Cannabis-based medicines for chronic neuropathic pain in adults

Clinical Data for the Use of Cannabis-Based Treatments: A Comprehensive Review of the Literature

Objective:

To compile and synthesize the available literature describing medical cannabis use across various disease states.

Data Sources:

PubMed, EBSCO, and Google Scholar searches were conducted using MeSH and/or keywords.

Study Selection and Data Extraction:

Studies were included if they described the use of cannabis-based products and medications in the treatment of a predefined list of disease states in humans and were published in English. The extraction period had no historical limit and spanned through April 2019.

Data Synthesis:

Evidence was compiled and summarized for the following medical conditions: Alzheimer disease, amyotrophic lateral sclerosis, autism, cancer and cancer-associated adverse effects, seizure disorders, human immunodeficiency virus, inflammatory bowel disease, multiple sclerosis (MS), nausea, pain, posttraumatic stress disorder, and hospice care.

Relevance to Patient Care and Clinical Practice:

Based on identified data, the most robust evidence suggests that medical cannabis may be effective in the treatment of chemotherapy-induced nausea and vomiting, seizure disorders, MS-related spasticity, and pain (excluding diabetic neuropathy). Overall, the evidence is inconsistent and generally limited by poor quality. The large variation in cannabis-based products evaluated in studies limits the ability to make direct comparisons. Regardless of the product, a gradual dose titration was utilized in most studies. Cannabis-based therapies were typically well tolerated, with the most common adverse effects being dizziness, somnolence, dry mouth, nausea, and euphoria.

Conclusions:

As more states authorize medical cannabis use, there is an increasing need for high-quality clinical evidence describing its efficacy and safety. This review is intended to serve as a reference for clinicians, so that the risks and realistic benefits of medical cannabis are better understood.

The perils of recreational marijuana use: relationships with mental health among emergency department patients

INTRODUCTION

Marijuana is a commonly used drug in the United States. Many states have legalized the recreational use of marijuana. The effects of marijuana on mental health are unknown.

METHODS

In this prospective survey study, eligible participants included ED patients age 18 and older, who had ever used recreational marijuana. A survey instrument was developed, piloted, and revised. Data collected included reasons for marijuana use, marijuana's perceived effectiveness, and history of mental health conditions, including depression, anxiety, and suicidal thoughts.

RESULTS

Among 303 participants (86% response rate), the median age of first marijuana use was 16 ([IQR 14, 19], range 6-65). The most commonly cited reasons for marijuana use included recreational use (70%; n = 211), to treat anxiety (30%; n = 89), to treat pain (25%; n = 74), and to treat depression (17%; n = 51). Mental health issues were common in the study population. A majority of patients reported anxiety in the last 30 days (59%; n = 176), and a significant minority of patients reported serious depression in the last 30 days (46%; n = 137). Some patients reported suicidal thoughts in the last 30 days (9%; n = 29). Participants who used marijuana more frequently reported more days of anxiety (median 15.5, compared to 1; P = 0.001). Among participants with mental health conditions, most began using marijuana before the onset of the mental health conditions (77%, n = 167). Earlier age of starting to use marijuana was correlated with higher number of years of anxiety or tension in lifetime (r = -0.11, P = 0.05, n = 301). Perceived effects of marijuana use on mental health were variable. Most participants stated that marijuana improved their mental health (62%; n = 163), and some reported that marijuana did not improve their mental health (37%; n = 98).

CONCLUSIONS

Many ED patients have used marijuana, either currently or in the past. Mental health conditions are also common, including anxiety, depression, and suicidal thoughts. Most participants reported marijuana use starting at an age under 18. Marijuana use preceded the onset of mental health conditions in the majority of participants.

Practical Considerations of Hypotheses and Evidence in Cannabis Pharmacotherapy: Refining Expectations of Clinical Endocannabinoid Deficiency

An Industry founded on the promotion of presumed health and wellness benefits of cannabis use continues to grow in the United States, despite the lack of substantial evidence in support of the many claims being made. Several hypotheses exist regarding the role of endocannabinoids in human health and the pertinence of phytocannabinoids as pharmacotherapies for addressing their dysregulation. An opinion is offered regarding the tenuous nature of these assumptions and questions are raised regarding how best to interpret the complex metabolic interplay of the still vaguely defined endocannabinoid system.

Children and Youth Who Use Cannabis for Pain Relief: Benefits, Risks, and Perceptions

We provide up-to-date perspectives on the benefits and risks of medical cannabis for pain management in children and youth. To date, only two studies (a case report and a small observational study) have examined the effects of medical cannabis on pain in children and youth. No controlled trial has commented on long-term safety of medical cannabis. Findings from the recreational cannabis literature reveal significant potential short- and long-term risks of regular cannabis use, including impaired driving, depression, suicidality, psychosis, and tolerance. Despite this, many children and youth are self-medicating with cannabis, and perceive regular cannabis use to be safe. There is a need for better education and counselling of patients regarding the benefits and risks of medical cannabis use.

