Cannabis-based medicines for chronic neuropathic pain in adults

[Diagnostics and therapy of neuropathic pain]

Neuropathic pain is pain caused by a lesion or disease of the somatosensory nervous system. Scientific studies have shown that neuropathic pain is the result of complex altered signalling processes in the peripheral and central nervous system. Current forms of treatment of neuropathic pain are causally oriented but also aim at symptomatic analgesia by pharmacological and nonpharmacological methods. Furthermore, psychological pain management techniques are used in a supportive role. This review summarizes the contemporary diagnostics of neuropathic pain using frequent diseases as examples and presents the evidence from randomized controlled trials on the treatment of neuropathic pain. Treatment guidelines for pharmacological management of neuropathic pain include evidence-based use of antidepressants, anticonvulsants, opioids, capsaicin and lidocaine.

Triptolide Attenuates Neuropathic Pain by Regulating Microglia Polarization through the CCL2/CCR2 Axis

Triptolide (T10) is a common anti-inflammatory and analgesic drug. However, the activation of microglia and elimination of the corresponding inflammatory response are new targets for the treatment of neuropathic pain. Chemokine CCL (CCL2) is a key mediator for activating microglia. In this study, the effects of triptolide on the activation and polarization of microglia cells and CCL2 and its corresponding receptor, chemokine receptor 2 (CCR2), were mainly discussed. Microglia were stimulated with 1 μg/mL lipopolysaccharide (LPS) and pretreated with 10, 20, and 40 nM T10 and CCR2 antagonist (RS102895), respectively. The quantitative polymerase chain reaction (QPCR) and western blot results showed that T10 could obviously inhibit the upregulation of CCL2 and CCR2 induced by LPS stimulation in microglia cells, inhibit the fluorescence intensity of glial fibrillary acidic protein (GFAP) and inducible nitric oxide synthase (iNOS) antibody immunostaining in cells, and upregulate the fluorescence intensity of arginase 1 antibody in cells. The expression of interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) was inhibited in a dose-dependent manner. RS102895 can significantly reverse the activation and M2 polarization of microglia pretreated with 40 nM T10 and weaken the anti-inflammatory effect of T10. The addition of CCL2 did not extremely affect the function of RS102895. T10 may inhibit microglia activation and M1 polarization by inhibiting the expression of CCL2 and CCR2, promoting M2 polarization, reducing the level of inflammatory factors in cells, and exerting its analgesic effect, which is worthy of clinical promotion as a drug for neuropathic pain.

Safety and Tolerability of Natural and Synthetic Cannabinoids in Older Adults: A Systematic Review and Meta-Analysis of Open-Label Trials and Observational Studies

BACKGROUND AND OBJECTIVE

Although cannabinoid-based medications are increasingly used by older adults, their safety and tolerability in this age group remain unclear. The purpose of this systematic review was to examine the safety and tolerability of cannabinoid-based medications by conducting a meta-analysis of open-label observational studies of cannabinoid-based medications for all indications in individuals with a mean age of ≥50 years.

METHODS

A systematic search was conducted on PubMed, PsycINFO, MEDLINE, EMBASE and CINHAL. Study quality was assessed using an adapted version of the Grading of Recommendations Assessment, Development and Evaluation criteria and Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed. We included studies that (a) were published from 1990 onwards; (b) included older adults (mean age ≥50 years); and (c) provided data on the safety and tolerability of medical cannabinoids. Data were pooled using a random-effects approach. Risk of adverse events, serious adverse events and withdrawals was computed as the incidence rate (IR). Separate analyses were conducted by the cannabinoid-based medication used, for delta-9-tetrahydrocannabinol (THC), cannabidiol (CBD) and a combination of THC and CBD (THC:CBD).

RESULTS

Thirty-eight studies were identified (THC = 23; CBD = 6; THC:CBD = 9; N = 2341, mean age: 63.19 ± 8.08 years, men: 53.86%). THC had a very low incidence of all-cause and treatment-related adverse events (IR: 122.18, 95% confidence interval [CI] 38.23-253.56; IR: 84.76, 95% CI 0.13-326.01, respectively) and negligible serious adverse events (IR = 0). Similar IRs for CBD (all cause, IR: 111.91, 95% CI 1.24-495.93; treatment related, IR: 1.76, 95% CI 4.63-23.05) and no serious adverse events (IR = 0). CBD was not associated with a risk of treatment-related withdrawals. THC had a low risk of all-cause and treatment-related withdrawals (IR: 25.18, 95% CI 12.35-42.52; IR: 7.83, 95% CI 3.26-14.38, respectively). The THC:CBD treatment had a low risk of all-cause and treatment-related adverse events (IR: 100.72, 95% CI 0.25-383.00; IR: 55.38, 95% CI 8.61-142.80, respectively), but reported a risk of all-cause and treatment-related serious adverse events (IR: 21.32, 95% CI 0.18-93.26; IR: 3.71, 95% CI 0.21-11.56, respectively), and all-cause and treatment-related withdrawals (IR: 78.63, 95% CI 17.43-183.90; IR: 34.31, 95% CI 6.09-85.52, respectively). Significant heterogeneity (I² >55%) was present in most analyses.

CONCLUSIONS

Although cannabinoid-based medications were generally safe and acceptable to adults aged over 50 years, these estimates are limited by the lack of a control condition and considerable heterogeneity. Nevertheless, they complement and are consistent with comparable evidence from randomised controlled trials.

Possible opioid-saving effect of cannabis-based medicine using individual-based data from the Norwegian Prescription Database

Some ecological studies have shown that areas with higher use of cannabis may have lower opioid use and fewer opioid-related problems. Newer studies are questioning this finding. Few individually based studies have been performed. Using data from the Norwegian Prescription Database, this study investigated the individual level effect of prescribed cannabis extract (Sativex®) in prescription opioid users on their opioid use in the following year. Looking at all those filling a prescription for Sativex®, opioid use was only marginally lowered in the follow-up period. Some Sativex® users, however, filled more prescriptions for Sativex® and were able to reduce their opioid use substantially. Further studies are needed to elucidate more details on these patients, so as to know who can benefit from such cannabis-based extracts in reducing their opioid use.

Cannabinoid use and effects in patients with epidermolysis bullosa: an international cross-sectional survey study

BACKGROUND

Epidermolysis bullosa (EB) patient anecdotes and case reports indicate that cannabinoid-based medicines (CBMs) may alleviate pain and pruritus and improve wound healing. CBM use has not been characterized in the EB patient population.

OBJECTIVES

To evaluate CBM use among EB patients, including CBM types, effects on symptoms (e.g., pain and pruritus), disease process (e.g., blistering, wounds, and inflammation), well-being (e.g., sleep, appetite) and concomitant medications.

METHODS

English-speaking EB patients or caregivers completed an online international, anonymous, cross-sectional survey regarding CBM use. Respondents reported the types of CBMs, subsequent effects including perceived EB symptom alteration, changes in medication use, and side effects.

RESULTS

Seventy-one EB patients from five continents reported using or having used CBMs to treat their EB. Missing question responses ranged between 0 (0%) and 33 (46%). Most used more than one CBM preparation (mean: 2.4 ± 1.5) and route of administration (mean: 2.1 ± 1.1). Topical and ingested were the most common routes. Pain and pruritus were reported retrospectively to decrease by 3 points (scale: 0-10; p < 0.001 for both) after CBM use. Most reported that CBM use improved their overall EB symptoms (95%), pain (94%), pruritus (91%) and wound healing (81%). Most participants (79%) reported decreased use of pain medications. The most common side-effect was dry mouth (44%).

CONCLUSIONS

CBMs improve the perception of pain, pruritus, wound healing, and well-being in EB patients and reduced concomitant medication use. Nevertheless, a direct relation between the use of CBMs and reduction of the above-mentioned symptoms cannot be proven by these data. Therefore, future controlled studies using pharmaceutically standardised CBM preparations in EB are warranted to delineate the risks and benefits of CBMs.

The Effectiveness of Cannabis and Cannabis Derivatives in Treating Lower Back Pain in the Aged Population: A Systematic Review

BACKGROUND/AIMS

Cannabis is increasingly used in the management of pain, though minimal research exists to support its use since approval. Reduction in stigma has led to a growing interest in pharmaceutical cannabinoids as a possible treatment for lower back pain (LBP). The objective of this review was to assess the role and efficacy of cannabis and its derivatives in the management of LBP and compile global data related to the role of cannabis in the management of LBP in an aging population.

METHODS

A systematic review was conducted using predetermined keywords by 3 independent researchers. Predetermined inclusion and exclusion criteria were applied, and 23 articles were selected for further analysis.

