The effectiveness of topically applied capsaicin. A meta-analysis

Treatment options for osteoarthritis: considerations for older adults

Osteoarthritis (OA) is the most common form of arthritis and the leading cause of disability among older adults in the United States. Treatment options such as acetaminophen and nonsteroidal anti-inflammatory drugs are the most widely used agents to manage mild-to-moderate pain. Treatment with tramadol or opioids is usually reserved for severe pain associated with OA. These agents do not come without risk, especially for older adults. Patient-specific parameters and comorbid conditions must be considered when evaluating treatment options for older adults. This article reviews pharmacological and nonpharmacological approaches to the management of OA in older adults.

Evidence for the efficacy of complementary and alternative medicines in the management of osteoarthritis: a systematic review

Objectives. To critically evaluate the evidence regarding complementary and alternative medicine (CAM) taken orally or applied topically (excluding glucosamine and chondroitin) in the treatment of OA. Methods. Randomized clinical trials of OA using CAMs, in comparison with other treatments or placebo, published in English up to January 2009, were eligible for inclusion. They were identified using systematic searches of bibliographic databases and manual searching of reference lists. Information was extracted on outcomes, and statistical significance, in comparison with alternative treatment of placebo, and side effects were reported. The methodological quality of the primary studies was determined. Results. The present review found consistent evidence that capsaicin gel and S-adenosyl methionine were effective in the management of OA. There was also some consistency to the evidence that Indian Frankincense, methylsulphonylmethane and rose hip may be effective. For other substances with promising evidence, the evidence base was either insufficiently large or the evidence base was inconsistent. Most of the CAM compounds studied were free of major adverse effects. Conclusion. The major limitation in reviewing the evidence is the paucity of randomized controlled trials in the area: widening the evidence base, particularly for those compounds for which there is promising evidence, should be a priority for both researchers and funders.

OARSI recommendations for the management of hip and knee osteoarthritis: part III: Changes in evidence following systematic cumulative update of research published through January 2009

OBJECTIVE

To update evidence for available therapies in the treatment of hip and knee osteoarthritis (OA) and to examine whether research evidence has changed from 31 January 2006 to 31 January 2009.

METHODS

A systematic literature search was undertaken using MEDLINE, EMBASE, CINAHL, AMED, Science Citation Index and the Cochrane Library. The quality of studies was assessed. Effect sizes (ESs) and numbers needed to treat were calculated for efficacy. Relative risks, hazard ratios (HRs) or odds ratios were estimated for side effects. Publication bias and heterogeneity were examined. Sensitivity analysis was undertaken to compare the evidence pooled in different years and different qualities. Cumulative meta-analysis was used to examine the stability of evidence.

RESULTS

Sixty-four systematic reviews, 266 randomised controlled trials (RCTs) and 21 new economic evaluations (EEs) were published between 2006 and 2009. Of 51 treatment modalities, new data on efficacy have been published for more than half (26/39, 67%) of those for which research evidence was available in 2006. Among non-pharmacological therapies, ES for pain relief was unchanged for self-management, education, exercise and acupuncture. However, with new evidence the ES for pain relief for weight reduction reached statistical significance, increasing from 0.13 [95% confidence interval (CI) -0.12, 0.36] in 2006 to 0.20 (95% CI 0.00, 0.39) in 2009. By contrast, the ES for electromagnetic therapy which was large in 2006 (ES=0.77, 95% CI 0.36, 1.17) was no longer significant (ES=0.16, 95% CI -0.08, 0.39). Among pharmacological therapies, the cumulative evidence for the benefits and harms of oral and topical non-steroidal anti-inflammatory drugs, diacerhein and intra-articular (IA) corticosteroid was not greatly changed. The ES for pain relief with acetaminophen diminished numerically, but not significantly, from 0.21 (0.02, 0.41) to 0.14 (0.05, 0.22) and was no longer significant when analysis was restricted to high quality trials (ES=0.10, 95% CI -0.0, 0.23). New evidence for increased risks of hospitalisation due to perforation, peptic ulceration and bleeding with acetaminophen >3g/day have been published (HR=1.20, 95% CI 1.03, 1.40). ES for pain relief from IA hyaluronic acid, glucosamine sulphate, chondroitin sulphate and avocado soybean unsponifiables also diminished and there was greater heterogeneity of outcomes and more evidence of publication bias. Among surgical treatments further negative RCTs of lavage/debridement were published and the pooled results demonstrated that benefits from this modality of therapy were no greater than those obtained from placebo.

CONCLUSION

Publication of a large amount of new research evidence has resulted in changes in the calculated risk-benefit ratio for some treatments for OA. Regular updating of research evidence can help to guide best clinical practice.

The development of new analgesics over the past 50 years: a lack of real breakthrough drugs

Fifty-nine drugs identified as analgesics were introduced from 1960 to 2009 and remain in use. Seven can be regarded as having novel molecular targets; however, only one, sumatriptan, was sufficiently effective to motivate the introduction of many similar drugs acting at the same target (triptans). Publication productivity in the area of pain grew exponentially during this period. Pain-related publications on morphine were dominant among other analgesics. Very intensive research efforts directed at diverse molecular targets related to pain mechanisms produced thousands of publications, but those efforts have not yet yielded new analgesics with sufficient effectiveness to change the share of publications on opioids or nonsteroidal antiinflammatory drugs. Morphine and aspirin, introduced for the treatment of pain more than a century ago, continue to dominate biomedical publications despite their limited effectiveness in many areas (e.g., neuropathic pain) and multiple serious adverse effects. The present assessment reveals the lack of real breakthroughs in analgesic drug development despite intense research efforts. Possible factors contributing to the apparent drought of novel analgesics are discussed.