[Method report of the second update of the guidelines on long-term opioid therapy for chronic noncancer pain]

BACKGROUND

The update of the German S3 guidelines on long-term opioid therapy of chronic noncancer pain (CNCP), the LONTS (AWMF registration number 145/003), was scheduled for February 2020 due to the expiry of the validity period.

METHODS

The guidelines were updated by 28 scientific societies and 2 patient self-help organizations under the coordination of the German Pain Society and the Association of the Scientific Medical Societies in Germany (AWMF).

RESULTS

A systematic literature search was performed in the CENTRAL, MEDLINE and Scopus databases from October 2013 to December 2018. The previous meta-analyses of randomized controlled trials (RCT) of opioids in CNPC syndromes with a study duration of ≥4 weeks were updated. Levels of evidence were assigned according to the Oxford Centre for Evidence-Based Medicine version 2009 classification system. The formulation and strength of recommendations was established in a multistep formalized consensus procedure, in accordance with AWMF rules and standards. The guidelines were reviewed by four experts not involved in the development of the guidelines. The public was given the opportunity to comment on the guidelines. The guidelines were approved by the executive boards of the societies that were engaged in development of the guidelines.

CONCLUSION

The guidelines will be published in several forms: complete and short scientific versions as well as clinical practice and patient versions.

A population-based survey to assess the association between cannabis and quality of life among colorectal cancer survivors

Background

As more states legalize cannabis for medical and recreational use, people increasingly use cannabis to treat medical conditions and associated symptoms. The prevalence and utility of cannabis for cancer-related symptoms may be clarified by examining cannabis use among patients with a common cancer diagnosis. We aimed to determine the prevalence of cannabis use among colorectal cancer (CRC) survivors and its associations with quality of life (QoL) and cancer-related symptomatology.

Methods

A cross-sectional survey of patient-reported QoL outcomes and behaviors, including cannabis use, was conducted within the Patient Outcomes To Advance Learning network’s (PORTAL) CRC Cohort. The cohort included a population-based sample of healthcare system members ≥18 years old diagnosed with adenocarcinoma of the colon or rectum from 2010 through 2016. We assessed the association between cannabis use and QoL using the European Organization for Research and Treatment of Cancer QLQ-C30 summary score.

Results

Of the 1784 respondents, 293 (16.4%) reported cannabis use following CRC diagnosis. Current tobacco smokers were more likely to use cannabis compared to former or never tobacco smokers (adjusted odds ratio [aOR] 2.71, 95% confidence interval [CI] 1.56 to 4.70). Greater alcohol use (> 4 drinks per month versus ≤4 drinks per month) was associated with cannabis use (aOR 2.17, 95% CI 1.65 to 2.85). There was an association between cannabis use and cancer stage at diagnosis, with stage 3 or 4 CRC patients more likely to use cannabis than stage 1 or 2 CRC patients (aOR 1.68, 95% CI 1.25 to 2.25). After adjusting for demographics, medical comorbidities, stage and site of CRC diagnosis, and prescription opioid use, people who used cannabis had significantly lower QoL than people who did not use cannabis (difference of − 6.14, 95% CI − 8.07 to − 4.20).

Conclusion

Among CRC survivors, cannabis use was relatively common, associated with more advanced stages of disease, associated with tobacco and alcohol use, and not associated with better QoL. Clinicians should inquire about cannabis use among their patients and provide evidence-based recommendations for cancer-related symptoms.

Sensitivity of the Fasciae to the Endocannabinoid System: Production of Hyaluronan-Rich Vesicles and Potential Peripheral Effects of Cannabinoids in Fascial Tissue

The demonstrated expression of endocannabinoid receptors in myofascial tissue suggested the role of fascia as a source and modulator of pain. Fibroblasts can modulate the production of the various components of the extracellular matrix, according to type of stimuli: physical, mechanical, hormonal, and pharmacological. In this work, fascial fibroblasts were isolated from small samples of human fascia lata of the thigh, collected from three volunteer patients (two men, one woman) during orthopedic surgery. This text demonstrates for the first time that the agonist of cannabinoid receptor 2, HU-308, can lead to in vitro production of hyaluronan-rich vesicles only 3–4 h after treatment, being rapidly released into the extracellular environment. We demonstrated that these vesicles are rich in hyaluronan after Alcian blue and Toluidine blue stainings, immunocytochemistry, and transmission electron microscopy. In addition, incubation with the antagonist AM630 blocked vesicles production by cells, confirming that release of hyaluronan is a cannabinoid-mediated effect. These results may show how fascial cells respond to the endocannabinoid system by regulating and remodeling the formation of the extracellular matrix. This is a first step in our understanding of how therapeutic applications of cannabinoids to treat pain may also have a peripheral effect, altering the biosynthesis of the extracellular matrix in fasciae and, consequently, remodeling the tissue and its properties.

