Capsaicin cream 0.025% as Monotherapy for Osteoarthritis: A double-blind study

Efficacy and safety of topical capsaicin in the treatment of osteoarthritis pain: A systematic review and meta-analysis

Osteoarthritis (OA) affects hundreds of millions of people worldwide. The objective was to critically appraise the efficacy and safety of topical capsaicin in reducing pain in OA. MEDLINE (PubMed) and Embase (Ebsco) were searched from inceptions until February 2023. The eligibility criteria included randomized controlled trials (RCTs), evaluating topical capsaicin in OA patients. Standard Cochrane methods were used to extract data and to appraise eligible studies. Eight double-blind RCTs involving 498 patients were included. Five trials (62.5%) were at an overall low risk of bias, and three (37.5%) were at a high risk of bias. Meta-analysis showed that, in various OA patients, compared with placebo, topical capsaicin (0.0125%-5%) may reduce pain severity measured with visual analog scale (standardized mean difference = -0.84, 95% confidence intervals [CIs] = -1.48 to -0.19, p = 0.01; eight studies). However, topical capsaicin may increase burning sensation at the application site (risk ratio = 5.56, 95% CI = 1.75-17.69, p = 0.004, numbers needed to harm = 3; five studies) when compared with placebo. Limitations include short study durations, small sample sizes, high heterogeneity, and overall low-to-very-low certainty of the evidence. Topical capsaicin may reduce OA pain at follow-ups of up to 3 months. Larger trials, potentially evaluating capsaicin in combination with phytopharmaceuticals having anti-inflammatory effects, with longer follow-ups might be needed to reduce the existing uncertainties. Topical capsaicin might be recommended for short-term management of pain in OA patients intolerant to nonsteroidal anti-inflammatory drugs.

A solid lipid particle formulation of long pepper extract reduces pain and astrocyte activation in a rat model of neuropathic pain

OBJECTIVES

To investigate the effects of solid lipid microparticle (SLM) creams containing a long pepper extract (LPE) or piperine on neuropathy-related pain and the expression of glial fibrillary acidic protein (GFAP) as a measure of astrogliosis.

METHODS

Neuropathic pain in male Spraque Dawley rats was induced by sciatic nerve ligation (SNL) and followed by treatment with LPE-SLM, piperine-SLM, capsaicin or vehicle creams. The pain score was assessed by thermal hyperalgesia test. The GFAP expression in the spinal cord was determined by immunohistochemistry.

RESULTS

Pain scores were significantly increased after SNL and decreased when treated by LPE-SLM. The number of GFAP immunopositive cells was significantly increased in the SNL rats. Treated by LPE-SLM and capsaicin creams resulted in a significant reduction of the number of GFAP immunopositive cells. The LPE-SLM treated rats showed greater effects than the piperine and capsaicin preparations.

CONCLUSIONS

The LPE-SLM cream has a potential effect on pain attenuation via a decrease of spinal astrocyte activation-related mechanism. The LPE in SLM preparation could provide an alternative therapeutic strategy for treating neuropathic pain.

Prospects for Therapies in Osteoarthritis

Osteoarthritis (OA) is a chronic, debilitating disease affecting millions of people worldwide. Management of OA involves pharmacological and non-pharmacological approaches. Conventional pharmacological treatments have limited efficacy and are associated with a number of side-effects, restricting the number of patients who can use them. New pharmacological therapies for managing OA are required and a number have been developed targeting different tissues in OA: bone and cartilage, synovium and nerves. However, there has been overall limited success. Disease-modifying osteoarthritis drugs (DMOADs) are a putative class of therapies aimed at improving OA structural pathologies and consequent symptoms. Recent DMOAD studies have demonstrated some promising therapies but also provided new considerations for future trials.

Fight fire with fire: Neurobiology of capsaicin-induced analgesia for chronic pain

Capsaicin, the pungent ingredient in chili peppers, produces intense burning pain in humans. Capsaicin selectively activates the transient receptor potential vanilloid 1 (TRPV1), which is enriched in nociceptive primary afferents, and underpins the mechanism for capsaicin-induced burning pain. Paradoxically, capsaicin has long been used as an analgesic. The development of topical patches and injectable formulations containing capsaicin has led to application in clinical settings to treat chronic pain conditions, such as neuropathic pain and the potential to treat osteoarthritis. More detailed determination of the neurobiological mechanisms of capsaicin-induced analgesia should provide the logical rationale for capsaicin therapy and help to overcome the treatment's limitations, which include individual differences in treatment outcome and procedural discomfort. Low concentrations of capsaicin induce short-term defunctionalization of nociceptor terminals. This phenomenon is reversible within hours and, hence, likely does not account for the clinical benefit. By contrast, high concentrations of capsaicin lead to long-term defunctionalization mediated by the ablation of TRPV1-expressing afferent terminals, resulting in long-lasting analgesia persisting for several months. Recent studies have shown that capsaicin-induced Ca²⁺/calpain-mediated ablation of axonal terminals is necessary to produce long-lasting analgesia in a mouse model of neuropathic pain. In combination with calpain, axonal mitochondrial dysfunction and microtubule disorganization may also contribute to the longer-term effects of capsaicin. The analgesic effects subside over time in association with the regeneration of the ablated afferent terminals. Further determination of the neurobiological mechanisms of capsaicin-induced analgesia should lead to more efficacious non-opioidergic analgesic options with fewer adverse side effects.

Conditional Recommendations for Specific Dietary Ingredients as an Approach to Chronic Musculoskeletal Pain: Evidence-Based Decision Aid for Health Care Providers, Participants, and Policy Makers

OBJECTIVE

Approximately 55-76% of Service members use dietary supplements for various reasons; although such use has become popular for a wide range of pain conditions, decisions to use supplements are often driven by information that is not evidence-based. This work evaluates whether the current research on dietary ingredients for chronic musculoskeletal pain provides sufficient evidence to inform decisions for practice and self-care, specifically for Special Operations Forces personnel.

METHODS

A steering committee convened to develop research questions and factors required for decision-making. Key databases were searched through August 2016. Eligible systematic reviews and randomized controlled trials were assessed for methodological quality. Meta-analysis was applied where feasible. GRADE was used to determine confidence in the effect estimates. A decision table was constructed to make evidence-informed judgments across factors required for decision-making, and recommendations were made for practice and self-care use.

