Comparison of electromotive drug administration with ketorolac or with placebo in patients with pain from rheumatic disease: a double-masked study

Efficacy, Safety and Targets in Topical and Transdermal Active and Excipient Delivery

A key requirement for topical and transdermal active delivery is the effective delivery of an active to a desired target site, to achieve both safe and efficacious outcomes. This chapter seeks to explore the importance of the pharmacological, toxicological and therapeutic properties of actives and excipients, as well as the site of action as complementary components in percutaneous absorption. This is crucial for optimized topical and transdermal product design.

Non-steroidal anti-inflammatory drugs (NSAIDs) for treating lateral elbow pain in adults

BACKGROUND

Lateral elbow pain, or tennis elbow, is a common condition that causes pain in the elbow and forearm. Although self-limiting, it can be associated with significant disability and often results in work absence. It is often treated with topical and oral non-steroidal anti-inflammatory drugs (NSAIDs). This is an update of a review first published in 2002 (search date October 11, 2012).

OBJECTIVES

To assess the benefits and harms of topical and oral NSAIDs for treating people with lateral elbow pain.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, CINAHL, EMBASE and SciSearch up to October 11, 2012. No language restriction was applied.

SELECTION CRITERIA

Studies were included if they were randomised or quasi-randomised controlled trials (RCTs or CCTs) that compared topical or oral NSAIDs with placebo or another intervention, or compared two NSAIDs in adults with lateral elbow pain. Outcomes of interest were pain, function, quality of life, pain-free grip strength, overall treatment success, work loss and adverse effects.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the studies for inclusion, extracted the data, and performed a risk of bias assessment.

MAIN RESULTS

Fifteen trials, involving 759 participants and reporting 17 comparisons, were included in the review. Four new trials identified from the updated search were included, along with 11 of 14 trials included in the original review (three trials included in the previous review were found not to meet inclusion criteria). Of eight trials that studied topical NSAIDs (301 participants), five compared topical NSAIDs with placebo, one compared manipulative therapy and topical NSAIDs with manipulative therapy alone, one compared leech therapy with topical NSAIDs and one compared two different topical NSAIDs. Of seven trials that investigated oral NSAIDs (437 participants), two compared oral NSAIDs with placebo, one compared oral NSAIDs and bandaging with bandaging alone, three compared oral NSAIDs with glucocorticoid injection, one compared oral NSAIDs with a vasodilator and two compared two different oral NSAIDs. No trials directly compared topical NSAIDs with oral NSAIDs. Few trials used intention-to-treat analysis, and the sample size of most was small. The median follow-up was 2 weeks (range 1 week to 1 year).Low-quality evidence was obtained from three trials (153 participants) suggesting that topical NSAIDs were significantly more effective than placebo with respect to pain in the short term (mean difference -1.64, 95% confidence interval (CI) -2.42 to -0.86) and number needed to treat to benefit (7 (95% CI 3 to 21) on a 0 to 10 scale). Low-quality evidence was obtained from one trial (85 participants) indicating that significantly more participants report fair, good or excellent effectiveness with topical NSAIDs versus placebo at 28 days (14 days of therapy) (risk ratio (RR) 1.49, 95% CI 1.04 to 2.14). No participants withdrew as the result of adverse events, but some studies reported mild adverse effects such as rash in 2.5% of those exposed to topical NSAIDs compared with 1.3% of those exposed to placebo.Low-quality and conflicting evidence regarding the benefits of oral NSAIDs obtained from two trials could not be pooled. One trial found significantly greater improvement in pain compared with placebo, and the other trial found no between-group differences; neither trial found differences in function. One trial reported a withdrawal due to adverse effects for a participant in the NSAIDs group. Use of oral NSAIDs was associated with increased risk of gastrointestinal side effects compared with placebo in one trial in the review. Another trial reported discontinuation of treatment due to gastrointestinal side effects in four participants taking NSAIDs, and another participant developed an allergic reaction in response to oral NSAIDs.Very scant and conflicting evidence regarding the comparative effects of oral NSAIDs and glucocorticoid injection was obtained. One trial reported a significant improvement in pain with glucocorticoid injection, and another found no between-group differences; treatment success was similar between groups (RR of fair, good or excellent effectiveness 0.74; 95% CI 0.43 to 1.26). Transient pain may occur following injection.

AUTHORS' CONCLUSIONS

There remains limited evidence from which to draw firm conclusions about the benefits or harms of topical or oral NSAIDs in treating lateral elbow pain. Although data from five placebo-controlled trials suggest that topical NSAIDs may be beneficial in improving pain (for up to 4 weeks), non-normal distribution of data and other methodological issues precluded firm conclusions. Some people may expect a mild transient skin rash. Evidence about the benefits of oral NSAIDs has been conflicting, although oral NSAID use may result in gastrointestinal adverse effects in some people. No direct comparisons between oral and topical NSAIDs were available. Some trials demonstrated greater benefit from glucocorticoid injection than from NSAIDs in the short term, but this was not apparent in all studies and was not apparent by 6 months in the only study that included longer-term outcomes.

