Capsaicin Patch Research Articles

Effect of Cooling Capsaicin Application Site on Reducing Burning Sensation in Neuropathic Pain Patients: A Randomized Controlled Trial

PurposeTreatment of localized neuropathic pain continues to represent an unmet need. The primary objective of the present study was to evaluate the efficacy of cryotherapy to reduce the burning pain induced by capsaicin (8%) patches (QUTENZA) in a neuropathic pain cohort. We also investigated subsequent neuropathic pain during an 8-week follow-up. DesignThe present work resulted from a prospective, randomized, two-center, open-label, interventional French trial. MethodsThis study aimed to investigate the effects of cooling of the application area of QUTENZA patches. Visual analog scale (VAS) scores were measured 30 and 60 minutes after patch application. Weekly neuropathic VAS scores were then collated for 2 months. Ninety-nine patients were included and randomized into a cryotherapy group (n = 50 [80% women], median age = 51 years old) and a no cryotherapy group (n = 49 [69% women], median age = 48 years old). ResultsCooling at the application site of the patch resulted in a reduction by 3.20 in burning pain VAS score at 60 minutes, with no cooling VAS 6.99 (95% CI [6.2, 7.77]) versus 3.78 (95% CI [3, 4.56]) for cryotherapy. Neuropathic VAS pain scores over the follow-up period were not statistically different. ConclusionsCryotherapy at the application site significantly reduced the burning pain induced by capsaicin patches but had no effect on neuropathic pain for the 8 weeks following application. Clinical ImplicationsThe use of cooling during capsaicin patch application, by ameliorating the therapeutic alliance, improves the clinical management of neuropathic pain.© 20XX by the American Society for Pain Management Nursing

Topical capsaicin modulates the two-point discrimination threshold-Modulation depends on stimulation modality and intensity.

Spatial acuity concerns the ability to localize and discriminate sensory input and is often tested using the two-point discrimination threshold (2PDT). Sensitization of the pain system can affect the spatial acuity, but it is unclear how 2PDTs of different testing modalities are affected. The aim was to investigate if the 2PDTs for mechanical and heat stimulation at different intensities were modulated by topical capsaicin sensitization. 30 healthy subjects were divided into either a capsaicin or a placebo group. The 2PDT was tested using two different modalities, mechanical and thermal (laser) delivered at innocuous and noxious intensities. The 2PDT were determined at baseline and re-assessed 48 h later. In the follow-up session, the subjects either had a capsaicin patch (8%) or placebo patch placed in the testing area for 30 min before re-testing the 2PDT. The 2PDT was highly dependent on stimulation modality and intensity. The lowest 2PDT was found for innocuous mechanical stimuli (40.0 mm, 95% CI 38.1-41.9 mm), and the highest 2PDT was found for innocuous thermal stimuli (81.7 mm, 95% CI 73.9-89.5 mm). Topical capsaicin generally increased the 2PDT, but this was only significant for innocuous mechanical stimuli. The perceived intensity of the stimuli was increased following capsaicin and was generally higher for noxious stimuli than for innocuous stimuli (ANOVA, p < 0.001). This study showed that capsaicin provoked pain sensitization increased the 2PDT. The 2PDT tested using innocuous mechanical stimuli showed less variable results indicating that this test is most suitable to detect this aspect of spatial acuity. This study investigated how the two-point discrimination threshold (2PDT) can be modulated by topical capsaicin. The 2PDT was assessed for two different modalities (thermal and mechanical) and for two different intensities (innocuous and noxious) before and after capsaicin. The results showed that the 2PDT was generally impaired following capsaicin, but this was only significant for mechanical innocuous stimuli. Furthermore, it was shown that mechanical innocuous stimuli assessed the 2PDT with lower variability than other combinations.

Is there a role for capsaicin in cancer pain management?