Nursing Students' Knowledge and Attitudes Regarding Medical Marijuana: A Descriptive Cross-Sectional Study

Marijuana use for medical purposes dates back to ancient times. Despite its high therapeutic potential, its adverse effects have raised important legal restrictions. However, this situation in Spain may soon undergo significant changes, without anyone so far having studied the knowledge and/or the level of acceptance of medical marijuana by future healthcare professionals. The aim of the present study was to determine nursing students’ knowledge of and attitudes towards medical marijuana. A cross-sectional design was used. A total of 578 nursing students from the University of Santiago de Compostela (Spain), ≥18 years old and of both sexes, were invited to complete the Spanish version of the questionnaire “Medical Marijuana” between January and May 2019. A total of 364 students decided to participate in the study. More than 75% of the students agreed with the legalization of medical marijuana, although their knowledge and confidence levels regarding efficacy, safety and drug interactions of medical marijuana were low. Nursing students showed a clear lack of knowledge about medical marijuana and thus, in light of possible regulatory changes, it would be necessary to strengthen the training of nurses with respect to medical marijuana in order to make responsible use of it.

Cannabinoids in Pain Treatment: An Overview

The current landscape contains conflicting reports regarding the use of medical marijuana, creating fields of misinformation and lack of understanding by health care providers about cannabinoids. In this article we provide a dispassionate look at medical marijuana, while providing a clinical overview focusing on pain management. We examine the mechanisms of the endocannabinoid system, along with the pharmacology of cannabinoids. Current research on the use of marijuana for the treatment of pain is reviewed. Finally, recommendations for pain management nurses on integrating research, clinical practice, and U.S. drug policy are made.

Matched pilot study examining cannabis-based dronabinol for acute pain following traumatic injury

Background

To determine whether adjunctive dronabinol, a licensed form of delta-9-tetrahydrocannabinol, reduces opioid consumption when used off-label for managing acute pain following traumatic injury.

Methods

This matched cohort study included patients who were admitted with a traumatic injury between 1 March 2017 and 30 October 2017. The hospital pharmacy database was used to identify patients who received dronabinol (cases), and they were matched 1:1 to patients who did not receive dronabinol (controls) using age, cause of injury and hospital length of stay. The primary outcome, change in opioid consumption, was calculated using morphine milligram equivalents (MME). The change in MME was calculated for cases as total MME over 48 hours with adjunctive dronabinol minus 48 hours prior to dronabinol, and for controls as total MME 48-96 hours from admission minus 0-48 hours from admission. Data are presented as mean and SE or median and IQR. Statistical analysis was performed using paired t-tests and McNemar's tests.

Results

There were 66 patients included: 33 cases and 33 matched controls. Dronabinol was initiated 55 (28-107) hours from admission. Cases and controls were well matched. Cases had a significant reduction in opioid consumption with adjunctive dronabinol (-79 (20) MME, p<0.001), while opioid consumption was unchanged for controls (-9 (20) MME, p=0.63). This resulted in a ninefold greater reduction in opioid consumption for cases versus controls that was statistically different between pairs (p=0.02). Nineteen (58%) cases reported using marijuana; in this subset, opioid consumption was reduced with adjunctive dronabinol (-97 (24) MME, p<0.001) versus a non-significant increase in opioid consumption in matched controls (11 (29) MME, p=0.70); difference between groups, p=0.01.

Conclusions

The results of this study suggest adjunctive dronabinol reduces opioid consumption following traumatic injury. The opioid-sparing effect of dronabinol may be greater in patients who are marijuana users.

Level of evidence

III.

[Treatment of polyneuropathy: autonomic symptoms and pain]

BACKGROUND

The treatment of polyneuropathy includes symptomatic therapy of sensory, motor and autonomic dysfunctions.

AIM

This article provides an overview of the current treatment recommendations for polyneuropathy, focusing on pain.

METHODS

Current treatment guidelines will be discussed based on a literature research.

RESULTS

Calcium-channel anticonvulsants gabapentin/pregabalin as well as antidepressants duloxetine and amitriptyline are recommended as first line therapeutics. Alternatively, topical therapeutics can be used in the case of localized disorders. In individual cases, opioids or other antidepressants/anticonvulsants may be effective. Pharmacological treatment is often limited due to adverse events, which affect the central nervous system in particular.

DISCUSSION

In general, treatment for polyneuropathy should follow a multimodal concept and include the treatment of other symptoms. When choosing pain medication, comorbidities, patient's age and adverse events need to be taken into consideration. Phenotype-based stratification may support specialized pain therapy and achieve the best medical treatment.

Cannabinoids in the Pathophysiology of Skin Inflammation

Cannabinoids are increasingly-used substances in the treatment of chronic pain, some neuropsychiatric disorders and more recently, skin disorders with an inflammatory component. However, various studies cite conflicting results concerning the cellular mechanisms involved, while others suggest that cannabinoids may even exert pro-inflammatory behaviors. This paper aims to detail and clarify the complex workings of cannabinoids in the molecular setting of the main dermatological inflammatory diseases, and their interactions with other substances with emerging applications in the treatment of these conditions. Also, the potential role of cannabinoids as antitumoral drugs is explored in relation to the inflammatory component of skin cancer. In vivo and in vitro studies that employed either phyto-, endo-, or synthetic cannabinoids were considered in this paper. Cannabinoids are regarded with growing interest as eligible drugs in the treatment of skin inflammatory conditions, with potential anticancer effects, and the readiness in monitoring of effects and the facility of topical application may contribute to the growing support of the use of these substances. Despite the promising early results, further controlled human studies are required to establish the definitive role of these products in the pathophysiology of skin inflammation and their usefulness in the clinical setting.

