Novel Treatment of Radicular Pain With a Multi-Mechanistic Combination Topical Agent: A Case Series and Literature Review

Clinical management and outcomes for goats, sheep, and pigs hospitalized for treatment of burn injuries sustained in wildfires: 28 cases (2006, 2015, and 2018)

OBJECTIVE

To characterize injuries and describe medical management and clinical outcomes of goats, sheep, and pigs treated at a veterinary medical teaching hospital for burn injuries sustained during wildfires.

ANIMALS

Goats (n = 9), sheep (12), and pigs (7) that sustained burn injuries from wildfires.

PROCEDURES

Medical records were searched to identify goats, sheep, and pigs that had burn injuries associated with California wildfires in 2006, 2015, and 2018. Data regarding signalment, physical examination findings, treatments, clinical outcomes, time to discharge from the hospital, and reasons for death or euthanasia were recorded.

RESULTS

The eyes, ears, nose, mouth, hooves, perineum, and ventral aspect of the abdomen were most commonly affected in both goats and sheep. In pigs, the ventral aspect of the abdomen, distal limb extremities, ears, and tail were most commonly affected. The median (range) time to discharge from the hospital for goats and pigs was 11 (3 to 90) and 85.5 (54 to 117) days, respectively. One of 9 goats, 12 of 12 sheep, and 5 of 7 pigs died or were euthanized. Laminitis and devitalization of distal limb extremities were common complications (13/28 animals) and a common reason for considering euthanasia in sheep and pigs.

CONCLUSIONS AND CLINICAL RELEVANCE

Burn injuries in small ruminants and pigs required prolonged treatment in some cases. Results suggested prognosis for survival may be more guarded for sheep and pigs with burn injuries than for goats; however, further research is needed to confirm these findings.

Topical Treatments and Their Molecular/Cellular Mechanisms in Patients with Peripheral Neuropathic Pain-Narrative Review

Neuropathic pain in humans results from an injury or disease of the somatosensory nervous system at the peripheral or central level. Despite the considerable progress in pain management methods made to date, peripheral neuropathic pain significantly impacts patients' quality of life, as pharmacological and non-pharmacological methods often fail or induce side effects. Topical treatments are gaining popularity in the management of peripheral neuropathic pain, due to excellent safety profiles and preferences. Moreover, topical treatments applied locally may target the underlying mechanisms of peripheral sensitization and pain. Recent studies showed that peripheral sensitization results from interactions between neuronal and non-neuronal cells, with numerous signaling molecules and molecular/cellular targets involved. This narrative review discusses the molecular/cellular mechanisms of drugs available in topical formulations utilized in clinical practice and their effectiveness in clinical studies in patients with peripheral neuropathic pain. We searched PubMed for papers published from 1 January 1995 to 30 November 2020. The key search phrases for identifying potentially relevant articles were "topical AND pain", "topical AND neuropathic", "topical AND treatment", "topical AND mechanism", "peripheral neuropathic", and "mechanism". The result of our search was 23 randomized controlled trials (RCT), 9 open-label studies, 16 retrospective studies, 20 case (series) reports, 8 systematic reviews, 66 narrative reviews, and 140 experimental studies. The data from preclinical studies revealed that active compounds of topical treatments exert multiple mechanisms of action, directly or indirectly modulating ion channels, receptors, proteins, and enzymes expressed by neuronal and non-neuronal cells, and thus contributing to antinociception. However, which mechanisms and the extent to which the mechanisms contribute to pain relief observed in humans remain unclear. The evidence from RCTs and reviews supports 5% lidocaine patches, 8% capsaicin patches, and botulinum toxin A injections as effective treatments in patients with peripheral neuropathic pain. In turn, single RCTs support evidence of doxepin, funapide, diclofenac, baclofen, clonidine, loperamide, and cannabidiol in neuropathic pain states. Topical administration of phenytoin, ambroxol, and prazosin is supported by observational clinical studies. For topical amitriptyline, menthol, and gabapentin, evidence comes from case reports and case series. For topical ketamine and baclofen, data supporting their effectiveness are provided by both single RCTs and case series. The discussed data from clinical studies and observations support the usefulness of topical treatments in neuropathic pain management. This review may help clinicians in making decisions regarding whether and which topical treatment may be a beneficial option, particularly in frail patients not tolerating systemic pharmacotherapy.