Advances in oncological therapies have resulted in an increase in the number of patients living with and beyond cancer. The personal and societal impact of chronic pain in the survivor population represents an area of significant unmet need. Capsaicin (a TRPV1 agonist) may provide analgesia with limited systemic side effects. This review looks to summarise the most recent evidence regarding the use of capsaicin in the management of cancer pain. Various international guidelines have recently endorsed the use of high concentration capsaicin patches in the treatment of chronic painful chemotherapy induced peripheral neuropathy. Numerous studies support the use of capsaicin in the treatment of peripheral neuropathic pain. This promising data is predominantly yielded from pain secondary to herpes zoster and diabetic neuropathy, with an expanding but small evidence base for its utility in other neuropathic pains. Emerging data suggests that treatments are better tolerated and provide analgesia more rapidly when compared with systemic treatments. Whilst randomised controlled trial data in the treatment of cancer pain are lacking, recent large cohort studies, and international guidelines, support the use of high concentration capsaicin patches in a wide variety of neuropathic pain secondary to cancer treatments.

Effect of limb position change on capsaicin-evoked pain: Evidence of interplays between the vascular and nociceptive systems?

This experiment aimed at confirming our incidental observation that, when capsaicin is applied on the volar forearm, raising the arm to a vertical position leads to a dramatic increase in capsaicin-evoked pain and to explore possible underlying mechanisms. Twenty healthy volunteers received a 2% capsaicin patch on one forearm and a vehicle patch on the other. Patches were kept in place for 60 min. The perception caused by the patch was assessed repeatedly before, during and after patch application, both with the arm in horizontal resting position and raised vertically. In addition, capsaicin-induced secondary hyperalgesia was assessed using mechanical pinprick stimuli. Half of the participants were seated upright while the other half were lying supine, to assess whether the effect of limb position on capsaicin-evoked pain was due to gravity. After a few minutes of patch application, raising the capsaicin-treated arm (but not the vehicle-treated arm) led to a strong increase of the pain experienced at the patch. This effect of raising the arm did not differ between participants in the supine and seated groups and is therefore likely related to the position of the arm relative to the ground rather than to the body. Mechanical secondary hyperalgesia and the arm raising effect were strongly decorrelated at the last time point after patch removal, indicating different underlying mechanisms. Our results indicate that capsaicin-evoked pain can be strongly modulated by limb posture and that this effect may be caused by an interplay between vascular and nociceptive systems. Capsaicin-evoked pain can be strongly modulated by limb posture and this effect may be caused by an interplay between vascular and nociceptive systems.

Diabetic Neuropathy: A Guide to Pain Management.

Diabetic neuropathy is a common complication of diabetes mellitus (DM) and can affect up to 50% of DM patients during their lifetime. Patients typically present with numbness, tingling, pain, and loss of sensation in the extremities. Since there is no treatment targeting the underlying mechanism of neuropathy, strategies focus on preventative care and pain management. Up to 69% of patients with diabetic neuropathy receive pharmacological treatment for neuropathic pain. The United States Food and Drug Administration (FDA) confirmed four drugs for painful diabetic neuropathy (PDN): pregabalin, duloxetine, tapentadol, and the 8% capsaicin patch. Nonpharmacological treatments such as spinal cord stimulation (SCS) and transcutaneous electrical nerve stimulation (TENS) both show promise in reducing pain in DM patients. Despite the high burden associated with PDN, effective management remains challenging. This update covers the background and management of diabetic neuropathy, including its epidemiology, pathogenesis, preventative care, and current therapeutic strategies.

A Pain Physician’s Perspective on Recent Advances in Painful Diabetic Peripheral Neuropathy Management