RESULTS

Studies identified both significant and insignificant impacts of cannabis on LBP. Contradicting evidence was noted on the role of cannabis in the management of anxiety and insomnia, 2 common comorbidities with LBP. The existing literature suggests that cannabis may be used in the management of LBP and comorbid symptoms.

CONCLUSIONS

Further research is needed to consider cannabis as an independent management option. There is a lack of evidence pertaining to the benefits of cannabis in an aged population, and thus, additional research is warranted to support its use in the aged population.

Prevalence of Cannabidiol Use in Patients With Spine Complaints: Results of an Anonymous Survey

BACKGROUND

Cannabidiol (CBD) is a cannabis derivative that has been popularized as a medicinal product with analgesic and anti-inflammatory effects. Given the anecdotal observations that several patients have reported use of CBD for spine-related pain, this study was designed to characterize CBD consumption patterns and perceived effects in patients with spine-related complaints.

METHODS

The study design was a cross-sectional survey. Over a 4-week period, an anonymous paper survey was administered to all patients presenting for evaluation by 1 of 9 spine surgeons at a single institution. Surveys were given upon registration for the office visit and collected by the office manager or nurse before evaluation by the surgeon. Patients were included regardless of surgical status (ie, preoperative, postoperative, or nonoperative) or region of pathology (lumbar, thoracic, or cervical). The survey consisted of multiple-choice questions on patient patterns of CBD use.

RESULTS

Out of 300 surveys, 214 (71%) were completed. CBD use for spine-related pain was reported by 54 (25.2%) patients. CBD was initially used for potential relief of back pain (66.7%), neck pain (37.0%), leg pain (35.2%), and/or arm pain (9.3%). Users also sought improvements in insomnia (25.9%) and mood (18.5%). Oil was the most popular formulation (64.8%). CBD was most often consumed 2-5 times (40.7%) or 6-10 times (31.5%) per week. The most common source of initial recommendation for CBD was friends or family (75.9%). Reported benefits were pain relief (46.3%), improved sleep (33.3%), and reduced anxiety (20.4%); however, 24.1% of patients reported no benefit from CBD use. The most reported side effect was fatigue (7.4%). Most users (63.0%) would recommend CBD to a friend for pain relief.

CONCLUSION

CBD is already used by many patients, and further high-quality research on this supplement is essential.

LEVEL OF EVIDENCE

4.

CLINICAL RELEVANCE

CBD is a commonly used by spine patients as an off label treatment.

Consensus recommendations on dosing and administration of medical cannabis to treat chronic pain: results of a modified Delphi process

BACKGROUND

Globally, medical cannabis legalization has increased in recent years and medical cannabis is commonly used to treat chronic pain. However, there are few randomized control trials studying medical cannabis indicating expert guidance on how to dose and administer medical cannabis safely and effectively is needed.

METHODS

Using a multistage modified Delphi process, twenty global experts across nine countries developed consensus-based recommendations on how to dose and administer medical cannabis in patients with chronic pain.

RESULTS

There was consensus that medical cannabis may be considered for patients experiencing neuropathic, inflammatory, nociplastic, and mixed pain. Three treatment protocols were developed. A routine protocol where the clinician initiates the patient on a CBD-predominant variety at a dose of 5 mg CBD twice daily and titrates the CBD-predominant dose by 10 mg every 2 to 3 days until the patient reaches their goals, or up to 40 mg/day. At a CBD-predominant dose of 40 mg/day, clinicians may consider adding THC at 2.5 mg and titrate by 2.5 mg every 2 to 7 days until a maximum daily dose of 40 mg/day of THC. A conservative protocol where the clinician initiates the patient on a CBD-predominant variety at a dose of 5 mg once daily and titrates the CBD-predominant dose by 10 mg every 2 to 3 days until the patient reaches their goals, or up to 40 mg/day. At a CBD-predominant dose of 40 mg/day, clinicians may consider adding THC at 1 mg/day and titrate by 1 mg every 7 days until a maximum daily dose of 40 mg/day of THC. A rapid protocol where the clinician initiates the patient on a balanced THC:CBD variety at 2.5-5 mg of each cannabinoid once or twice daily and titrates by 2.5-5 mg of each cannabinoid every 2 to 3 days until the patient reaches his/her goals or to a maximum THC dose of 40 mg/day.

CONCLUSIONS

In summary, using a modified Delphi process, expert consensus-based recommendations were developed on how to dose and administer medical cannabis for the treatment of patients with chronic pain.

Marie B, Milavetz G, Herr K. Cannabidiol (CBD) Use by Older Adults for Acute and Chronic Pain

Legalization of cannabidiol (CBD) products has ignited interest in clinical practice and research. One desired indication includes possible pain-relieving effects of CBD. The purposes of the current article are to (1) clarify terminology relevant to cannabinoids; (2) explain and understand the pharmacotherapeutics of CBD; (3) examine research of the current use of CBD by older adults for treating pain; (4) discuss safety considerations with using CBD products; and (5) provide best practice recommendations for clinicians as they advise their older adult patients. A review of the literature demonstrated mixed results on the efficacy of CBD in relieving pain in older adults. There is inconsistency in the labeling of over-the-counter CBD products that can result in safety issues and will require more federal quality control. Likewise, gaps in knowledge regarding safety and efficacy of CBD use in older adults are vast and require further research. [Journal of Gerontological Nursing, 47(7), 6-15.].

[Cannabis and cannabinoids for the treatment of acute and chronic pain]

Since the Act on the medical use of cannabis, at which cannabis-based medicines and cannabinoids became law, there has been an exponential increase in prescriptions for the acquisition of cannabis for medical purposes. The aim of this leading article is to compile and assess the currently available relevant clinical evidence for the use of cannabis and cannabinoids for treatment of acute and chronic pain. Based on the systematic literature review "Cannabis-Potential and risks (CAPRIS)" commissioned by the German Federal Ministry of Health and the recently published recommendations of the European Pain Federation EFIC, this article aims to give an orientation aid for the decision-making process in the clinical routine.

Use and Reported Helpfulness of Cannabinoids Among Primary Care Patients in Vermont

Introduction: While cannabis has been medically legal in Vermont since 2004 and recreationally legal since 2018 there has been minimal published research regarding the use and practices in the adult population. This gap in understanding results in primary care providers having difficulty navigating conversations surrounding cannabinoid use. The purpose of this research was to identify current use and perceptions of cannabinoids, including Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), in adult primary care patients in Vermont. Methods: An anonymous written survey was given to 1009 Vermont primary care patients aged 18 years and older. All measures were patient-reported and included use of CBD and THC products, perceived helpfulness for certain medical conditions, knowledge of CBD and THC, perceived knowledge of their provider, and concerns regarding cannabis legalization. Results: 45% of adult primary care patients reported using cannabinoids in the past year. Only 18% of patients reported their provider as being a good source of information regarding cannabis. Of the patients who used cannabis in the past year, a majority reported it helpful for conditions such as anxiety and depression, arthritis, pain, sleep, and nausea. Conclusions: Primary care providers need to be knowledgeable about cannabinoids to best support patient care. In addition, with a significant number of patients reporting cannabinoids helpful for medical conditions common in primary care, it is important that research continue to identify the potential benefits and harms of cannabis.

Dietary Supplementation for Para-Athletes: A Systematic Review

The use of dietary supplements is high among athletes and non-athletes alike, as well as able-bodied individuals and those with impairments. However, evidence is lacking in the use of dietary supplements for sport performance in a para-athlete population (e.g., those training for the Paralympics or similar competition). Our objective was to examine the literature regarding evidence for various sport supplements in a para-athlete population. A comprehensive literature search was conducted using PubMed, SPORTDiscus, MedLine, and Rehabilitation and Sports Medicine Source. Fifteen studies met our inclusion criteria and were included in our review. Seven varieties of supplements were investigated in the studies reviewed, including caffeine, creatine, buffering agents, fish oil, leucine, and vitamin D. The evidence for each of these supplements remains inconclusive, with varying results between studies. Limitations of research in this area include the heterogeneity of the subjects within the population regarding functionality and impairment. Very few studies included individuals with impairments other than spinal cord injury. Overall, more research is needed to strengthen the evidence for or against supplement use in para-athletes. Future research is also recommended on performance in para-athlete populations with classifiable impairments other than spinal cord injuries.