Transient receptor potential channels in pain and inflammation: therapeutic opportunities

In ancient times, physicians had a limited number of therapies to provide pain relief. Not surprisingly, plant extracts applied topically often served as the primary analgesic plan. With the discovery of the capsaicin receptor (transient receptor potential cation channel, subfamily V, member 1 [TRPV1]), the search for "new" analgesics has returned to compounds used by physicians thousands of years ago. One such compound, capsaicin, couples the paradoxical action of nociceptor activation (burning pain) with subsequent analgesia following repeat or high-dose application. Investigating this "paradoxical" action of capsaicin has revealed several overlapping and complementary mechanisms to achieve analgesia including receptor desensitization, nociceptor dysfunction, neuropeptide depletion, and nerve terminal destruction. Moreover, the realization that TRPV1 is both sensitized and activated by endogenous products of inflammation, including bradykinin, H+, adenosine triphosphate, fatty acid derivatives, nerve growth factor, and trypsins, has renewed interest in TRPV1 as an important site of analgesia. Building on this foundation, a new series of preclinical and clinical studies targeting TRPV1 has been reported. These include trials using brief exposure to high-dose topical capsaicin in conjunction with prior application of a local anesthetic. Clinical use of resiniferatoxin, another ancient but potent TRPV1 agonist, is also being explored as a therapy for refractory pain. The development of orally administered high-affinity TRPV1 antagonists holds promise for pioneering a new generation of analgesics capable of blocking painful sensations at the site of inflammation and tissue injury. With the isolation of other members of the TRP channel family such as TRP cation channel, subfamily A, member 1, additional opportunities are emerging in the development of safe and effective analgesics.

Amitriptyline vs. pregabalin in painful diabetic neuropathy: a randomized double blind clinical trial

AIMS

To compare the efficacy and safety of pregabalin and amitriptyline in alleviating pain associated with diabetic peripheral neuropathy.

METHODS

A randomized, double-blind, crossover, active-control, clinical trial with variable dose titration was carried out (n = 51). Amitriptyline orally, at doses of 10, 25 and 50 mg at night-time and pregabalin orally, at doses of 75, 150 and 300 mg twice daily, by optional titration was used. Each drug treatment was of 5 weeks. There was a placebo washout period for 3 weeks between the two drugs. Assessment for pain relief, overall improvement and adverse events were carried out.

RESULTS

Good, moderate and mild pain relief were noted in 21 (48%), 6 (13%) and 7 (15%) patients on pregabalin and 15 (34%), 5 (11%) and 12 (27%) patients on amitriptyline, respectively, by patient's global assessment of efficacy and safety. Patient and physician's global assessment, McGill pain questionnaire, Likert pain scale and Patient Global Impression of Change showed no significant difference between the treatments, although improvement with both treatments was seen from the first week. Of the 52 adverse events reported, 34 (65.4%) were with amitriptyline, drowsiness being the commonest [in 19 (43%) patients]. Pregabalin caused adverse events in 18 (25%), of which drowsiness was the most common in nine (20%) patients. The preferred pregabalin dose was 150 mg twice daily.

CONCLUSIONS

As there are few differences between the two treatments in efficacy, pregabalin 150 mg twice daily might be the alternative choice as it is associated with fewer adverse effects in our population.

Bibliographical investigation of complementary alternative medicines for osteoarthritis and rheumatoid arthritis

BACKGROUND

A variety of complementary and alternative medicine (CAM) treatments are provided to the elderly. We investigated the efficacy and safety of CAM substances that are available to patients with osteoarthritis (OA) and rheumatoid arthritis (RA), both in Japan and overseas.

METHODS

Information on CAM products was collected from the World Wide Web, using the keywords "arthritis" and "supplement" in five languages (Japanese, English, French, Italian and German) using a popular search engine for each of the languages. References to published work on the products were researched using PubMed with the keywords of "arthritis", "anti-inflammatory" and "analgesics". Such published work was classified according to the evidence levels established by the Cochrane Library.

RESULTS

Two-hundred and sixty CAM products for OA or RA were available in Japan, of which 41 CAM products had been tested in randomized controlled trials (RCT); there was no scientific evidence for the remaining 219 CAM products. Most of the previous RCT suggested that CAM was effective in OA or RA. Herein, we confirmed the significant OA relieving effects of chondroitin sulfate through a meta-analysis. Effectiveness was assessed using subjective scores, not disease-specific immunological or serological markers for assessment. Toxicological investigations had only been performed for a few CAM products.

CONCLUSION

Some CAM products that are effective against RA may be used together with biological therapy. However, some of the CAM products available in Japan should be tested using objective markers. Some CAM products for OA could be used for the relief of pain.

Instilled or injected purified natural capsaicin has no adverse effects on rat hindlimb sensory-motor behavior or osteotomy repair

BACKGROUND

A novel formulation of > or = 98% pure capsaicin (4975) is currently undergoing clinical investigation using novel routes of delivery to provide selective analgesia lasting weeks to months with a single dose. We conducted this study to assess the safety and effects of instilled and injected 4975 in rat models of wound healing osteotomy repair and sensory-motor nerve function.

METHODS

Adult male and female Sprague-Dawley rats were used. To assess the effects of 4975 on nerve or muscle, 0.0083 or 0.025 mg 4975 or vehicle (25% polyethylene glycol-300) was applied to exposed sciatic nerve, or 0.1 mg 4975 or vehicle was injected into the surrounding muscle (Group 1). To assess the effect of 4975 on bone healing, an osteotomy was made in one femur and 0.5 mg of 4975 or vehicle was instilled into the site (Group 2). Behavioral testing was performed on both groups of rats and histological evaluation of the sciatic nerve, and surrounding soft tissue and bone was done at days 3, 14, and 28 after surgery. Femurs from osteotomy rats were assessed using peripheral quantitative computed tomography and biomechanical testing. Standard statistical tests were used to compare groups.