Abstract Diabetic peripheral neuropathy (DPN) is a prevalent neurological complication linked to diabetes mellitus, exerting a substantial impact on the quality of life for those affected. This review article aims to discuss and review advances in the pain management of patients with DPN. We reviewed recent DPN management literature primarily from PubMed and SCOPUS using specific keywords, focusing on original research and recent advancements. The pathophysiology of DPN involves metabolic and vascular changes in nerve fibers, leading to direct damage and a decrease in their natural repair capacity. Effective glycemic control plays a central role in managing DPN, along with addressing other contributing factors such as comorbidities and lifestyle modifications. Nutraceuticals, including alpha-lipoic acid and Vitamin B12, have shown promising results in some studies. Antineuropathic agents such as calcium channel a2-δ ligands, serotonin and noradrenaline reuptake inhibitors, tricyclic antidepressants, and sodium channel blockers are commonly used in DPN pain management. Topical therapies, including capsaicin and lidocaine patches, have also demonstrated efficacy. Opioids are generally discouraged due to weak evidence and long-term deleterious side effects, along with the risk of addictive potential. Neuromodulation has emerged as a modality in resistant cases not responding to pharmacological management. Individualized treatment plans based on symptomatology, comorbidities, and side effect profiles should be developed for DPN patients. Comprehensive management of DPN involves a multidisciplinary approach, emphasizing patient education, regular assessment, and counseling to prevent further damage and complications.

Neuropathic pain: Evidence based recommendations

Neuropathic pain continues to be a significant problem that lacks effective solutions for every single patient. In 2015, international guidelines (NeuPSIG) were published, while the French recommendations were updated in 2020. The purpose of this minireview is to provide an update on the process of developing evidence-based recommendations and explore potential changes to the current recommendations. Primary treatments for neuropathic pain include selective serotonin-norepinephrine reuptake inhibitors (SNRIs) such as duloxetine and venlafaxine, gabapentin, tricyclic antidepressants, as well as topical lidocaine and transcutaneous electrical nerve stimulation, which are specifically suggested for focal peripheral neuropathic pain. Pregabalin is a first line treatment according to international guidelines but second-line in the more recent French guidelines, due to lower efficacy seen in more recent studies and misuse risk. Additionally, tramadol, combination therapies, and psychotherapy as adjuncts are proposed second line; high-concentration capsaicin patches, and botulinum toxin A are proposed specifically for focal peripheral neuropathic pain. In cases where primary and secondary treatments prove insufficient, third-line options come into play. These include high-frequency repetitive transcranial magnetic stimulation (rTMS) targeting the motor cortex, spinal cord stimulation, and the use of strong opioids when no alternative is available. To ensure optimal management of neuropathic pain in real-life situations, it is imperative to disseminate these recommendations widely and secure the acceptance of practitioners. By doing so, we can bridge the gap between theory and practice, and enhance the overall care and treatment of individuals suffering from neuropathic pain.

Adhesive capsaicin 8% patch for improved control of pain caused by chemotherapy-induced peripheral neuropathy in patients with multiple myeloma: A single-centre, seven-case series.

Capsaicin is a highly selective agonist of the transient receptor potential vanilloid 1. The adhesive capsaicin patch provides a high capsaicin concentration (8%) directly in the painful area - its efficacy in benign peripheral neuropathic pain (diabetic neuropathy or postherpetic neuralgia) has recently been described in the literature. However, there is scant evidence of its efficacy in chemotherapy-induced peripheral neuropathy (CIPN). This is a concern for patients with multiple myeloma, who suffer from peripheral neuropathic pain induced by first-line treatments (bortezomib or thalidomide). To describe improved control of CIPN in patients with multiple myeloma using adhesive capsaicin 8% patch. We opted for a retrospective observational case series. Between October 2017 and October 2020, we collected clinical data from adult multiple myeloma patients affected by CIPN who were administered the capsaicin 8% patch in our palliative care outpatient clinic. We compiled Numerical Pain Rating Scale (NPRS) scores, patients' medication needs and performance status before and after patch application. Two women and five men with an average age of 62.85 years received bortezomib. Two patients (28.57% of the sample) also received thalidomide. The average NPRS score before patch application was 6.42/10. Five of the seven patients (71.42%) received a mean daily oral morphine dose of 52.85 mg/day, five (71.42%) received gabapentinoids and one (14.28%) received antidepressants. The average NPRS score decreased to 4/10 seven days after patch application, while the mean daily oral morphine dose remained stable. Performance status improved slightly in two patients (28.57%) and remained stable in the rest. One patient (14.28%) required an extra analgesic dose during patch application. Capsaicin 8% patch application appears to reduce pain intensity in patients with multiple myeloma suffering from CIPN.

