Efficacy and safety of low-dose submicron diclofenac for the treatment of osteoarthritis pain: a 12 week, phase 3 study

Non-operative Treatment Options for Osteoarthritis in the Hip

With the increased disability associated with osteoarthritis (OA) progression, and the significant socioeconomic burden of joint replacement surgeries, there is a need for more reliable conservative treatments for patients presenting with hip OA. Most studies of OA treatments involve the knee. We conducted a literature search and reviewed non-operative hip OA treatment recommendations by the Osteoarthritis Research Society International, the American College of Rheumatology, American Academy of Orthopedic Surgeons, and European Alliance of Associations for Rheumatology, as well as Cochrane Reviews. Non-steroidal anti-inflammatory drugs and corticosteroid injections are the most supported and recommended options for hip OA; other medications with potential benefits for short-term pain relief include acetaminophen and tramadol. Most societies recommend against the use of glucosamine, typical opioids, and viscosupplementation injections. Platelet-rich plasma has potential benefits, but evidence of its effectiveness is incomplete. Further research is needed to better inform and guide clinicians who create treatment plans for patients with symptomatic hip OA.

Low-Dose NSAIDs Efficacy in Orthopedic Applications

Non-steroidal anti-inflammatory drugs (NSAIDs) [cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) inhibitors] and COXIBs (the COX-2 selective inhibitors) may induce several potentially severe and life-threatening issues especially in elderly patients. The use of low-dose NSAIDs is associated with lower risk of side effects compared to the standard dosage. Low-dose NSAIDs could minimize the side effects of these drugs while maintaining their clinical efficacy and effectiveness. The present study evaluates the effectiveness and safety of low-dose NSAIDs in musculoskeletal applications.

Benefits of Applying Nanotechnologies to Hydrogels in Efficacy Tests in Osteoarthritis Models-A Systematic Review of Preclinical Studies

Osteoarthritis (OA) is a severe musculoskeletal disease with an increasing incidence in the worldwide population. Recent research has focused on the development of innovative strategies to prevent articular cartilage damage and slow down OA progression, and nanotechnologies applied to hydrogels have gained particular interest. The aim of this systematic review is to investigate the state of the art on preclinical in vitro and in vivo efficacy studies applying nanotechnologies to hydrogels in OA models to elucidate the benefits of their applications. Three databases were consulted for eligible papers. The inclusion criteria were in vitro and in vivo preclinical studies, using OA cells or OA animal models, and testing hydrogels and nanoparticles (NPs) over the last ten years. Data extraction and quality assessment were performed. Eleven papers were included. In vitro studies evidenced that NP-gels do not impact on cell viability and do not cause inflammation in OA cell phenotypes. In vivo research on rodents showed that these treatments could increase drug retention in joints, reducing inflammation and preventing articular cartilage damage. Nanotechnologies in preclinical efficacy tests are still new and require extensive studies and technical hits to determine the efficacy, safety, fate, and localization of NPs for translation into an effective therapy for OA patients.

From Pathogenesis to Therapy in Knee Osteoarthritis: Bench-to-Bedside

Osteoarthritis (OA) is currently the most widespread musculoskeletal condition and primarily affects weight-bearing joints such as the knees and hips. Importantly, knee OA remains a multifactorial whole-joint disease, the appearance and progression of which involves the alteration of articular cartilage as well as the synovium, subchondral bone, ligaments, and muscles through intricate pathomechanisms. Whereas it was initially depicted as a predominantly aging-related and mechanically driven condition given its clear association with old age, high body mass index (BMI), and joint malalignment, more recent research identified and described a plethora of further factors contributing to knee OA pathogenesis. However, the pathogenic intricacies between the molecular pathways involved in OA prompted the study of certain drugs for more than one therapeutic target (amelioration of cartilage and bone changes, and synovial inflammation). Most clinical studies regarding knee OA focus mainly on improvement in pain and joint function and thus do not provide sufficient evidence on the possible disease-modifying properties of the tested drugs. Currently, there is an unmet need for further research regarding OA pathogenesis as well as the introduction and exhaustive testing of potential disease-modifying pharmacotherapies in order to structure an effective treatment plan for these patients.