RESULTS

Nineteen dietary ingredients were included. Conditional evidence-based recommendations were made for the use of avocado soybean unsaponifiables, capsaicin, curcuma, ginger, glucosamine, melatonin, polyunsaturated fatty acids, and vitamin D. In these cases, desirable effects outweighed undesirable effects, but there was uncertainty about the trade-offs, either because the evidence was low quality or because benefits and downsides were closely balanced.

CONCLUSIONS

The evidence showed that certain dietary ingredients, when taken as part of a balanced diet and/or as a supplement (e.g., pill, tablet, capsule, cream), may alleviate musculoskeletal pain with no to minimal risk of harm. This finding emphasizes and reinforces the critical importance of shared decision-making between Operators and their health care providers.

Toxicokinetic Study of a Gastroprotective Dose of Capsaicin by HPLC-FLD Method

BACKGROUND

A low dose of capsaicin and its natural homologs and analogs (capsaicinoids) have shown to prevent development of gastric mucosal damage of alcohol and non-steroid anti-inflammatory drugs. Based on this experimental observation, a drug development program has been initiated to develop per os applicable capsaicin containing drugs to eliminate gastrointestinal damage caused by non-steroid anti-inflammatory drugs.

METHODS

As a part of this program, a sensitive and selective reverse-phase high-performance liquid chromatography-based method with fluorescence detection has been developed for quantification of capsaicin and dihydrocapsaicin in experimental dog's plasma.

RESULTS

The method was evaluated for a number of validation characteristics (selectivity, repeatability, and intermediate precision, LOD, LOQ, and calibration range). The limit of detection (LOD) was 2 ng/mL and the limit of quantification (LOQ) was 10 ng/mL for both capsaicin and dihydrocapsaicin. The method was used for analysis of capsaicin and dihydrocapsaicin in the plasma samples obtained after per os administration of low doses (0.1, 0.3, and 0.9 mg/kg bw) of Capsaicin Natural (USP 29) to the experimental animals.

CONCLUSIONS

The obtained results indicated that the administered capsaicinoids did not reach the general circulation.

Update on novel pharmacological therapies for osteoarthritis

Osteoarthritis (OA) is a chronic painful arthritis with increasing global prevalence. Current management involves non-pharmacological interventions and commonly used pharmacological treatments that generally have limited analgesic efficacy and multiple side effects. New treatments are therefore required to relieve patient symptoms and disease impact. A number of existing pharmacological therapies have been recently trialled in OA. These include extended-release triamcinolone and conventional disease-modifying anti-rheumatic drugs (DMARDs) used in the management of rheumatoid arthritis; generally, DMARDs have not shown a benefit in treating OA. Novel analgesic therapies are in development, including those targeting peripheral pain pathways. Disease-modifying osteoarthritis drugs (DMOADs) target key tissues in the OA pathophysiology process and aim to prevent structural progression; a number of putative DMOADs are in phase II development. There is preliminary evidence of structural improvement with some of these therapies but without concomitant symptom improvement, raising new considerations for future DMOAD trials.

The relative efficacy of topical non-steroidal anti-inflammatory drugs and capsaicin in osteoarthritis: a network meta-analysis of randomised controlled trials

OBJECTIVE

To compare the efficacy of topical non-steroidal anti-inflammatory drugs (NSAIDs) with topical capsaicin for pain relief in osteoarthritis (OA).

DESIGN

A systematic literature search was conducted for randomised controlled trials (RCTs) examining any topical NSAID or capsaicin in OA. Pain relief at or nearest to 4 weeks was pooled using a random-effects network meta-analysis (NMA) in a Frequentist and Bayesian setting. Analysis was conducted for all trials and for trials using drugs listed as licensed for OA in the British National Formulary (BNF).

RESULTS

The trial network comprised 28 RCTs (7372 participants), of which 17 RCTs (3174 participants) were included in the as licensed analyses. No RCTs directly compared topical NSAIDs with capsaicin. Placebo was the only common comparator for topical NSAIDs and capsaicin. Frequentist and Bayesian effect size (ES) estimates were in agreement. Topical NSAIDs were statistically superior to placebo overall (ES 0.30, 95% confidence interval [CI] 0.19 to 0.41) and as licensed (ES 0.32, 95% CI 0.24 to 0.39). However, capsaicin was only statistically superior to placebo when used at licensed doses (ES 0.41, 95% CI 0.17 to 0.64). No significant differences were observed in pain relief between topical NSAIDs and capsaicin (overall: ES 0.04, 95% CI -0.26 to 0.33; as licensed: ES-0.09, 95% CI -0.34 to 0.16).

CONCLUSIONS

Current evidence indicates that topical NSAIDs and capsaicin in licensed doses may be equally effective for pain relief in OA. Whether the equivalence varies between individuals remains unknown.

Harnessing the Therapeutic Potential of Capsaicin and Its Analogues in Pain and Other Diseases

Capsaicin is the most predominant and naturally occurring alkamide found in Capsicum fruits. Since its discovery in the 19th century, the therapeutic roles of capsaicin have been well characterized. The potential applications of capsaicin range from food flavorings to therapeutics. Indeed, capsaicin and few of its analogues have featured in clinical research covered by more than a thousand patents. Previous records suggest pleiotropic pharmacological activities of capsaicin such as an analgesic, anti-obesity, anti-pruritic, anti-inflammatory, anti-apoptotic, anti-cancer, anti-oxidant, and neuro-protective functions. Moreover, emerging data indicate its clinical significance in treating vascular-related diseases, metabolic syndrome, and gastro-protective effects. The dearth of potent drugs for management of such disorders necessitates the urge for further research into the pharmacological aspects of capsaicin. This review summarizes the historical background, source, structure and analogues of capsaicin, and capsaicin-triggered TRPV1 signaling and desensitization processes. In particular, we will focus on the therapeutic roles of capsaicin and its analogues in both normal and pathophysiological conditions.

A Mechanism-Based Approach to the Management of Osteoarthritis Pain

Pain from osteoarthritis (OA) affects millions of people worldwide, yet treatments are limited to acetaminophen, NSAIDs, physical therapy, and ultimately, surgery when there is significant disability. In recent years, our understanding of pain pathways in OA has developed considerably. Though joint damage and inflammation play a significant role in pain generation, it is now understood that both central and peripheral nervous system mechanisms exacerbate symptoms. Evolving management strategies for OA address central factors (e.g., sleep difficulties, catastrophizing, and depression) with treatments such as cognitive behavioral therapy and exercise. In addition, emerging data suggest that antibodies against peripheral signaling neuropeptides, such as nerve growth factor-1 (NGF-1), may significantly alleviate pain. However, concerns regarding potential adverse effects, such as rapidly progressive OA, still remain. A nuanced understanding is essential if we are to make headway in developing more effective treatments for OA.