Characteristics and outcomes of peripheral neuropathic pain patients with repeated applications of high-concentration capsaicin cutaneous patch: Results of a retrospective chart review in Germany.

The aim of this study was to evaluate patient characteristics, concomitant analgesic medication, and pain intensity in a real-world setting in Germany, focusing on the repeated application of high-concentration capsaicin patch (HCCP) for neuropathic pain. Data were collected from electronic medical records of patients who received at least two HCCP treatments between January 2011 and July 2022. Subgroup analyses were performed based on the number of HCCP treatments, age groups, and specific neuropathic pain conditions. The study was conducted at an outpatient pain center in Wiesbaden, Germany. The study included 97 patients, primarily diagnosed with neuropathic back pain, postoperative or post-traumatic neuropathic pain, and postherpetic neuralgia. The daily dose of concomitant medications (eg, opioids and anticonvulsants) at the start of capsaicin therapy was compared with the average within 2 years of capsaicin therapy. The last observation carried forward method was used if HCCP treatment was discontinued before the end of the 2-year period. The majority of patients received concomitant medications, with opioids, anticonvulsants, and antidepressants being the most common. The average daily morphine equivalent dose decreased significantly during HCCP treatment. Pain intensity at baseline was generally high, but substantial improvements were observed in patients who received at least three HCCP applications. This study provides evidence for the effectiveness of HCCP treatment in reducing pain intensity and concomitant opioid use in patients with neuropathic pain. Further research is needed to explore the long-term outcomes and optimal treatment regimens for different patient populations.

Targeting TRPV1 for Cancer Pain Relief: Can It Work?

Chronic intractable pain affects a large proportion of cancer patients, especially those with metastatic bone disease. Blocking sensory afferents for cancer pain relief represents an attractive alternative to opioids and other drugs acting in the CNS in that sensory nerve blockers are not addictive and do not affect the mental state of the patient. A distinct subpopulation of sensory afferents expresses the capsaicin receptor TRPV1. Intrathecal resiniferatoxin, an ultrapotent capsaicin analog, ablates TRPV1-expressing nerve endings exposed to the cerebrospinal fluid, resulting in permanent analgesia in women with cervical cancer metastasis to the pelvic bone. High-dose capsaicin patches are effective pain killers in patients with chemotherapy-induced peripheral neuropathic pain. However, large gaps remain in our knowledge since the mechanisms by which cancer activates TRPV1 are essentially unknown. Most important, it is not clear whether or not sensory denervation mediated by TRPV1 agonists affects cancer progression. In a murine model of breast cancer, capsaicin desensitization was reported to accelerate progression. By contrast, desensitization mediated by resiniferatoxin was found to block melanoma growth. These observations imply that TRPV1 blockade for pain relief may be indicated for some cancers and contraindicated for others. In this review, we explore the current state of this field and compare the analgesic potential of TRPV1 antagonism and sensory afferent desensitization in cancer patients.

Topical treatment of chemotherapy-induced peripheral neuropathy (CIPN) with high-concentration (179 mg) capsaicin patch in breast cancer patients - results of the QUCIP study.

