Compliance and Persistence of Antidepressants Versus Anticonvulsants in Patients With Neuropathic Pain During the First Year of Therapy

Patient satisfaction and patient accessibility in a small fiber neuropathy diagnostic service in the Netherlands: A single-center, prospective, survey-based cohort study

INTRODUCTION

Small fiber neuropathy (SFN) is a common cause of neuropathic pain in peripheral neuropathies. Good accessibility of diagnostics and treatment is necessary for an accurate diagnosis and treatment of SFN. Evidence is lacking on the quality performance of the diagnostic SFN service in the Netherlands. Our aim was to determine the patient satisfaction and -accessibility of the diagnostic SFN service, and to identify areas for improvement.

METHODS

In a single-center, prospective, survey-based cohort study, 100 visiting patients were asked to fill in the SFN patient satisfaction questionnaire (SFN-PSQ), with 10 domains and 51 items. Cut-off point for improvement was defined as ≥ 25% dissatisfaction on an item. A chi-square test and linear regression analyses was used for significant differences and associations of patient satisfaction.

RESULTS

From November 2020 to May 2021, 98 patients with SFN-related complaints filled in the online SFN-PSQ within 20 minutes. In 84% of the patients SFN was confirmed, average age was 55.1 (52.5-57.8) years and 67% was female. High satisfaction was seen in the domains 'Waiting List Period', Chest X-ray', 'Consultation with the Doctor or Nurse Practitioner (NP)', 'Separate Consultation with the Doctor or NP about Psychological Symptoms', and 'General' of the SFN service. Overall average patient satisfaction score was 8.7 (IQR 8-10) on a 1-to-10 rating scale. Main area for improvement was shortening the 8-week period for receiving the results of the diagnostic testing (p < 0.05). General health status was statistically significant associated with patient satisfaction (p < 0.05).

CONCLUSION

A good reflection of the high patient satisfaction and -accessibility of the SFN-service is shown, with important points for improvement. These results could help hospitals widely to optimize the logistic and diagnostic pathway of SFN analysis, benchmarking patient satisfaction results among the hospitals, and to improve the quality of care of comparable SFN services.

Pain management with transdermal drug administration: A review

Pain management is an urgent issue to solve with complex mechanisms. Localized acute pain requires rapid and accurate delivery of drugs with less distribution in the blood circulation while chronic pain requires controlled release of drugs with long drug retention time. The transdermal route, a promising way with high patient compliance was known for painless delivery, long drug retention time, stable blood concentration, easily controlled dosage and release rate as well as the fewer side effects. This review presents transdermal route for pain management according to the different sites of action which drugs aim to reach, and illustrates different analgesic mechanisms, dosage forms, transdermal enhancements and clinical applications. In addition, the review concludes the difference of pain types and presents the future aims of pain management, thereby providing a reference for researches focusing on percutaneous analgesia.

Effects of dose titration on adherence and treatment duration of pregabalin among patients with neuropathic pain: A MarketScan database study

OBJECTIVE

To examine pregabalin dose titration and its impact on treatment adherence and duration in patients with neuropathic pain (NeP).

METHODS

MarketScan database (2009-2014) was used to extract a cohort of incident adult pregabalin users with NeP who had at least 12 months of follow-up data. Any dose augmentation within 45 days following the first pregabalin claim was defined as dose titration. Adherence (measured by medication possession ratio/MPR) and persistence (measured as the duration of continuous treatment) were compared between the cohorts with and without dose titration. Logistic regressions and Cox proportional hazards models were used to identify the factors associated with adherence (MPR ≥ 0.8) and predictors of time to discontinuation.

RESULTS

Among the 5,186 patients in the analysis, only 18% of patients had dose titration. Patients who had dose titration were approximately 2.6 times as likely to be adherent (MPR ≥ 0.8) (odds ratio = 2.59, P < 0.001) than those who did not have dose titration. Kaplan-Meier analysis shows that the time to discontinuation or switch was significantly longer among patients who had dose titration (4.99 vs. 4.04 months, P = 0.009).

CONCLUSIONS

Dose titration was associated with improved treatment adherence and persistence among NeP patients receiving pregabalin. The findings will provide valuable evidence to increase physician awareness of dose recommendations in the prescribing information and to educate patients on the importance of titration and adherence.