Antipsychotic dosing and drug delivery

This chapter addresses the current state of affairs regarding proposed mechanism of action for antipsychotic medications and how this mechanism relates to dosing and delivery strategies. The initial portion describes the history of antipsychotic medication, including key discoveries that contribute to the dopamine hypothesis of schizophrenia and provide evidence that dopamine D2 receptor antagonism remains the most copasetic explanation for both determination of dose and degree of efficacy for current antipsychotic medications. Early observations regarding the unique properties of clozapine and how those observations led to the misconception and misnomer of atypicality are also discussed. Subsequent sections relate the dosing of available medications using chlorpromazine equivalents, with a discussion of non-D2-related mechanisms to antipsychotic effects. The balance of the chapter explores the temporal pattern of receptor occupancy as a key determinant of antipsychotic effectiveness, noting that continuous infusion would present the optimal method of treatment. In addition to the pharmacodynamic benefits of continuous long-term delivery systems, the incidence, causes, and clinical consequences of poor adherence are addressed. These observations are then discussed in the context of clinical studies and meta-analyses, demonstrating superiority of long-term depot preparations over oral administration. However, despite overwhelming evidence in favor of long-term delivery systems, few options are available to provide such ideal medication delivery profiles. Barriers to creating traditional depot preparations for a large number of antipsychotic agents, as well as efforts to address these limitations with polymer-based microspheres are described. The potential extension of current formulations to very long-term delivery implants using biodegradable and nonbiodegradable platforms is then described. Benefits as well as limitations of such systems are discussed with respect to clinical and ethical issues as well as a brief description of potential regulatory and logistic barriers to developing better delivery options. In summary, this chapter describes the basis for relating the dose of all existing antipsychotic medications to dopamine D2 receptor affinity and the potential contribution of continuous occupancy to enhanced efficacy through superior biological effects and improved adherence.

Acid-sensing ion channels 3: a potential therapeutic target for pain treatment in arthritis

Acid-sensing ion channels 3 (ASIC3) is the most sensitive to such a pH change, predominantly distributed in the sensory peripheral nervous system, and strongly correlated with pain. Recently, there is increasing evidence that ASIC3 may contribute to the pathogenesis of chronic inflammatory pain diseases due to it is predominantly expressed in dorsal root ganglia (DRG) neurons making it a good candidate for a pain sensor. Elevated expression of ASIC3 was found in DRG of rodents with inflamed hind paws. In addition, it has been shown that ASIC3 gene knock-out mice (ASIC3-/-) exhibited no enhanced hyperalgesia in inflamed joint. All theses findings suggest that ASIC3 have important biological effects in inflammation that might be a promising therapeutic target for arthritis pain. In this review, we will briefly discuss the biological features of ASIC3 and summarize recent advances on the role of ASIC3 in the pathogenesis and treatment of arthritis pain.

Determination of the in vivo bioavailability of iontophoretically delivered diclofenac using a methyl nicotinate skin inflammation assay

BACKGROUND/AIMS

In this study, we investigated the bioavailability of iontophoretically delivered diclofenac with the methylnicotinate (MN) test. The inhibition of an erythema provoked by MN is proportional to the bioavailability of diclofenac in the skin. It was our aim to use this procedure in the determination of the contribution of, respectively, passive diffusion, occlusion and electrically assisted delivery during an iontophoretic procedure as used in physiotherapy.

METHOD

A total of six application sites were marked on the volar forearms of each volunteer (n=12), for the following treatment and/or control modes: A=cathodal iontophoresis of 12 mg/cm(2) Voltaren Emulgel (diethylammonii diclofenac 1%) for 20 min; B=passive diffusion under a contact sponge; C=passive diffusion without any covering; D=current alone; E=standard MN response; and F=blanco site. Tristimulus surface colorimetry and Laser Doppler flowmetry were used to measure, respectively, the skin color and the perfusion of the microcirculation. Bioavailability was assessed by quantification of an MN-induced erythema under the different conditions.

RESULTS

A significant reduction of the MN-induced erythema was observed with the Chromameter and Laser Doppler measurements for the following treatment modalities: (1) electrically assisted delivery: respectively, 65% and 100%, (2) application under a contact sponge: 66% and 97% and (3) passive diffusion without any covering: 32% and 65%. A significant reduction was equally observed for the site treated with the current alone: 19% and 42%. There was no significant difference between the response after iontophoretic-delivered diclofenac (mode A) and application of diclofenac under a contact sponge (mode B).