Alternative methods of pain management for the older adult population: Review of topical pain medications

The older adult population is one of the fastest growing age groups in the United States. As this population continues to expand, determining the safest way to provide pain management has become increasingly important. More than 50% of community-dwelling older adults experience pain on a daily basis, and up to 83% of those in assisted living facilities experience persistent pain. Pain is exceedingly challenging to treat safely and effectively in the elderly because of the physiologic changes that occur as people age. In addition, many nonnarcotic medications with analgesic properties are listed in both the 2012 American Geriatrics Society Beers Criteria for Potentially Inappropriate Medication Use in Older Adults and the Pharmacy Quality Alliance high-risk medications lists. An approach to the growing challenge of managing pain in the elderly that is gaining popularity among community-dwelling patients is the use of topical pain medications. The goal of this article is to review some of the available literature regarding the use of various topical analgesics alone or in combination, and to discuss their known or theoretical mechanisms of peripheral pain modulation. Commercially available or compounded topical pain medications may be used to replace or augment doses of oral medications in an effort to decrease the risk of adverse drug events for older adult patients. When prescribing topical pain medications physicians should consider the nature of the pain targeted, the type of analgesia expected from each ingredient, the potential for systemic absorption, and related side effects.

A randomized double-blind clinical trial on the treatment of knee osteoarthritis: the efficacy of polynucleotides compared to standard hyaluronian viscosupplementation

BACKGROUND

This randomized, double-blind, parallel-group clinical trial aims to assess the equivalence of intra-articular polynucleotides compared to standard hyaluronic acid (HA) viscosupplementation in the treatment of knee osteoarthritis (OA).

METHODS

75 patients affected by knee OA were assessed for eligibility and 72 were enrolled and randomized to receive either intra-articular polynucleotides (Condrotide-36 patients) or hyaluronic acid (Hyalubrix-36 patients) at the Orthopedic Institute "Gaetano Pini" (Milan). All patients underwent three intra-articular injections of Condrotide or Hyalubrix with an interval of 1week. Participants, care givers, and investigators responsible for outcome assessment were all blinded to group assignment. Primary outcome measurements (KOOS and pain level (1) at rest, (2) at weight-bearing and (3) during physical activity) were evaluated at baseline (T0) and after one (T1), two (T2), six (T6), ten (T10), and 26 (T26)weeks. Secondary measurements included the determination of COMP serum levels at T0, T6 and T26.

RESULTS

The reduction of pain and the increase of KOOS values from baseline were statistically significant for both treatments; nevertheless, for parameter KOOS "symptoms" the treatment with Condrotide showed significant results already after twoweeks (at T2 p=0.003) while the results obtained with Hyalubrix became significant only after 18 weeks (at T18 p=0.01). No significant adverse events were reported.

CONCLUSIONS

Condrotide is as effective as Hyalubrix in reducing knee OA symptoms but showed an earlier response on pain reduction and can therefore be considered a valid alternative to the use of HA in the treatment of OA, avoiding the adverse events of NSAIDs and of intra-articular corticosteroids.

Capsaicin for osteoarthritis pain

Capsaicin appears to be effective for osteoarthritis pain but it is uncertain whether the effect has a dose response, is consistent across joints, or changes over time.

METHODS

Randomized controlled trials of topical capsaicin use in OA were identified from PubMed, EMBASE, and ISI Web of Knowledge. Effect on pain scores, patient global evaluation of treatment effectiveness and application site burning were assessed by standardised mean differences (SMD), using RevMan.

RESULTS

Five double-blind randomized controlled trials and one case-crossover trial of topical capsaicin use were identified. Formulations ranged from 0.025 to 0.075%, and trial durations from 4 to 12 weeks. Trials assessed OA of the knee (n = 3), hand (n = 1), and a mix of joints (n = 2). Capsaicin treatment efficacy (vs. placebo) for change in VAS pain score was moderate, at 0.44 (95% CI 0.25-0.62) over 4 weeks of treatment. There was no heterogeneity between studies, indicating no between-study differences, including effect of OA site or treatment concentration. Two studies reported treatment beyond 4 weeks, with divergent results. One study reported an effect size of -9 mm after 12 weeks, and maximal between-group differences at 4 weeks. A second study reported that between-group differences increased over time, up to 20 weeks. Capsaicin was reported as being safe and well-tolerated, with no systemic toxicity. Mild application site burning affected 35-100% of capsaicin-treated patients with a risk ratio of 4.22 (95% CI 3.25-5.48, n = 5 trials); incidence peaked in week 1, with incidence rates declining over time.

CONCLUSIONS

Topical capsaicin treatment four times daily is moderately effective in reducing pain intensity up to 20 weeks regardless of site of application and dose in patients with at least moderate pain and clinical or radiologically defined OA, and is well tolerated.

Topical herbal therapies for treating osteoarthritis

BACKGROUND

Before extraction and synthetic chemistry were invented, musculoskeletal complaints were treated with preparations from medicinal plants. They were either administered orally or topically. In contrast to the oral medicinal plant products, topicals act in part as counterirritants or are toxic when given orally.

OBJECTIVES

To update the previous Cochrane review of herbal therapy for osteoarthritis from 2000 by evaluating the evidence on effectiveness for topical medicinal plant products.

SEARCH METHODS

Databases for mainstream and complementary medicine were searched using terms to include all forms of arthritis combined with medicinal plant products. We searched electronic databases (Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, AMED, CINAHL, ISI Web of Science, World Health Organization Clinical Trials Registry Platform) to February 2013, unrestricted by language. We also searched the reference lists from retrieved trials.

SELECTION CRITERIA

Randomised controlled trials of herbal interventions used topically, compared with inert (placebo) or active controls, in people with osteoarthritis were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, assessed the risk of bias of included studies and extracted data.