Cannabinoids in the Older Person: A Literature Review

INTRODUCTION

Medical cannabinoids have received significant mainstream media attention in recent times due to an evolving political and clinical landscape. Whilst the efficacy of cannabinoids in the treatment of some childhood epilepsy syndromes is increasingly recognized, medical cannabinoids may also have potential clinical roles in the treatment of older adults. Prescribing restrictions for medical cannabinoids in certain jurisdictions (including the UK) has recently been relaxed. However, few geriatricians have the detailed knowledge or awareness of the potential risks or rewards of utilizing cannabinoids in the older person; even fewer geriatricians have direct experience of using these drugs in their own clinical practice. Older persons are more likely to suffer from medical illness representing potential indications for medical cannabinoids (e.g., pain); equally they may be more vulnerable to any adverse effects.

AIM

This narrative literature review aims to provide a brief introduction for the geriatrician to the potential indications, evidence-base, contra-indications and side effects of medical cannabinoids in older people.

METHODS

A search was conducted of CENTRAL, Medline, Embase, CINAHL and psycINFO, Cochrane and Web of Science databases. Reference lists were hand searched. Abstracts and titles were screened, followed by a full text reading of relevant articles.

RESULTS

35 studies were identified as relevant for this narrative review.

CONCLUSIONS

Cannabinoids demonstrate some efficacy in the treatment of pain and chemotherapy-related nausea; limited data suggest potential benefits in the treatment of spasticity and anxiety. Risks of cannabinoids in older patients appear to be moderate, and their frequency comparable to other analgesic drug classes. However, the quality of research is weak, and few older patients have been enrolled in cannabinoid studies. Dedicated research is needed to determine the efficiency and safety of cannabinoids in older patients.

2-Linoleoylglycerol Is a Partial Agonist of the Human Cannabinoid Type 1 Receptor that Can Suppress 2-Arachidonolyglycerol and Anandamide Activity

Introduction: The cannabinoid type 1 (CB1) receptor and cannabinoid type 2 (CB2) receptor are widely expressed in the body and anandamide (AEA) and 2-arachidonoylglycerol (2-AG) are their best characterized endogenous ligands. The diacylglycerol lipases (diacylglycerol lipase alpha and diacylglycerol lipase beta) not only synthesize essentially all the 2-AG in the body but also generate other monoacylglycerols, including 2-linoleoylglycerol (2-LG). This lipid has been proposed to modulate endocannabinoid (eCB) signaling by protecting 2-AG from hydrolysis. However, more recently, 2-LG has been reported to be a CB1 antagonist. Methods: The effect of 2-LG on the human CB1 receptor activity was evaluated in vitro using a cell-based reporter assay that couples CB1 receptor activation to the expression of the β-lactamase enzyme. Receptor activity can then be measured by a β-lactamase enzymatic assay. Results: When benchmarked against 2-AG, AEA, and arachidonoyl-2'-chloroethylamide (a synthetic CB1 agonist), 2-LG functions as a partial agonist at the CB1 receptor. The 2-LG response was potentiated by JZL195, a drug that inhibits the hydrolysis of monoacylglycerols. The 2-LG response was also fully inhibited by the synthetic CB1 antagonist AM251 and by the natural plant derived antagonist cannabidiol. 2-LG did not potentiate, and only blunted, the activity of 2-AG and AEA. Conclusions: These results support the hypothesis that 2-LG is a partial agonist at the human CB1 receptor and capable of modulating the activity of the established eCBs.

Cannabis-based medicines and the perioperative physician

The increasing availability of cannabis for both recreational and medicinal purposes means that anaesthetists will encounter an increasing number of patients taking cannabis-based medications. The existing evidence base is conflicted and incomplete regarding the indications, interactions and long-term effects of these substances. Globally, most doctors have had little education regarding the pharmacology of cannabis-based medicines, despite the endocannabinoid system being one of the most widespread in the human body. Much is unknown, and much is to be decided, including clarifying definitions and nomenclature, and therapeutic indications and dosing. Anaesthetists, Intensivists, Pain and Perioperative physicians will want to contribute to this evidence base and attempt to harness such therapeutic benefits in terms of pain relief and opiate-avoidance, anti-emesis and seizure control. We present a summary of the pharmacology of cannabis-based medicines including anaesthetic interactions and implications, to assist colleagues encountering these medicines in clinical practice.