Chemotherapy-induced peripheral neuropathy (CIPN) following oral or intravenous chemotherapy often results in neuropathic pain, accompanied by symptoms such tingling, burning and hypersensitivity to stimuli, with a notable decline in quality of life (QoL). Effective therapies for CIPN are lacking, with a high demand for analgesics to address this issue. The QUCIP study aimed to assess the effectiveness of high concentration (179 mg) capsaicin patch (HCCP) in alleviating neuropathic pain and associated symptoms in breast cancer patients with confirmed CIPN. QUCIP is a prospective, multi-center observational study spanning 36 weeks with up to three HCCP treatments. Initial treatment (visit V0) was followed by two telephone contacts (T1, T2) and subsequent face-to-face visits every 12 weeks or upon retreatment (visits V1-V3). 73 female patients with painful CIPN post neoadjuvant/adjuvant breast cancer therapy were enrolled. Primary endpoint was the reduction of neuropathic pain symptom score (painDETECT®). Secondary endpoints included improvements in CIPN-specific QoL (QLQ-CIPN20), reductions in pain intensity (numeric pain rating scale, NPRS), and achievement of ≥ 30% and ≥ 50% pain reduction. Median age was 61 years, with 52.0% of patients experiencing peripheral neuropathic pain for > 1 year (> 2 years: 34.2%). The painDETECT® score significantly decreased from baseline (19.71 ± 4.69) to 15.80 ± 6.20 after initial treatment (p < 0.0001) and continued to decrease at follow-up visits. The NPRS indicated significant pain intensity reduction at each time point, particularly pronounced in patients receiving three HCCP treatments. Clinically significant pain relief of ≥ 30% increased from 25.0% at week 4 (T2) to 36.2%, 43.5%, and 40.0% at weeks 12 (V1), 24 (V2), and 36 (V3), respectively. The percentage of patients achieving pain relief of ≥ 50% increased from 14.7% at T2 to 15.5%, 21.7% and 32.5% at V1, V2 and V3, respectively. Patients further reported a significant improvement in their CIPN-related QoL throughout the study. Adverse drug reactions (ADRs) mainly included application site reactions. In this study, HCCP shows benefit in managing CIPN in real-world settings. The data demonstrate a sustained and progressive reduction in neuropathic pain and symptomatology, confirming the clinical benefit of repeated treatment observed in former clinical trials. HCCP treatment has also the potential to significantly improve the QoL associated with CIPN. The safety profile of HCCP was confirmed, supporting its use in clinical practice.

Topical capsaicin 8% patch in peripheral neuropathic pain: Efficacy and quality of life.

Peripheral neuropathic pain (PNP) is one of the most challenging diseases to treat with a significant negative impact on the patients' health-related quality of life (HRQoL). Capsaicin 8% patch has arisen in the last decades as an alternative to oral drugs in the treatment of PNP with fewer side effects and promising results in efficacy. This work aims to evaluate the effectiveness of the topical application of capsaicin in PNP and its impact on patients' HRQoL based on the use of capsaicin in a tertiary hospital of Oporto. This study included 100 patients with localized PNP with poor pain control and without improvement with previous treatments that were treated at least once with an 8% capsaicin patch. Effectiveness on pain relief, number of treatments needed, safety and impact on HRQoL were assessed through a set of questionnaires. Regarding the aetiology of PNP, 67.6% (N = 46) have post-surgery or trauma induced PNP with 64.7% (N = 44) of patients reporting pain in the lower limb. After the treatment, 30.9% (N = 21) felt minimally improved, 22.1 (N = 15) felt much improved and 13.2 (N = 9) felt very much improved. On a scale from 1 to 10, in the week prior to the survey, the median intensity of pain was 6 and the median interference in quality of life was 7. The majority of patients still report limitations in mobility and daily activities and moderate pain. Capsaicin 8% patch is effective in PNP treatment at least in the short term. Repeated applications may be important for long-term analgesia. The low systemic dose and few side effects mean that the treatment is generally well tolerated by patients. Due to the analgesic effect, capsaicin can improve the HRQoL of patients with PNP.

Pharmacological and Nonpharmacological Treatments for Painful Diabetic Peripheral Neuropathy.