Concept Endpoints Informing Design Considerations for Confirmatory Clinical Trials in Osteoarthritis

OBJECTIVE

There is an unmet need for therapies that target the underlying pathophysiology of osteoarthritis (OA). However, defining appropriate measures for clinical trials of such therapies is challenging. Our objective is to propose concept clinical endpoints that directly capture clinical benefit in this setting and evaluate the feasibility of their use.

METHODS

This analysis used the multi-center, longitudinal, observational Osteoarthritis Initiative (OAI) database. OAI participants primarily had knee OA, with follow-up of up to nine years and assessments of joints, surgical interventions, performance outcomes, and patient-reported outcomes (PROs). We examined this dataset to identify existing outcome measures of direct clinical benefit. We evaluated the feasibility of conducting trials using these candidate endpoints by estimating incidence rates and resulting required sample sizes and study durations in time-to-event analyses.

RESULTS

We identified candidate endpoints based on total knee replacement (TKR) and composite endpoints defined by TKR and conservative thresholds of PROs of pain and function. Using time to TKR as an endpoint, a study with an average follow-up time of three years requires approximately 3,000 to 18,000 subjects depending on effect size. Alternatively, a composite endpoint such as 'time to TKR or severe pain or severely impaired functioning', the required sample sizes ranged from approximately 2,000 to 11,000 for a three-year study.

CONCLUSION

The proposed concept endpoints can reliably and feasibly evaluate effectiveness of therapies for this unmet need. In particular, the composite endpoint approach can substantially reduce sample sizes (up to approximately 40%) compared to the use of TKR alone.

Targeting nerve growth factor, a new option for treatment of osteoarthritis: a network meta-analysis of comparative efficacy and safety with traditional drugs

OBJECTIVE

Osteoarthritis (OA) is the most common joint disease and leading cause of pain and disability in the elderly population. Most guidelines recommend the use of non-steroidal anti-inflammatory drugs (NSAIDs) and opioids for the non-operative treatment of OA. Monoclonal nerve growth factor (NGF) antibodies are new drugs with the potential to provide pain relief and functional improvement in OA. We compared the efficacy (pain reduction and functional improvement), and safety of monoclonal NGF antibodies with NSAIDs and opioids in the treatment of OA with a Bayesian network meta-analysis.

RESULTS

38 articles, comprising 41 trials and 20489 patients with OA were included. Overall from the network meta-analysis, anti-NGFs were the most effective drugs for pain relief (Standardized Mean Difference or SMD compared with placebo 4.25, 95% CI 2.87 to 5.63, Surface Under the Cumulative RAnking curve or SUCRA=93.7%) and for functional improvement (SMD 4.90, 95% CI 3.46 to 6.33, SUCRA=98.3%). Although anti-NGFs were associated with higher risk of peripheral sensation abnormality (paresthesia and pruritus), they were not associated with higher risk of other AEs (headaches and nausea) or with higher withdrawal rates related to AEs.

CONCLUSIONS

Monoclonal NGF antibodies provide significantly greater pain relief and functional improvement in OA compared to NSAIDs and opioids. Monoclonal NGF antibodies are not associated with severe AEs. More studies are needed to confirm these findings.

METHODS

PubMed, CNKI, Web of Science, Scopus, Embase and Cochrane Library databases were searched for relevant studies (OA treated with anti-NGFs, opioids, selective COX-2 inhibitors or NSAIDs) published between January 1999 to January 2020. Bayesian network and conventional meta-analyses were conducted. Pain relief, functional improvement and AEs were assessed.

Is Lutikizumab, an Anti-Interleukin-1α/β Dual Variable Domain Immunoglobulin, efficacious for Osteoarthritis? Results from a bayesian network meta-analysis

Objective

Most guidelines recommend the use of nonsteroidal anti-inflammatory drugs (NSAIDs), duloxetine, and tramadol for the nonoperative treatment of osteoarthritis (OA), but the use of them is limited by the tolerability and safety concerns. Lutikizumab is a novel anti–IL-1α/β dual variable domain immunoglobulin that can simultaneously bind and inhibit IL-1α and IL-1β to relieve the pain and dysfunction symptoms. We conducted this network meta-analysis to comprehensively compare the clinical efficacy and safety of lutikizumab with other drugs recommended by guidelines.