RESULTS

Rats with direct application of 4975 to the sciatic nerve and surrounding muscle were no different from the controls in nociceptive sensory responses (F = 0.910, P = 0.454), grip strength (F = 0.550, P = 0.654), or histology of the muscle or sciatic nerve. In osteotomy rats, there were no statistical differences between 4975 and vehicle-treated rats for bone area (H = 2.858, P = 0.414), bone mineral content (F = 0.945, P = 0.425), or bone mineral density (F = 0.87, P = 0.462) and no difference in soft tissue healing. There were neither differences in bone stiffness (F = 1.369, P = 0.268) nor were there noticeable differences in the macro- or microscopic appearance of the right femur osteotomy healing site and surrounding soft tissues between the control group and the 4975-treated animals.

CONCLUSION

A single, clinically relevant application of instilled or injected 4975 has no observable adverse effect on wound and bone healing after osteotomy or on the structural integrity of exposed muscle and nerve.

Osteoarthritis: An Update on Data Currently Reshaping Practice

Osteoarthritis is common, has considerable health consequences, and will affect increasing numbers of persons in coming years. Nonpharmacological interventions are of paramount importance in achieving adequate symptom control. Acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) play a pivotal role in osteoarthritis pharmacotherapy. Acetaminophen, due to its safety profile, should be adequately trialed before resorting to NSAIDs. NSAIDs and celecoxib, a selective inhibitor of cyclooxygenase-2, should be selected thoughtfully so as to balance the likelihood of treatment success with gastrointestinal bleeding and cardiovascular events. Celecoxib may be used when the risk for gastrointestinal bleeding is high and the risk of cardiovascular events low. Otherwise, NSAIDs, usually naproxen, should be paired with a gastroprotective agent. Topical NSAIDs, including a recently approved diclofenac patch and gel, may also be useful when systemic exposure is undesirable. The role of glucosamine and chondroitin is controversial and the data conflicting. Other modalities, such as tramadol, opioids, and viscosupplementation should be tailored to the patient and clinical situation. Appropriate deployment of agents in the osteoarthritis armamentarium can maximize efficacy and safety thereby improving the disease burden for patients.

Management of painful diabetic neuropathy

The commonest cause of peripheral neuropathy is diabetes and pain occurs in approximately 30% of diabetic patients with neuropathy. It is extremely distressing for the patient and poses significant difficulties in management, as no treatment to date provides total relief and the side effects of therapy limit dose titration. Understanding the pathogenesis of diabetic neuropathy may lead to the development of new treatments for preventing nerve damage. Furthermore, a better understanding of the mechanisms that modulate pain may lead to more effective relief of painful symptoms. This review provides an update on the assessment and treatment of painful diabetic neuropathy.

[Treatment of osteoarthritis with drugs and other modalities]

There is an increasing incidence in osteoarthritis, particularly following the 5th life-decade. However, also young people may suffer from severe osteoarthritis, which is estimated to be the most common cause of disability in adults resulting in substantial economic burden. To this end, effective therapies are needed. Therapeutic options are very comprehensive, which are presented in this review as non-pharmacological, pharmacological and surgical treatment modalities. Treatment efficacy will be discussed with regard to alleviation of symptoms and potential prevention of disease progression according to the given evidence.

Review of the pharmaceutical properties and clinical effects of the topical NSAID formulation, diclofenac epolamine

BACKGROUND

Topical formulations of non-steroidal anti-inflammatory drugs (NSAIDs), in particular diclofenac (DI), have become popular for treating various acute and chronic painful inflammatory conditions.

OBJECTIVE

To perform a literature review of (1) the use of topical NSAIDs; (2) the pharmaceutical, pharmacokinetic and pharmacodynamic properties of a medicated plaster (patch) containing diclofenac epolamine (DI-EP, Flector Tissugel, Flector patch) compared with other formulations of topical NSAIDs; and (3) evaluation of the clinical findings from studies with this novel DI-EP patch.

OUTCOMES

(1) Pharmacokinetic studies involved determination of DI from DI-EP and separately epolamine (EP) and the epoxide metabolite (N-oxide-EP) in laboratory animals and humans; the latter being the major metabolite in humans. About 2% of DI is absorbed by the skin in humans and is excreted in the urine. Maximum plasma concentrations of 17.4 ng/mL DI are reached at 5.4 hours (approximate steady state conditions); the plasma elimination half-time (t(1/2)) being 26.4 hours. Low systemic levels of DI and EP are produced from DI-EP. Pronounced accumulation of DI occurs in the muscle layers and in synovial fluids of arthritic patients; (2) No significant toxicity occurs from EP nor N-oxide-EP, while that of oral DI-EP was similar to that from DI; and (3) In acute musculoskeletal conditions (sprains, tendonitis and sports injuries) and osteoarthritis DI-EP patches control pain and signs of joint or physical injury compared with placebo controls by 3-5 days with almost complete pain relief at 14 days. DI-EP was shown to have equivalent therapeutic effect to another DI diethylammonium gel formulation (Voltaren Emulgel). There were no reports of serious adverse events in the gastro-intestinal (GI) tract, kidneys or liver from DI-EP. Mild GI symptoms and skin reactions occur in 2 and 10% of patients, respectively.

CONCLUSIONS

The patch delivery of DI in DI-EP affords controlled delivery of the active drug in contrast to that from application of gels or ointments of NSAIDs.

