Local action transcutaneous flurbiprofen in the treatment of soft tissue rheumatism

Topical NSAIDs for chronic musculoskeletal pain in adults

BACKGROUND

Use of topical nonsteroidal anti-inflammatory drugs (NSAIDs) to treat chronic musculoskeletal conditions has become widely accepted because they can provide pain relief without associated systemic adverse events. This review is an update of 'Topical NSAIDs for chronic musculoskeletal pain in adults', originally published in Issue 9, 2012.

OBJECTIVES

To review the evidence from randomised, double-blind, controlled trials on the efficacy and safety of topically applied NSAIDs for chronic musculoskeletal pain in adults.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and our own in-house database; the date of the last search was February 2016. We also searched the references lists of included studies and reviews, and sought unpublished studies by asking personal contacts and searching online clinical trial registers and manufacturers' web sites.

SELECTION CRITERIA

We included randomised, double-blind, active or inert carrier (placebo) controlled trials in which treatments were administered to adults with chronic musculoskeletal pain of moderate or severe intensity. Studies had to meet stringent quality criteria and there had to be at least 10 participants in each treatment arm, with application of treatment at least once daily.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion and extracted data. We used numbers of participants achieving each outcome to calculate risk ratio and numbers needed to treat (NNT) or harm (NNH) compared to carrier or other active treatment. We were particularly interested to compare different formulations (gel, cream, plaster) of individual NSAIDs. The primary outcome was 'clinical success', defined as at least a 50% reduction in pain, or an equivalent measure such as a 'very good' or 'excellent' global assessment of treatment, or 'none' or 'slight' pain on rest or movement, measured on a categorical scale.

MAIN RESULTS

We identified five new studies for this update, which now has information from 10,631 participants in 39 studies, a 38% increase in participants from the earlier review; 33 studies compared a topical NSAID with carrier. All studies examined topical NSAIDs for treatment of osteoarthritis, and for pooled analyses studies were generally of moderate or high methodological quality, although we considered some at risk of bias from short duration and small size.In studies lasting 6 to 12 weeks, topical diclofenac and topical ketoprofen were significantly more effective than carrier for reducing pain; about 60% of participants had much reduced pain. With topical diclofenac, the NNT for clinical success in six trials (2343 participants) was 9.8 (95% confidence interval (CI) 7.1 to 16) (moderate quality evidence). With topical ketoprofen, the NNT for clinical success in four trials (2573 participants) was 6.9 (5.4 to 9.3) (moderate quality evidence). There was too little information for analysis of other individual topical NSAIDs compared with carrier. Few trials compared a topical NSAID to an oral NSAID, but overall they showed similar efficacy (low quality evidence). These efficacy results were almost completely derived from people with knee osteoarthritis.There was an increase in local adverse events (mostly mild skin reactions) with topical diclofenac compared with carrier or oral NSAIDs, but no increase with topical ketoprofen (moderate quality evidence). Reporting of systemic adverse events (such as gastrointestinal upsets) was poor, but where reported there was no difference between topical NSAID and carrier (very low quality evidence). Serious adverse events were infrequent and not different between topical NSAID and carrier (very low quality evidence).Clinical success with carrier occurred commonly - in around half the participants in studies lasting 6 to 12 weeks. Both direct and indirect comparison of clinical success with oral placebo indicates that response rates with carrier (topical placebo) are about twice those seen with oral placebo.A substantial amount of data from completed, unpublished studies was unavailable (up to 6000 participants). To the best of our knowledge, much of this probably relates to formulations that have never been marketed.

AUTHORS' CONCLUSIONS

Topical diclofenac and topical ketoprofen can provide good levels of pain relief beyond carrier in osteoarthritis for a minority of people, but there is no evidence for other chronic painful conditions. There is emerging evidence that at least some of the substantial placebo effects seen in longer duration studies derive from effects imparted by the NSAID carrier itself, and that NSAIDs add to that.

