduce negative mood (depression and anxiety), disability, catastrophic thinking, and in some cases, pain. Although the overall effect is positive, we do not know enough about exactly which type of treatment is best for which person.

Psychological therapies for the management of chronic and recurrent pain in children and adolescents.

Eccleston C, Palermo TM, Williams ACDC, Lewandowski A, Morley S, Fisher E, Law E. Cochrane Database of Systematic Reviews 2012, Issue 12.


Psychological therapies (relaxation, hypnosis, coping skills training, biofeedback, cognitive behavioural therapy) are treatments that may help people manage pain and its disabling consequences. For children and adolescents there is good evidence that both relaxation and cognitive behavioural therapy (treatment that helps people test and revise their thoughts and actions) are effective in reducing the severity and frequency of pain in chronic headache, recurrent abdominal pain, fibromyalgia, sickle cell disease, and juvenile idiopathic arthritis immediately after treatment is delivered. Psychological therapies also have a lasting effect for improving mood and reducing pain for chronic headache. Forty-nine per cent of children who received psychological therapies reported less pain compared with 17% of children who did not receive a psychological therapy. Disability is improved immediately after treatment for many pain conditions (not chronic headache) which helps young people to participate in important daily activities. More studies are needed to understand whether psychological therapies can improve mood and have more lasting effects on pain and disability in other groups of young people who have chronic pain.



National or Internationa Guideline

Spinal cord stimulation for chronic pain of neuropathic or ischaemic origin. NICE 2008

Cochrane Reviews

Spinal cord stimulation for chronic pain.

Mailis-Gagnon A, Furlan, MD PhD AD, Sandoval JA, Taylor RS. Cochrane Database of Systematic Reviews 2004, Issue 3.


There is insufficient evidence to assess the benefits and harms of spinal cord stimulation for the relief of chronic pain. Spinal cord stimulation (SCS) is a form of therapy used to treat certain types of chronic pain. It involves an electrical generator that delivers pulses to a targeted spinal cord area. The exact mechanism of action of SCS is poorly understood. We undertook a review of the available evidence and found two randomized controlled trials of this intervention. One trial studied the effects of SCS for Failed Back Surgery Syndrome andthe other was a trial of patients with Complex Regional Pain Syndrome Type 1 (reflex sympathetic dystrophy). We concluded that SCS might be effective for certain patients but there is little evidence available to assess the benefits and harms of this treatment.

Spinal cord stimulation for cancer-related pain in adults.

Lihua P, Su M, Zejun Z, KeW, Bennett MI. Cochrane Database of Systematic Reviews 2013, Issue 2.


Cancer-related pain is an emerging heavy burden on public health. Spinal cord stimulation (SCS) is a minimally invasive and potentially effective tool against chronic pain.This systematic review intended to evaluate the efficacy and effectiveness of SCS for cancer-related pain compared with standard care using conventional analgesic medication. No randomised controlled trials were identified. Four before-and-after case series studies (92 participants) were included in this systematic review. Current evidence is insufficient to establish the role of SCS in treating refractory cancer-related pain in comparison with other analgesic approaches. In addition, the studies reported significant side effects such as local infection.

Non-invasive brain stimulation techniques for chronic pain.

O’Connell NE, Wand BM, Marston L, Spencer S, DeSouza LH. Cochrane Database of Systematic Reviews 2010, Issue 9.


Various devices are available that can electrically stimulate the brain without the need for surgery or any invasive treatment. There are three main treatment types: repetitive transcranial magnetic stimulation (rTMS) in which the brain is stimulated by a coil applied to the scalp, cranial electrotherapy stimulation (CES) in which electrodes are clipped to the ears or applied to the scalp and transcranial direct current stimulation (tDCS), in which electrodes are applied to the scalp. These have been used to try to reduce pain by aiming to alter the activity of the brain but the efficacy of these treatments is uncertain.

This review included 33 studies, 19 of rTMS, eight of CES and six of tDCS. Only one study was judged as having a low risk of bias. Analysis suggests that low-frequency rTMS is not effective but that a single-dose of high-frequency stimulation of the motor cortex area of the brain provides short-term pain relief. This effect appears to be small. There is limited and conflicting evidence from studies involving multiple doses of rTMS. Most studies of rTMS are small and there is substantial variation between studies in terms of the treatment methods used.

There was insufficient evidence from which to draw strong conclusions regarding CES or tDCS but the available evidence does not suggest that CES is an effective treatment. There is limited evidence that tDCS to the motor cortex may have short-term effects on chronic pain but it is not possible to estimate the size of this effect accurately.

The reporting of side effects varied across the studies. Of the studies that clearly reported side effects only short-lived and minor side effects such as headache, nausea and skin irritation were reported.

More studies of rigorous design and adequate size are required to evaluate all forms of non-invasive brain stimulation for the treatment of chronic pain accurately.

Transcutaneous electrical nerve stimulation (TENS) for chronic pain. 

Nnoaham KE, Kumbang J. Cochrane Database of Systematic Reviews 2008, Issue 3.


Despite the widespread use of TENS machines, the analgesic effectiveness of TENS still remains uncertain. This has mainly been due to inadequate methodology and reporting in earlier studies but more recent studies of TENS for chronic pain fail to offer necessary improvements in methodological rigour to define the place of TENS in chronic pain management with any certitude. The search process identified 124 studies; 25 met the inclusion criteria for evaluation in this review but there were insufficient extractable data to make meta-analysis possible. New studies of rigorous design and adequate size are needed before any evidence-based recommendations can be made for patients or health professionals.