Molecular network of cartilage homeostasis and osteoarthritis

This review article presents the current understanding of the molecular basis of articular cartilaginous homeostasis, and outlines potential areas to focus on within the developing field of therapeutics for cartilage disorders. Articular cartilage, an integral component of joints in extremities and the vertebral column, is essential for locomotion. Disturbance of joint development or cartilage homeostasis causes congenital osteocartilaginous dysplasia or osteoarthritic diseases, respectively. Symptomatic treatments and surgical replacement of joints are effective but can also be problematic in terms of quality of life over time. Recently, new insights into the molecular biological basis of chondrocyte differentiation and cartilage homeostasis have been reported. While joint formation is regulated by several growth factors such as Wnts (wingless-related MMTV integration site) and Gdfs (growth and differentiation factors), the pathology of osteoarthritis is now interpreted as the disruption of balance between anabolic and catabolic signals. Current findings in molecular biology on joint development are reviewed concisely to aid in the understanding of the molecular network that governs articular cartilage development and homeostasis.

Capsaicin (TRPV1 Agonist) therapy for pain relief: farewell or revival?

OBJECTIVE

In this review, we explain our current understanding of the molecular basis for pain relief by capsaicin and other transient receptor potential vanilloid subfamily, member 1 (TRPV1) agonists. We summarize disease-related changes in TRPV1 expression and its implications for therapy and potential adverse effects. Last, we provide an overview of the current clinical uses of topical and injectable TRPV1 agonist preparations in both oncologic and nononcologic populations.

METHOD

Search of MEDLINE and other databases.

RESULTS

The capsaicin receptor TRPV1 is a polymodal nociceptor exhibiting a dynamic threshold of activation that could be lowered under inflammatory conditions. Consistent with this model, TRPV1 knock-out mice are devoid of post-inflammatory thermal hyperalgesia. TRPV1 desensitization of primary sensory neurons is a powerful approach to relieve symptoms of nociceptive behavior in animal models of chronic pain. However, over-the-counter capsaicin creams have shown moderate to poor analgesic efficacy. This is in part related to low dose, poor skin absorption, and compliance factors. Recently developed site-specific capsaicin therapy with high-dose patches and injectable preparations seem to be safe and reportedly provide long-lasting analgesia with rapid onset.

CONCLUSIONS

We argue that TRPV1 agonists and antagonists are not mutually exclusive but rather complimentary pharmacologic approaches for pain relief and we predict a "revival" for capsaicin and other TRPV1 agonists in the clinical management of pain associated with inflammation, metabolic imbalances (eg, diabetes), infections (HIV), and cancer, despite the current focus of the pharmaceutical industry on TRPV1 antagonists.

An open-label pilot study of high-concentration capsaicin patch in painful HIV neuropathy

Peripheral neuropathy is the most frequent neurological complication of human immunodeficiency virus (HIV)-1 infection and is commonly associated with the development of chronic pain. This open-label, 12-week pilot study assessed the efficacy, tolerability, and safety of a high-concentration capsaicin dermal patch (NGX-4010; capsaicin, 640microg/cm2, 8% w/w) to treat painful HIV-associated distal sensory polyneuropathy (DSP). Eligible patients had moderate-to-severe pain in both feet due to HIV-associated DSP or antiretroviral toxic neuropathy. Patients received a single 60-minute application of the investigational high-concentration capsaicin patch to the affected areas. The primary outcome measure was the mean percent change in numeric pain rating scale (NPRS) during weeks two to 12 postadministration. After a single 60-minute NGX-4010 application, the mean percent change from baseline in "average pain for past 24 hours" NPRS scores during weeks two to 12 was -40% (95% CI: -61%, -19%; P=0.0020). Similar results were observed for "worst pain for past 24 hours" and "pain now" scores. Eight of 12 patients (67%) were treatment responders (> or =30% pain decrease). Four of 12 patients (33%) experienced a > or =50% reduction in pain. Treatment was generally well tolerated. Treatment-associated pain was self-limited and could be managed with short-acting opioids. This study demonstrates that treatment of painful HIV-associated neuropathy with a single application of NGX-4010, a high-concentration capsaicin patch, was feasible, well tolerated, and associated with significant reduction in pain over the 12 weeks studied. No safety concerns were identified. Controlled studies of NGX-4010 for the treatment of painful HIV-associated neuropathy are warranted.

OARSI recommendations for the management of hip and knee osteoarthritis, Part II: OARSI evidence-based, expert consensus guidelines

PURPOSE

To develop concise, patient-focussed, up to date, evidence-based, expert consensus recommendations for the management of hip and knee osteoarthritis (OA), which are adaptable and designed to assist physicians and allied health care professionals in general and specialist practise throughout the world.

METHODS

Sixteen experts from four medical disciplines (primary care, rheumatology, orthopaedics and evidence-based medicine), two continents and six countries (USA, UK, France, Netherlands, Sweden and Canada) formed the guidelines development team. A systematic review of existing guidelines for the management of hip and knee OA published between 1945 and January 2006 was undertaken using the validated appraisal of guidelines research and evaluation (AGREE) instrument. A core set of management modalities was generated based on the agreement between guidelines. Evidence before 2002 was based on a systematic review conducted by European League Against Rheumatism and evidence after 2002 was updated using MEDLINE, EMBASE, CINAHL, AMED, the Cochrane Library and HTA reports. The quality of evidence was evaluated, and where possible, effect size (ES), number needed to treat, relative risk or odds ratio and cost per quality-adjusted life years gained were estimated. Consensus recommendations were produced following a Delphi exercise and the strength of recommendation (SOR) for propositions relating to each modality was determined using a visual analogue scale.