Painful and non-painful chemotherapy-induced peripheral neuropathy and quality of life in colorectal cancer survivors: results from the population-based PROFILES registry

Purpose

This study aims to (1) examine the prevalence of painful versus non-painful chemotherapy-induced peripheral neuropathy (CIPN) among long-term colorectal cancer (CRC) survivors, (2) identify sociodemographic, clinical, and psychological factors associated with painful and non-painful CIPN, and (3) examine the associations of painful CIPN with health-related quality of life (HRQoL) in comparison with non-painful CIPN, i.e., numbness/tingling.

Methods

All CRC survivors diagnosed between 2000 and 2009 as registered by the population-based Netherlands Cancer Registry (Eindhoven region) were eligible for participation. Chemotherapy-treated survivors (n = 477) completed questions on CIPN (EORTC QLQ-CIPN20) and HRQoL (EORTC QLQ-C30).

Results

Painful CIPN was reported by 9% (n = 45) of survivors and non-painful CIPN was reported by 22% (n = 103). Time since diagnosis was related to painful CIPN, and time since diagnosis, a higher disease stage, osteoarthritis, and more anxiety symptoms were related to non-painful CIPN. Finally, survivors with painful CIPN reported a worse global quality of life and worse physical, role, cognitive, and social functioning compared to survivors with non-painful CIPN and those without any sensory CIPN. No differences were found between survivors with non-painful CIPN and those without sensory CIPN.

Conclusions

It seems that painful CIPN must be distinguished from non-painful CIPN, as only painful CIPN was related to a worse HRQoL. Future research is needed to examine whether painful CIPN must be distinguished from non-painful CIPN regarding predictors, mechanisms, and treatment.

Topical loperamide for the treatment of localized neuropathic pain: a case report and literature review

Peripheral nerve damage can result in neuronal hyperexcitability, resulting in neuropathic pain. Localized neuropathic pain is confined to a specific area not larger than a letter-size piece of paper. Topical analgesics are increasingly popular for the treatment of localized neuropathic pain because systemic agents for managing neuropathic pain often produce undesirable and intolerable side effects. Commonly used agents for topical use are amitriptyline, baclofen, ketamine and lidocaine; however, these agents do not always give the desired analgesic effect in some patients. We report for the first time a patient with chronic idiopathic axonal polyneuropathy and intractable localized neuropathic pain treated successfully with loperamide 5% cream. After application of loperamide 5% cream, the patient reported a complete reduction of pain within 30 mins, lasting for 2.5 hrs. Subsequently, the patient was able to reduce his daily intake of oxycodone, while using topical loperamide for pain relief. Loperamide is a nonprescription opioid agonist, commonly used against diarrhea. As a topical formulation, it is preferable over other opioids due to its low systemic bioavailability and low risk of crossing the blood–brain barrier. Peripheral upregulation and sensitization of opioid receptors at peripheral nerve endings and perhaps at other cell populations in the epidermis might be targets of topical loperamide.

Phytochemicals of Cinnamomi Cortex: Cinnamic Acid, but not Cinnamaldehyde, Attenuates Oxaliplatin-Induced Cold and Mechanical Hypersensitivity in Rats

A chemotherapy drug, oxaliplatin, induces cold and mechanical hypersensitivity, but effective treatments for this neuropathic pain without side effects are still lacking. We previously showed that Cinnamomi Cortex suppresses oxaliplatin-induced pain behaviors in rats. However, it remains unknown which phytochemical of Cinnamomi Cortex plays a key role in that analgesic action. Thus, here we investigated whether and how cinnamic acid or cinnamaldehyde, major components of Cinnamomi Cortex, alleviates cold and mechanical allodynia induced by a single oxaliplatin injection (6 mg/kg, i.p.) in rats. Using an acetone test and the von Frey test for measuring cold and mechanical allodynia, respectively, we found that administration of cinnamic acid, but not cinnamaldehyde, at doses of 10, 20 and 40 mg/kg (i.p.) significantly attenuates the allodynic behaviors in oxaliplatin-injected rats with the strongest effect being observed at 20 mg/kg. Our in vivo extracellular recordings also showed that cinnamic acid (20 mg/kg, i.p.) inhibits the increased activities of spinal wide dynamic range neurons in response to cutaneous mechanical and cold stimuli following the oxaliplatin injection. These results indicate that cinnamic acid has an effective analgesic action against oxaliplatin-induced neuropathic pain through inhibiting spinal pain transmission, suggesting its crucial role in mediating the effect of Cinnamomi Cortex.