MAIN RESULTS

Seven studies (six different medicinal plant interventions; 785 participants) were included. Single studies (five studies) and non-comparable studies (two studies) precluded pooling of results.Moderate evidence from a single study of 174 people with hand osteoarthritis indicated that treatment with Arnica extract gel probably results in similar benefits as treatment with ibuprofen (non-steroidal anti-inflammatory drug) with a similar number of adverse events. Mean pain in the ibuprofen group was 44.2 points on a 100 point scale; treatment with Arnica gel reduced the pain by 4 points after three weeks: mean difference (MD) -3.8 points (95% confidence intervals (CI) -10.1 to 2.5), absolute reduction 4% (10% reduction to 3% increase). Hand function was 7.5 points on a 30 point scale in the ibuprofen-treated group; treatment with Arnica gel reduced function by 0.4 points (MD -0.4, 95% CI -1.75 to 0.95), absolute improvement 1% (6% improvement to 3% decline)). Total adverse events were higher in the Arnica gel group (13% compared to 8% in the ibuprofen group): relative risk (RR) 1.65 (95% CI 0.72 to 3.76).Moderate quality evidence from a single trial of 99 people with knee osteoarthritis indicated that compared with placebo, Capsicum extract gel probably does not improve pain or knee function, and is commonly associated with treatment-related adverse events including skin irritation and a burning sensation. At four weeks follow-up, mean pain in the placebo group was 46 points on a 100 point scale; treatment with Capsicum extract reduced pain by 1 point (MD -1, 95% CI -6.8 to 4.8), absolute reduction of 1% (7% reduction to 5% increase). Mean knee function in the placebo group was 34.8 points on a 96 point scale at four weeks; treatment with Capsicum extract improved function by a mean of 2.6 points (MD -2.6, 95% CI -9.5 to 4.2), an absolute improvement of 3% (10% improvement to 4% decline). Adverse event rates were greater in the Capsicum extract group (80% compared with 20% in the placebo group, rate ratio 4.12, 95% CI 3.30 to 5.17). The number needed to treat to result in adverse events was 2 (95% CI 1 to 2).Moderate evidence from a single trial of 220 people with knee osteoarthritis suggested that comfrey extract gel probably improves pain without increasing adverse events. At three weeks, the mean pain in the placebo group was 83.5 points on a 100 point scale. Treatment with comfrey reduced pain by a mean of 41.5 points (MD -41.5, 95% CI -48 to -34), an absolute reduction of 42% (34% to 48% reduction). Function was not reported. Adverse events were similar: 6% (7/110) reported adverse events in the comfrey group compared with 14% (15/110) in the placebo group (RR 0.47, 95% CI 0.20 to 1.10).Although evidence from a single trial indicated that adhesive patches containing Chinese herbal mixtures FNZG and SJG may improve pain and function, the clinical applicability of these findings are uncertain because participants were only treated and followed up for seven days. We are also uncertain if other topical herbal products (Marhame-Mafasel compress, stinging nettle leaf) improve osteoarthritis symptoms due to the very low quality evidence from single trials.No serious side effects were reported.

AUTHORS' CONCLUSIONS

Although the mechanism of action of the topical medicinal plant products provides a rationale basis for their use in the treatment of osteoarthritis, the quality and quantity of current research studies of effectiveness are insufficient. Arnica gel probably improves symptoms as effectively as a gel containing non-steroidal anti-inflammatory drug, but with no better (and possibly worse) adverse event profile. Comfrey extract gel probably improves pain, and Capsicum extract gel probably will not improve pain or function at the doses examined in this review. Further high quality, fully powered studies are required to confirm the trends of effectiveness identifed in studies so far.

Neuromodulators for pain management in rheumatoid arthritis

BACKGROUND

Pain management is a high priority for patients with rheumatoid arthritis (RA). Despite deficiencies in research data, neuromodulators have gained widespread clinical acceptance as adjuvants in the management of patients with chronic musculoskeletal pain.

OBJECTIVES

The aim of this review was to determine the efficacy and safety of neuromodulators in pain management in patients with RA. Neuromodulators included in this review were anticonvulsants (gabapentin, pregabalin, phenytoin, sodium valproate, lamotrigine, carbamazepine, levetiracetam, oxcarbazepine, tiagabine and topiramate), ketamine, bupropion, methylphenidate, nefopam, capsaicin and the cannabinoids.

SEARCH METHODS

We performed a computer-assisted search of the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, 4th quarter), MEDLINE (1950 to week 1 November 2010), EMBASE (Week 44, 2010) and PsycINFO (1806 to week 2 November 2010). We also searched the 2008 and 2009 American College of Rheumatology (ACR) and European League against Rheumatism (EULAR) conference abstracts and performed a handsearch of reference lists of articles.

SELECTION CRITERIA

We included randomised controlled trials which compared any neuromodulator to another therapy (active or placebo, including non-pharmacological therapies) in adult patients with RA that had at least one clinically relevant outcome measure.

DATA COLLECTION AND ANALYSIS

Two blinded review authors independently extracted data and assessed the risk of bias in the trials. Meta-analyses were used to examine the efficacy of a neuromodulator on pain, depression and function as well as their safety.

MAIN RESULTS

Four trials with high risk of bias were included in this review. Two trials evaluated oral nefopam (52 participants) and one trial each evaluated topical capsaicin (31 participants) and oromucosal cannabis (58 participants).The pooled analyses identified a significant reduction in pain levels favouring nefopam over placebo (weighted mean difference (WMD) -21.16, 95% CI -35.61 to -6.71; number needed to treat (NNT) 2, 95% CI 1.4 to 9.5) after two weeks. There were insufficient data to assess withdrawals due to adverse events. Nefopam was associated with significantly more adverse events (RR 4.11, 95% CI 1.58 to 10.69; NNTH 9, 95% CI 2 to 367), which were predominantly nausea and sweating.In a mixed population trial, qualitative analysis of patients with RA showed a significantly greater reduction in pain favouring topical capsaicin over placebo at one and two weeks (MD -23.80, 95% CI -44.81 to -2.79; NNT 3, 95% CI 2 to 47; MD -34.40, 95% CI -54.66 to -14.14; NNT 2, 95% CI 1.4 to 6 respectively). No separate safety data were available for patients with RA, however 44% of patients developed burning at the site of application and 2% withdrew because of this.One small, low quality trial assessed oromucosal cannabis against placebo and found a small, significant difference favouring cannabis in the verbal rating score 'pain at present' (MD -0.72, 95% CI -1.31 to -0.13) after five weeks. Patients receiving cannabis were significantly more likely to suffer an adverse event (risk ratio (RR) 1.82, 95% CI 1.10 to 3.00; NNTH 3, 95% CI 3 to 13). These were most commonly dizziness (26%), dry mouth (13%) and light headedness (10%).