Targeting the endocannabinoid system for management of HIV-associated neuropathic pain: A systematic review

Human immunodeficiency virus (HIV) infection and antiretroviral therapy can independently induce HIV-associated neuropathic pain (HIV-NP). There is a dearth of drugs or therapeutic modalities that can alleviate HIV-NP. Smoked cannabis has been reported to improve pain measures in patients with neuropathic pain. Cannabis, phytocannabinoids, and the endocannabinoids such N-arachidonoylethanolamine (anandamide; AEA) and 2-arachidonoylglycerol (2-AG), produce some of their effects via cannabinoid receptors (CBRs). Endocannabinoids are degraded by various enzymes such as fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase. We searched PubMed, Google Scholar, clinicaltrials.gov and clinicaltrialsregister.eu using various key words and their combinations for published papers that studied HIV-NP and cannabis, cannabinoids, or endocannabinoids up to 27th December 2020. All original research articles that evaluated the efficacy of molecules that modulate the endocannabinoid system (ECS) for the prevention and/or treatment of pain in HIV-NP animal models and patients with HIV-NP were included. The PubMed search produced a total of 117 articles, whereas the Google Scholar search produced a total of 9467 articles. Amongst the 13 articles that fulfilled the inclusion criteria 11 articles were found in both searches whereas 2 articles were found in Google Scholar only. The clinicaltrials.gov and clinicaltrialsregister.eu searches produced five registered trials of which three were completed and with results. Ten preclinical studies found that the endocannabinoids (2-AG and AEA), synthetic mixed CB1R/CB2R agonist WIN 55,212-2, a CB2R-selective phytocannabinoid β-caryophyllene, synthetic CB2R-selective agonists (AM1710, JWH015, JWH133 and Gp1a, but not HU308); FAAH inhibitors (palmitoylallylamide, URB597 and PF-3845) and a drug combination of indomethacin plus minocycline, which produces its effects in a CBR-dependent manner, either prevented the development of and/or attenuated established HIV-NP. Two clinical trials demonstrated greater efficacy of smoked cannabis over placebo in alleviating HIV-NP, whereas another clinical trial demonstrated that cannabidivarin, a cannabinoid that does not activate CBRs, did not reduce HIV-NP. The available preclinical results suggest that targeting the ECS for prevention and treatment of HIV-NP is a plausible therapeutic option. Clinical evidence shows that smoked cannabis alleviates HIV-NP. Further research is needed to find out if non-psychoactive drugs that target the ECS and are delivered by other routes than smoking could be useful as treatment options for HIV-NP.

A Mapping Literature Review of Medical Cannabis Clinical Outcomes and Quality of Evidence in Approved Conditions in the USA from 2016 to 2019

In 2017, a National Academies of Sciences, Engineering, and Medicine (NASEM) report comprehensively evaluated the body of evidence regarding cannabis health effects through the year 2016. The objectives of this study are to identify and map the most recently (2016-2019) published literature across approved conditions for medical cannabis and to evaluate the quality of identified recent systematic reviews, published following the NASEM report. Following the literature search from 5 databases and consultation with experts, 11 conditions were identified for evidence compilation and evaluation: amyotrophic lateral sclerosis, autism, cancer, chronic noncancer pain, Crohn's disease, epilepsy, glaucoma, human immunodeficiency virus/AIDS, multiple sclerosis (MS), Parkinson's disease, and posttraumatic stress disorder. A total of 198 studies were included after screening for condition-specific relevance and after imposing the following exclusion criteria: preclinical focus, non-English language, abstracts only, editorials/commentary, case studies/series, and non-U.S. study setting. Data extracted from studies included: study design type, outcome definition, intervention definition, sample size, study setting, and reported effect size. Few completed randomized controlled trials (RCTs) were identified. Studies classified as systematic reviews were graded using the Assessing the Methodological Quality of Systematic Reviews-2 tool to evaluate the quality of evidence. Few high-quality systematic reviews were available for most conditions, with the exceptions of MS (9 of 9 graded moderate/high quality; evidence for 2/9 indicating cannabis improved outcomes; evidence for 7/9 indicating cannabis inconclusive), epilepsy (3 of 4 graded moderate/high quality; 3 indicating cannabis improved outcomes; 1 indicating cannabis inconclusive), and chronic noncancer pain (12 of 13 graded moderate/high quality; evidence for 7/13 indicating cannabis improved outcomes; evidence from 6/7 indicating cannabis inconclusive). Among RCTs, we identified few studies of substantial rigor and quality to contribute to the evidence base. However, there are some conditions for which significant evidence suggests that select dosage forms and routes of administration likely have favorable risk-benefit ratios (i.e., epilepsy and chronic noncancer pain). The body of evidence for medical cannabis requires more rigorous evaluation before consideration as a treatment option for many conditions, and evidence necessary to inform policy and treatment guidelines is currently insufficient for many conditions.

Cancer Initiation, Progression and Resistance: Are Phytocannabinoids from Cannabis sativa L. Promising Compounds?

Cannabis sativa L. is a source of over 150 active compounds known as phytocannabinoids that are receiving renewed interest due to their diverse pharmacologic activities. Indeed, phytocannabinoids mimic the endogenous bioactive endocannabinoids effects through activation of CB1 and CB2 receptors widely described in the central nervous system and peripheral tissues. All phytocannabinoids have been studied for their protective actions towards different biological mechanisms, including inflammation, immune response, oxidative stress that, altogether, result in an inhibitory activity against the carcinogenesis. The role of the endocannabinoid system is not yet completely clear in cancer, but several studies indicate that cannabinoid receptors and endogenous ligands are overexpressed in different tumor tissues. Recently, in vitro and in vivo evidence support the effectiveness of phytocannabinoids against various cancer types, in terms of proliferation, metastasis, and angiogenesis, actions partially due to their ability to regulate signaling pathways critical for cell growth and survival. The aim of this review was to report the current knowledge about the action of phytocannabinoids from Cannabis sativa L. against cancer initiation and progression with a specific regard to brain, breast, colorectal, and lung cancer as well as their possible use in the therapies. We will also report the known molecular mechanisms responsible for such positive effects. Finally, we will describe the actual therapeutic options for Cannabis sativa L. and the ongoing clinical trials.

Efficacy of cannabinoids in fibromyalgia: a literature review

Fibromyalgia is a chronic disease of unclear etiology, involving a neural oversensitization and impaired pain modulation, in addition to a clinical deficiency of the endocannabinoid system. Fibromyalgia is associated with a number of somatic and psychological disorders and hence multiple pharmacological approaches have been used, including   opioids, antidepressants, antiepileptics, and more recently medical cannabis. This narrative review comprises a review of the current literature on the efficacy of   cannabinoids in fibromyalgia. The studies describe a possible influence of cannabis on pain control in patients with fibromyalgia, with positive effects on quality of life and sleep. The use of cannabis seems to be beneficial in patients with fibromyalgia; however, more robust studies are still needed to establish is actual efficacy in pain management, quality of life and improvement of associated symptoms.

Pain in Women: A Perspective Review on a Relevant Clinical Issue that Deserves Prioritization

Introduction

Gender equity and gender medicine are opportunities not to be missed, and this Expert Group Opinion Paper on pain in women aims to review the treatment of pain conditions mainly affecting women, as well as the fundamental aspects of the different clinical response to drug treatment between the genders, and what can be done for gender-specific rehabilitation.

Methods

Perspective review.

Results

Genotypic and phenotypic differences in pain between the sexes are conditioned by anatomical, physiological, neural, hormonal, psychological, social, and cultural factors, such as the response to pharmacological treatment to control pain. The examination of these factors shows that women are affected by pain diseases more frequently and severely than men and that they report pain more frequently and with a lower pain threshold than men. Some forms of pain are inherently related to gender differences, such as pain related to the genitourinary system. However, other forms of chronic pain are seen more frequently in women than men, such as migraine, rheumatological, and musculoskeletal pain, in particular fibromyalgia.

Discussion

Research is needed into the pathophysiological basis for gender differences in the generation of acute pain and maintenance of chronic pain, including the factors that put women at higher risk for developing chronic pain. In addition, different specialties need to collaborate to develop gender-related diagnostic and therapeutic guidelines, and healthcare professionals need to upskill themselves in the appropriate management of pain using existing diagnostic tools and therapeutic options.

Medical cannabis for the treatment of fibromyalgia syndrome: a retrospective, open-label case series

BACKGROUND

The use of cannabis for treating fibromyalgia syndrome (FMS) has not been comprehensively investigated. Thus, we have assessed the efficacy and adverse events (AEs) of short- and long-term medical cannabis (MC) treatment for FMS.

METHODS

Data were obtained from medical reports archived in the pain clinic of Ponderano (Italy; retrospective study). FMS patients, who were resistant to conventional therapy, received licensed MC with various Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) content, as powdered whole flowers (decoction or vaporization) or oil extracts. Demographic and clinical parameters, including Numerical Rating Scale (NRS), Oswestry Disability Index (ODI), Hospital Anxiety and Depression Scale, Widespread Pain Index (WPI), Severity Score (SyS), and side effects, were obtained after 1, 3, and 12 months. Data were analyzed with Wilcoxon signed-rank tests for paired data.