RESULTS

Twenty-three treatment guidelines for the management of hip and knee OA were identified from the literature search, including six opinion-based, five evidence-based and 12 based on both expert opinion and research evidence. Twenty out of 51 treatment modalities addressed by these guidelines were universally recommended. ES for pain relief varied from treatment to treatment. Overall there was no statistically significant difference between non-pharmacological therapies [0.25, 95% confidence interval (CI) 0.16, 0.34] and pharmacological therapies (ES=0.39, 95% CI 0.31, 0.47). Following feedback from Osteoarthritis Research International members on the draft guidelines and six Delphi rounds consensus was reached on 25 carefully worded recommendations. Optimal management of patients with OA hip or knee requires a combination of non-pharmacological and pharmacological modalities of therapy. Recommendations cover the use of 12 non-pharmacological modalities: education and self-management, regular telephone contact, referral to a physical therapist, aerobic, muscle strengthening and water-based exercises, weight reduction, walking aids, knee braces, footwear and insoles, thermal modalities, transcutaneous electrical nerve stimulation and acupuncture. Eight recommendations cover pharmacological modalities of treatment including acetaminophen, cyclooxygenase-2 (COX-2) non-selective and selective oral non-steroidal anti-inflammatory drugs (NSAIDs), topical NSAIDs and capsaicin, intra-articular injections of corticosteroids and hyaluronates, glucosamine and/or chondroitin sulphate for symptom relief; glucosamine sulphate, chondroitin sulphate and diacerein for possible structure-modifying effects and the use of opioid analgesics for the treatment of refractory pain. There are recommendations covering five surgical modalities: total joint replacements, unicompartmental knee replacement, osteotomy and joint preserving surgical procedures; joint lavage and arthroscopic debridement in knee OA, and joint fusion as a salvage procedure when joint replacement had failed. Strengths of recommendation and 95% CIs are provided.

CONCLUSION

Twenty-five carefully worded recommendations have been generated based on a critical appraisal of existing guidelines, a systematic review of research evidence and the consensus opinions of an international, multidisciplinary group of experts. The recommendations may be adapted for use in different countries or regions according to the availability of treatment modalities and SOR for each modality of therapy. These recommendations will be revised regularly following systematic review of new research evidence as this becomes available.

Osteoarthritis of the knee in primary care

Topical NSAIDS are as effective as oral NSAIDs, and patients prefer them

OARSI recommendations for the management of hip and knee osteoarthritis, part I: critical appraisal of existing treatment guidelines and systematic review of current research evidence

PURPOSE

As a prelude to developing updated, evidence-based, international consensus recommendations for the management of hip and knee osteoarthritis (OA), the Osteoarthritis Research Society International (OARSI) Treatment Guidelines Committee undertook a critical appraisal of published guidelines and a systematic review (SR) of more recent evidence for relevant therapies.

METHODS

Sixteen experts from four medical disciplines (primary care two, rheumatology 11, orthopaedics one and evidence-based medicine two), two continents and six countries (USA, UK, France, Netherlands, Sweden and Canada) formed the guidelines development team. Three additional experts were invited to take part in the critical appraisal of existing guidelines in languages other than English. MEDLINE, EMBASE, Science Citation Index, CINAHL, AMED, Cochrane Library, seven Guidelines Websites and Google were searched systematically to identify guidelines for the management of hip and/or knee OA. Guidelines which met the inclusion/exclusion criteria were assigned to four groups of four appraisers. The quality of the guidelines was assessed using the AGREE (Appraisal of Guidelines for Research and Evaluation) instrument and standardised percent scores (0-100%) for scope, stakeholder involvement, rigour, clarity, applicability and editorial independence, as well as overall quality, were calculated. Treatment modalities addressed and recommended by the guidelines were summarised. Agreement (%) was estimated and the best level of evidence to support each recommendation was extracted. Evidence for each treatment modality was updated from the date of the last SR in January 2002 to January 2006. The quality of evidence was evaluated using the Oxman and Guyatt, and Jadad scales for SRs and randomised controlled trials (RCTs), respectively. Where possible, effect size (ES), number needed to treat, relative risk (RR) or odds ratio and cost per quality-adjusted life year gained (QALY) were estimated.

RESULTS

Twenty-three of 1462 guidelines or consensus statements retrieved from the literature search met the inclusion/exclusion criteria. Six were predominantly based on expert opinion, five were primarily evidence based and 12 were based on both. Overall quality scores were 28%, 41% and 51% for opinion-based, evidence-based and hybrid guidelines, respectively (P=0.001). Scores for aspects of quality varied from 18% for applicability to 67% for scope. Thirteen guidelines had been developed for specific care settings including five for primary care (e.g., Prodigy Guidance), three for rheumatology (e.g., European League against Rheumatism recommendations), three for physiotherapy (e.g., Dutch clinical practice guidelines for physical therapy) and two for orthopaedics (e.g., National Institutes of Health consensus guidelines), whereas 10 did not specify the target users (e.g., Ontario guidelines for optimal therapy). Whilst 14 guidelines did not separate hip and knee, eight were specific for knee but only one for hip. Fifty-one different treatment modalities were addressed by these guidelines, but only 20 were universally recommended. Evidence to support these modalities ranged from Ia (meta-analysis/SR of RCTs) to IV (expert opinion). The efficacy of some modalities of therapy was confirmed by the results of RCTs published between January 2002 and 2006. These included exercise (strengthening ES 0.32, 95% confidence interval (CI) 0.23, 0.42, aerobic ES 0.52, 95% CI 0.34, 0.70 and water-based ES 0.25, 95% CI 0.02, 0.47) and nonsteroidal anti-inflammatory drugs (NSAIDs) (ES 0.32, 95% CI 0.24, 0.39). Examples of other treatment modalities where recent trials failed to confirm efficacy included ultrasound (ES 0.06, 95% CI -0.39, 0.52), massage (ES 0.10, 95% CI -0.23, 0.43) and heat/ice therapy (ES 0.69, 95% CI -0.07, 1.45). The updated evidence on adverse effects also varied from treatment to treatment. For example, while the evidence for gastrointestinal (GI) toxicity of non-selective NSAIDs (RR=5.36, 95% CI 1.79, 16.10) and for increased risk of myocardial infarction associated with rofecoxib (RR=2.24, 95% CI 1.24, 4.02) were reinforced, evidence for other potential drug related adverse events such as GI toxicity with acetaminophen or myocardial infarction with celecoxib remained inconclusive.