CONCLUSION

The procedure used enabled us to evaluate the bioavailability of a non-steroidal anti-inflammatory drug in the skin. Under the conditions used, we did not find an increased bioavailability after electrically assisted delivery of diclofenac compared with the passive percutaneous penetration under the contact sponge.

Iontophoretic drug delivery

The composition and architecture of the stratum corneum render it a formidable barrier to the topical and transdermal administration of therapeutic agents. The physicochemical constraints severely limit the number of molecules that can be considered as realistic candidates for transdermal delivery. Iontophoresis provides a mechanism to enhance the penetration of hydrophilic and charged molecules across the skin. The principal distinguishing feature is the control afforded by iontophoresis and the ability to individualize therapies. This may become significant as the impact of interindividual variations in protein expression and the effect on drug metabolism and drug efficacy is better understood. In this review we describe the underlying mechanisms that drive iontophoresis and we discuss the impact of key experimental parameters-namely, drug concentration, applied current and pH-on iontophoretic delivery efficiency. We present a comprehensive and critical review of the different therapeutic classes and molecules that have been investigated as potential candidates for iontophoretic delivery. The iontophoretic delivery of peptides and proteins is also discussed. In the final section, we describe the development of the first pre-filled, pre-programmed iontophoretic device, which is scheduled to be commercialized during the course of 2004.

Agents physiques antalgiques

Analgesic electrotherapy is now based on more consistent scientific data; the biological action of the electric current, of the electromagnetic radiations and of the mechanical vibrations is better approached. But the randomized control trials still provide contradictory results concerning the analgesic efficiency of the cryotherapy, the TENS, the pulsed electro-magnetic fields, the ultrasound and laser therapy, the shock waves; iontophoresis, short waves, microwaves, infrasound vibrations are very few investigated. The analgesic electrotherapy cannot be recommended nor prohibited; physical agents represent only therapeutic options. On the basis of the scientific data and of their personal experience, the therapists can use them. More controlled clinical investigations of higher methodological levels are still required.

Non-steroidal anti-inflammatory drugs (NSAIDs) for treating lateral elbow pain in adults

BACKGROUND

Lateral elbow pain, or tennis elbow, is a common condition causing pain in the elbow and forearm and lack of strength and function of the elbow and wrist. It is often treated with non-steroidal anti-inflammatory drugs (NSAIDs), either orally or by topical application.

OBJECTIVES

To assess effectiveness of NSAIDs (oral or topical) in the treatment of adults with lateral elbow pain with respect to symptom (pain) reduction, improvement in function, grip strength and adverse effects.

SEARCH STRATEGY

We searched the Musculoskeletal Review Group's trials register database, the Cochrane Clinical Trials Register (Cochrane Library issue 2, 2001), MEDLINE, CINAHL, EMBASE and SCISEARCH up to June 2001.

SELECTION CRITERIA

Randomised and pseudo randomised trials in all languages of NSAIDs (oral or topical) compared to placebo or another intervention, or comparing two NSAIDs (oral or topical) to each other, in adults with lateral elbow pain (tennis elbow). Outcomes of interest were pain, function, disability and quality of life, strength, participant satisfaction with treatment and adverse effect.

DATA COLLECTION AND ANALYSIS

Two reviewers independently applied selection criteria and assessed study quality.

MAIN RESULTS

Fourteen trials were included in the review. Few trials used intention to treat analysis, and the sample size of most was small. The median follow up was 2 weeks (range 1-12 weeks). There is evidence that topical NSAIDs are significantly more effective than placebo with respect to pain [weighted main difference= -1.88, (95% confidence intervals -2.54 to -1.21)] and participant satisfaction [relative risk 0.39, (95% confidence intervals 0.23 to 0.66)] in the short term, and this finding is robust against the possible bias introduced by the inclusion of unblinded trials and publication bias. The adverse effects reported were minor. Only two included trials assessed the effect of oral NSAID and these were not able to be pooled. There is some evidence for short term benefit with respect to pain and function from oral NSAIDs, but this benefit was not sustained. Significantly more gastrointestinal adverse effects were reported by those taking oral NSAIDs [relative risk = 3.17, (95% confidence intervals 1.35 to 7.41)]. In the short term there may be some advantage in steroid injection over oral NSAID [patient's perception of benefit relative risk = 3.06, (95% confidence intervals 1.55 to 6.06)], but this was not sustained in the longer term.

REVIEWER'S CONCLUSIONS

There is some support for the use of topical NSAIDs to relieve lateral elbow pain at least in the short term. There remains insufficient evidence to recommend or discourage the use of oral NSAID, although it appears injection may be more effective than oral NSAID in the short term. A direct comparison between topical and oral NSAID has not been made and so no conclusions can be drawn regarding the best method of administration.

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.