Topical Sevoflurane: A Novel Treatment for Chronic Pain Caused by Venous Stasis Ulcers

In the US, an estimated 1 - 2% of chronic venous insufficiency (CVI) patients (of 6 - 7 million nationwide) develop at least one venous stasis ulcer (VSU) during their illness. Of these, approximately 40% develop subsequent ulcers, making VSU prognostically poor. Current management of VSU is costly, with poor prognosis, high recurrence rate, inadequate pain management, and significantly reduced quality of life (QoL). Topical volatile anesthetic agents, such as sevoflurane, offer improved pain relief and symptom control in patients suffering from chronic VSU. The immediate impact of topical sevoflurane in reducing pain associated with ulcer bed debridement has several implications in improving the quality of life in patients with CVI induced ulcers and in the prognosis and healing of the ulcers. This review summarizes a topical formulation of a volatile anesthetic and its implications for the management of VSUs.

Topical drug therapeutics for neuropathic pain

INTRODUCTION

Neuropathic pain (NP) is a particularly severe and intractable chronic condition that is not well treated by commonly recommended systemic pharmacological therapies, partly due to dose-limiting side effects or adverse events. The use of topical therapeutics for NP is growing and benefits from the reduced potential for adverse effects, as well as the ability to directly target peripheral pathological processes.

AREAS COVERED

The current review defines and describes the limitations of various commonly prescribed systemic pharmacological therapies for NP. It also provides a justification for increased research aimed at developing topical therapeutics for NP, particularly localized and peripheral NP. The review discusses the various classes of topical treatments used for NP, including agents that: block sensory inputs; activate inhibitory systems; provide mechanism-based therapeutics; are used in mucosal tissues; and include combinations that produce multimodal therapeutic effects.

EXPERT OPINION

There are arguments that the current topical therapeutics for NP rely too heavily on the use of local anesthetics and capsaicinoids, and more research is certainly needed on topical therapies that are multimodal and/or are targeted at the peripheral sources of pathology. The potential for novel topical therapeutics may be enhanced by further research on topical co-drugs, drug-drug salts, co-crystals and hydrates, and ionic liquids.

The Results of Treating Failed Back Surgery Syndrome by Adhesiolysis: Comparing the One- and Three-Day Protocols

Background

The optimal treatment of failed back surgery syndrome (FBSS) is controversial. Limited studies have demonstrated the satisfactory outcomes of percutaneous adhesiolysis in FBSS, which can be performed as a 1 day or 3 days procedure. In the current randomized clinical trial, we compared the clinical and functional outcomes of these 2 techniques.

Methods

In this study, 60 patients with FBSS were randomly assigned into 2 equal groups: 1 day group and 3 days group. Before and at 4 and 12 weeks after the procedure, pain intensity was measured using visual analogue scale (VAS). The Oswestry disability index (ODI) was also completed. Pain reduction of 50% or more was defined as treatment success.

Results

Significant pain relief and ODI improvement were obtained in the 2 groups with adhesiolysis (P < 0.001). However, pain intensity remained the same before and at 4 and 12 weeks after adhesiolysis. ODI score was significantly lower in 1 day group in the 1 month visit (P < 0.001). Treatment was successful in 76.7% and 83.3% of the patients in 1 day and 3 days groups, respectively (P = 0.519).

Conclusions

Adhesiolysis is an effective treatment for pain relief and functional improvement in FBSS. The results of 1 day and 3 days procedures are comparable. Based on these findings, the authors recommend using 1 day technique, which can potentially decrease the patients' discomfort, hospital stay, and cost of treatment.

Topical Treatments for Localized Neuropathic Pain

Purpose of Review

Topical therapeutic approaches in localized neuropathic pain (LNP) syndromes are increasingly used by both specialists and general practitioners, with a potentially promising effect on pain reduction. In this narrative review, we describe the available compounds for topical use in LNP syndromes and address their potential efficacy according to the literature.

Recent Findings

Local anaesthetics (e.g., lidocaine, bupivacaine and mepivacaine), as well as general anaesthetic agents (e.g., ketamine), muscle relaxants (e.g., baclofen), capsaicin, anti-inflammatory drugs (e.g., diclofenac), salicylates, antidepressants (e.g., amitriptyline and doxepin), α2 adrenergic agents (e.g., clonidine), or even a combination of them have been tested in various applications for the treatment of LNP. Few of them have reached a sufficient level of evidence to support systematic use as treatment options.

Summary

Relatively few systemic side effects or drug–drug interactions and satisfactory efficacy seem to be the benefits of topical treatments. More well-organized and tailored studies are necessary for the further conceptualization of topical treatments for LNP.