Diabetic peripheral neuropathy (DPN) is one of the most prevalent chronic complications of diabetes. The lifetime prevalence of DPN is thought to be >50%, and 15%-25% of patients with diabetes experience neuropathic pain, referred to as "painful DPN." Appropriate treatment of painful DPN is important because this pain contributes to a poor quality of life by causing sleep disturbance, anxiety, and depression. The basic principle for the management of painful DPN is to control hyperglycemia and other modifiable risk factors, but these may be insufficient for preventing or improving DPN. Because there is no promising diseasemodifying medication for DPN, the pain itself needs to be managed when treating painful DPN. Drugs for neuropathic pain, such as gabapentinoids, serotonin-norepinephrine reuptake inhibitors, tricyclic antidepressants, alpha-lipoic acid, sodium channel blockers, and topical capsaicin, are used for the management of painful DPN. The U.S. Food and Drug Administration (FDA) has approved pregabalin, duloxetine, tapentadol, and the 8% capsaicin patch as drugs for the treatment of painful DPN. Recently, spinal cord stimulation using electrical stimulation is approved by the FDA for the treatment for painful DPN. This review describes the currently available pharmacological and nonpharmacological treatments for painful DPN.

Recent Advancements in the Management of Neuropathic Pain

Neuropathic pain is defined as ‘pain arising as a direct consequence of a lesion or disease affecting the Somatosensory system, regarding the most important aspects of analgesic treatment in NP its strongly advised to make use of a confirmatory questionnaire for NP Dx, such as DN4 or LANSS, as the Screening Tools. Administer analgesic medications in accordance with the strong evidence presented in NP. Keep in mind the medications that have been given the approval for NP. Tricyclic antidepressants, selective serotonin reuptake inhibitors (SNRIs; duloxetine, venlafaxine), and gabapentinoids; pregabalin and gabapentin; alone or in combination with topical (lidocaine patch, capsaicin patch) are all indicated as first-line analgesics for patients with peripheral NP. If a medication from the first line is unsuccessful, try another medication from the same group or move on to the second line. Tramadol and oxycodone are both considered to be analgesics of the second line. Tapentadol as a replacement drug in cases of persistent pain, it may be necessary to mix medications that work via distinct mechanisms of action. Alternatively, in the event that pharmacology is unsuccessful, analgesic invasive treatments may be combined with drugs.

Pain-free default mode network connectivity contributes to tonic experimental pain intensity beyond the role of negative mood and other pain-related factors.

Alterations in the default mode network (DMN) connectivity across pain stages suggest a possible DMN involvement in the transition to persistent pain. This study examined whether pain-free DMN connectivity at lower alpha oscillations (8-10 Hz) accounts for a unique variation in experimental peak pain intensity beyond the contribution of factors known to influence pain intensity. Pain-free DMN connectivity was measured with electroencephalography prior to 1 h of capsaicin-evoked pain using a topical capsaicin patch on the right forearm. Pain intensity was assessed on a (0-10) numerical rating scale and the association between peak pain intensity and baseline measurements was examined using hierarchical multiple regression in 52 healthy volunteers (26 women). The baseline measurements consisted of catastrophizing (helplessness, rumination, magnification), vigilance, depression, negative and positive affect, sex, age, sleep, fatigue, thermal and mechanical pain thresholds and DMN connectivity (medial prefrontal cortex [mPFC]-posterior cingulate cortex [PCC], mPFC-right angular gyrus [rAG], mPFC-left Angular gyrus [lAG], rAG-mPFC and rAG-PCC). Pain-free DMN connectivity increased the explained variance in peak pain intensity beyond the contribution of other factors (ΔR2 = 0.10, p = 0.003), with the final model explaining 66% of the variation (R2 = 0.66, ANOVA: p < 0.001). In this model, negative affect (β = 0.51, p < 0.001), helplessness (β = 0.49, p = 0.007), pain-free mPFC-lAG connectivity (β = 0.36, p = 0.003) and depression (β = -0.39, p = 0.009) correlated significantly with peak pain intensity. Interestingly, negative affect and depression, albeit both being negative mood indices, showed opposing relationships with peak pain intensity. This work suggests that pain-free mPFC-lAG connectivity (at lower alpha) may contribute to individual variations in pain-related vulnerability. These findings could potentially lead the way for investigations in which DMN connectivity is used in identifying individuals more likely to develop chronic pain.

Topical capsaicin for the management of painful diabetic neuropathy: a narrative systematic review.