RESULTS

Thirty-eight patients were included. Thirty, 18, and 12 patients continued therapy for 1, 3, and 12 months, respectively. Significant improvements (p < 0.01) were observed in NRS, ODI, WPI, and SyS at 1 month; in NRS, ODI, and WPI at 3 months; and in NRS, ODI, and SyS at 12 months. Therapy was interrupted by 17 patients (48.6%) owing to nonserious AEs according to the FDA. The most common side effects were mental confusion (37%), dizziness (14%), nausea/vomiting (14%), and restlessness/irritation (14%). The median daily dose of milled flowers administered as THC-dominant MC and hybrid MC (with similar THC/CBD ratio) was 200 mg/day and 400 mg/day, respectively. After 3 months of titration, the median content of THC administered with THC-dominant MC cultivars was 46.2 mg, and of THC + CBD administered as a hybrid MC cultivar, was 23.6 mg + 38 mg. At 3 months, median THC content administered in the oil extract of the THC-dominant MC cultivars was 9.7 mg, while that of THC + CBD administered in the oil extract of the hybrid MC cultivars was 1.8 mg + 2 mg.

CONCLUSIONS

MC may represent an alternative treatment for patients with FMS who are unresponsive to conventional therapy. However, its application may be limited by the incidence of nonserious AEs.

Complementary and Alternative (CAM) Treatment Options for Women with Pelvic pain

Purpose of review

I.To provide an overview of the current complementary and alternative (CAM) treatment options for women with chronic pelvic pain (CPP).

Recent findings

II.Recent studies on chronic pain at cellular, molecular and network level and their interaction with the immune system has unfolded several mechanisms for pain making it promising to explore the alternative paradigm to manage the incredibly complex chronic pelvic pain condition where multifactorial etiology often limits successful outcomes.

Summary

III.The multifactorial nature and complexity in establishing the underlying diagnosis in CPP limits predictable response to traditional medical and interventional options. Complementary and alternative options have been studied to improve outcomes. Incorporation of exercise-based CAM, pelvic floor physical therapy, acupuncture and cognitive behavioral therapy are suggested to show promising results but well powered randomized studies are needed to draw conclusions on their efficacy. Evidence for non-opioid alternatives such as oral cannabinoids are preliminary and may emerge to be safe and effective.

High-Frequency Spinal Cord Stimulation at 10 kHz for the Treatment of Nonsurgical Refractory Back Pain: Design of a Pragmatic, Multicenter, Randomized Controlled Trial

BACKGROUND

Spinal cord stimulation (SCS) has been shown to provide pain relief for chronic back and leg pain due to failed back surgery syndrome. But many patients with chronic back pain have not had major back surgery or are not good candidates for surgery, and conventional medical management (CMM) provides limited relief. We have termed this condition nonsurgical refractory back pain (NSRBP). Level 1 evidence does not yet exist showing the therapeutic benefit of SCS for NSRBP.

OBJECTIVE

To compare 10-kHz SCS plus CMM (10-kHz SCS + CMM) to CMM alone for treatment of NSRBP in terms of clinical and cost effectiveness.

STUDY DESIGN

Multicenter, randomized controlled trial (RCT), with subjects randomized 1:1 to either 10-kHz SCS + CMM or CMM alone. Optional crossover occurs at 6 months if treatment does not achieve ≥50% pain relief.

METHODS

Patients with NSRBP as defined above may be enrolled if they are ineligible for surgery based on surgical consultation. Subjects randomized to 10-kHz SCS + CMM will receive a permanent implant if sufficient pain relief is achieved in a temporary trial. Both groups will receive CMM per standard of care and will undergo assessments at baseline and at follow-ups to 12 months. Self-report outcomes include pain, disability, sleep, mental health, satisfaction, healthcare utilization, and quality of life.

RESULTS

Enrollment was initiated on September 10, 2018. Prespecified independent interim analysis at 40% of the enrollment target indicated the sample size was sufficient to show superiority of treatment at the primary endpoint; therefore, enrollment was stopped at 211.

CONCLUSIONS

This large multicenter RCT will provide valuable evidence to guide clinical decisions in NSRBP.

Pharmacotherapy to Manage Central Post-Stroke Pain

Central post-stroke pain is a chronic neuropathic pain syndrome following a cerebrovascular accident. The development of central post-stroke pain is estimated to occur in 8 to 55% of stroke patients and is described as constant or intermittent neuropathic pain accompanied by dysesthesia of temperature and/or pressure sensations. These pain and sensory deficits are within the area of the body corresponding to the stroke lesion. The onset of pain is usually gradual, though it can develop either immediately after stroke or years after. Given the diversity in its clinical presentation, central post-stroke pain is a challenging diagnosis of exclusion. Furthermore, central post-stroke pain is often resistant to pharmacological treatment options and a clear therapeutic algorithm has not been established. Based on current evidence, amitriptyline, lamotrigine, and gabapentinoids should be used as first-line pharmacotherapy options when central post-stroke pain is suspected. Other drugs, such as fluvoxamine, steroids, and Intravenous infusions of lidocaine, ketamine, or even propofol, can be considered in intractable cases. In addition, interventional therapies such as motor cortex stimulation or transcranial magnetic stimulation have been shown to provide relief in difficult-to-treat patients.

Broadly Neutralizing Synthetic Cannabinoid Vaccines

Synthetic cannabinoids (SCs) constitute a significant portion of psychoactive substances forming a major public health risk. Due to the wide variety of SCs, broadly neutralizing antibodies generated by active immunization present an intriguing pathway to combat cannabinoid use disorder. Here, we probed hapten design for antibody affinity and cross reactivity against two classes of SCs. Of the 10 haptens screened, 3 vaccine groups revealed submicromolar IC₅₀, each targeting 5-6 compounds in our panel of 22 drugs. Moreover, SCs were successfully sequestered when administered by vaping or intraperitoneal injection, which was confirmed within animal models by observing locomotion, body temperature, and pharmacokinetics. We also discovered synergistic effects to simultaneously blunt two drug classes through an admixture vaccine approach. Collectively, our study provides a comprehensive foundation for the development of vaccines against SCs.

Mixed methods study of the potential therapeutic benefits from medical cannabis for patients in Florida

OBJECTIVES

To evaluate medical marijuana patients' perceptions of therapeutic benefits for self-reported medical conditions.

DESIGN

The study was a concurrent mixed methods study with adult medical marijuana patients. Survey data were collected using a web-based survey, and interviews were conducted in person or over the phone.

SETTING

The study recruited 196 medical marijuana patients to complete surveys and 13 patients to participate in qualitative interviews in Florida.

MEASURES

A validated patient survey was distributed via Florida medical marijuana social media groups to examine the therapeutic benefits of the cannabis plant for medical conditions and overall well-being. Concurrently, qualitative interviews were conducted to understand barriers and facilitators to accessing medical cannabis and explore preferences for different forms and strains, as well as any unexpected side effects.

RESULTS

Patients used medical cannabis for relief of chronic pain or depression, followed by arthritis and nausea. Survey results indicated 89 % of patients reported "great relief" for their medical condition. Over 76 % of patients reported a score of 8 or higher on a 10-point scale that their medical condition had improved, and over 68 % reported a score of 8 or higher that medical cannabis had reduced their pain. Interviews indicated medical cannabis was effective for pain relief and reducing the use of prescription medicines, but the drug was perceived as too expensive.

CONCLUSIONS

Medical marijuana patients were positive about the health benefits they received and the fact they were able to reduce or eliminate many prescription medications; however, there were concerns about the costs.

Disposition of Phytocannabinoids, Their Acidic Precursors and Their Metabolites in Biological Matrices of Healthy Individuals Treated with Vaporized Medical Cannabis

Inhalation by vaporization is a useful application mode for medical cannabis. In this study, we present the disposition of Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), their acidic precursors, and their metabolites in serum, oral fluid, and urine together with the acute pharmacological effects in 14 healthy individuals treated with vaporized medical cannabis. THC and CBD peaked firstly in serum and then in oral fluid, with higher concentrations in the first biological matrices and consequent higher area under the curve AUCs. Acidic precursors Δ-9-tetrahydrocannabinolic acid A (THCA) and cannabidiolic acid (CBDA) showed a similar time course profile but lower concentrations due to the fact that vaporization partly decarboxylated these compounds. All THC and CBD metabolites showed a later onset with respect to the parent compounds in the absorption phase and a slower decrease to baseline. In agreement with serum kinetics, THC-COOH-GLUC and 7-COOH-CBD were the significantly most excreted THC and CBD metabolites. The administration of vaporized medical cannabis induced prototypical effects associated with the administration of cannabis or THC in humans, with a kinetic trend overlapping that of parent compounds and metabolites in serum. The pharmacokinetics of cannabinoids, their precursors, and their metabolites in biological fluids of individuals treated with vaporized medical cannabis preparations showed a high interindividual variability as in the case of oral medical cannabis decoction and oil. Inhaled medical cannabis was absorbed into the organism earlier than decoction and oil. Cannabinoids reached higher systemic concentrations, also due to the fact that the acid precursors decarboxylated to parent cannabinoids at high temperatures, and consequently, the physiological and subjective effects occurred earlier and resulted with higher intensity. No serious adverse effects were observed.