Methods

We conducted a Bayesian network and conventional meta-analyses to compare the efficacy and safety of lutikizumab with other traditional drugs. All eligible randomized clinical trials, in PubMed, CNKI, EMBASE, and Web of Science databases, from January 2000 to January 2020, were included. The Cochrane risk of the bias assessment tool was used for quality assessment. Pain relief, function improvement, and risk of adverse effects (AEs) were compared in this study.

Results

24 articles with 11858 patients were included. Duloxetine (DUL) had the largest effect for pain relief (4.76, 95% CI [2.35 to 7.17]), and selective cox-2 inhibitors (SCI) were the most efficacious treatment for physical function improvement (SMD 3.94, 95% CI [2.48 to 5.40]). Lutikizumab showed no benefit compared with placebo for both pain relief (SMD 1.11, 95% CI [-2.29 to 4.52]) and function improvement (SMD 0.992, 95% CI [-0.433 to 4.25]). Lutikizumab and all other drugs are of favorable tolerance for patients in the treatment of OA compared with placebo.

Conclusions

Lutikizumab, the new anti–Interleukin-1α/β dual variable domain immunoglobulin, showed no improvement in pain or function when compared with placebo. Selective cox-2 inhibitors and duloxetine remain the most effective and safest treatment for OA. More high-quality trials are still needed to reconfirm the findings of this study.

Nanoformulation strategies for improving intestinal permeability of drugs: A more precise look at permeability assessment methods and pharmacokinetic properties changes

The therapeutic efficacy of orally administered drugs is often restricted by their inherent limited oral bioavailability. Low water solubility, limited permeability through the intestinal barrier, instability in harsh environment of the gastrointestinal (GI) tract and being substrate of the efflux pumps and the cytochrome P450 (CYP) can impair oral drug bioavailability resulting in erratic and variable plasma drug profile. As more drugs with low membrane permeability are developed, new interest is growing to enhance their intestinal permeability and bioavailability. A wide variety of nanosystems have been developed to improve drug transport and absorption. Sufficient evidence exists to suggest that nanoparticles are able to increase the transepithelial transport of drug molecules. However, key questions remained unanswered. What types of nanoparticles are more efficient? What are preclinical (or clinical) achievements of each type of nanoformulation in terms of pharmacokinetic (PK) parameters? Addressing this issue in this paper, we have reviewed the current literature regarding permeability enhancement, permeability assessment methods and changes in PK parameters following administration of various nanoformulations. Although permeability enhancement by various nanoformulations holds great promise for oral drug delivery, many challenges still need to be addressed before development of more clinically successful nanoproducts.

Single-dose diclofenac in healthy volunteers can cause decrease in renal perfusion measured by functional magnetic resonance imaging

OBJECTIVES

We investigated changes of renal perfusion after topical and oral diclofenac administration in healthy volunteers using functional magnetic resonance imaging (MRI) with arterial spin labelling (ASL).

METHODS

Twenty-four healthy human participants (21-51 years) underwent 1.5T MRI before and 1 h after a single oral dose of diclofenac (50 mg). Twelve of 24 participants underwent an additional MRI examination following 3-day topical diclofenac administration. For renal perfusion imaging, a flow-sensitive alternating inversion-recovery TrueFISP ASL sequence was applied. Plasma concentrations of diclofenac and serum concentrations of thromboxane were determined.

KEY FINDINGS

After oral diclofenac application, large interindividual differences in plasma concentrations were observed (range <3-4604 nm). Topical diclofenac application did not result in relevant systemic diclofenac levels (range 5-75 nm). MRI showed a significant reduction of renal perfusion in individuals with diclofenac levels ≥225 nm (baseline: 347 ± 7 vs diclofenac: 323 ± 8 ml/min/100 g, P < 0.01); no significant differences were observed in participants with diclofenac levels <225 nm. Diclofenac levels correlated negatively with thromboxane B2 levels pointing towards target engagement.