AUTHORS' CONCLUSIONS

There is currently weak evidence that oral nefopam, topical capsaicin and oromucosal cannabis are all superior to placebo in reducing pain in patients with RA. However, each agent is associated with a significant side effect profile. The confidence in our estimates is not strong given the difficulties with blinding, the small numbers of participants evaluated and the lack of adverse event data. In some patients, however, even a small degree of pain relief may be considered worthwhile. Until further research is available, given the relatively mild nature of the adverse events, capsaicin could be considered as an add-on therapy for patients with persistent local pain and inadequate response or intolerance to other treatments. Oral nefopam and oromucosal cannabis have more significant side effect profiles however and the potential harms seem to outweigh any modest benefit achieved.

Civamide Cream 0.075% in Patients with Osteoarthritis of the Knee: A 12-Week Randomized Controlled Clinical Trial with a Longterm Extension

Objective.

To evaluate the safety and efficacy of civamide cream 0.075% for the treatment of osteoarthritis (OA) of the knee.

Methods.

We conducted a 12-week, multicenter, randomized, double-blind study with a 52-week open-label extension. Patients with OA of the knee received either civamide cream 0.075% or a lower dose of civamide cream, 0.01%, as the control. The 3 co-primary endpoints in the double-blind study were the time-weighted average (TWA) of change from baseline to Day 84 in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale, the WOMAC physical function subscale, and the Subject Global Evaluation (SGE). In the 52-week open-label extension study, the Osteoarthritis Pain Score and SGE were assessed.

Results.

A total of 695 patients were randomized to receive civamide cream 0.075% (n = 351) or civamide cream 0.01% (control; n = 344) in the double-blind study. Significance in favor of civamide cream 0.075% was achieved for the TWA for all 3 co-primary efficacy variables: WOMAC pain (p = 0.009), WOMAC physical function (p < 0.001), and SGE (p = 0.008); and at Day 84 for these 3 variables (p = 0.013, p < 0.001, and p = 0.049, respectively). These analyses accounted for significant baseline-by-treatment interactions. In the 52-week open-label extension, efficacy was maintained. Civamide cream 0.075% was well tolerated throughout the studies.

Conclusion.

These studies demonstrate the efficacy of civamide cream for up to 1 year of continuous use. Civamide cream, with its lack of systemic absorption, does not have the potential for serious systemic toxicity, in contrast to several other OA treatments.

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.

Efficacy of intra-articular polynucleotides in the treatment of knee osteoarthritis: a randomized, double-blind clinical trial

This randomized, double-blind clinical trial was conducted over 16 weeks to assess the efficacy and safety profile of intra-articular polynucleotides gel injections in the treatment of knee osteoarthritis associated with persistent knee pain. 60 patients were enrolled and randomized to receive intra-articular polynucleotides (n = 30) or hyaluronan (n = 30); patients received five weekly intra-articular knee injections and the follow-up period was 3 months after the end of treatment. Primary endpoint was to determine polynucleotides (PN) efficacy in reducing knee pain at the end of the study, over baseline value and over standard hyaluronan viscosupplementation (HA). Pain levels were measured using a 0-10 cm Visual Analogue Scale (VAS). Secondary endpoints included Knee Osteoarthritis Outcome Score (KOOS), NSAIDs consumption, crackling during movement and articular mobility limitation. The mean global VAS pain decreased from 5.7 + or - 1.9 cm (T0) to 1.9 + or - 1.5 cm (T16) in polynucleotide group and from 4.9 + or - 2.0 cm (T0) to 2.1 + or - 1.4 cm (T16) in hyaluronan group. The reduction in pain was statistically significant for both groups. KOOS increases from baseline values were statistically significant in both groups. No significant adverse events were reported. These findings suggest that intra-articular polynucleotides can be a valid alternative to traditional hyaluronan supplementation for the treatment of knee osteoarthritis.

Evidence of effectiveness of herbal medicinal products in the treatment of arthritis. Part I: Osteoarthritis

Herbal medicinal products (HMPs) are used in a variety of oral and topical forms for the treatment of osteoarthritis. The aim of this study was to update a previous systematic review published in 2000. We searched electronic databases (MEDLINE, EMBASE, CISCOM, AMED, CINAHL, Cochrane registers) to June 2007, unrestricted by date or language, and included randomized controlled trials that compared HMPs with inert (placebo) or active controls in patients with osteoarthritis. Five reviewers contributed to data extraction. Disagreements were discussed and resolved by consensus with reference to Cochrane guidelines and advice from the Cochrane Collaboration.Thirty-five studies (30 studies identified for this review update, and 5 studies included in the original review) evaluating the effectiveness of 22 HMPs were included. However, due to differing HMPs, interventions, comparators, and outcome measures, meta-analysis was restricted to data from studies of three HMPs: topical capsaicin, avocado-soybean unsaponifiables, and the Chinese herbal mixture SKI306X showed benefit in the alleviation of osteoarthritic pain.Several studies investigating products from devil's claw, and a powder from rose hip and seed, reported favorable effects on osteoarthritic pain, whereas two studies of a willow bark extract returned disparate results. Three studies of Phytodolor N(R) were of limited use because doses and measures were inconsistent among trials. The remaining single studies for each HMP provided moderate evidence of effectiveness. No serious side effects were reported with any herbal intervention.Despite some evidence, the effectiveness of none of the HMPs is proven beyond doubt. The obvious potential benefits of HMPs in the treatment of osteoarthritis are reduced reliance on synthetic medications with the associated risks of harmful adverse events, but further clinical trials are necessary before HMPs can be adopted in osteoarthritis treatment guidelines.

Topical therapy for osteoarthritis: clinical and pharmacologic perspectives

Nonsteroidal anti-inflammatory drugs (NSAIDs) have shown efficacy in patients with osteoarthritis (OA) pain but are also associated with a dose-dependent risk of gastrointestinal, cardiovascular, hematologic, hepatic, and renal adverse events (AEs). Topical NSAIDs were developed to provide analgesia similar to their oral counterparts with less systemic exposure and fewer serious AEs. Topical NSAIDs have long been available in Europe for the management of OA, and guidelines of the European League Against Rheumatism and the Osteoarthritis Research Society International specify that topical NSAIDs are preferred over oral NSAIDs for patients with knee or hand OA of mild-to-moderate severity, few affected joints, and/or a history of sensitivity to oral NSAIDs. In contrast, the guidelines of the American Pain Society and American College of Rheumatology have in the past recommended topical methyl salicylate and topical capsaicin, but not topical NSAIDs. This reflects the fact that the American guidelines were written several years before the first topical NSAID was approved for use in the United States. Neither salicylates nor capsaicin have shown significant efficacy in the treatment of OA. In October 2007, diclofenac sodium 1% gel (Voltaren Gel) became the first topical NSAID for OA therapy approved in the United States following a long history of use internationally. Topical diclofenac sodium 1% gel delivers effective diclofenac concentrations in the affected joint with limited systemic exposure. Clinical trial data suggest that diclofenac sodium 1% gel provides clinically meaningful analgesia in OA patients with a low incidence of systemic AEs. This review discusses the pharmacology, clinical efficacy, and safety profiles of diclofenac sodium 1% gel, salicylates, and capsaicin for the management of hand and knee OA.