Medical Cannabis in Oncology: a Valuable Unappreciated Remedy or an Undesirable Risk?

OPINION STATEMENT

The use of the cannabis plant by cancer patients has been rising significantly in the past few years worldwide, primarily driven by public demand. There is an obvious need for more reliable scientific data, pharmacology information, a better understanding of its mode of action, and available clinical evidence supporting its robust use. Physicians must complete a thorough medical assessment, screening for potential drugs, or treatment contraindications before allowing its consumption. In light of the growing popularity of cannabis usage, it is highly essential that, in the near future, the medical community will be able to provide practical recommendations and explicit guidelines, including doses, and that cannabinoid concentrations in the used products are defined regarding its prescription before any medical procedure involving its usage is authorized. Here, we review and describe the favorable outcomes demonstrating the benefits of cannabis as an adjunctive treatment to conventional medicines for chemotherapy-induced nausea, vomiting, and cancer-related pain (primarily refractory chronic or neuropathic pain). Although not yet substantial enough, the treatment of anorexia, insomnia, depression, and anxiety is also seemingly favorable. To date, reports regarding its anti-neoplastic effects or its potent immunosuppressive properties influencing response to immunotherapy are still very conflicting and controversial. Thus, with the current state of evidence, cannabis use is not advisable as initial treatment, as an adjunct or an advanced line of care. In the coming years, we expect that preclinical data and animal models will shift to the clinical arena, and more patients will be recruited for clinical trials, and their reports will advance the field. Thus, physicians should prescribe cannabis only if careful clarification and consideration is provided together with a follow-up response evaluation.

Adverse Effects of Recreational and Medical Cannabis

PURPOSE OF REVIEW

This comprehensive review discusses the adverse effects known today about marijuana, for either medical or recreational use. It reviews the role of cannabis in the treatment of chronic pain, cognitive and neurological adverse effects, special cases and addiction.

RECENT FINDINGS

Cannabinoids work through the endocannabinoids system and inhibit the release of GABA and glutamate in the brain, impact neuromodulation, as well as dopamine, acetylcholine and norepinephrine release. They affect reward, learning and pain. The use of cannabis is increasing nationally and world-wide for both recreational and medicinal purposes, however, there is relatively only low quality evidence to the efficacy and adverse effects of this. Cannabis and its derivatives may be used for treatment of chronic pain. They are via CB1 receptors that are thought to modulate nociceptive signals in the brain. CB2 receptors in the DRG likely affect pain integration in the afferent pathways, and peripherally CB2 also affects noradrenergic pathways influencing pain. A large proportion of users may see more than 50% of chronic pain alleviation compared with placebo. Cannabis affects cognition, most notably executive function, memory and attention, and may deteriorate the boundary between emotional and executive processing. Cannabis impairs memory in the short run, which become more significant with chronic use, and may also be accompanied by poorer effort, slower processing and impacted attention. It is generally believed that long-term use and earlier age are risk factor for neurocognitive deficits; neuroimaging studies have shown reduced hippocampal volume and density. Executive functions and memory are worse in adolescent users versus adults. Cannabis addiction is different and likely less common than other addictive substances, but up to 10% of users meet criteria for lifetime cannabis dependence. Addiction patterns may be linked to genetic and epigenetic differences. It is still unclear whether abstinence reverses patterns of addiction, and more research is required into this topic.

SUMMARY

Cannabis use has become more abundant for both medical and recreational use. It carries likely benefits in the form of analgesia, anti-emesis and improved appetite in chronic patients. The evidence reviewing adverse effects of this use are still limited, however, exiting data points to a clear link with neurocognitive deterioration, backed by loss of brain volume and density. Addiction is likely complex and variable, and no good data exists to support treatment at this point. It is becoming clear that use in earlier ages carries a higher risk for long-term deficits. As with any other drug, these risks should be considered alongside benefits prior to a decision on cannabis use.

Protocol: mixed-methods study of how implementation of US state medical cannabis laws affects treatment of chronic non-cancer pain and adverse opioid outcomes

BACKGROUND

Thirty-three US states and Washington, D.C., have enacted medical cannabis laws allowing patients with chronic non-cancer pain to use cannabis, when recommended by a physician, to manage their condition. However, clinical guidelines do not recommend cannabis for treatment of chronic non-cancer pain due to limited and mixed evidence of effectiveness. How state medical cannabis laws affect delivery of evidence-based treatment for chronic non-cancer pain is unclear. These laws could lead to substitution of cannabis in place of clinical guideline-discordant opioid prescribing, reducing risk of opioid use disorder and overdose. Conversely, state medical cannabis laws could lead to substitution of cannabis in place of guideline-concordant treatments such as topical analgesics or physical therapy. This protocol describes a mixed-methods study examining the implementation and effects of state medical cannabis laws on treatment of chronic non-cancer pain. A key contribution of the study is the examination of how variation in state medical cannabis laws' policy implementation rules affects receipt of chronic non-cancer pain treatments.

METHODS

The study uses a concurrent-embedded design. The primary quantitative component of the study employs a difference-in-differences design using a policy trial emulation approach. Quantitative analyses will evaluate state medical cannabis laws' effects on treatment for chronic non-cancer pain as well as on receipt of treatment for opioid use disorder, opioid overdose, cannabis use disorder, and cannabis poisoning among people with chronic non-cancer pain. Secondary qualitative and survey methods will be used to characterize implementation of state medical cannabis laws through interviews with state leaders and representative surveys of physicians who treat, and patients who experience, chronic non-cancer pain in states with medical cannabis laws.

DISCUSSION

This study will examine the effects of medical cannabis laws on patients' receipt of guideline-concordant non-opioid, non-cannabis treatments for chronic non-cancer pain and generate new evidence on the effects of state medical cannabis laws on adverse opioid outcomes. Results will inform the dynamic policy environment in which numerous states consider, enact, and/or amend medical cannabis laws each year.

Clinical Conditions and Prescription Drug Utilization among Early Medical Marijuana Registrants in Florida

Initial legalization of medical marijuana (MM) in Florida required providers to submit initial and follow-up treatment plan forms to the University of Florida to support research on MM safety and efficacy. This study retrospectively analyzed all treatment plan forms submitted between program inception (August 2016) through July 2017 and describes early Florida MM registrants by clinical conditions and prescription drug utilization. Among 7,548 unique treatment plans, the initial visit was characterized by registrants who were mostly white (83.7%), 52.3 (SD 16.4) years of age on average, and who were assessed by the provider as at least moderately ill (79.6%). Musculoskeletal and spasticity-related conditions (44.8%), chronic pain (41.9%), and mental health disorders (17.0%) were the most frequent medical complaints for seeking MM treatment with more than one condition per patient possible. One in four (25.9%) patients reported use of prescription opioids and over one-fifth of patients frequently utilized at least one psychotropic medication as well as cardiovascular agents. There were 2,075 unique follow-up plans available which were mostly characterized by clinical improvement and reported reductions in utilization of some drug classes. Further research is needed to guide clinicians on the risks and benefits of MM used concomitantly with prescription drugs.

Pain Profiles among Young Adult Cannabis Users: An Analysis of Antecedent Factors and Distal Outcomes

BACKGROUND

Pain is a primary reason for medical cannabis use among young adults, however little is known about the patterns of pain in this group. This study identified pain profiles among young adult cannabis users and examined related antecedents and distal outcomes.

METHODS

Past 30-day cannabis users aged 18-26, both medical cannabis patients and non-patients, were enrolled in Los Angeles in 2014-2015. A latent class analysis was used to identify pain classes based on history of chronic pain conditions and recent non-minor pain. The study assessed the predictors of membership in pain classes and examined the association of classes with recent mental health characteristics, cannabis use motives and practices.

RESULTS

Three classes were identified: Low pain (56.3%), Multiple pain (27.3%), and Nonspecific pain (16.4%). In adjusted models, lifetime insomnia was associated with membership in Multiple pain and Nonspecific pain classes versus the Low pain class. Medical cannabis patients and Hispanics/Latinos were more likely to belong to the Multiple pain class than the other classes. Regarding recent outcomes, the Multiple pain and Nonspecific pain classes were more likely than the Low pain class to use cannabis to relieve physical pain. Additionally, the Multiple pain class had a higher probability of psychological distress, self-reported medical cannabis use, consuming edibles, and using cannabis to sleep compared to one or both other classes.