Therapeutic Approaches for Peripheral and Central Neuropathic Pain

Neuropathic pain is a chronic secondary pain condition, which is a consequence of peripheral or central nervous (somatosensory) system lesions or diseases. It is a devastating condition, which affects around 7% of the general population. Numerous etiological factors contribute to the development of chronic neuropathic pain. It can originate from the peripheral part of the nervous system such as in the case of trigeminal or postherpetic neuralgia, peripheral nerve injury, painful polyneuropathies, or radiculopathies. Central chronic neuropathic pain can develop as a result of spinal cord or brain injury, stroke, or multiple sclerosis. As first-line pharmacological treatment options, tricyclic antidepressants, serotonin-norepinephrine reuptake inhibitors, and gabapentinoids are recommended. In trigeminal neuralgia, carbamazepine and oxcarbazepine are the first-choice drugs. In drug-refractory cases, interventional, physical, and psychological therapies are available. This review was structured based on a PubMed search of papers published in the field from 2010 until May 2019.

Cannabinoids versus placebo or no intervention for pain: protocol for a systematic review with meta-analysis and trial sequential analysis

INTRODUCTION

Pain is a frequent clinical symptom with significant impact on the patient's well-being. Therefore, adequate pain management is of utmost importance. While cannabinoids have become a more popular alternative to traditional types of pain medication among patients, the quality of evidence supporting the use of cannabinoids has been questioned. The beneficial and harmful effects of cannabinoids in patients with pain is unknown. Accordingly, we aim to assess the efficacy, tolerability and safety of cannabinoids (herbal, plant-derived extracts and synthetic) compared with placebo or no intervention for any type of pain.

METHODS AND ANALYSES

We will conduct a systematic review of randomised clinical trials with meta-analysis and Trial Sequential Analysis to assess the beneficial and harmful effects of cannabinoids in any dose, formulation and duration. We will accept placebo or no treatment as control interventions. We will include participants with any type of pain (acute and chronic pain, cancer-related pain, headache, neuropathic pain or any other types of pain). We will systematically search The Cochrane Library, MEDLINE, Embase, Science Citation Index and BIOSIS for relevant literature. We will follow the recommendations by Cochrane and the Preferred Reporting Items for Systematic Review and Meta-Analysis statement. The risk of systematic errors (bias) and random errors (play of chance) will be assessed. The overall certainty of evidence will be evaluated using the Grading of Recommendations Assessment, Development and Evaluation approach.

ETHICS AND DISSEMINATION

Ethical approval is not a requirement since no primary data will be collected. The findings of this systematic review will be submitted for peer-reviewed publication and disseminated in national and international conferences.

DISCUSSION

Although cannabinoids are now being used to manage different pain conditions, the evidence for the clinical effects are unclear. The present review will systematically assess the current evidence for the benefits and harms of cannabinoids to inform practice and future research.

Using cannabis for pain management after spinal cord injury: a qualitative study

Study design

A descriptive qualitative study.

Objectives

To explore why individuals with spinal cord injury (SCI) choose to use cannabis to manage their pain and their experiences in doing so.

Setting

Community-dwelling adults with SCI in New Zealand.

Methods

Semi-structured interviews were conducted with individuals who had a SCI, experienced pain, and self-reported use of cannabis to manage their pain. Interviews were recorded, transcribed, and subject to thematic analysis.

Results

Eight individuals participated in this study. We interpreted six themes that captured the participants' perspectives regarding their choice to, and perceptions of, using cannabis to manage SCI pain. Participants were motivated to use cannabis when other pain management strategies had been ineffective and were well-informed, knowledgeable cannabis consumers. Participants reported cannabis reduced their pain quickly and enabled them to engage in activities of daily living and participate in life roles without the drowsiness of traditional prescribed pain medication. Despite the positive aspects, participants were concerned about the irregularity of supply and inconsistent dosage.

Conclusions

Findings show that cannabis is used to reduce pain after SCI and enable increased community participation. Findings suggest that future studies examining the efficacy of cannabinoids in managing pain include function and participation outcome measures rather than solely focusing on measuring pain intensity. Focusing on meaningful outcomes may contribute to a greater understanding of the experiences of people with SCI.

[Cannabis medicines in pain management : Interim analysis of the survey accompanying the prescription of cannabis-based medicines in Germany with regard to pain as primarily treated symptom]

BACKGROUND

In Germany, physicians who prescribe cannabis-based medicines at the expense of the statutory health insurance are obliged to take part in an accompanying survey. Pain was the most commonly reported diagnosis, making an interim evaluation for the indication of pain feasible.

METHODS

Patient-related data was transmitted to the German Federal Institute for Drugs and Medical Devices via an online portal. In addition to demographic data, information on the treated disease or symptoms, the course of therapy, adverse reactions and treatment success were evaluated.

RESULTS

A total of 3138 data sets were evaluated for the main diagnosis of pain. Dronabinol was the most frequently (64%) prescribed cannabis-based drug. On average, patients were 57 years old and women and men were equally represented. Patients treated with cannabis flowers were significantly younger (48 years). The proportion of men in this group was 68% and 83% in the group of 18- to 40-year-olds. According to the assessment by treating physicians, pain was significantly improved in 35.5% of the patients. The most frequent side effects (fatigue, dizziness, nausea) corresponded to those already known from the product information of the cannabis-based medicinal products authorized under the pharmaceutical law. Treatment was discontinued in 1179 patients within 1 year.