Topical analgesics

Historically, analgesics were applied by the topical route of administration. With the advent of oral formulations of drugs, topical application became less popular among physicians, although patients still rated this method of drug delivery as efficacious and practical. We now appreciate that peripheral mechanisms of actions of a variety of preparations rationalizes their topical application and gives further opportunity to target peripheral receptors and neural pathways that previously required systemic administration to achieve therapeutic effect. Therefore, a peripheral effect can be generated by using locally applied drug and, consequently, systemic concentrations of that drug may not reach the level at which systemic side effects can occur.

Topical analgesics

Our knowledge and understanding of the pathophysiology and treatment of pain is increasing; however, we should not lose sight of the simple opportunities that exist for intercepting pain at peripheral targets. Although systemic medication often has peripheral and central modes of action, the appeal for provision of medication close to where these peripheral targets exist should be high. If these sites can be attacked with relatively high concentrations of active drug while keeping systemic levels of that drug below the level at which systemic side effects become apparent, then this should lead to desirable outcomes. Even though the number of true topical agents with an indication for this use is small, a number of other topical agents are available that evidence suggests have the possibility of being effective. Given the increased understanding of pain, the likelihood of further topical agents becoming available is high.

Complementary and alternative medicine for noncancer pain

In summary, the past several years have shown an increase in the quality of trials examining the clinical efficacy of various CAM modalities for pain conditions. There is still need to raise the quality of the studies from a scientific and methodological point of view in many areas of CAM research by randomization, appropriate sample size, blinding, and developing more sophisticated sham procedures. However, much work still has to be done to find ways to preserve the clinical authenticity of CAM treatment methods when brought into the light of a research protocol. Recent attempts have been made to find a method of maintaining the standardization and reproducibility of research protocols while allowing the kind of flexible treatment that would normally be applied in a clinical setting. Other questions that should be answered with future studies include understanding how treatment length influences outcome, if maintenance treatments are needed for chronic conditions, and cost and risk comparisons with standard pharmacological treatment. Providing this kind of detail will assist both with reproducibility as well as help us gain a better understanding about whether certain treatment paradigms are superior to others for specific clinical conditions. Finally, physicians who have an interest in pursuing CAM research should educate themselves both about the methodological issues inherent with the particular area of interest as well as about ways to maintain the authenticity of the CAM treatment protocols so that the literature is not populated with more poorly designed studies. With the emerging interest in integrative medicine, there is a growing interest in collaboration and a greater number of physicians are interested in obtaining training in CAM modalities to help bridge this gap between CAM and conventional clinicians. For example, the American Academy of Medical Acupuncturists (AAMA) has been formed to help as both an educational and research forum for physician acupuncturists and the American Holistic Medical Association provides educational exposure in a broad range of Integrative and CAM modalities. The future of medicine will likely be Integrative and the more health care providers can educate themselves about this area of medicine, the better they will be able to provide the highest quality of care to their patients.

Can we reduce disease burden from osteoarthritis?

The comparison of disparate interventions for the prevention and management of osteoarthritis (OA) is limited by the quality and quantity of published efficacy studies and the use of disparate measures for reporting clinical trial outcomes. The "transfer to utility" technique was used to translate published trial outcomes into a health-related quality-of-life (utility) scale, creating a common metric which supported comparisons between disparate interventions. Total hip replacement (THR) and total knee replacement (TKR) surgery were the most effective treatments and also highly cost-effective, at estimated cost per quality-adjusted life-year (QALY) of 7500 dollars for THR and 10000 dollars for TKR (best estimate). Other apparently highly cost-effective interventions were exercise and strength training for knee OA (< 5000 dollars/QALY), knee bracing, and use of capsaicin or glucosamine sulfate (< 10000 dollars/QALY). The cost per QALY estimates of non-specific and COX-2 inhibitor non-steroidal anti-inflammatory drugs were affected by treatment-related deaths and highly sensitive to the discounting of life-years lost. OA interventions that have been shown to be ineffective (eg, arthroscopy) are targets for redistribution of healthcare resources. OA interventions which lack efficacy studies (eg, prevention programs) require further research to assist priority setting. The application of the Health-sector Wide model to OA demonstrates its role as an evidence-based model that can be successfully applied to identify marginal interventions - those to be expanded and contracted to reduce the expected burden of disease, within current healthcare resources.

Arthritis and related diseases of the foot and ankle: rehabilitation and biomechanical considerations

Arthritis and other rheumatic conditions are among the most common disabilities in the United States. Although arthritic conditions affect the knee and hip joints more frequently than the joints of the foot, disorders of the foot are particularly disabling. This article outlines the types of arthritis conditions affecting the foot and discusses strategies for management and rehabilitation.

Effect of a Topical Herbal Cream on the Pain and Stiffness of Osteoarthritis

This study compared the efficacy of an herbal ointment to a placebo ointment in relieving the pain and stiffness of osteoarthritis. The herbal preparation contained substances believed by alternative practitioners to be helpful in treating osteoarthritis. This study was a double-blind randomized placebo-controlled clinical trial. Subjects were solicited from patients attending an arthritis clinic in Dallas, Texas. Selection of subjects with osteoarthritis was based on the criteria developed by the American College of Rheumatology. Subjects were randomized to an active (n = 11) or a placebo (n = 8) group. Herbal ointment and control contained small amounts of capsaicin and menthol and were similar when applied. Subjects graded their levels of pain and stiffness for a 1-week no-treatment baseline. Subjects then applied the herbal or sham ointment to the involved joint(s) for 28 consecutive days and recorded their levels of pain and stiffness daily on visual analog scales. Significant differences between the active and placebo groups for pain (P < 0.05) and stiffness (P < 0.05) were found when the baseline phase was compared with the fourth week. An herbal ointment was shown to be effective in relieving the pain and stiffness of osteoarthritis without adverse effects. If future studies confirm effectiveness of this treatment, it may have a role as an adjunct to standard drug therapy.