CONCLUSION

Twenty-three guidelines have been developed for the treatment of hip and/or knee OA, based on opinion alone, research evidence or both. Twenty of 51 modalities of therapy are universally recommended by these guidelines. Although this suggests that a core set of recommendations for treatment exists, critical appraisal shows that the overall quality of existing guidelines is sub-optimal, and consensus recommendations are not always supported by the best available evidence. Guidelines of optimal quality are most likely to be achieved by combining research evidence with expert consensus and by paying due attention to issues such as editorial independence, stakeholder involvement and applicability. This review of existing guidelines provides support for the development of new guidelines cognisant of the limitations in existing guidelines. Recommendations should be revised regularly following SR of new research evidence as this becomes available.

Plasma concentration of selected neuropeptides in patients suffering from psoriasis

The aim of this study was to evaluate plasma levels of substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY) during psoriasis course.

METHODS

Seventy-three patients with psoriasis and 32 healthy volunteers were included. Detailed demographic and disease anamnesis was obtained from every patient. The disease severity was assessed using the Psoriasis Area and Severity Index score. Plasma levels of SP, CGRP, VIP and NPY were measured radioimmunologically.

RESULTS

Plasma levels of SP and NPY did not significantly differ between patients with psoriasis and controls (median SP: 52.8 and 57.9 pg/ml, respectively; P = 0.32; median NPY: 8.5 and 8.2 pg/ml, respectively; P = 0.67). CGRP plasma concentration was significantly elevated in psoriatic individuals both before (median 43.1 pg/ml) and after treatment (median 45.4 pg/ml), in comparison with healthy donors (median 13.5 pg/ml; P < 0.01 and P = 0.03, respectively). Treatment did not significantly influence plasma CGRP levels (P = 0.3). Median VIP plasma concentration in psoriatics before treatment was significantly higher compared with healthy controls (medians 66.9 and 60.1 pg/ml, respectively; P = 0.04), but the therapy resulted in significant decrease in VIP plasma level (median 19.0 pg/ml; P < 0.001). In psoriatic patients significant correlations were noted between NPY and VIP (R = 0.34; P < 0.01), and VIP and CGRP plasma levels, both before (R = 0.28; P = 0.03) and after the treatment (R = 0.44; P < 0.01).

CONCLUSIONS

Based on our results and previous literature data it could be suggested that neuropeptides may be involved in the development of psoriatic lesions.

Randomized double-blind study comparing the efficacy and safety of lamotrigine and amitriptyline in painful diabetic neuropathy

AIMS

To compare the efficacy and safety of lamotrigine and amitriptyline in controlling chronic painful peripheral neuropathy in diabetic patients.

METHODS

A randomized, double-blind, crossover, active-control, clinical trial with variable dose titration was carried out (n = 53). Amitriptyline orally, at doses of 10, 25 and 50 mg at night-time, each dose for 2 weeks, and lamotrigine orally, at doses of 25, 50 and 100 mg twice daily, each dose for 2 weeks, by optional titration were used. There was a placebo washout period for 2 weeks between the two drugs. Assessment for pain relief, overall improvement and adverse events were carried out.

RESULTS

Good, moderate and mild pain relief were noted in 19 (41%), six (13%) and seven (15%) patients on lamotrigine and 13 (28%), five (11%) and 15 (33%) patients on amitriptyline, respectively, by patient's global assessment of efficacy and safety. Patient and physicians global assessment, McGill pain questionnaire and Likert pain scale showed no significant difference between the treatments, although improvement with both treatments was seen from 2 weeks. Of the 44 adverse events reported, 33 (75%) were with amitriptyline, sedation being the commonest [in 19 (43%) patients]. Lamotrigine caused adverse events in 11 (25%), of which rash in three (7%) and elevations of creatinine in four (9%) were the most common. The preferred lamotrigine dose was 25 mg twice daily.

CONCLUSIONS

As there are few differences between the two treatments in efficacy, lamotrigine 25 mg twice daily might be the first choice as it is associated with fewer adverse effects in our population.

Topical agents for the management of musculoskeletal pain

The recent recognition of the magnitude of cardiovascular risk of both nonselective nonsteroidal anti-inflammatory drugs and COX-2 selective inhibitors, in addition to the persistent concerns about the use of opioids, has brought increased attention to nonsystemic, topical analgesics. These agents have a favorable safety profile and there is increasing evidence indicating their efficacy for a variety of pain disorders. The use of topical analgesics in the treatment of the most prevalent musculoskeletal pain syndromes is described, with a focus on mechanisms for drug delivery and clinical trials data.