CONCLUSIONS

Single-dose diclofenac caused a decrease in renal perfusion in participants with diclofenac levels ≥225 nm. We demonstrated that even a single dose of diclofenac can impair renal perfusion, which could be detrimental in patients with underlying chronic kidney disease or acute kidney injury.

Defining acute flares in knee osteoarthritis: a systematic review

OBJECTIVE

To identify and critically synthesise definitions of acute flares in knee osteoarthritis (OA) reported in the medical literature.

DESIGN

Systematic review and narrative synthesis. We searched Medline, EMBASE, Web of science and six other electronic databases (inception to July 2017) for original articles and conference abstracts reporting a definition of acute flare (or synonym) in humans with knee OA. There were no restrictions by language or study design (apart from iatrogenic-induced flare-ups, eg, injection-induced). Data extraction comprised: definition, pain scale used, flare duration or withdrawal period, associated symptoms, definition rationale, terminology (eg, exacerbation or flare), baseline OA severity, age, gender, sample size and study design.

RESULTS

Sixty-nine articles were included (46 flare design trials, 17 observational studies, 6 other designs; sample sizes: 15-6085). Domains used to define flares included: worsening of signs and symptoms (61 studies, 27 different measurement tools), specifically increased pain intensity; minimum pain threshold at baseline (44 studies); minimum duration (7 studies, range 8-48 hours); speed of onset (2 studies, defined as 'sudden' or 'quick'); requirement for increased medication (2 studies). No definitions included activity interference.

CONCLUSIONS

The concept of OA flare appears in the medical literature but most often in the context of flare design trials (pain increases observed after stopping usual treatment). Key domains, used to define acute events in other chronic conditions, appear relevant to OA flare and could provide the basis for consensus on a single, agreed definition of 'naturally occurring' OA flares for research and clinical application.

PROSPERO REGISTRATION NUMBER

CRD42014010169.

Mixed Treatment Comparisons for Nonsurgical Treatment of Knee Osteoarthritis: A Network Meta-analysis

INTRODUCTION

Knee osteoarthritis (KOA) is a significant health problem with lifetime risk of development estimated to be 45%. Effective nonsurgical treatments are needed for the management of symptoms.

METHODS

We designed a network meta-analysis to determine clinically relevant effectiveness of nonsteroidal anti-inflammatory drugs, acetaminophen, intra-articular (IA) corticosteroids, IA platelet-rich plasma, and IA hyaluronic acid compared with each other as well as with oral and IA placebos. We used PubMed, EMBASE, and Cochrane Central Register of Controlled Trials to perform a systematic search of KOA treatments with no date limits and last search on October 7, 2015. Article inclusion criteria considered the following: target population, randomized controlled study design, English language, human subjects, treatments and outcomes of interest, ≥30 patients per group, and consistent follow-up. Using the best available evidence, two abstractors independently extracted pain and function data at or near the most common follow-up time.

RESULTS

For pain, all active treatments showed significance over oral placebo, with IA corticosteroids having the largest magnitude of effect and significant difference only over IA placebo. For function, no IA treatments showed significance compared with either placebo, and naproxen was the only treatment showing clinical significance compared with oral placebo. Cumulative probabilities showed naproxen to be the most effective individual treatment, and when combined with IA corticosteroids, it is the most probable to improve pain and function.

DISCUSSION

Naproxen ranked most effective among conservative treatments of KOA and should be considered when treating pain and function because of its relative safety and low cost. The best available evidence was analyzed, but there were instances of inconsistency in the design and duration among articles, potentially affecting uniform data inclusion.

Lowering side effects of NSAID usage in osteoarthritis: recent attempts at minimizing dosage

INTRODUCTION

Osteoarthritis is a burdensome disease that causes progressive damage to articular cartilage. Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the preferred treatments for symptomatic relief. However, NSAIDs can cause serious dose-dependent side effects, which has prompted experts to recommend the minimization of NSAID dosage.