Drug-inorganic-polymer nanohybrid for transdermal delivery

For transdermal drug delivery, we prepared a drug-inorganic nanohybrid (FB-LDH) by intercalating a transdermal model drug, flurbiprofen (FB), into the layered double hydroxides (LDHs) via coprecipitation reaction. The X-ray diffraction patterns and FT-IR spectra of the FB-LDH indicated that the FB molecules were successfully intercalated via electrostatic interaction within the LDH lattices. The in vitro drug release revealed that the Eudragit(®) S-100 in release media could facilitate the drug out-diffusion by effectively replacing the intercalated drug and also enlarging the lattice spacing of the FB-LDH. In this work, a hydrophobic gel suspension of the FB-LDH was suggested as a transdermal controlled delivery formulation, where the suspensions were mixed with varying amounts of Eudragit(®) S-100 aqueous solution. The Frantz diffusion cell experiments using mouse full-skins showed that a lag time and steady-state flux of the drug could be controlled from 12.8h and 3.28μgcm(-2)h(-1) to less than 1h and 14.57μgcm(-2)h(-1), respectively, by increasing the mass fraction of Eudragit(®) S-100 solution in gel suspensions from 0% to 20% (w/w), respectively. Therefore, we conclude gel formulation of the FB-LDH have a potential for transdermal controlled drug delivery.

Topical NSAIDs for chronic musculoskeletal pain in adults

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly taken orally, but they are also available in topical preparations to be applied to or rubbed onto the skin of a painful joint, typically one affected by arthritis, with the aim of relieving pain locally. Topical NSAIDs are widely used in some parts of the world for acute and chronic painful conditions, but have not been universally accepted until recently. One of the problems has been that older clinical studies were generally short, lasting four weeks or less, and short duration studies are not regarded as adequate in ongoing painful conditions.

OBJECTIVES

To examine the use of topical NSAIDs in chronic musculoskeletal pain, focusing on studies of high methodological quality, and examining the measured effect of the preparations according to study duration. The principal aim was to estimate treatment efficacy in longer duration studies of at least 8 weeks.

SEARCH METHODS

A series of electronic searches, together with bibliographic searches, and searches of in-house databases were combined with electronic searches of clinical trial registers and manufacturers of topical NSAIDs, or companies known to be actively researching topical NSAIDs. There had to be at least 10 participants in each treatment arm, with application of treatment at least once daily.

SELECTION CRITERIA

Randomised, double blind studies with placebo or active comparators, where at least one treatment was a topical NSAID product, in any topical formulation (cream, gel, patch, solution), in studies lasting at least two weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study quality and validity, and extracted data. Numbers of participants achieving each outcome were used to calculate relative risk (RR) and numbers needed to treat (NNT) or harm (NNH) compared to placebo or other active treatment.

MAIN RESULTS

Information was available from 7688 participants in 34 studies from 32 publications; 23 studies compared a topical NSAID with placebo. Topical NSAIDs were significantly more effective than placebo for reducing pain due to chronic musculoskeletal conditions. The best data were for topical diclofenac in osteoarthritis, where the NNT for at least 50% pain relief over 8 to 12 weeks compared with placebo was 6.4 for the solution, and 11 for the gel formulation. There were too few data of good quality to calculate NNTs for other individual topical NSAIDs compared with placebo. Direct comparison of topical NSAID with an oral NSAID did not show any difference in efficacy. There was an increase in local adverse events (mostly mild skin reactions) with topical NSAIDs compared with placebo or oral NSAIDs, but no increase in serious adverse events. Gastrointestinal adverse events with topical NSAID did not differ from placebo, but were less frequent than with oral NSAIDs.A substantial amount of data from unpublished studies was unavailable. Much of this probably relates to formulations that have never been marketed.

AUTHORS' CONCLUSIONS

Topical NSAIDs can provide good levels of pain relief; topical diclofenac solution is equivalent to that of oral NSAIDs in knee and hand osteoarthritis, but there is no evidence for other chronic painful conditions. Formulation can influence efficacy. The incidence of local adverse events is increased with topical NSAIDs, but gastrointestinal adverse events are reduced compared with oral NSAIDs.