CONCLUSION

Findings suggest that young adult cannabis users can be separated into distinct groups with different pain profiles. The Multiple pain profile was associated with medically-oriented cannabis use motives and practices.

Microencapsulation of Cannabidiol in Liposomes as Coating for Cellulose for Potential Advanced Sanitary Material

The microencapsulation of the cannabidiol and its integration into the tampon can eliminate vaginal inflammation, which at the same time lead to relaxation of the abdominal muscles. The tampon, which contains the active substance cannabidiol (CBD), was developed as an advanced fibrous composite for sanitary application. The active substances were microencapsulated, and, as a carrier, liposomes micro/nano capsules were used. The CBD liposome formulation was analyzed by particle size, polydispersity index, zeta potential, and encapsulation efficiency. Particle size of the CBD liposome liquid formulation was increased by 19%, compared to the liposome liquid formulation and the encapsulation efficiency of CBD in liposome particles, which was 90%. The CBD liposome formulation was applied to cellulose material. The composition of the fibrous composite material was evaluated by Fourier transform infrared spectroscopy, the fiber morphology was analyzed by scanning electron spectroscopy, while the bioactive properties were assessed by antioxidant efficiency, antimicrobial properties, and desorption kinetics. CBD liposome functionalized tampons have both antioxidant and antimicrobial properties. Antimicrobial properties were more pronounced against Gram-positive bacteria. The desorption kinetics of the CBD liposome immobilized on the surface of the composite material was studied using antioxidant activity in the desorption bath. The prepared CBD liposome functionalized tampon additionally shows higher biodegradability compared to references. This high-quality, biodegradable sanitary material based on microencapsulated CBD components as a functional coating provides a platform for many different applications besides medical textiles, also for packaging, pharmaceuticals, paper and wood-based materials, etc.

Inhaled Cannabis Suppresses Chemotherapy-Induced Neuropathic Nociception by Decoupling the Raphe Nucleus: A Functional Imaging Study in Rats

BACKGROUND

Efficacy of inhaled cannabis for treating pain is controversial. Effective treatment for chemotherapy-induced neuropathy represents an unmet medical need. We hypothesized that cannabis reduces neuropathic pain by reducing functional coupling in the raphe nuclei.

METHODS

We assessed the impact of inhalation of vaporized cannabis plant (containing 10.3% Δ⁹-tetrahydrocannabinol/0.05% cannabidiol) or placebo cannabis on brain resting-state blood oxygen level-dependent functional connectivity and pain behavior induced by paclitaxel in rats. Rats received paclitaxel to produce chemotherapy-induced peripheral neuropathy or its vehicle. Behavioral and imaging experiments were performed after neuropathy was established and stable. Images were registered to, and analyzed using, a 3D magnetic resonance imaging rat atlas providing site-specific data on more than 168 different brain areas.

RESULTS

Prior to vaporization, paclitaxel produced cold allodynia. Inhaled vaporized cannabis increased cold withdrawal latencies relative to prevaporization or placebo cannabis, consistent with Δ⁹-tetrahydrocannabinol-induced antinociception. In paclitaxel-treated rats, the midbrain serotonergic system, comprising the dorsal and median raphe, showed hyperconnectivity to cortical, brainstem, and hippocampal areas, consistent with nociceptive processing. Inhalation of vaporized cannabis uncoupled paclitaxel-induced hyperconnectivity patterns. No such changes in connectivity or cold responsiveness were observed following placebo cannabis vaporization.

CONCLUSIONS

Inhaled vaporized cannabis plant uncoupled brain resting-state connectivity in the raphe nuclei, normalizing paclitaxel-induced hyperconnectivity to levels observed in vehicle-treated rats. Inhaled vaporized cannabis produced antinociception in both paclitaxel- and vehicle-treated rats. Our study elucidates neural circuitry implicated in the therapeutic effects of Δ⁹-tetrahydrocannabinol and supports a role for functional imaging studies in animals in guiding indications for future clinical trials.

Safety Considerations in Cannabinoid-Based Medicine

Cannabinoids are a diverse class of chemical compounds that are increasingly recognized as potential therapeutic options for a range of conditions. While many studies and reviews of cannabinoids focus on efficacy, safety is much less well reported. Overall assessment of the safety of cannabinoid-based medicines is confounded by confusion with recreational cannabis use as well as different study designs, indications, dosing, and administration methods. However, clinical studies in registered products are increasingly available, and this article aims to discuss and clarify what is known regarding the safety profiles of cannabinoid-based medicines, focusing on the medical and clinical safety evidence and identifying areas for future research. The two most well-studied cannabinoids are Δ9-tetrahydrocannabinol (THC), or its synthetic variants (dronabinol, nabilone), and cannabidiol (CBD). Across diverse indications, dizziness and fatigue are generally the most common adverse events experienced by patients receiving THC or combined THC and CBD. Patients receiving THC may experience adverse cognitive effects and impairment in psychomotor skills, with implications for driving and some occupations, while CBD may help to lower the psychotropic effects of THC when used in combination. Studies on dependency and addiction in a medical context are limited, but have shown inconsistent findings regarding misuse potential. Generally, the recommended route of administration is oral ingestion, as smoking medicinal cannabinoid products potentially releases mutagenic and carcinogenic by-products. There are several potential drug-drug interactions and contraindications for cannabinoid-based medicines, which physicians should account for when making prescribing decisions. The available evidence shows that, as with any other class of pharmaceuticals, cannabinoid-based medicines are associated with safety risks which should be assessed in the context of potential therapeutic benefits. Each patient should be assessed on an individual basis and physicians must rely on informed, evidence-based decision-making when determining whether a cannabinoid-based medicine could be an appropriate treatment option.

Impact of cannabis on non-medical opioid use and symptoms of posttraumatic stress disorder: a nationwide longitudinal VA study

BACKGROUND

Multiple states have authorized cannabis as an opioid substitution agent and as a treatment for posttraumatic stress disorder (PTSD).

OBJECTIVES

This study sought to investigate the relationship between cannabis use, non-medical opioid use, and PTSD symptoms among U.S. veterans.

METHODS

From 1992-2011, veterans admitted to specialized intensive PTSD treatment participated in a national evaluation with assessments at intake and four months after discharge. Participants with non-medical opioid use ≥ 7 days during the 30 days preceding admission were divided into two groups: those with cannabis use ≥ 7 days, and those without cannabis use. These two groups were compared on measures of substance use and PTSD symptoms at baseline and 4-months outpatient follow-up. We hypothesized that, at both assessments, the group with baseline cannabis use would show less non-medical opioid use and less severe PTSD symptoms.

RESULTS

Of 1,413 veterans with current non-medical opioid use, 438 (30.3%) also used cannabis, and 985 (69.7%) did not. At baseline, veterans with concurrent non-medical opioid and cannabis use had slightly fewer days of non-medical opioid use (p < .005; d = -0.16), greater use of other substances (p < .0001) and more PTSD symptoms (p = .003; d = 0.16), compared to veterans who used non-medical opioids but not cannabis. At follow-up, substance use or PTSD symptoms did not significantly differ.

CONCLUSION

Cannabis use was not associated with a substantial reduction of non-medical opioid use, or either improvement or worsening of PTSD symptoms in this population. Hence, these data do not encourage cannabis use to treat either non-medical opioid use or PTSD.

A Literature Analysis on Medicinal Use and Research of Cannabis in the Meiji Era of Japan

Cannabis is a historical plant which has been used as a medicine in East Asia. These days, there are active debates about using cannabis in clinical field. Collecting and comparing cannabis research articles which had been published in the Opening of Japan to spot the interactions between the traditional medicine of Japan, Rangaku which was established in Edo Period and the European medicine which is transferred after Perry Expedition is academically meaningful. This study searched publications, which were listed on Open-Access databases by Dec. 11th, 2019. We collected research articles which had been published from January 3rd, 1867 to July 30th, 1912 also known as Meiji era and uploaded on Open-Access databases. Our searching databases were J-stage, CiNii (Scholarly and Academic Information Navigator), Tokyo Metropolitan Library, The National Diet Library, IRDB (Institutional Repositories DataBase) and KAKEN (Grant-in-Aid for Scientific Research Database). Searching keywords were cannabis, hemp and all their Japanese synonyms and available combinations. We selected final 15 studies which met every selection criteria in the 346,393 collected studies. Cannabis was prescribed in Meiji era of Japan to alleviate pain and cure the digestive, respiratory, urinary, and nervous system diseases such as indigestion, asthma, tuberculosis, gonorrhea and its complications, insomnia, and nervous prostration. Cannabis was medically used in Meiji era of Japan and the reporting and sharing of its clinical effect was published on the medical journals like present days. There were already Cannabis regulations in that era, but its medicinal use was more liberated than nowadays. It may be a chance to reconsider the current legal system, which strictly controls the use of Cannabis.