CONCLUSION

Physicians should comply with their legal obligation to participate in the accompanying survey. Pain is by far the most common diagnosis in cannabis drugs. For about one third of these patients, physicians reported a clear improvement in pain. Due to the amount of data hitherto and the limitations in the accompanying survey, the results should not be overinterpreted in terms of efficacy and should always be related to existing reviews. The lower age and higher proportion of men among patients treated with cannabis flowers were remarkable. At 37.6%, the overall drop-out rate was high. The most frequent side effects related to vigilance and are therefore highly relevant in terms of driving ability, work ability and risk of falling. For a differentiated evaluation of treatment success, more data needs to be available.

[Medicinal cannabis and cannabis-based medication: an appeal to physicians, journalists, health insurances, and politicians for their responsible handling]

Since the adoption of the law of March 6, 2017, any German physician can prescribe medical cannabis flowers and cannabis-based magistral and finished medicinal products. No specific indications for prescriptions are provided in the law. The statutory health insurance companies bear the costs once an application for cost coverage has been approved by the Medical Service of the Health Funds. The German associations of psychiatry (child, adolescents, and adults), neurology, palliative care, addictology, and pain medicine are watching these developments in the media, politics, and medical world with concern due to: the option to prescribe cannabis flowers despite the lack of sound evidence and against the recommendations of the German Medical Association; the lack of distinction between medical cannabis flowers and cannabis-based magistral and finished medical products; the indiscriminately positive reports on the efficacy of cannabis-based medicines for chronic pain and mental disorders; the attempts by the cannabis industry to influence physicians; the increase in potential indications by leaders of medical opinion paid by manufacturers of cannabis-based medicines. The medical associations make the following appeal to journalists: To report on the medical benefits and risks of cannabis-based medicines in a balanced manner. To physicians: to prescribe cannabis-based medicines with caution; to prefer magistral and finished medicinal products over cannabis flowers. To politicians: to consider data according to the standards of evidence-based medicine when making decisions and provide financial support for medical research into cannabis-based medicines.

[Cannabis-based medicines for chronic pain: indications, selection of drugs, effectiveness and safety : Experiences of pain physicians in Saarland]

BACKGROUND

There are uncertainties among physicians with respect to the indications, selection of drugs, effectiveness and safety of cannabis-based medicines for chronic pain.

METHODS

All statutory health insurance pain physicians in Saarland were asked to complete a self-developed questionnaire assessing their experiences with cannabis-based medicines, which they prescribed between 10 March 2017 and 30 November 2018 for adult patients with chronic cancer and non-cancer pain.

RESULTS

All statutory health insurance pain physicians participated in the survey and 13 out of 20 reported having prescribed cannabis-based medicines. The most frequent reasons for prescriptions in 136 patients (1.9% of the patients of the institutions) were failure of established treatment (73%) and desire of the patient (63%). In 35% of patients the type of pain was nociceptive, in 34% neuropathic, in 29% nociceptive and neuropathic and in 13% nociplastic. Dronabinol was prescribed for 95% of the patients and 71% were responders (clinically relevant reduction of pain or of other symptoms). In 29% of patients treatment was terminated due to either a lack of efficacy or adverse events.

CONCLUSION

Statutory health insurance pain physicians in Saarland were reluctant to prescribe cannabis-based medicines. Dronabinol was effective and well-tolerated in the majority of the highly selected patients.

[Position paper on medical cannabis and cannabis-based medicines in pain medicine]

Since March 2017, the prescription of medical cannabis at the expense of the statutory health insurance is possible after approval by the respective medical services. Chronic pain is the most common indication, as health claims data and the accompanying survey show. From the point of view of the law, a prescription is indicated in cases of serious illness, missing or not indicated established therapeutic approaches and a not entirely remote prospect of improvement of the illness or its symptoms. This describes a broader indication spectrum than can currently be based on randomised controlled clinical trials. There is weak evidence of low efficacy for neuropathic pain. For pain related to spasticity and cancer-related pain there is evidence of improvements in quality of life, but effects on pain are of little relevance. For all other indications, only an individual therapeutic trial can be justified based on the available external evidence. However, this usually corresponds to the demand of "a not entirely remote prospect" of a noticeably positive effect of medical cannabis. It is also problematic that almost no long-term studies for the application and efficacy of flowers and extracts are available.Current knowledge on the use of cannabis-based drugs and, more clearly, medical cannabis for chronic pain is insufficient. The increase in the number of countries with marketing authorisations or exemptions for medicinal cannabis or cannabis-based drugs for chronic pain will also pave the way for larger empirical and population-based studies that will further improve the evidence base of research and clinical use.