Cutaneous Reactions to Transdermal Therapeutic Systems

Transdermal therapeutic systems have been increasingly used in the past two decades. However, cutaneous side effects are fairly common and may result in poor patient compliance. This review article summarizes the spectrum of reactions due to transdermal therapeutic systems and provides a current list of known allergens.

Topical NSAIDs for chronic musculoskeletal pain: systematic review and meta-analysis

: A previous systematic review reported that topical NSAIDs were effective in relieving pain in chronic conditions like osteoarthritis and tendinitis. More trials, a better understanding of trial quality and bias, and a reclassification of certain drugs necessitate a new review.

METHODS

Studies were identified by searching electronic databases, and writing to manufacturers. We identified randomised, double blind trials comparing topical NSAID with either placebo or another active treatment, in adults with chronic pain. The primary outcome was a reduction in pain of approximately 50% at two weeks, and secondary outcomes were local and systemic adverse events and adverse event-related withdrawals. Relative benefit and number-needed-to-treat (NNT), and relative harm and number-needed-to-harm (NNH) were calculated, and the effects of trial quality, validity and size, outcome reported, and condition treated, were examined by sensitivity analyses.

RESULTS

Twelve new trials were added to 13 trials from a previous review. Fourteen double blind placebo-controlled trials had information from almost 1,500 patients. Topical NSAID was significantly better than placebo with relative benefit 1.9 (95% confidence interval 1.7 to 2.2), NNT 4.6 (95% confidence interval 3.8 to 5.9). Results were not affected by trial quality, validity or size, outcome reported, or condition treated. Three trials with 764 patients comparing a topical with an oral NSAID found no difference in efficacy. Local adverse events (6%), systemic adverse events (3%), or the numbers withdrawing due to an adverse event were the same for topical NSAID and placebo.

CONCLUSIONS

Topical NSAIDs were effective and safe in treating chronic musculoskeletal conditions for two weeks. Larger and longer trials are necessary to fully elucidate the place of topical NSAIDs in clinical practice.

Oral versus topical NSAIDs in rheumatic diseases: a comparison

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most commonly prescribed drugs worldwide and are responsible for approximately one-quarter of all adverse drug reaction reports. NSAIDs are widely prescribed for patients with rheumatic disease--a population at increased risk for serious gastrointestinal (GI) complications. Topical administration of NSAIDs offers the advantage of local, enhanced drug delivery to affected tissues with a reduced incidence of systemic adverse effects, such as peptic ulcer disease and GI haemorrhage. NSAIDs administered topically penetrate slowly and in small quantities into the systemic circulation; bioavailability and maximal plasma NSAID concentration after topical application are generally less than 5 and 15%, respectively, compared with equivalent oral administration. Product formulation may have a dramatic impact, not only on absorption rates but also on penetration depth. Compared with oral administration, topical application leads to relatively high NSAID concentrations in the dermis. Concentrations achieved in the muscle tissue below the site of application are variable, but are at least equivalent to that obtained with oral administration. NSAIDs applied topically do reach the synovial fluid, but the extent and mechanism (topical penetration versus distribution via the systemic circulation) remain to be determined. In addition, marked interindividual variability was noted in all studies; percutaneous absorption may be strongly influenced by individual skin properties. In general, interpretation of clinical studies measuring efficacy of topical NSAIDs in rheumatic disease states is difficult because of a remarkably high placebo response rate, use of rescue paracetamol (acetaminophen), and significant variability in percutaneous absorption and response rates between patients. Overall efficacy rates attributable to topical NSAIDs in patients with rheumatic disorders ranged from 18 to 92% of treated patients. Topically applied NSAIDs have a superior safety profile to oral formulations. Adverse effects secondary to topical NSAID application occur in approximately 10 to 15% of patients and are primarily cutaneous in nature (rash and pruritus at site of application). GI adverse drug reactions are rare with topically applied NSAIDs, compared with a 15% incidence reported for oral NSAIDs. Available clinical studies suggest, but do not document, equivalent efficacy of topical over oral NSAIDs in rheumatic diseases.

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.