A Rapid Review of the Impact of Systems-Level Policies and Interventions on Population-Level Outcomes Related to the Opioid Epidemic, United States and Canada, 2014-2018

OBJECTIVES

In the United States, rising rates of overdose deaths and recent outbreaks of hepatitis C virus and HIV infection are associated with injection drug use. We updated a 2014 review of systems-level opioid policy interventions by focusing on evidence published during 2014-2018 and new and expanded opioid policies.

METHODS

We searched the MEDLINE database, consistent with the 2014 review. We included articles that provided original empirical evidence on the effects of systems-level interventions on opioid use, overdose, or death; were from the United States or Canada; had a clear comparison group; and were published from January 1, 2014, through July 19, 2018. Two raters screened articles and extracted full-text data for qualitative synthesis of consistent or contradictory findings across studies. Given the rapidly evolving field, the review was supplemented with a search of additional articles through November 17, 2019, to assess consistency of more recent findings.

RESULTS

The keyword search yielded 535 studies, 66 of which met inclusion criteria. The most studied interventions were prescription drug monitoring programs (PDMPs) (59.1%), and the least studied interventions were clinical guideline changes (7.6%). The most common outcome was opioid use (77.3%). Few articles evaluated combination interventions (18.2%). Study findings included the following: PDMP effectiveness depends on policy design, with robust PDMPs needed for impact; health insurer and pharmacy benefit management strategies, pill-mill laws, pain clinic regulations, and patient/health care provider educational interventions reduced inappropriate prescribing; and marijuana laws led to a decrease in adverse opioid-related outcomes. Naloxone distribution programs were understudied, and evidence of their effectiveness was mixed. In the evidence published after our search's 4-year window, findings on opioid guidelines and education were consistent and findings for other policies differed.

CONCLUSIONS

Although robust PDMPs and marijuana laws are promising, they do not target all outcomes, and multipronged interventions are needed. Future research should address marijuana laws, harm-reduction interventions, health insurer policies, patient/health care provider education, and the effects of simultaneous interventions on opioid-related outcomes.

Daily Cannabis Users with Sickle Cell Disease Show Fewer Admissions than Others with Similar Pain Complaints

Introduction: Previous studies have shown that cannabis use is common in adults with sickle cell disease (SCD), and that many patients report using cannabis to treat pain. Methods: We performed a cross-sectional study of adults with SCD and compared daily users of cannabis with others using validated patient-reported measures of pain and quality of life as well as opioid and health care utilization. Results: Daily cannabis users with SCD had worse pain episode severity scores than others (56.7 vs. 48.8, p=0.02) yet had 1.8 fewer annual admissions (p=0.01) and 1.2 fewer annual emergency room (ER) visits (p=0.01), and similar amounts of opioids dispensed to others after matching for age, gender, SCD genotype, hydroxyurea use, and pain impact scores. Conclusions: We show that people with SCD with more severe pain crisis are more likely to use daily cannabis, yet have lower rates of hospital admission and ER use as compared with others with similar disease severity and pain impact. Randomized controlled trials should be performed.

The costs and benefits of cannabis control policies

As is the case for most drugs, cannabis use has costs and benefits, and so do the policies that attempt to minimize the first and maximize the second. This article summarizes what we know about the harmful effects of recreational cannabis use and the benefits of medical cannabis use under the policy of prohibition that prevailed in developed countries until 2012. It outlines three broad ways in which cannabis prohibition may be relaxed, namely, the depenalization of personal possession and use, the legalization of medical use, and the legalization of adult recreational use. It reviews evidence to date on the impacts of each of these forms of liberalization on the costs and benefits of cannabis use. It makes some plausible conjectures about the future impacts of the commercialization of cannabis using experience from the commercialization of the alcohol, tobacco, and gambling industries. Cannabis policy entails unavoidable trade-offs between competing social values in the face of considerable uncertainty about the effects that more liberal cannabis policies will have on cannabis use and its consequences for better or worse.
.

Medical marijuana certification for patients with sickle cell disease: a report of a single center experience

More than one-third of adults with sickle cell disease (SCD) report using cannabis-based products. Many states list SCD or pain as qualifying conditions for medical marijuana, but there are few data to guide practitioners whether or whom should be certified. We postulated that certifying SCD patients may lead to a reduction in opioid use and/or health care utilization. Furthermore, we sought to identify clinical characteristics of patients who would request this intervention. Retrospective data obtained over the study period included rates of health care and opioid utilization for 6 months before certification and after certification. Patients who were certified but failed to obtain medical marijuana were compared with those who obtained it. Patients who were certified were invited to participate in a survey regarding their reasons for and thoughts on certification. Patients who were certified for medical marijuana were compared with 25 random patients who did not request certification. Fifty adults with SCD were certified for medical marijuana and 29 obtained it. Patients who obtained medical marijuana experienced a decrease in admission rates compared with those who did not and increased use of edible cannabis products. Neither group had changes in opioid use. Patients who were certified for medical marijuana had higher rates of baseline opioid use and illicit cannabis use compared with those who did not request certification. Most patients with SCD who requested medical marijuana were already using cannabis illicitly. Obtaining medical marijuana decreased inpatient hospitalizations.

Potential Pharmacokinetic Drug-Drug Interactions between Cannabinoids and Drugs Used for Chronic Pain

Choosing an appropriate treatment for chronic pain remains problematic, and despite the available medication for its treatment, still, many patients complain about pain and appeal to the use of cannabis derivatives for pain control. However, few data have been provided to clinicians about the pharmacokinetic drug-drug interactions of cannabinoids with other concomitant administered medications. Therefore, the aim of this brief review is to assess the interactions between cannabinoids and pain medication through drug transporters (ATP-binding cassette superfamily members) and/or metabolizing enzymes (cytochromes P450 and glucuronyl transferases).

Cannabinoid-Induced Immunomodulation during Viral Infections: A Focus on Mitochondria

This review examines the impact of cannabinoids on viral infections, as well as its effects on the mitochondria of the nervous and immune system. The paper conveys information about the beneficial and negative impacts of cannabinoids on viral infections, especially HIV-1. These include effects on the inflammatory response as well as neuroprotective effects. We also explore non-apoptotic mitochondrial pathways modulated by the activity of cannabinoids, resulting in modifications to cellular functions. As a large part of the literature derives from studies of the nervous system, we first compile the information related to mitochondrial functions in this system, particularly through the CB1 receptor. Finally, we reflect on how this knowledge could complement what has been demonstrated in the immune system, especially in the context of the CB2 receptor and Ca²⁺ uptake. The overall conclusion of the review is that cannabinoids have the potential to affect a broad range of cell types through mitochondrial modulation, be it through receptor-specific action or not, and that this pathway has a potential implication in cases of viral infection.

An adaptive randomized clinical trial in interstitial cystitis/bladder pain syndrome evaluating efficacy of ASP3652 and the relationship between disease characteristics and Hunner's lesions

PURPOSE

The primary purpose of this study was to evaluate the effect of the fatty acid amide hydrolase (FAAH) inhibitor ASP3652 on efficacy and safety in patients with Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS). The secondary purpose was to evaluate phenotyping based on Hunner's lesions (HL).

METHODS

In this randomized trial, adult female patients with moderate/severe IC/BPS received 12 weeks of treatment with an oral dose of ASP3652 (50, 150, or 300 mg twice daily) or placebo. A Bayesian model was employed using accumulating data to adjust the randomization probability and to analyze the primary efficacy variable (change from baseline to end of treatment in Mean Daily Pain [MDP; range 0-10]). Study outcomes and patient characteristics of patients with and without HL (HL+ and HL-) were compared.

RESULTS

In total, 287 patients were randomized. The 300 mg dose group (n = 97) showed the largest effect, i.e., a mean change from baseline to end of treatment of -1.73 in MDP. However, the mean difference from placebo was 0.02. The probability that this dose was better than placebo was 13.5%. Adverse event incidence was low and similar between study groups. HL+ patients were older and had more severe symptoms than HL-. An association was suggested in HL+ patients between changes in micturition frequency and MDP (R = 0.41 [95% CI 0.18, 0.63]), which was not observed in HL- (R = 0.04 [95% CI -0.16, 0.29]).

CONCLUSION

ASP3652 was safe and well tolerated, but did not show efficacy in IC/BPS. The observed differences between HL+ and HL- suggest that IC/BPS diagnosis and treatment may be approached differently in these two phenotypes.