Phenytoin Cream for the Treatment for Neuropathic Pain: Case Series

BACKGROUND: Neuropathic pain can be disabling, and is often difficult to treat. Within a year, over half of all patients stop taking their prescribed neuropathic pain medication, which is most probably due to side effects or disappointing analgesic results. Therefore, new therapies are needed to alleviate neuropathic pain. As such, topical analgesics could be a new inroad in the treatment of neuropathic pain. In 2014, we developed a new topical formulation containing either phenytoin or sodium phenytoin. After optimization of the formulation, we were able to reach a 10% concentration and combine phenytoin with other co-analgesics in the same base cream. OBJECTIVE: To describe a series of 70 neuropathic pain patients who were treated with phenytoin cream. MATERIAL AND METHODS: Cases treated with phenytoin 5% or 10% creams were gathered. The mean onset of pain relief, the duration of effect, and reduction in pain intensity measured on the 11-point numerical rating scale (NRS) were all studied. A single-blind response test with phenytoin 10% and placebo creams was conducted on 12 patients in order to select responders prior to prescribing the active cream. Plasma phenytoin concentrations were measured in 16 patients. RESULTS: Nine patients applied phenytoin 5% cream, and 61 patients used phenytoin 10% cream. After grouping the effects of all of the patients, the mean onset of pain relief was 16.3 min (SD: 14.8), the mean duration of analgesia was 8.1 h (SD: 9.1), and the mean pain reduction on the NRS was 61.2% (SD: 25.0). The mean pain reduction on the NRS while using phenytoin cream was statistically significant compared with the baseline, with a reduction of 4.5 (CI: 4.0 to 5.0, p < 0.01). The 12 patients on whom a single-blind response test was performed experienced a statistically significant reduction in pain in the area where the phenytoin 10% cream was applied in comparison to the area where the placebo cream was applied (p < 0.01). Thirty minutes after the test application, the mean pain reduction on the NRS in the areas where the phenytoin 10% cream and the placebo cream were applied was 3.3 (CI: 2.3 to 4.4, p < 0.01) and 1.1 (CI: 0.4 to 1.9, p < 0.05), respectively. In all 16 patients, the phenytoin plasma levels were below the limit of detection. So far, no systemic side effects were reported. Two patients only reported local side effects: a transient burning aggravation and skin rash. CONCLUSION: In this case series, the phenytoin cream had reduced neuropathic pain considerably, with a fast onset of analgesic effect.

Neuropathic pain in a rehabilitation setting after spinal cord injury: an interpretative phenomenological analysis of inpatients' experiences

Study design

Qualitative, semi-structured interviews.

Objectives

Neuropathic pain (NP) can be psychologically and physically debilitating, and is present in approximately half of the spinal cord injured (SCI) population. However, under half of those with NP are adherent to pain medication. Understanding the impact of NP during rehabilitation is required to reduce long-term impact and to promote adherence to medication and psychoeducation recommendations.

Setting

United Kingdom.

Methods

Five males and three females with SCI and chronic NP, resident in rehabilitation wards at a specialist SCI center in the United Kingdom, took part. Semi-structured interviews were conducted with participants less than 15 months post-SCI (mean = 8.4 months). Verbatim transcripts were subject to interpretative phenomenological analysis (IPA).

Results

Three super-ordinate themes were identified, mediating pain and adherence: (1) the dichotomy of safety perceptions; (2) adherence despite adversity; and (3) fighting the future. Analyses suggest that experience of the rehabilitation setting and responsiveness of care shapes early distress. Attitudes to medication and psychosocial adjustment are relevant to developing expectations about pain management.

Conclusions

Enhancing self-efficacy, feelings of safety in hospital, and encouraging the adoption of adaptive coping strategies may enhance psychosocial and pain-related outcomes, and improve adherence to medication. Encouraging adaptive responses to, and interpretation of, pain, through the use of interventions such as coping effectiveness training, targeted cognitive behavioral pain management, and acceptance-based interventions such as mindfulness, is recommended in order to reduce long-term reliance on medication.