Topical NSAIDs for musculoskeletal conditions. A review of the literature

In recent years a growing number of topical nonsteroidal anti-inflammatory drugs (NSAIDs) have become available. This has been prompted in large part by the high incidence of serious gastrointestinal adverse events associated with the use of systemic NSAIDs, and the premise that minimisation of plasma concentrations of active drug may result in fewer systemic adverse effects. Evidence in humans and animals with topical NSAIDs demonstrates lower plasma concentrations than with systemically administered drugs, while those in soft tissues are still of a magnitude considered consistent with exerting an anti-inflammatory effect. In joints, however, the evidence is less strong, and there is still dispute whether in this case the drug reaches the joint predominantly via the transcutaneous or systemic route. There has been a sufficient number of studies of soft tissue conditions to demonstrate the superiority of topical NSAIDs over placebo and to suggest equivalent efficacy in comparison with some oral NSAIDs. For arthropathies, however, the literature is more sparse. Although several studies claim a benefit for topical NSAIDs against placebo, the results are less conclusive and further study is required. Trials of topical agents against intra-articular corticosteroids and rubefacients are either lacking or inconclusive. The adverse event profile of topical agents is reasonable: minor cutaneous effects occur in up to 2% of patients but tend to be self-limiting. Gastrointestinal events appear from the existing literature to be infrequent and minor, although long term studies are required. Bronchospasm and renal impairment have been reported and may be more frequent in patients who have experienced these effects with oral agents. The initial costs of topical agents tend to be higher than those of oral agents but a cost-effectiveness analysis suggests an overall benefit: this issue requires further clarification.

Efficacy and tolerability of a topical NSAID patch (local action transcutaneous flurbiprofen) and oral diclofenac in the treatment of soft-tissue rheumatism

The efficacy and safety of local action transcutaneous flurbiprofen 40 mg [flurbiprofen LAT] patches and diclofenac sodium tablets, 50 mg b.d., were compared in an open, multicentre, randomized, parallel-group study in patients with soft-tissue rheumatism. Patches were replaced at 12-hourly intervals. Clinical assessments were performed after 7 and 14 days of treatment. Fifty-six patients were treated with flurbiprofen LAT and 53 with diclofenac. Six withdrawals (three from each group) occurred during the treatment period. A statistically significant difference was observed in favour of flurbiprofen LAT for the principal measure, namely the investigator's opinion of overall change in clinical condition: 49/53 (92%) patients treated with flurbiprofen LAT had improved by day 14 compared with 36/49 (73%) patients receiving diclofenac sodium (p = 0.03; eligible dataset). There were also statistically significant differences in favour of flurbiprofen LAT for the investigator's assessments of the overall severity of the clinical condition (p = 0.03; eligible dataset), for the severity of pain at the region treated (p = 0.04; intent-to-treat), and for the severity of tenderness (p < 0.001; intent-to-treat). Supplementary analgesia (paracetamol) was required by two patients in the flurbiprofen LAT group and by eight diclofenac-treated patients. The difference in favour of flurbiprofen LAT in the average daily consumption of paracetamol was significant (p = 0.04). The patients' assessment of severity of pain on movement also favoured flurbiprofen LAT (p = 0.049; eligible dataset), but there were no statistically significant differences in day or night pain or quality of sleep. For the patients' opinion of treatment there was, however, a statistically significant difference in favour of flurbiprofen LAT (p = 0.02). Of the patients receiving flurbiprofen LAT, 94% regarded it as a convenient form of treatment. With respect to tolerability 8/56 (14%) patients applying flurbiprofen patches reported a total of nine adverse effects (AEs) (mainly local, mild skin irritations), vs 9/52 (17%) patients receiving diclofenac, who reported 12 AEs. Most AEs in the enteric-coated diclofenac group were of a gastrointestinal nature (one of which was severe). In terms of the proportion of patients reporting AEs related to the digestive system, there was a statistically significant difference in favour of flurbiprofen LAT (p = 0.011). In conclusion, local treatment of soft-tissue rheumatism with flurbiprofen LAT was demonstrably superior to benchmark oral therapy with diclofenac sodium over a 2-week period in terms of both efficacy and gastrointestinal tolerability. Flurbiprofen LAT provided both an effective and convenient form of topical SAID treatment.