Aim: To investigate the potential benefit of topical capsaicin formulations. Materials& methods: A narrative systematic review was employed. Results: About8% Capsaicin patches were found to significantly reduce symptoms of diabetic peripheral neuropathy. Capsaicin was found to improve sleep quality (p=0.02). Capsaicin patch exposure for 60minshowed significant reduction in symptoms (-32.8%). Capsaicin cream significantly reduced pain at weeks 2 and 6 (p=0.003 andp=0.03, respectively), but not at week 8 in comparative studies. 0.025% Capsaicin gel had an insignificant reduction in pain compared with placebo (p=0.53), however 0.075% was found to be significant (p=0.038). Capsaicin cream did not have superior improvement of pain as compared with clonidine gel (p=0.931). The most common adverse events included application site discomfort, erythemaand burning. Conclusion: Topical capsaicin treatments are a potentially beneficial peripherally acting medication. Further research is needed to determine the best means of ameliorating the side effects of treatments.

Localized neuropathic pain.

Localized neuropathic pain (LNP) is of peripheral origin and is characterized by circumscribed areas of pain with abnormal skin sensitivity or spontaneous symptoms that are characteristic of neuropathic pain, e.g., burning pain. It should be noted that LNP is confined to a specific area no larger than a letter size sheet of paper. LNP accounts for 60 % of neuropathic pain syndromes. There is no single etiology of LNP. The diagnostic approach is similar to that for other neuropathic pain conditions. General diagnostic tools are used to assess clinical features. So far, there are no specific guidelines for the management of LNP; for this reason, guidelines for general neuropathic pain are used. Topical treatments are included as part of second-line strategies in the Canadian Pain Society guidelines. Despite the lack of guidelines, 5 % lidocaine patches and 8 % capsaicin patches have been proven effective in LNP models.

Treatment of DPN with 8% topical capsaicin without the use of a topical anesthetic

PURPOSEA qualitative study was done to look at the use of 8% topical capsaicin without the use of a topical anesthetic prior to treatment of DPN. In the PI it is indicated to anesthetize the affected area with topical lidocaine prior to the treatment for painful diabetic peripheral neuropathy of the feet. Many patients with diabetic peripheral neuropathy have significant numbness in their feet and limited feeling and there may not be a need for a topical anesthetic prior to application of the topical system. Applying a topical anesthetic can be time consuming to allow it to take full effect and may not be necessary. For the purposes of this study the clinics ethics committee was consulted, and approval was granted. METHODSIs topical anesthetic necessary before the procedure for the treatment of painful diabetic peripheral neuropathy with 8% topical capsaicin? 15 patient charts were reviewed at random that had received treatment with administered 8% topical capsaicin patches for their diabetic peripheral neuropathy. No topical anesthetic was used prior to the procedure. The patient was monitored throughout the procedure and ice was offered to place over the top of the patch, if needed for administration site pain. RESULTSMost patient's that did not have a topical anesthetic prior to their procedure of 8% topical capsaicin for the treatment of painful diabetic peripheral neuropathy, tolerated the procedure well without any significant increased pain or the need for interventions, such as ice. CONCLUSIONTopical anesthetic can be time consuming and cumbersome. In many patients with severe diabetic peripheral neuropathy that has resulted in significant paresthesia, a topical anesthetic is not necessary due to the patient's limited feeling in the feet. This results in a more streamline process with less time for the patient to be in the office.

Transversus Abdominis Plane Block in the Treatment of Chronic Postsurgical Abdominal Wall Pain Improves Patient Quality of Life: A Retrospective Study and Literature Review

