The Effect of Local Application of Glyceryl Trinitrate (Nitroglycerine) on Raynaud's Disease and Raynaud's Phenomenon

Optimization of Sodium Iodide-Based Root Filling Material for Clinical Applications: Enhancing Physicochemical Properties

Premature loss of root canal-treated primary teeth has long been a concern in dentistry. To address this, researchers developed a sodium iodide-based root canal-filling material as an alternative to traditional iodoform-based materials. The goal of this study was to improve the physicochemical properties of the sodium iodide-based material to meet clinical use standards. To resolve high solubility issues in the initial formulation, researchers adjusted component ratios and added new ingredients, resulting in a new paste called L5. This study compared L5 with L0 (identical composition minus lanolin) and Vitapex as controls, conducting physicochemical and antibacterial tests. Results showed that L5 met all ISO 6876 standards, demonstrated easier injection and irrigation properties than Vitapex, and exhibited comparable antibacterial efficacy to Vitapex, which is currently used clinically. The researchers conclude that if biological stability is further verified, L5 could potentially be presented as a new option for root canal-filling materials in primary teeth.

Part II: The treatment of primary and secondary Raynaud's phenomenon

Raynaud phenomenon (RP) presents with either primary or secondary disease, and both have the potential to negatively impact patient quality of life. First-line management of RP should include lifestyle modifications in all patients. Some patients with primary RP and most with secondary RP require pharmacologic therapies, which may include calcium channel blockers, topical nitrates, phosphodiesterase 5 inhibitors, or endothelin antagonists. Additional approaches to treatment for those with signs of critical ischemia or those who fail pharmacologic therapy include botulinum toxin injection and digital sympathectomy. Herein, we describe in detail the treatment options for patients with RP as well as provide treatment algorithms for each RP subtype.

Raynaud's phenomenon and digital ulcers: advances in evaluation and management

PURPOSE OF REVIEW

The aim of this review is to give an update on advances in evaluation and management of systemic sclerosis (SSc)-related Raynaud's phenomenon and digital ulceration, focusing on reports from the last 18 months. The increasing recognition of the huge impact of Raynaud's phenomenon and of digital ulceration on the everyday lives of patients with SSc has sparked enthusiasm internationally to develop better outcome measures and better treatments, and so a review is timely.

RECENT FINDINGS

There have been recent advances in the development of patient reported outcome instruments [e.g. the Hand Disability in Systemic Sclerosis-Digital Ulcers (HDISS-DU) instrument] and also in noninvasive imaging techniques, including thermography and laser Doppler methods. Improved outcome measures will facilitate future clinical trials, both early phase proof-of-concept and later phase trials. New insights have been gained into mechanisms of action and methods of administration of 'conventional' therapies, for example phosphodiesterase inhibitors and intravenous prostanoids. New treatment approaches are being investigated, including topical and procedural therapies.

SUMMARY

Clinicians can look forward to seeing these advances translating into clinical benefit over the next 5 years. To help ensure this, they should strive whenever possible to recruit patients with SSc-related digital vasculopathy into observational studies and clinical trials.

Public interest in Raynaud's phenomenon: A Google Trends analysis

Raynaud's phenomenon is a common disorder affecting body extremities and other vascular beds. As infodemiological methods have developed, online search tools could be used to explore the public interest of the disease. The study aimed to determine the annual trend, seasonal pattern, and associated topics of Raynaud's phenomenon. Google Trends was used to collect the data. "Raynaud syndrome" was selected as the search term. Data on monthly relative search volume (RSV) were collected from four selected countries (United States, United Kingdom, Australia, and New Zealand) and globally. Related topics were obtained, and annual-related topics were also collected for analysis. The maximum RSV appeared in January 2019, and the minimum value was observed in August 2011. The peak for RSV occurred in winter, and the bottom appeared in summer. In top related topics, "Maurice Raynaud" was the most related. In rising related topics, disease manifestations and autoimmune connective diseases were highly concerned. For annual-related topics, associated diseases were attracting more attention over time. The population is interested in related diseases, pathogenesis, and treatment. There was a peak in winter for searching and supported the importance of season variation on the impact of Raynaud's phenomenon.

A systematic review and meta-analysis of new interventions for peripheral intravenous cannulation of children

OBJECTIVE

Establishing intravenous access in children is often challenging for health professionals. Multiple attempts at peripheral intravenous cannulation (PIVC) cause increased pain and delayed delivery of therapy. Our objective was to synthesize and evaluate the best evidence for novel interventions designed to improve pediatric PIVC.

METHODS

We searched for published and unpublished studies using MEDLINE, Cochrane Central Register of Controlled Trials, EMBASE, CINAHL, Web of Science, ClinicalTrials.gov, and Google.ca. We included studies for meta-analysis if they were randomized, evaluated an intervention other than ultrasound, and reported on 1 of 3 primary outcome measures: success or failure of PIVC, number of attempts to successful cannulation, and procedure time. Two blinded reviewers assessed studies for eligibility and applied a data extraction form to those included. Study quality was assessed using the Cochrane Risk of Bias Tool.