TRIAL REGISTRATION

EudraCT number 2011-004555-39, date of registration: 2012-05-07.

Medical cannabis for the reduction of opioid dosage in the treatment of non-cancer chronic pain: a systematic review

BACKGROUND

Medical cannabis (MC) is currently being used as an adjunct to opiates given its analgesic effects and potential to reduce opiate addiction. This review assessed if MC used in combination with opioids to treat non-cancer chronic pain would reduce opioid dosage.

METHODS

Four databases-Ovid (Medline), Psyc-INFO, PubMed, Web of Science, and grey literature-were searched to identify original research that assessed the effects of MC on non-cancer chronic pain in humans. Study eligibility included randomized controlled trials, controlled before-and-after studies, cohort studies, cross-sectional studies, and case reports. All databases were searched for articles published from inception to October 31, 2019. Cochrane's ROBINS-I tool and the AXIS tool were used for risk of bias assessment. PRISMA guidelines were followed in reporting the systematic review.

RESULTS

Nine studies involving 7222 participants were included. There was a 64-75% reduction in opioid dosage when used in combination with MC. Use of MC for opioid substitution was reported by 32-59.3% of patients with non-cancer chronic pain. One study reported a slight decrease in mean hospital admissions in the past calendar year (P = .53) and decreased mean emergency department visits in the past calendar year (P = .39) for patients who received MC as an adjunct to opioids in the treatment of non-cancer chronic pain compared to those who did not receive MC. All included studies had high risk of bias, which was mainly due to their methods.

CONCLUSIONS

While this review indicated the likelihood of reducing opioid dosage when used in combination with MC, we cannot make a causal inference. Although medical cannabis' recognized analgesic properties make it a viable option to achieve opioid dosage reduction, the evidence from this review cannot be relied upon to promote MC as an adjunct to opioids in treating non-cancer chronic pain. More so, the optimal MC dosage to achieve opioid dosage reduction remains unknown. Therefore, more research is needed to elucidate whether MC used in combination with opioids in the treatment of non-cancer chronic pain is associated with health consequences that are yet unknown.

SYSTEMATIC REVIEW REGISTRATION

This systematic review was not registered.

Neuropathic Pain and Sickle Cell Disease: a Review of Pharmacologic Management

PURPOSE OF REVIEW

Sickle cell disease (SCD) remains among the most common and severe monogenic disorders present in the world today. Although sickle cell pain has been traditionally characterized as nociceptive, a significant portion of sickle cell patients has reported neuropathic pain symptoms. Our review article will discuss clinical aspects of SCD-related neuropathic pain, epidemiology of neuropathic pain among individuals with SCD, pain mechanisms, and current and future potential pharmacological interventions.

RECENT FINDINGS

Neuropathic pain in SCD is a complicated condition that often has a lifelong and significant negative impact on life; therefore, improved pain management is considered a significant and unmet need. Neuropathic pain mechanisms are heterogeneous, and the difficulty in determining their individual contribution to specific pain types may contribute to poor treatment outcomes in this population. Our review article outlines several pharmacological modalities which may be employed to treat neuropathic pain in SCD patients.

Perioperative pain and addiction interdisciplinary network (PAIN): protocol for the perioperative management of cannabis and cannabinoid-based medicines using a modified Delphi process

INTRODUCTION

At the conception of this study (January 2019), a literature search by the authors found no evidence-based or consensus perioperative guidelines for patients consuming cannabis products, or for those patients in whom a cannabinoid medication could be considered for perioperative treatment. Currently, there is a large global population that consumes cannabis. The availability of cannabis has also increased this decade with greater legal access to cannabis products in some countries such as USA, Canada, Uruguay, Israel, Australia and Germany. There are recognised possible therapeutic benefits for the use of cannabis in patients with chronic pain, chronic neuropathic pain and chemotherapy-induced nausea and vomiting. There are also potential side effects from cannabis use such as psychosis, cannabis hyperemesis syndrome, misuse disorder and cannabis withdrawal syndrome. There is evidence that cannabis may also affect factors in the perioperative period such as monitoring, quality of analgesia, sleep and opioid consumption. Given the large population of persons using cannabis, the heterogeneity of cannabis products and the paucity (and heterogeneity) of perioperative literature surrounding it, perioperative guidelines for cannabis consuming patients are both lacking and necessary. In this paper, we present the design for a modified Delphi technique that has been started with the intent of deriving cannabis perioperative guidelines from the available medical literature and the consensus of multidisciplinary experts.

MATERIALS, METHODS AND ANALYSIS

This study will use a scoping narrative literature review and modified Delphi process to generate cannabis perioperative guidelines. A scoping narrative review of cannabis in the perioperative period by the authors of this proposal was completed and provided to a panel of 17 experts. These experts were recruited for their knowledge and expertise regarding cannabis and/or perioperative medicine. They were asked to rate a series of indications and clinical scenarios in two rounds. During the first round, the expert panel was blinded to each other's participation. During the second round of this process, the expert panel met after being provided with an analysis of the first round's submissions so they could be discussed further and, if possible, reach a further consensus regarding them. Using the results obtained from the Delphi review process, a draft of proposed cannabis perioperative guidelines will be generated. These proposed guidelines will be returned to the expert panel for critiquing prior to their finalisation.

ETHICS AND DISSEMINATION

Study and panellist data will be deidentified and stored as per institutional (Toronto General Hospital) guidelines. Institutional research ethics board provided a waiver for this modified Delphi protocol. Findings will be presented and published in peer-reviewed publications and conferences.

Therapeutic potential of opioid/cannabinoid combinations in humans: Review of the evidence

The endogenous opioid and cannabinoid receptor systems are widely distributed and co-localized throughout central and peripheral nervous system regions. A large body of preclinical evidence suggests that there are functional interactions between these two systems that may be leveraged to address various health conditions. Numerous animal studies have shown that cannabinoid agonists (e.g., delta-9-tetrahydrocannabinol [Δ⁹-THC]) enhance the analgesic effects of µ-opioid analgesics as evidenced by decreasing the opioid dose required for analgesia (i.e., opioid sparing) and extending the duration of the opioid analgesia. In contrast, controlled human laboratory studies and clinical trials have not demonstrated robust analgesic or opioid-sparing effects from opioid-cannabinoid combinations. Meta-analyses of the literature (clinical trials, controlled laboratory studies; some non-controlled studies/case reports) have examined the effects of cannabis/cannabinoids for pain relief in those taking a wide variety of analgesics, including prescription opioid medications. These data do not strongly support the use of cannabinoids for chronic pain nor do prospective studies demonstrate significant cannabinoid-mediated opioid-sparing effects. Preclinical studies have also suggested a role for cannabinoids for the treatment of opioid withdrawal. Controlled laboratory and clinical studies suggest that there may be a modest signal for Δ⁹-THC to suppress some opioid signs and symptoms but they are not completely ameliorated and there may also be concerns around safety of Δ⁹-THC administration in a state of heightened autonomic arousal as occurs with opioid withdrawal. Despite anecdotal and correlational reports suggesting a benefit of cannabis on reducing opioid overdose, there is no strong data supporting this contention and emerging reports have conflicting results. In summary, there is a groundswell of public advocacy supporting the use of cannabis and cannabinoids to replace opioid analgesics or to reduce opioid use; however, the extant controlled clinical data do not support the role of cannabinoids for opioid replacement or opioid-sparing effects when treating opioid use disorder or chronic pain.

Guideline "diagnosis and non interventional therapy of neuropathic pain" of the German Society of Neurology (deutsche Gesellschaft für Neurologie)

2019 the DGN (Deutsche Gesellschaft für Neurology) published a new guideline on the diagnosis and non-interventional therapy of neuropathic pain of any etiology excluding trigeminal neuralgia and CRPS (complex regional pain syndrome). Neuropathic pain occurs after lesion or damage of the somatosensory system. Besides clinical examination several diagnostic procedures are recommended to assess the function of nociceptive A-delta and C-Fibers (skin biopsy, quantitative sensory testing, Laser-evoked potentials, Pain-evoked potentials, corneal confocal microscopy, axon reflex testing). First line treatment in neuropathic pain is pregabalin, gabapentin, duloxetine and amitriptyline. Second choice drugs are topical capsaicin and lidocaine, which can also be considered as primary treatment in focal neuropathic pain. Opioids are considered as third choice treatment. Botulinum toxin can be considered as a third choice drug for focal limited pain in specialized centers only. Carbamazepine and oxcarbazepine cannot be generally  recommended, but might be helpful in single cases. In Germany, cannabinoids can be prescribed, but only after approval of reimbursement. However, the use is not recommended, and can only be considered as off-label therapy within a multimodal therapy concept.