Multimodal approaches to the management of neuropathic pain: the role of topical analgesia

Because of their localized activity and low systemic absorption, topical analgesics have a favorable safety profile and a low risk for drug-drug interactions. There is a growing body of evidence on the efficacy and safety of these agents in a variety of pain disorders, including the most prevalent neuropathic pain conditions. The molecular basis for the usage of peripheral analgesics in neuropathic pain and the available clinical trial evidence for a wide variety of topical agents are reviewed.

EULAR evidence based recommendations for the management of hand osteoarthritis: report of a Task Force of the EULAR Standing Committee for International Clinical Studies Including Therapeutics (ESCISIT)

OBJECTIVES

To develop evidence based recommendations for the management of hand osteoarthritis (OA).

METHODS

The multidisciplinary guideline development group comprised 16 rheumatologists, one physiatrist, one orthopaedic surgeon, two allied health professionals, and one evidence based medicine expert, representing 15 different European countries. Each participant contributed up to 10 propositions describing key clinical points for management of hand OA. Final recommendations were agreed using a Delphi consensus approach. A systematic search of Medline, Embase, CINAHL, Science Citation Index, AMED, Cochrane Library, HTA, and NICE reports was used to identify the best available research evidence to support each proposition. Where possible, the effect size and number needed to treat were calculated for efficacy. Relative risk or odds ratio was estimated for safety, and incremental cost effectiveness ratio was used for cost effectiveness. The strength of recommendation was provided according to research evidence, clinical expertise, and perceived patient preference.

RESULTS

Eleven key propositions involving 17 treatment modalities were generated through three Delphi rounds. Treatment topics included general considerations (for example, clinical features, risk factors, comorbidities), non-pharmacological (for example, education plus exercise, local heat, and splint), pharmacological (for example, paracetamol, NSAIDs, NSAIDs plus gastroprotective agents, COX-2 inhibitors, systemic slow acting disease modifying drugs, intra-articular corticosteroids), and surgery. Of 17 treatment modalities, only six were supported by research evidence (education plus exercise, NSAIDs, COX-2 inhibitors, topical NSAIDs, topical capsaicin, and chondroitin sulphate). Others were supported either by evidence extrapolated from studies of OA affecting other joint sites or by expert opinion. Strength of recommendation varied according to level of evidence, benefits and harms/costs of the treatment, and clinical expertise.

CONCLUSION

Eleven key recommendations for treatment of hand OA were developed using a combination of research based evidence and expert consensus. The evidence was evaluated and the strength of recommendation was provided.

Management of neuropathic pain: translating mechanistic advances and evidence-based research into clinical practice

The concept of rational polypharmacy is now well established in the field of pain management. This concept has evolved in concert with progress in understanding the pathophysiologic mechanisms of pain diseases and disorders and how medications affect these processes. Other clinical factors must be considered in formulating the pain management strategy most likely to succeed in both controlling pain and improving function in a given patient. This article will review how pain diagnosis, pain mechanisms, pain phenomenology, medication efficacy, and risk profile influence medication selection in pain medicine practice, with a selective focus on the treatment of neuropathic pain. In addition, the role of psychosocial factors as they affect pain management will be discussed.

The pharmacotherapy of chronic pain: a review

The past two decades have contributed a large body of preclinical work that has assisted in our understanding of the underlying pathophysiological mechanisms that cause chronic pain. In this context, it has been recognized that effective treatment of pain is a priority and that treatment often involves the use of one or a combination of agents with analgesic action. The current review presents an evidence-based approach to the pharmacotherapy of chronic pain. Medline searches were done for all agents used as conventional treatment in chronic pain. Published papers up to June 2005 were included. The search strategy included randomized, controlled trials, and where available, systematic reviews and meta-analyses. Further references were found in reference sections of papers located using the above search strategy. Agents for which there were no controlled trials supporting efficacy in treatment of chronic pain were not included in the present review, except in cases where preclinical science was compelling, or where initial human work has been positive and where it was thought the reader would be interested in the scientific evidence to date.

Use of Herbal Therapies to Relieve Pain: A Review of Efficacy and Adverse Effects

To find holistic treatment with effective pain relief and few side effects, Americans spend billions of dollars annually on complementary and alternative medicine, including herbal therapies. Despite extensive use, the lack of regulatory scrutiny of these herbal supplements contributes to the paucity of reliable clinical data assessing their efficacy and safety. This review summarizes the existing studies investigating the efficacy of herbal therapies as a treatment for pain. Possible side effects, potential drug-herb interactions, and information about common herbal therapies are also summarized. MEDLINE, AMED, and the Cochrane Library databases were searched for the period from January 1966 to June 2005. Uses, dosages, routes of administration, and side effects were summarized. Strength of empirical evidence also was evaluated. This review found few well-controlled clinical studies. Furthermore, these studies documented limited efficacy of herbal therapies to treat pain. The information presented here may be used to further educate nurses and patients on the use of herbal therapies as well as direct future research efforts.

The effects of intraarticular resiniferatoxin in experimental knee-joint arthritis

In this study we sought to determine whether an intraarticular administration of a vanilloid agonist resiniferatoxin (RTX) produces an analgesic effect in experimental arthritis. Knee joint inflammation was induced in rats by intraarticular carrageenan (2%, 30 microL). Pain score and left/right hind leg weight distribution ratio were used to assess pain behavior. Changes in knee dimensions were evaluated by measuring external circumference and intraarticular area (ultrasound scanning). The intraarticular administration of RTX (0.0003% or 0.003%, 30 microL) provided a significant analgesic effect. Twenty-four hours after RTX administration, the pain score was reduced from 15.1 +/- 4.7 to 6.9 +/- 4.4 (P < 0.01) with 0.0003% and was abolished (P < 0.0001) with 0.003%. The improvement in weight distribution ratio lasted for several days after the RTX administration. Reduction in knee circumference demonstrated that intraarticular RTX suppressed the carrageenan-induced edema by at least one third. Ultrasound scanning revealed no RTX-induced decrease of the intraarticular area. The experiments demonstrated that intraarticular RTX inhibits pain behavior in knee-joint arthritis and that this effect is dose-dependent. These results suggest a new direction for peripheral analgesia.