A clinical evaluation of flurbiprofen LAT and piroxicam gel: a multicentre study in general practice

A prospective, randomized, multicentre, open, crossover study of the comparative efficacy, tolerability and acceptability of two topical nonsteroidal anti-inflammatory drug (NSAID) therapies, flurbiprofen local-action transcutaneous (LAT) patch (40 mg b.d.) and piroxicam gel (3 cm, 0.5% q.d.s), was conducted in general practice in the UK in 137 men and women with soft-tissue rheumatism of the shoulder or elbow (e.g. epicondylitis, tendinitis, bursitis and adhesive capsulitis). Patients received one therapy for 4 days before crossing over to the other NSAID for a further 4 days, followed by 6 days of their preferred therapy. Clinical assessment of severity of pain, tenderness and overall clinical condition was carried out at baseline and after 4, 8 and 14 days. Patients self-assessed the severity of pain during the day and at night, and also the quality of their sleep during each treatment phase. More patients showed a greater improvement in all of the clinical assessments of efficacy following treatment with flurbiprofen LAT during the crossover phase. There was a statistically significant reduction in the severity of pain, the principal measure of efficacy, in favour of flurbiprofen LAT: 42% of patients showed greater improvement with flurbiprofen LAT compared with 26% who showed a greater improvement with piroxicam gel (p = 0.012; n = 131, intent-to-treat). Eligible dataset (n = 126) analysis revealed statistically significant differences in favour of flurbiprofen LAT in the severity of lesion tenderness (p = 0.03) and the overall change in clinical condition (p = 0.04) compared with baseline status. Superior efficacy for flurbiprofen LAT was also indicated in the patients' assessment at the end of the crossover phase (day 8), at which 69% chose to continue treatment with flurbiprofen LAT compared with only 31% of patients who chose piroxicam gel (n = 126; p < 0.001). There were, in addition, statistically significant differences in favour of flurbiprofen LAT in assessments for night pain (p < 0.001), quality of sleep (p = 0.004) and the patients' overall opinion of treatment (p < 0.001). Both treatments were well tolerated with a low incidence of mainly local adverse events. These results showed that flurbiprofen LAT had a greater efficacy than piroxicam gel, and was also preferred by patients in the treatment of painful soft-tissue rheumatism of the shoulder and elbow.

Pharmacokinetic comparison of oral and local action transcutaneous flurbiprofen in healthy volunteers

Flurbiprofen is a propionic acid-derived non-steroidal anti-inflammatory drug (NSAID) used widely in the treatment of rheumatism and non-arthritic pain. The pharmacokinetics of topically and orally administered flurbiprofen were compared in a two-part, open study involving healthy adult volunteers. In the first (cross-over) part of the study, 12 Caucasians were randomized to receive either a single oral dose of 50 mg flurbiprofen or a single topical application of a novel 40 mg flurbiprofen-containing patch on the right wrist for 12 h. In the second part of the study, each subject applied a flurbiprofen-containing patch twice daily to the same wrist for 7 days. Plasma concentrations of flurbiprofen and urinary concentrations of the NSAID and its metabolites were measured by high-performance liquid chromatography assay, to enable comparison of the pharmacokinetic parameters for delivery of the drug by both routes. Maximum concentrations of the NSAID in plasma (Cmax) were much lower after a single application of the topical 40 mg flurbiprofen patch than after a single oral dose of 50 mg of the NSAID (mean +/- SD: 43 +/- 16 ng/ml versus 5999 +/- 1300 ng/ml, respectively). After repeated application of the topical patch, Cmax increased only slightly to 103 +/- 57 ng/ml. The mean relative bioavailability of flurbiprofen from the patch was 3.5 +/- 1.7%, calculated from plasma area under the curve data and 4.4 +/- 2.8% from urinary excretion data.(ABSTRACT TRUNCATED AT 250 WORDS)