Topical phenytoin for the treatment of neuropathic pain

We developed and tested a new putative analgesic cream, based on the anticonvulsant phenytoin in patients suffering from treatment refractory neuropathic pain. The use of commercial topical analgesics is not widespread due to the facts that capsaicin creams or patches can give rise to side effects, such as burning, and analgesic patches (e.g., lidocaine 5% patches) have complex handling, especially for geriatric patients. Only in a few countries, compounded creams based on tricyclic antidepressants or other (co-)analgesics are available. Such topical analgesic creams, however, are easy to administer and have a low propensity for inducing side effects. We, therefore, developed a new topical cream based on 5% and 10% phenytoin and described three successfully treated patients suffering from neuropathic pain. All patients were refractory to a number of other analgesics. In all patients, phenytoin cream was effective in reducing pain completely, without any side effects, and the tolerability was excellent. The onset of action of the phenytoin creams was within 30 minutes. Phenytoin cream might become a new treatment modality of the treatment of neuropathic pain.

Prevalence and determinants of medication non-adherence in chronic pain patients: a systematic review

BACKGROUND

Chronic pain is commonly treated with analgesic medication. Non-adherence to prescribed pain medication is very common and may result in sub-optimal treatment outcome. The aim of this review was to investigate the prevalence of medication non-adherence and to present determinants that may help identify patients at risk for non-adherence to analgesic medication.

METHODS

A search was performed in PubMed and Embase with systematic approach including PRISMA recommendations. Individual risk of bias was assessed and systematic data extraction was performed.

RESULTS

Twenty-five studies were included. Non-adherence rates to pain prescriptions ranged from 8% to 62% with a weighted mean of 40%. Underuse of pain medication was more common than overuse in most studies. Factors that were commonly positively associated with non-adherence were dosing frequency, polymedication, pain intensity, and concerns about pain medication. Factors negatively associated with non-adherence were age, again pain intensity and quality of the patient-caregiver relationship. Underuse was positively associated with active coping strategies and self-medication, and negatively associated with perceived need for analgesic medication. Overuse was positively associated with perceived need, pain intensity, opioid use, number of prescribed analgesics, a history of drug abuse, and smoking.

CONCLUSION

Non-adherence to analgesic medication use is very common in the chronic pain population. The choice for pharmacological therapy should not only be based upon pain diagnosis but should also take the risks of non-adherence into account. The value of adherence monitoring or adherence enhancing interventions has to be investigated in future studies.

Adherence to Adjuvant Neuropathic Pain Medications in a Palliative Care Clinic

BACKGROUND

Currently, few studies exist on patient adherence to adjuvant neuropathic pain (NP) medications in the palliative care setting.

OBJECTIVES

We assessed patient adherence rates to NP medications in a palliative care clinic and compared patient self-reported adherence to pharmacy refill records.

METHODS

This was an observational single-site cross-sectional study of patients with NP receiving at least one NP medication for at least three months. Participants who met the inclusion criteria and agreed to participate completed the eight-item Morisky Medication Adherence Scale (MMAS-8) and a seven-day-recall (7DR) adherence measure. Patients gave permission to contact their pharmacy after the visit to collect refill records for the six months prior to the clinic visit. This information was used to calculate the medication possession ratio (MPR).

RESULTS

We analyzed 32 patients; most (81%) had NP related to a cancer diagnosis. Approximately 87.5% had low or medium adherence using the MMAS-8. The mean self-reported adherence based on 7DR was 94%. The mean MPR was 63%. A majority of patients (88%) had high self-reported adherence (>80%); however only 44% of patients had an MPR >80%.

CONCLUSION

Results indicated that the MPR might be a more accurate measure of adherence than patient self-report. More research is needed to assess and improve adherence with NP medications in the outpatient palliative care setting.