Analgesia and the patient with osteoarthritis

Osteoarthritis is the most common form of arthritis, its prevalence increasing with age: as much as 80% of the population over 75 years show radiologic signs of the condition. Symptoms include pain, stiffness, and functional impairment; however, not all patients are symptomatic. Management starts with nonpharmacologic interventions, followed by pharmacologic means, and ultimately by surgical intervention. The management is multidisciplinary and is tailored to the needs of the individual patient. It is, therefore, a good model of collaborative care: multidisciplinary management of a chronic condition for which the patients themselves coordinate the use of the management options, with information and guidance from health care professionals and written materials, as needed. Guidelines for the management of osteoarthritis have been developed and are applied in different continents. These guidelines are based on searches of the literature and evidence-based interpretation, in combination with expert opinion. Pharmacologic management guidelines state that based on its overall efficacy, toxicity profile, and cost, paracetamol-acetaminophen should be tried first and, if successful, should be used as the preferred long-term analgesic. In patients who do not experience adequate symptomatic relief with paracetamol-acetaminophen, alternative or additional pharmacologic agents should be considered, especially nonsteroidal anti-inflammatory drugs (NSAIDs). When the combination of paracetamol-acetaminophen with NSAIDs fails, tramadol may be given. Most patients with osteoarthritis are able, after discussion with their physician, to manage their symptoms themselves. They make use of educational occupational, and physical advisers, and they use their medication on demand. The basis of this self-administered pharmacologic management is paracetamol-acetaminophen, sometimes in combination with NSAIDs. A promising option for the future is the development of symptomatic slow-acting drugs for osteoarthritis that possess structure-modifying properties.

The addition of glyceryltrinitrate to capsaicin cream reduces the thermal allodynia associated with the application of capsaicin alone in humans

The aim of this study was to determine whether topical application of capsaicin cream causes thermal allodynia and the extent to which this is attenuated by the addition of glyceryltrinitrate (GTN). This was a double blind placebo controlled study of 40 consenting adult subjects. Each of four cream combinations (GTN, capsaicin, GTN/capsaicin and vehicle) were applied to the subjects with at least a 1 day interval between each application. Water at a known temperature was applied to the standard area of skin where cream had been applied. Subjects rated the resulting thermal allodynia using a 0-10 Likhert score. Thermal allodynia is usually apparent when warm water is applied to skin containing capsaicin. The thermal allodynia caused by the topical application of capsaicin was significantly reduced by the addition of GTN. The addition of GTN to capsaicin cream significantly reduces the thermal allodynia associated with the application of capsaicin cream alone.

Meeting the therapeutic challenge of the patient with osteoarthritis

OBJECTIVE

To discuss the diagnosis of osteoarthritis and the efficacy of available pharmacologic and nonpharmacologic treatment options.

DATA SOURCES

Published reports on the diagnosis and treatment of osteoarthritis were identified through a MEDLINE search of English-language journal articles using a focused title search for the keywords acetaminophen, nonsteroidal anti-inflammatory, COX-2 nonsteroidal, opioids, capsaicin, tramadol, glucosamine, hyaluronic acid, and osteoarthritis and by reviewing the bibliographies of selected reviews. The American College of Rheumatology (ACR) guidelines, as updated in September 2000, for the treatment of osteoarthritis of the hip and knee were analyzed with appropriate references to clinical and scientific studies, review articles, and other published guidelines.

DATA SYNTHESIS

Each patient's medical history and level of pain should decide the most appropriate treatment. Nonpharmacologic therapies should always be included in the treatment regimen. If further pain management is required, the most appropriate pharmacologic treatments are acetaminophen or nonsteroidal anti-inflammatory drugs for mild-to-moderate pain, tramadol or opioid combinations for moderate-to-moderately severe pain, and opioids for severe pain. Adjunctive treatments, intraarticular injections, and surgery are also viable options for some patients.

CONCLUSION

If used properly, the ACR guidelines for the treatment of osteoarthritis are important tools in the care of the patient with this disease.

Herbal medicines for the treatment of osteoarthritis: a systematic review

OBJECTIVE

Limitations in the conventional medical management of osteoarthritis indicate a real need for safe and effective treatment of osteoarthritis patients. Herbal medicines may provide a solution to this problem. The aim of this article was to review systematically all randomized controlled trials on the effectiveness of herbal medicines in the treatment of osteoarthritis.

METHODS

Computerized literature searches were carried out on five electronic databases. Trial data were extracted in a standardized, predefined manner and assessed independently.

RESULTS

Twelve trials and two systematic reviews fulfilled the inclusion criteria. The authors found promising evidence for the effective use of some herbal preparations in the treatment of osteoarthritis. In addition, evidence suggesting that some herbal preparations reduce consumption of non-steroidal anti-inflammatory drugs was found. The reviewed herbal medicines appear relatively safe.

CONCLUSIONS

Some herbal medicines may offer a much-needed alternative for patients with osteoarthritis.

The analgesic efficacy of topical capsaicin is enhanced by glyceryl trinitrate in painful osteoarthritis: a randomized, double blind, placebo controlled study

The aim of this study was to assess if the pain of osteoarthritis is reduced by topical capsaicin and to determine whether addition of glyceryl trinitrate has an effect on analgesic efficacy and tolerability of capsaicin. A randomized, double blind, placebo controlled study was carried out on 200 adult patients attending a Pain Clinic with osteoarthritis pain. Patients applied one of four creams topically over the affected joint over a 6 week period. Creams contained either placebo (vehicle), 0.025% capsaicin, 1.33% glyceryl trinitrate or 0.025% capsaicin + 1.33% glyceryl trinitrate. Analgesic efficacy, tolerability of cream and analgesic consumption were assessed. One hundred and sixty-seven of 200 patients completed the study. Baseline visual analogue scores (0-10 scale) for pain were 6.40. There was a significant reduction in pain scores in the glyceryl trinitrate group (mean decrease 0.59, p< 0.05, 95% confidence limits 0.04-1.14), 0.025% capsaicin group (mean decrease 0.5, p< 0.05, 95% confidence limits 0.05-1.05) and the glyceryl trinitrate capsaicin group (mean decrease 1.1, p<0.05, 95% confidence limits 0.22-1.98). Baseline discomfort of application scores were similar for all but the capsaicin groups (they were significantly higher (by 2.1 units, p< 0.001)). The odds ratio in favour of continuing treatment was 2.1 (95% confidence limits 1.0-4.4) for glyceryl trinitrate and 2.4 (95% confidence limits 1.2-5.1) for capsaicin and 5.0 (95% confidence limits 3.8-6.4) for capsaicin GTN combination. The study showed that topical capsaicin and glyceryl trinitrate have an analgesic effect in painful osteoarthritis. When used together this effect is increased with the combination being more tolerable than capsaicin alone. Analgesic consumption is decreased by capsaicin, glyceryl trinitrate and to a greater extent by both combined.