AREAS COVERED

This review focuses on three broad strategies that are currently being investigated or implemented to minimize NSAID dosage: nano-formulation, encapsulation, and topical delivery. The benefits, challenges and current status of these methods are discussed.

EXPERT OPINION

Multiple strategies are under investigation to lower NSAID dosage. There is great potential in developing formulations that utilize more than one of these strategies together. However, there are challenges to developing these lower dose preparations. In order to maximize the clinical potential of the abundance of NSAIDs that are both available and being developed, there is a major need for additional clinical studies directly comparing safety and efficacy of different preparations.

Developing anti-inflammatory therapeutics for patients with osteoarthritis

OA is the most common joint disorder in the world, but there are no approved therapeutics to prevent disease progression. Historically, OA has been considered a wear-and-tear joint disease, and efforts to identify and develop disease-modifying therapeutics have predominantly focused on direct inhibition of cartilage degeneration. However, there is now increasing evidence that inflammation is a key mediator of OA joint pathology, and also that the link between obesity and OA is not solely due to excessive load-bearing, suggesting therefore that targeting inflammation in OA could be a rewarding therapeutic strategy. In this review we therefore re-evaluate historical clinical trial data on anti-inflammatory therapeutics in OA patients, highlight some of the more promising emerging therapeutic targets and discuss the implications for future clinical trial design.

Defining Flare in Osteoarthritis of the Hip and Knee: A Systematic Literature Review — OMERACT Virtual Special Interest Group

Objective.

Beyond the exacerbation of pain in describing a flare in osteoarthritis (OA), patients and health professionals add other elements that deserve to be fully elucidated, such as effusion, swelling, and mobility limitation. To define and conceptualize the construct flare in OA, the objective was to identify the key variables, or symptoms, that worsen, and to clarify how these variables are described in the literature by patients and clinicians.

Methods.

A systematic review of the literature was conducted in Medline and PsychINFO. In brief, the search terms used were “osteoarthritis,” “knee,” “hip,” and “flare.” Specific characteristics of included studies were identified, including the type of study design, type of flare assessed, how the flare developed, and what definition of flare was used, including whether the definition was based on qualitative or quantitative analysis.

Results.

Pain was the major factor in the definition of flare within these studies. Four components of flare were identified: pain, other factors, composite criteria, and global assessment. While the majority of studies reported flare as an increase in pain using standardized outcome measures, only 1 study reported the antecedents and consequences of a pain flare using qualitative methods.

Conclusion.

The use of flare as an outcome or inclusion criterion in rheumatology trials is a common occurrence; however, this review highlights the wide variation in the definitions of OA flare currently in use and the emphasis on the measurement of pain. This variation in definition does not allow for direct comparison between trials and limits interpretation of evidence.

Low-dose SoluMatrix diclofenac in patients with osteoarthritis pain: impact on quality of life in a controlled trial

Low-dose SoluMatrix diclofenac was developed to provide effective pain relief for osteoarthritis pain. We evaluated the effects of SoluMatrix diclofenac on health-related quality of life (HRQoL) measures in patients with osteoarthritis, hypothesizing that SoluMatrix-treated patients would experience significant improvement compared with placebo. In this 12-week, phase 3 randomized controlled trial, 305 patients with osteoarthritis of the hip or knee received SoluMatrix diclofenac 35 mg three times (TID) or twice (BID) daily or placebo. Measures included HRQoL, assessed by Short Form 36 (SF-36, version 2), and pain, stiffness, and physical function, assessed by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline and at week 12. Descriptive statistics were calculated for mean changes from baseline; inferential statistics compared treatment groups with placebo. SoluMatrix diclofenac 35 mg BID (6.2 [0.75]; P = 0.0048) or TID (6.6 [0.80]; P = 0.0014) produced large improvements in the SF-36 physical component summary (PCS) scores at week 12 (least squares mean change from baseline [SE]) compared with placebo (3.5 [0.78]). Minimum clinically important differences were observed in six out of eight SF-36 domains among patients in SoluMatrix diclofenac groups and five out of eight domains in the placebo group; treatment with SoluMatrix diclofenac 35 mg TID produced significant improvements (P ≤ 0.03) in five out of eight domains versus placebo. SoluMatrix diclofenac 35 mg TID significantly improved responses to 23 out of 24 questions in the WOMAC versus placebo (P ≤ 0.0334). Low-dose SoluMatrix diclofenac 35 mg TID and BID significantly improved HRQoL, pain, stiffness, and physical function in patients with osteoarthritis of the hip or knee.