RESULTS

Seven studies met the inclusion criteria. Randomized controlled trials (RCTs) of 3 different interventions were identified. A meta-analysis of 3 RCTs found that use of a transilluminator was associated with a decreased risk of first-attempt PIVC failure (risk ratio, 0.66; confidence interval, 0.41-1.06). Meta-analysis of 3 other RCTs found that near-infrared light devices do not impact the risk of first-attempt PIVC failure (risk ratio, 0.99; confidence interval, 0.74-1.33).

CONCLUSIONS

Near-infrared light devices might be efficacious in selected subpopulations, but the available evidence does not support an overall benefit in the pediatric population. Transilluminators modestly improve pediatric PIVC, but the clinical significance of this benefit is questionable. Nitroglycerin ointments may increase the risk of PIVC failure and are associated with adverse effects.

A multi-centre, blinded, randomised, placebo-controlled, laboratory-based study of MQX-503, a novel topical gel formulation of nitroglycerine, in patients with Raynaud phenomenon

Objective

MQX-503 is a novel nitroglycerine preparation designed to absorb quickly and allow local vasodilatation in the skin. We examined the efficacy and tolerability of this medication in Raynaud phenomenon (RP) in a laboratory-based study.

Methods

In this multi-centre, double-blind, randomised, placebo-controlled, cross-over study, subjects were treated with 0.5% or 1.25% nitroglycerine or placebo gel. Subjects received each dose twice in a randomised order. Each study session consisted of baseline laser Doppler measurements, study gel application and 5 min of cold chamber exposure (−20°C). Blood flow (BF) was measured at the end of exposure and for the next 120 min at set intervals. Other outcome measures included achievement of baseline BF; the time to achieve 50% and 70% baseline skin temperature (ST); and pain, tingling and numbness scores.

Results

37 subjects completed 214 treatment periods. Time to achieve baseline BF was significantly shorter in the two treated groups (HR=1.77 and 2.02 for 0.5% and 1.25% vs placebo, respectively). The proportion of subjects achieving baseline BF was 45.8% for placebo, 66.2% for 0.5% and 69% for 1.25% (p=0.01 and p=0.002 for 0.5% and 1.25% vs placebo, respectively). No meaningful differences were seen in ST or pain/numbness/tingling scores. Treatment was well tolerated with no serious adverse events.

Conclusions

Treatment with MQX-503 caused a significant improvement in skin BF compared with placebo. Data from this proof of concept study suggest benefit of MQX-503 in subjects with RP.

The pathogenesis, diagnosis and treatment of Raynaud phenomenon

The past 10 years have seen the publication of results from several multicentre clinical trials in primary and systemic sclerosis (SSc)-related Raynaud phenomenon. The publication of these studies has occurred as a result of new insights into the pathogenesis of Raynaud phenomenon, which are directing new treatment approaches, and increased international collaboration between clinicians and scientists. Although the pathogenesis of Raynaud phenomenon is complex, abnormalities of the blood vessel wall, of neural control mechanisms and of intravascular (circulating) factors are known to interact and contribute. Key players relevant in drug development include nitric oxide, endothelin-1, alpha adrenergic receptor activation, abnormal signal transduction in vascular smooth muscle, oxidative stress and platelet activation. The main advances in diagnosis have been a clearer understanding of autoantibodies and of abnormal nailfold capillary patterns as independent predictors of SSc, and widespread use and increased availability of capillaroscopy. The ultimate aim is to translate the advances made in the pathophysiology and early diagnosis into development of treatments to prevent and reverse digital vascular dysfunction and injury. This Review provides an update of the pathogenesis, diagnosis and treatment of Raynaud phenomenon. Current and future treatment approaches are discussed, and some key unanswered questions are highlighted.

Recent achievements in the management of Raynaud's phenomenon

Raynaud's phenomenon is a clinical disorder with episodic digital ischemic vasospasm triggered by cold- or emotional-stress. It was first mentioned by Maurice Raynaud in 1862 describing "a local asphyxia of the extremities" and was further divided into primary Raynaud's disease and secondary Raynaud's phenomenon, which is often related to connective tissue diseases, but also physical or chemical strain. Though pathophysiology of Raynaud's phenomenon is still poorly understood, systemic and local vascular effects are most likely to be involved in primary Raynaud's disease. In secondary Raynaud's phenomenon additional abnormalities in vascular structure and function may play the major role. Thus, medical treatment of Raynaud's phenomenon remains unsatisfactory, due to limited understanding of pathophysiological mechanisms. This review addresses current evidence for medical treatment of primary and secondary Raynaud's phenomenon with regard to pathophysiological mechanisms as well as future perspectives.