[Interim analysis of the survey accompanying insurance-covered prescriptions of cannabis-based medicines in Germany]

In Germany, medical doctors who prescribe cannabis medicines at the expense of the statutory health insurance are obliged to take part in a noninterventional survey on the use of these cannabis medicines. The survey collects and evaluates anonymized treatment data and runs until 31 March 2022. Amongst other things, the results of the accompanying survey are the basis on which the Joint Federal Committee (G-BA) regulates the future assumption of treatment costs in the context of a therapy with cannabis medicines in accordance with the Social Code (SGB) V. The transmission of the data for the survey takes place via an online portal operated by the Federal Institute for Drugs and Medical Devices (BfArM). The first data transmission takes place after a treatment period of one year or, if the treatment discontinued before the end of one year, directly after discontinuation of therapy.At the time of the interim evaluation, 01 February 2019, there were 4153 complete datasets collected. Most frequently, the symptom "pain" was treated (69%), followed by spasticity (11%), and anorexia/wasting (8%). The observed adverse reactions correspond with those listed in the product information for the two cannabis-based proprietary medicinal products, Sativex® (GW Pharma Ltd, Salisbury, Wiltshire, UK) and Canemes® (AOP Orphan Pharmaceuticals AG, Vienna, Austria). Most often, insufficient effect was the reason for a discontinuation of treatment. The main indication of pain was already apparent in the licensing procedure for the acquisition of cannabis for medical purposes between the years 2005 and 2016. Further evaluations and subgroup analysis will be carried out when higher case numbers are available.

A National Survey of Marijuana Use Among US Adults With Medical Conditions, 2016-2017

IMPORTANCE

The number of states legalizing marijuana for medical and recreational use is increasing. Little is known regarding how or why adults with medical conditions use it.

OBJECTIVES

To report the prevalence and patterns of marijuana use among adults with and without medical conditions, overall and by sociodemographic group, and to further examine the associations between current marijuana use and the types and number of medical conditions.

DESIGN, SETTING, AND PARTICIPANTS

This survey study used a probability sample of US adults aged 18 years and older from the 2016 and 2017 Behavioral Risk Factor Surveillance System, a telephone-administered survey that collects data from a representative sample of US adult residents across the states regarding health-related risk behaviors, chronic health conditions, and use of preventive services.

MAIN OUTCOMES AND MEASURES

Current (past month) and daily (≥20 days in the last 30 days) marijuana use.

RESULTS

The study sample included 169 036 participants (95 780 female [weighted percentage, 52.0%]). Adults with medical conditions had higher odds of reporting current marijuana use than those without medical conditions (age 18-34 years: adjusted odds ratio, 1.8 [95% CI, 1.5-2.1]; age 35-54 years: adjusted odds ratio, 1.4 [95% CI, 1.2-1.7]; age ≥55 years: adjusted odds ratio, 1.6 [95% CI, 1.3-2.0]), especially among those with asthma, chronic obstructive pulmonary disease, arthritis, cancer, and depression. Among those with medical conditions, the prevalence of marijuana use decreased with increasing age, ranging from 25.2% (95% CI, 22.0%-28.3%) for those aged 18 to 24 years to 2.4% (95% CI, 2.0%-2.8%) for those aged 65 years or older for current marijuana use and from 11.2% (95% CI, 8.7%-13.6%) to 0.9% (95% CI, 0.7%-1.2%), respectively, for daily marijuana use. Most adults who used marijuana (77.5%; 95% CI, 74.7%-80.3%), either with or without medical conditions, reported smoking as their primary method of administration. Adults with medical conditions were more likely than those without medical conditions to report using marijuana for medical reasons (45.5% [95% CI, 41.1%-49.8%] vs 21.8% [95% CI, 17.8%-25.7%]; difference, 23.7% [95% CI, 17.8%-29.6%]) and less likely to report using marijuana for recreational purposes (36.2% [95% CI, 32.1%-40.3%] vs 57.7% [95% CI, 52.6%-62.9%]; difference, -21.5% [95% CI, -28.1% to 14.9%]).

CONCLUSIONS AND RELEVANCE

This study found that marijuana use was more common among adults with medical conditions than those without such conditions. Notably, 11.2% of young adults with medical conditions reported using marijuana on a daily basis. Clinicians should screen for marijuana use among patients, understand why and how patients are using marijuana, and work with patients to optimize outcomes and reduce marijuana-associated risks.

Establishing Practice Risk Management and Outcomes Claims for Medical Marijuana Dispensaries: Questions Legislators Should Ask

In a previous commentary in INNOVATIONS in Pharmacy, the case was made that a major oversight in approving the establishment of medical marijuana programs through commercially and not-for-profit operated dispensaries is the failure to put in place standards for the monitoring and reporting of outcomes. It was pointed out that the evidence base is limited for the range of dosing options, administrative routes and conditions treated. The concern is that the ease that patients have in obtaining medical marijuana certification in many states means that a medical marijuana program is, in effect, little different from a recreational program. Dispensaries understandably focus on sales and returns to investors with scant attention given to tracking and reporting outcomes across the range of conditions and symptoms presented. While this no doubt appeals to investors in reducing administration costs, it makes it virtually impossible to deliver the appropriate and coordinated level of care that patients should expect if a medical marijuana dispensary is to meet it responsibilities in its duty of care. This places dispensaries at malpractice risk. Given this, this commentary focuses on the questions that legislators should ask in licensing medical marijuana dispensaries to ensure they meet a defensible duty of care to their patients.