How does surgery compare with advanced intra-articular therapies in knee osteoarthritis: current thoughts

The objectives of osteoarthritis (OA) management are to reduce pain and inflammation, slow cartilage degradation, improve function and reduce disability. Current strategies for managing knee OA include nonpharmacological interventions, oral pharmacological treatments, localized intra-articular injections, and surgery. It has become evident that the inflammatory response is a key contributor to the development and progression of knee OA. Signaling pathways involving growth factors and cytokines are being investigated for the development of new therapies that target the underlying biological processes causing the disease. This concept of 'molecular orthopedics' enables more patient-centered diagnostic and treatment strategies. In contrast to other conservative therapies, which ultimately only address OA symptoms, intra-articular injections, in particular autologous conditioned serum (ACS), provide benefits that have the potential to outweigh those of established pharmacological treatments and surgery. Surgery has historically been considered the final solution for treatment of knee OA, both by treating physicians and by patients; however, there are increasing concerns regarding the lack of randomized clinical trials providing evidence to support this opinion. Intra-articular injection of ACS has demonstrated efficacy as a treatment for knee OA in a number of studies, with a very low rate of adverse events and side effects, compared with surgery. Treatment with ACS utilizes the release of anti-inflammatory cytokines and regenerative growth factors to support the natural healing processes in the knee, and has the potential to provide a valuable alternative to surgical intervention.

SoluMatrix® Diclofenac: Sustained Opioid-Sparing Effects in a Phase 3 Study in Patients with Postoperative Pain

OBJECTIVES

To evaluate opioid rescue medication usage and the opioid-sparing effect of low-dose SoluMatrix^® diclofenac developed using SoluMatrix Fine Particle Technology™ in a phase 3 study in patients experiencing pain following bunionectomy surgery.

DESIGN

Multicenter, randomized, double-blind, parallel-group study (NCT01462435).

SETTING

Four clinical research centers in the United States.

SUBJECTS

Four hundred twenty-eight patients aged 18 to 65 years who experienced moderate-to-severe pain following bunionectomy surgery.

METHODS

Patients were randomized to receive low-dose SoluMatrix diclofenac 35 mg or 18 mg capsules three times daily (35-mg group or 18-mg group), celecoxib 400 mg loading dose followed by 200-mg capsules twice daily (celecoxib 200-mg group), or placebo capsules postsurgery. Patients were permitted to receive opioid-containing rescue medication as needed.

RESULTS

Significantly fewer patients who received SoluMatrix diclofenac 35 mg or 18 mg or celecoxib required rescue medication during 0-24 h and >24-48 h postsurgery compared with placebo. Patients in the SoluMatrix diclofenac 35 mg or 18 mg groups or in the celecoxib group used fewer mean rescue medication tablets over 0-24 h and >24-48 h compared with placebo-treated patients. Patients in the SoluMatrix diclofenac 35 mg and 18 mg groups and in the celecoxib group also required rescue medication at later times and at slower rates compared with placebo-treated patients. No serious adverse effects occurred in patients receiving SoluMatrix diclofenac.

CONCLUSIONS

SoluMatrix diclofenac at two dosage strengths demonstrated an opioid-sparing effect postoperatively in this phase 3 study.

SUMMARY

The opioid-sparing effect following low-dose SoluMatrix diclofenac (35 mg or 18 mg three times daily) administration was evaluated in patients experiencing pain following bunionectomy. Significantly fewer patients receiving SoluMatrix diclofenac or celecoxib (400 mg loading, 200 mg twice daily) required rescue medication during 0-24 h and >24-48 h following bunionectomy compared with placebo. No serious adverse events were reported among patients who received SoluMatrix diclofenac. SoluMatrix diclofenac may reduce opioid usage in the postoperative setting in patients with acute pain.