Topical agents in the treatment of rheumatic disorders

Topical drug delivery may be the optimal route for the treatment of localized musculoskeletal disorders because higher drug concentrations can be achieved at the sites of clinical significance. The rationale for the use of topical salicylates and other nonsteroidal anti-inflammatory drugs (NSAIDs) in the treatment of soft-tissue rheumatic complaints and osteoarthritis is reviewed. Topical capsaicin offers another potentially beneficial therapy for the treatment of osteoarthritis of selected joints. Although there are extensive, uncontrolled experiences with DMSO that suggests its effectiveness in the treatment of musculoskeletal disorders, controlled trials yield conflicting results. The basis for the use of physical modalities such as phonophoresis and iontophoresis to improve topical drug efficacy is summarized.

The use of analgesics in the management of pain in rheumatic diseases

Pain is the most common complaint of patients who see rheumatologists. In this article, the current treatment options for pain are reviewed; these include acetaminophen, nonsteroidal anti-inflammatory drugs, new specific cyclooxygenase-2 inhibitors, opioid analgesics, centrally acting muscle relaxants, antidepressants, and topical analgesics and counterirritants. The doses of medication and known adverse effects of these medications are highlighted.

Non-NSAID pharmacologic treatment options for the management of chronic pain

Chronic pain affects 75 million US citizens. A number of pharmacologic treatments are available for chronic pain that does not respond adequately to nonpharmacologic methods. Long the mainstay of chronic pain management, nonsteroidal anti-inflammatory drugs (NSAIDs) are known to be associated with gastrointestinal (GI) and renal toxicities, a particular problem for the elderly population, which commonly experiences chronic pain, such as that associated with osteoarthritis (OA). Several non-NSAID, non-narcotic therapies are available for noninflammatory pain. Acetaminophen is as effective as NSAIDs for the management of mild-to-moderate OA pain and is the recommended first-line therapy by the American College of Rheumatology (ACR). Propoxyphene, widely believed to be safe and effective, may, in fact, be no more effective-and perhaps less effective-than acetaminophen or ibuprofen. A relatively new analgesic, tramadol, appears to be a useful therapy for patients who do not receive adequate pain relief with acetaminophen and are at risk for NSAID-related side effects. For localized chronic pain associated with OA, topical capsaicin is also an effective analgesic.

Management of osteoarthritis in the primary-care setting: an evidence-based approach to treatment

The most prevalent musculoskeletal condition that results in joint pain is osteoarthritis (OA), with nearly 70% of the population >65 years of age demonstrating radiographic evidence of this disease. The knee is the joint commonly affected. Therapy for OA of the knee is directed at decreasing joint pain and increasing function and includes both pharmacologic and nonpharmacologic interventions. Pharmacologic therapy begins with analgesic medications and proceeds to topical analgesics and nonsteroidal anti-inflammatory drugs (NSAIDs) as needed. Intra-articular injections of corticosteroids can relieve pain and inflammation but the effect is of very short duration and such therapy should only be employed infrequently. Nonpharmacologic therapy should include patient education, weight loss if clinically indicated, physical therapy directed at maintaining joint mobility and strengthening muscle groups or an organized low-impact exercise program, and assistive devices as needed. Total joint replacement appears to be a successful therapy when joint pain severely limits a patient's ability to function. Experimental therapies to modify pain and function in OA patients include intra-articular injections of hyaluronan or arthroscopic joint lavage and debridement. In summary, both pharmacologic and nonpharmacologic measures can contribute to the treatment of pain from OA of the knee.

Determination of capsaicin and zucapsaicin in human serum by high-performance liquid chromatography with fluorescence detection

A reversed-phase high-performance liquid chromatographic (HPLC) assay was developed to analyze capsaicin and zucapsaicin (civamide) in human serum at concentrations from 1 to 100 ng/ml. Human serum specimens were extracted twice with hexane-methyl tert.-butyl ether (1:1). The chromatographic separation was carried out on a C18 column at 40 degrees C using a mobile phase consisting of 40% acetonitrile in water with 5% tetrahydrofuran and 1% acetic acid. The concentration of the eluting compounds was monitored by a fluorescence detector with excitation at 270 nm and an emission cutoff of 300 nm. No interferences were observed from the extract of blank serum. The standard curves were linear in the detection range. The relative standard deviation of the assay was better than 8.4%. The limit of detection was 0.5 ng/ml.

Economics of osteoarthritis: a global perspective

Musculoskeletal disorders, of which osteoarthritis (OA) is the most common, incur significant economic, social and psychological costs. Costs of illness have risen over recent decades accounting for up to 1-2.5% of the gross national product for those countries studied so far, including the USA, Canada, the UK, France and Australia. Arthritis has a significant impact on psychosocial and physical function and is known to be the leading cause of disability in later life. There are also significant out-of-pocket costs and loss of earnings due to changes in occupation and roles in domestic duties. Current guidelines for the management of OA of hip and knee include the recommendation of inexpensive but effective interventions. Although the guidelines have not had a specific economic evaluation, cost reductions may be expected. OA is a very common disease and will become an increasing economic burden as the population ages.

Pharmacotherapy and osteoarthritis

Therapy for osteoarthritis (OA) is aimed at relieving symptoms and at maximizing function. Therapies can be considered as either symptom modifying OA drugs (SMOADs) or as disease modifying OA drugs (DMOADs). Currently available agents fall into the category of SMOADs. Analgesic medications, particularly paracetamol and capsaicin, have proven efficacy in OA and are recommended first line therapies. Non-steroidal anti-inflammatory drugs (NSAIDs) do appear to provide extra symptomatic benefit for some patients but have greater toxicity. Newer generation NSAIDs may have safety advantages which remain to be confirmed in practice. Further therapies are being developed which aim to prevent cartilage damage and/or aid cartilage restoration, but these DMOADs remain in the experimental stage.