Therapy: A local approach to Raynaud phenomenon

The current treatment options for Raynaud phenomenon are often ineffective and can have undesirable adverse effects. Topical, or transdermal, treatments that increase digital blood flow without systemic adverse effects are, therefore, an attractive option. A novel topical nitroglycerin formulation has shown promise in treating Raynaud attacks.

MQX-503, a novel formulation of nitroglycerin, improves the severity of Raynaud's phenomenon: a randomized, controlled trial

OBJECTIVE

Raynaud's phenomenon (RP) affects 3-9% of the general population and >90% of patients with systemic sclerosis. Nitrates are often prescribed for the treatment of RP, but currently available formulations are limited by side effects, particularly headaches, dizziness, and skin irritation. The purpose of this study was to evaluate the tolerability and efficacy of a novel formulation of topical nitroglycerin, MQX-503, in the treatment of RP in an ambulatory setting.

METHODS

We conducted a multicenter, randomized, placebo-controlled study with a 2-week single-blind run-in period to determine baseline severity, followed by a 4-week double-blind treatment phase. Two hundred nineteen adult patients with a clinical diagnosis of primary or secondary RP received 0.9% MQX-503 gel or matching placebo during the treatment period. Gel was applied immediately before or within 5 minutes of the beginning of an episode of RP (maximum of 4 applications daily). End points included the change in the mean Raynaud's Condition Score (RCS; scale 0-10), the frequency and duration of episodes, and subjective assessments at the target week (the week during the treatment phase that most closely matched the run-in period in terms of ambient temperature) compared with baseline.

RESULTS

The mean (%) change in the RCS at the target week compared with baseline was significantly greater in the MQX-503 group (0.48 [14.3%]) than that in the placebo group (0.04 [1.3%]; P = 0.04). Changes in the frequency and duration of RP episodes and subjective assessments were not statistically different between the groups. MQX-503 had a side effect profile similar to that of placebo.

CONCLUSION

MQX-503 is well tolerated and more effective than placebo for the treatment of RP.

Pharmacological treatment of Raynaud's phenomenon with special reference to calcium-entry blockers

The development of new vasoactive drugs has increased the possibilities to treat patients with digital vasospasm, known as Raynaud's phenomenon. The purpose of this paper is to give a review of recent clinical trials and also a short review of the pathophysiological reasons for each type of pharmacological treatment.

Pathogenesis and treatment of Raynaud's phenomenon

The pathogenetic theories and treatment of Raynaud's phenomenon are reviewed. In primary Raynaud's disease, most evidence supports a local defect at the digital artery level, with vasoconstriction or vasospasm of the digital arteries inducing the color changes. Normal sympathetic activity, low transmural arterial distending forces, and serotonin may be associated factors in the production of vasospastic attacks. In Raynaud's phenomenon, persistent vasoconstriction, thickened vessel walls, increased blood viscosity, and low digital artery blood pressure distal to obstructions may lead to vasospastic attacks with normal sympathetic nerve stimuli. Since the underlying cause of primary Raynaud's disease is unknown, treatment involves the use of agents to reduce sympathetic nerve activity or to prevent vascular smooth muscle contraction. Most patients will respond to conservative measures, but if they fail nifedipine is the drug of choice and alleviates the syndrome in about two thirds of patients. Reserpine and guanethidine may be as effective, but well-controlled studies have not been performed. The beneficial response to prazosin is moderate and dissipates with time. Side effects with these drugs prevent their use in many patients. Diltiazem and nitroglycerin ointments are of questionable value. Ketanserin, a serotonergic S2-receptor antagonist, which has been shown to decrease the frequency of vasospastic attacks, and parenteral prostacyclin are among the new promising therapies.

Topical glyceryl trinitrate as adjunctive treatment in Raynaud's disease

The effects of topical glyceryl trinitrate in Raynaud's disease were compared with those of placebo in a double-blind, crossover trial in 17 patients with bilateral Raynaud's disease and an associated collagen disease, who were receiving oral sympatholytic agents at the maximum levels they could tolerate. 1% glyceryl trinitrate ointment or a placebo of lanolin was applied to one hand only for 6 weeks, then patients changed to the other preparation for 6 weeks. The results were evaluated every 2 weeks. The frequency of attacks, severity of attacks, and size of ulcers in the treated hand were significantly lower when the patients were using glyceryl trinitrate ointment than when they were using placebo. The treatment of Raynaud's disease may be improved by using topical glyceryl trinitrate ointment as an adjunct to a basic regimen of oral sympatholytic agents. Glyceryl trinitrate ointment may obviate the need for more aggressive treatment, such as intraarterial reserpine, in selected patients.

A double-blind clinical trial of griseofulvin in patients with Raynaud's phenomenon

Twenty-four patients with Raynaud's phenomenon were treated with griseofulvin and a placebo in a double-blind cross-over clinical trial. The results were assessed subjectively and plotted sequentially. The number of patients able to distinguish the active from the placebo treatment was statistically significant (P=0·05). There were indications that the response was dose dependent. Further studies are needed to establish whether griseofulvin offers useful clinical improvement in this condition.