Evolution to low-dose NSAID therapy

All NSAIDs are to varying degrees associated with gastrointestinal, cardiovascular and renal adverse effects (AEs). Differences in selectivity for inhibition of the COX isozymes (COX-1/COX-2) have been used as an indicator of the likelihood of experiencing an AE, but the measure of 'selectivity' commonly used is less than desirable, and selectivity has not yielded unequivocal superior safety. Recent guidelines recommend that NSAIDs be used at the lowest effective dose and for the shortest period of time. In response, 'low-dose' NSAID formulations have been developed. Such formulations may help by reducing overall systemic exposure, thereby reducing the frequency or severity of AEs. It seems timely to review the need, rationale and application of such an approach.

Patient-reported Outcomes from A National, Prospective, Observational Study of Emergency Department Acute Pain Management With an Intranasal Nonsteroidal Anti-inflammatory Drug, Opioids, or Both

OBJECTIVES

Patient compliance and satisfaction with analgesics prescribed after emergency department (ED) care for acute pain are poorly understood, largely because of the lack of direct patient follow-up with the ED provider. Our objective was to compare patient satisfaction with three analgesia regimens prescribed for post-ED care-a nasally administered nonsteroidal anti-inflammatory drug (NSAID), an opioid, or combination therapy-by collecting granular follow-up on analgesic use, pain scores, side effects, work activity levels, and overall satisfaction directly from patients.

METHODS

We designed a prospective registry linking ED assessment and analgesic management for acute pain of specific musculoskeletal or visceral etiologies with self-reported automated telephonic follow-up daily for the 4 days post-ED discharge. Patients were prescribed a specific NSAID (SPRIX, ketorolac tromethamine for nasal instillation) only, an oral opioid only, or both with the opioid clearly defined as rescue therapy, at the ED provider's discretion.

RESULTS

There were 824 evaluable subjects. Maximum pain scores improved day to day more effectively with a ketorolac-based approach. Self-reported rates of return to work and work effectiveness were higher with SPRIX than with opioids or combination therapy. Adverse effects of nausea, constipation, drowsiness, and abdominal pain were higher each day among patients taking an opioid; nasal irritation was more common with SPRIX. Overall satisfaction at the end of the follow-up period was higher with SPRIX-based treatment than with opioid monotherapy.

CONCLUSIONS

Automated telephonic follow-up of ED patients prescribed short-term analgesia is feasible. Ketorolac-based analgesia after an ED visit for many acute pain syndromes was associated with favorable patient outcomes and higher satisfaction than opioid-based therapy. SPRIX, an NSAID that is not available over the counter and has a novel delivery approach, may be useful for short-term post-ED outpatient analgesia.

Low-dose SoluMatrix diclofenac : a review of safety across two Phase III studies in patients with acute and osteoarthritis pain

INTRODUCTION

Similar to other NSAIDs, diclofenac is associated with serious dose-related cardiovascular, gastrointestinal, and renal adverse events. Low-dose SoluMatrix diclofenac , containing submicron particles of diclofenac, was developed to provide effective analgesia at lower drug doses compared with currently available NSAIDs.

AREAS COVERED

The efficacy and safety of low-dose SoluMatrix diclofenac was evaluated in two randomized, placebo-controlled Phase III studies: a study in patients with acute pain following bunionectomy surgery and a study in patients with osteoarthritis pain of the hip or knee. In this review article, we summarize safety data from these studies.

EXPERT OPINION

The safety results from the Phase III studies indicate that all dosing regimens of low-dose SoluMatrix diclofenac up to 12 weeks are generally well tolerated. Few serious gastrointestinal, cardiovascular, renal, or hepatic adverse events commonly associated with NSAID use were reported in these studies. Although not directly compared, the safety of SoluMatrix diclofenac was similar to findings for other diclofenac drug products. The potential for safe and effective management of acute and chronic pain at reduced NSAID doses is attractive; definitive characterization of SoluMatrix diclofenac safety requires confirmation by long-term studies.