Small fiber neuropathy: a common and important clinical disorder

Small fiber neuropathy (SFN) is a neuropathy selectively involving small diameter myelinated and unmyelinated nerve fibers. Interest in this disorder has considerably increased during the past few years. It is often idiopathic and typically presents with peripheral pain and/or symptoms of autonomic dysfunction. Diagnosis is made on the basis of the clinical features, normal nerve conduction studies (NCS) and abnormal specialized tests of small nerve fibers. Among others, these tests include assessment of epidermal nerve fiber density, temperature sensation tests for sensory fibers and sudomotor and cardiovagal testing (QSART) for autonomic fibers. Unless an underlying disease is identified, treatment is usually symptomatic and directed towards alleviation of neuropathic pain.

Pregabalin for the treatment of painful diabetic peripheral neuropathy: a double-blind, placebo-controlled trial

A randomized, double-blind, placebo-controlled, parallel-group, multicenter, 8-week trial (with subsequent open-label phase) evaluated the effectiveness of pregabalin in alleviating pain associated with diabetic peripheral neuropathy (DPN). For enrollment, patients must have had at baseline: 1- to 5-year history of DPN pain; pain score > or =40 mm (Short-Form McGill Pain Questionnaire [SF-MPQ] visual analogue scale); average daily pain score of > or =4 (11-point numerical pain rating scale [0 = no pain, 10 = worst possible pain]). One hundred forty-six (146) patients were randomized to receive placebo (n = 70) or pregabalin 300 mg/day (n = 76). Primary efficacy measure was endpoint mean pain score from daily patient diaries (11-point numerical pain rating scale). Secondary measures included SF-MPQ scores; sleep interference scores; Patient and Clinical Global Impression of Change (PGIC and CGIC); Short Form-36 (SF-36) Health Survey scores; and Profile of Mood States (POMS) scores. Safety assessment included incidence and intensity of adverse events, physical and neurological examinations, and laboratory evaluations. Pregabalin produced significant improvements versus placebo for mean pain scores (P < 0.0001); mean sleep interference scores SF-36 Bodily Pain subscale (P < 0.0001); total SF-MPQ score (P < 0.01); SF-36 Bodily Pain subscale (P < 0.03); PGIC (P = 0.001); and Total Mood Disturbance and Tension-Anxiety components of POMS (P < 0.03). Pain relief and improved sleep began during week 1 and remained significant throughout the study (P < 0.01). Pregabalin was well tolerated despite a greater incidence of dizziness and somnolence than placebo. Most adverse events were mild to moderate and did not result in withdrawal. Pregabalin was safe and effective in decreasing pain associated with DPN, and also improved mood, sleep disturbance, and quality of life.

Immunohistochemical analysis of substance P containing nerve fibres and their contacts with mast cells in the diabetic rat's tongue

Sensory neuropathy is common symptom of the diabetes mellitus and the prevalence of oral lesions is higher in diabetic patients. The distribution of substance P was studied immunohistochemically in streptozotocin induced diabetic rat's tongue. The morphological association of sensory nerves (substance P immunoreactive) with mast cells (nerve fibre-mast cell contact) was monitored. The substance P nerve fibre mast cell contacts were very scanty in control tongue. The number of substance P nerve terminals and mast cells was significantly increased (p < 0.05) in diabetes mellitus after 4 weeks of the treatment compared with the control tongue. The number of mast cell nerve contacts was even more significantly increased (p < 0.001) in diabetes. The distance between nerve fibres and mast cells was about 1 mm and very often less than 200 nm. In some instances, the mast cells were degranulated in the vicinity to nerve fibres. Increased number of mast cell nerve contacts in neurogenic inflammation might cause vasoconstriction and lesions of the oral mucosa, so some disorders such lichen planus, leukoplakia and cancer might frequently develop in diabetes mellitus.

Use of complementary medicines for osteoarthritis--a prospective study

BACKGROUND

Patients with osteoarthritis commonly use complementary and alternative medicines (CAM), either as an adjunct to or in place of conventional analgesics.

OBJECTIVES

To undertake a prospective investigation of the prevalence of CAM use for osteoarthritis and the direct costs incurred.

METHODS

The subjects were 341 patients with osteoarthritis of the knee or hip drawn from central and northern Sydney, Australia, and comprising 83 community based patients and 258 awaiting joint replacement. Information on CAM use was obtained from prospective three monthly diaries. Variables of interest included health related quality of life scores. Prospective out of pocket costs were recorded over a 12 month follow up period.

RESULTS

The prevalence of CAM use was 40%, which falls within the range of previous studies. Average annual expenditure on CAM was 32.25 Australian dollars (range 0 to 603.30). CAM users were more likely to be female (odds ratio (OR) 1.8 (95% confidence interval, 1.1 to 3.0)), reported a higher level of bodily pain (OR 0.97 (0.95 to 0.99)), and were less likely to purchase conventional analgesics (OR 3.3 (1.6 to 7.0)), either prescribed or over the counter. Vitamin supplementation was the most common CAM reported, followed by celery extract, fish oils, and garlic extracts.

CONCLUSIONS

There are no good quality clinical trials to support the use of most preparations purchased by patients with osteoarthritis. There is a need for patient education on the risks and benefits of complementary medicine in osteoarthritis.