BACKGROUND: Although poorly studied, chronic postsurgical neuropathic pain (CPNP) represents the second most frequent chronic neuropathic pain etiology, probably affecting 0.5% to 75% of patients with a severe impact on quality of life (QoL). No consensus or treatment algorithm has been elaborated to date, despite a large variety of approaches now available. Transversus abdominis plane (TAP) block has been endorsed as an efficient treatment for acute postoperative pain although its effect on CPNP in terms of intensity and QoL has yet to be considered. OBJECTIVES: The main aim of this study was to evaluate the efficacy of TAP blocks in terms of QoL on patients suffering from abdominal CPNP, including a socio-economic analysis. Results were compared with those published in the recent literature. STUDY DESIGN: Retrospective, monocentric, observational clinical study. SETTING: This single-center retrospective study was conducted at the Chronic Pain Center, Department of Anesthesia, Robert Debré University Hospital, Reims, France. METHODS: From January 2018 through April 2021, all patients suffering from abdominal CPNP treated with a TAP block were enrolled. QoL was assessed using the SF-12 survey. Socio-economic and demographic data were also collected. A literature review was performed using appropriate Medical Subject Headings (MeSH) terms. RESULTS: A TAP block was administered to 44 consecutive patients suffering from CPNP. After a mean follow-up of 11.8 weeks, 86.7% of the patients reported significant effectiveness of the treatment, including an improvement in QoL (P &lt; 0.001), pain scale ratings (P &lt; 0.001) and analgesic requirement (P &lt; 0.001). In term of socio-economic results, one-fifth of the patients returned to work after treatment. The literature review yielded 60 research studies, only 2 of which met our inclusion criteria. These retrospective studies indicated a 76.5% and 81.9% efficacy rate after 12 and 15.5 weeks, respectively. LIMITATIONS: This was a retrospective study with a small sample size. Further investigation should include medical and economic parameters as well as a comparison of TAP block with second-line drug therapies such as transcutaneous neurostimulation, and capsaicin and lidocaine patches. Other anesthetic molecules such as onobotulinumtoxin A (botulinum toxin) combined with steroids should be assessed for these patients. CONCLUSION: The TAP block is easy to learn, easy to reproduce, and easy to administer. After pooling our results with those from the literature, a TAP block is deemed to be effective for the treatment of CPNP with 82.25% effectiveness over a mean time of 13.9 weeks. A TAP block improves long-term QoL, reduces consumption of painkillers and lowers pain scale scores. Thus, it may reduce health care costs. We argue that A TAP block should be considered early, from the onset of the first pain symptoms. KEY WORDS: Anesthetics therapeutic use, hernia, inguinal surgery, abdominal muscles innervation, nerve block methods, anesthesia, conduction methods, postoperative treatment, wounds and injuries, drug therapy

DoE-based formulation, physicochemical properties, and anti-inflammatory investigation of a topical patch preparing by partially neutralized polyacrylate-based adhesive hydrogel

A capsaicin patch was formulated by optimizing the adhesion, the release behavior of the patch, and the pharmacological effect. The aims of study were to 1) apply the design of experiments approach for investigating the simultaneous effect of Viscomate (partially neutralized polyacrylate)-based adhesive, glycerin plasticizing excipient and permeation enhancers on patch adhesion, and the permeation rate of model drug (capsaicin) and then 2) compare the optimal formulation with the reference product (Wellpatch®, Metholatum, U.S.A.) in terms of pharmacological effect. The topical patch was prepared by casting the drug-loaded adhesive hydrogel on the backing layer. The adhesive ability of patches was determined by testing a 90° peel rig on a texture analyzer, and the permeation rate of capsaicin (CAP) through mouse skin was evaluated using Franz diffusion cells. The effects of these critical factors on patch adhesion, CAP flux, and permeation enhancer interaction with the stratum corneum were analyzed using ANOVA and ATR-FTIR/skin hydration tests, respectively. Accordingly, Viscomate (adhesion excipient) and glycerin (plasticizing excipient) had a significant impact on patch adhesion (p < 0.05). Meanwhile, N-methyl pyrrolidone, the permeation enhancer, had a better permeation rate and higher hydration level of the stratum corneum than did Transcutol. The partially neutralized polyacrylate-based optimal formulation had a higher permeation rate of CAP, equal adhesion and comparable anti-inflammatory effects to those of the reference product which was also in agreement with the analysis of anatomical images of tissue structure and inflammatory cells. This study successfully integrated DoE method, release behavior and pharmacological research to develop a stable and highly effective topical product containing capsaicin.