Incorporating Natural Products, Pharmaceutical Drugs, Self-Care and Digital/Mobile Health Technologies into Molecular-Behavioral Combination Therapies for Chronic Diseases

Merging pharmaceutical and digital (mobile health, mHealth) ingredients to create new therapies for chronic diseases offers unique opportunities for natural products such as omega-3 polyunsaturated fatty acids (n-3 PUFA), curcumin, resveratrol, theanine, or α-lipoic acid. These compounds, when combined with pharmaceutical drugs, show improved efficacy and safety in preclinical and clinical studies of epilepsy, neuropathic pain, osteoarthritis, depression, schizophrenia, diabetes and cancer. Their additional clinical benefits include reducing levels of TNFα and other inflammatory cytokines. We describe how pleiotropic natural products can be developed as bioactive incentives within the network pharmacology together with pharmaceutical drugs and self-care interventions. Since approximately 50% of chronically-ill patients do not take pharmaceutical drugs as prescribed, psychobehavioral incentives may appeal to patients at risk for medication non-adherence. For epilepsy, the incentive-based network therapy comprises anticonvulsant drugs, antiseizure natural products (n-3 PUFA, curcumin or/and resveratrol) coupled with disease-specific behavioral interventions delivered by mobile medical apps. The add-on combination of antiseizure natural products and mHealth supports patient empowerment and intrinsic motivation by having a choice in self-care behaviors. The incentivized therapies offer opportunities: (1) to improve clinical efficacy and safety of existing drugs, (2) to catalyze patient-centered, disease self-management and behavior-changing habits, also improving health-related quality-of-life after reaching remission, and (3) merging copyrighted mHealth software with natural products, thus establishing an intellectual property protection of medical treatments comprising the natural products existing in public domain and currently promoted as dietary supplements. Taken together, clinical research on synergies between existing drugs and pleiotropic natural products, and their integration with self-care, music and mHealth, expands precision/personalized medicine strategies for chronic diseases via pharmacological-behavioral combination therapies.

Possible involvement of the Sigma-1 receptor chaperone in chemotherapeutic-induced neuropathic pain

Previous studies have shown that ligands of the sigma-1 receptor chaperone (Sig-1R) regulate pain-related behaviors. Clinical use of chemotherapeutics is often compromised due to their adverse side effects, particularly those related to neuropathy. Previous studies have shown that repeated administration of oxaliplatin and paclitaxel produces neuropathy in rodents. Therefore, the aim of the present study was to clarify the involvement of the Sig-1R in chemotherapeutic-induced neuropathy by examining the effects of oxaliplatin and paclitaxel on the Sig-1R levels in the spinal cord, and by examining the effects of Sig-1R agonist and antagonist on oxaliplatin- and paclitaxel-induced neuropathy in rats. Chemotherapeutic-induced neuropathic pain was accompanied by a significant reduction of the Sig-1R level in the spinal cord. Furthermore, the administration of paclitaxel to CHO cells that stably overexpressed Sig-1Rs induced the clustering of Sig-1Rs. We also found that the Sig-1R agonist SA4503 potently inhibited the neuropathy induced by oxaliplatin- and paclitaxel, whereas this action was abolished by the Sig-1R antagonist NE-100. These results suggest that the reduction of Sig-1R activity is involved in chemotherapeutic-induced neuropathy, and the Sig-1R agonist SA4503 could serve as a potential candidate for the treatment of chemotherapeutic-induced neuropathy.

Self-management of oxaliplatin-related peripheral neuropathy in colorectal cancer survivors

Purpose. The purpose of this study was to evaluate medications that cancer survivors with oxaliplatin-induced peripheral neuropathy take to control neuropathic symptom, and to explore self-management techniques used at home to provide temporary relief of painful neuropathy. This was a mixed methods, descriptive, cross-sectional study using self-reported data from colorectal cancer survivors previously treated with oxaliplatin. We analyzed demographic and medication data obtained from participants, along with written comments from an open-ended question regarding methods participants had tried to self-manage symptoms of neuropathy. Results. Twenty-nine percent of the sample reported taking some type of nutritional supplement with potential neuroprotective qualities. Opioids were being taken by 10% of the sample, and nonsteroidal anti-inflammatory and over-the-counter medications were taken by 15% of participants. Twelve percent of participants were taking antidepressants and 10% were taking anticonvulsants, primarily gabapentin. Recurrent themes for nonpharmacologic treatment included avoiding the cold/keeping warm, keeping moving, massaging or rubbing the affected area, and living with it. Conclusions. Patients treated with oxaliplatin for colorectal cancer utilize a variety of traditional pharmacologic agents and nutritional supplements in an effort to self-manage neuropathic symptoms. Patients also employ a variety of home-based therapies to provide temporary relief of peripheral neuropathy symptoms.