Advances in NSAID development: evolution of diclofenac products using pharmaceutical technology

Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) of the phenylacetic acid class with anti-inflammatory, analgesic, and antipyretic properties. Contrary to the action of many traditional NSAIDs, diclofenac inhibits cyclooxygenase (COX)-2 enzyme with greater potency than it does COX-1. Similar to other NSAIDs, diclofenac is associated with serious dose-dependent gastrointestinal, cardiovascular, and renal adverse effects. Since its introduction in 1973, a number of different diclofenac-containing drug products have been developed with the goal of improving efficacy, tolerability, and patient convenience. Delayed- and extended-release forms of diclofenac sodium were initially developed with the goal of improving the safety profile of diclofenac and providing convenient, once-daily dosing for the treatment of patients with chronic pain. New drug products consisting of diclofenac potassium salt were associated with faster absorption and rapid onset of pain relief. These include diclofenac potassium immediate-release tablets, diclofenac potassium liquid-filled soft gel capsules, and diclofenac potassium powder for oral solution. The advent of topical formulations of diclofenac enabled local treatment of pain and inflammation while minimizing systemic absorption of diclofenac. SoluMatrix diclofenac, consisting of submicron particles of diclofenac free acid and a proprietary combination of excipients, was developed to provide analgesic efficacy at reduced doses associated with lower systemic absorption. This review illustrates how pharmaceutical technology has been used to modify the pharmacokinetic properties of diclofenac, leading to the creation of novel drug products with improved clinical utility.

Pharmacokinetic properties and tolerability of low-dose SoluMatrix diclofenac

PURPOSE

This study compared the pharmacokinetic properties and safety profile of low-dose (18- and 35-mg) diclofenac capsules manufactured using SoluMatrix Fine Particle Technology (Trademark of iCeutica Inc. (Philadelphia, Pennsylvania), and the technology is licensed to Iroko Pharmaceuticals, LLC (Philadelphia, Pennsylvania) for exclusive use in NSAIDs), which produces submicron-sized drug particles with enhanced dissolution properties, to those of diclofenac potassium immediate-release (IR) 50-mg tablets.

METHODS

This Phase 1, single-center, randomized, open-label, single-dose crossover study was conducted in 40 healthy volunteers. Subjects received, in randomized order, SoluMatrix diclofenac 18- or 35-mg capsules in the fasting condition, SoluMatrix diclofenac 35-mg capsules under fed conditions, and diclofenac potassium IR 50-mg tablets under fasting and fed conditions. Pharmacokinetic parameters (T(max), C(max), AUC(0-t), AUC(0-∞)) were calculated from the concentrations of diclofenac in the plasma. Absorption, food effect, and dose proportionality were determined using a mixed-model ANOVA for C(max), AUC(0-t), AUC(0-∞). Tolerability was assessed by recording adverse events, physical examination findings, vital sign measurements: clinical laboratory test results.

FINDINGS

Overall, 35 healthy volunteers aged 18 to 52 years completed the study. The mean age of the subjects was 33.4 years, and approximately half were men (47.5%). Median T(max) values were similar between the low-dose SoluMatrix diclofenac 35-mg capsules and the diclofenac potassium IR 50-mg tablets (both, ~1.0 hour). The mean maximum plasma concentration (C(max)) after the administration of low-dose SoluMatrix diclofenac 35-mg capsules was 26% lower than that with diclofenac potassium IR 50-mg tablets under fasting conditions (868.72 vs 1194.21 ng/mL). The administration of low-dose SoluMatrix diclofenac 35-mg capsules was associated with a 23% lower overall systemic exposure compared with that of diclofenac potassium IR 50-mg tablets under fasting conditions. Food decreased the rate but not the overall extent of absorption of SoluMatrix diclofenac. No serious AEs and no clinically significant abnormalities in physical examination findings, including vital sign measurements, or clinical laboratory test results, were noted during this study.

IMPLICATIONS

The pharmacokinetic properties of low-dose SoluMatrix diclofenac capsules in the healthy volunteers in this study suggest rapid diclofenac absorption as measured by T(max). Low-dose SoluMatrix diclofenac capsules represent a potential option for the management of acute and osteoarthritis-related pain.