Efficacy and tolerability of a fixed dose combination of cortex phospholipid liposomes and cyanocobalamin for intramuscular use in peripheral neuropathies

Peripheral neuropathies are frequently encountered in clinical practice and are associated with a major impairment in quality of life. However, their management remains poor, and current therapies are often burdened with major side effects and can present poor efficacy on pain and functionality. Therefore, it has been suggested that the combination of two or more different drugs may improve analgesic efficacy and reduce side effects. Tricortin® 1000 is formulated with 12 mg of Brain cortex phospholipid liposomes + 1000 µg of Cyanocobalamin injectable solution (PL+CNCbl) for intramuscular use and is indicated in the treatment of poly-algo-neuropathic syndromes. This combination exerts a marked neurotrophic action by promoting the synthesis of endogenous phospholipids; moreover, the peculiar formulation optimizes the delivery of CNCbl which has analgesic and neurotrophic action. This paper discusses the pharmacotherapy of peripheral neuropathies, including low-back pain, neck pain, postherpetic neuropathy (PHN) and focuses on the fixed dose combination PL+CNCbl clinical efficacy in association with other treatments or in monotherapy.

Cannabis and multiple sclerosis

Patients with multiple sclerosis have long turned to complementary therapies to manage symptoms that licensed products can only partially control. Around half of patients with multiple sclerosis admit to previous or current cannabis use for medicinal purposes and would endorse legalisation. Despite many governments worldwide relaxing regulations around medicinal cannabis, there remain many unanswered questions as to how clinicians should prescribe or recommend products, and access to pharmaceutical-grade products remains highly restricted. Here we address what adult neurologists need to know about cannabis and its use in multiple sclerosis.

Legalized Cannabis in Colorado Emergency Departments: A Cautionary Review of Negative Health and Safety Effects

Cannabis legalization has led to significant health consequences, particularly to patients in emergency departments and hospitals in Colorado. The most concerning include psychosis, suicide, and other substance abuse. Deleterious effects on the brain include decrements in complex decision-making, which may not be reversible with abstinence. Increases in fatal motor vehicle collisions, adverse effects on cardiovascular and pulmonary systems, inadvertent pediatric exposures, cannabis contaminants exposing users to infectious agents, heavy metals, and pesticides, and hash-oil burn injuries in preparation of drug concentrates have been documented. Cannabis dispensary workers (“budtenders”) without medical training are giving medical advice that may be harmful to patients. Cannabis research may offer novel treatment of seizures, spasticity from multiple sclerosis, nausea and vomiting from chemotherapy, chronic pain, improvements in cardiovascular outcomes, and sleep disorders. Progress has been slow due to absent standards for chemical composition of cannabis products and limitations on research imposed by federal classification of cannabis as illegal. Given these factors and the Colorado experience, other states should carefully evaluate whether and how to decriminalize or legalize non-medical cannabis use.

The Landscape of Chronic Pain: Broader Perspectives

Chronic pain is a global health concern. This special issue on matters related to chronic pain aims to draw on research and scholarly discourse from an eclectic mix of areas and perspectives. The purpose of this non-systematic topical review is to précis an assortment of contemporary topics related to chronic pain and its management to nurture debate about research, practice and health care policy. The review discusses the phenomenon of pain, the struggle that patients have trying to legitimize their pain to others, the utility of the acute-chronic dichotomy, and the burden of chronic pain on society. The review describes the introduction of chronic primary pain in the World Health Organization's International Classification of Disease, 11th Revision and discusses the importance of biopsychosocial approaches to manage pain, the consequences of overprescribing and shifts in service delivery in primary care settings. The second half of the review explores pain perception as a multisensory perceptual inference discussing how contexts, predictions and expectations contribute to the malleability of somatosensations including pain, and how this knowledge can inform the development of therapies and strategies to alleviate pain. Finally, the review explores chronic pain through an evolutionary lens by comparing modern urban lifestyles with genetic heritage that encodes physiology adapted to live in the Paleolithic era. I speculate that modern urban lifestyles may be painogenic in nature, worsening chronic pain in individuals and burdening society at the population level.

Adverse Consequences of Co-Occurring Opioid Use Disorder and Cannabis Use Disorder Compared to Opioid Use Disorder Only

Background: While there is growing interest in the possibility that cannabis may be a partial substitute for opioids, studies have yet to examine whether individuals with co-occurring opioid and cannabis use disorders (OUD and CUD) have less risk of negative outcomes than those with OUD only. Objective: This study sought to compare the sociodemographic and clinical characteristics of patients diagnosed with co-occurring OUD and CUD to patients with OUD only, CUD only, and patients with any other drug use disorders. We hypothesized that co-occurring OUD and CUD would be associated with lower risk of inpatient admissions and emergency department (ED) visits, lower rates of homelessness, and fewer opioid prescriptions. Methods: Comparisons were based on bivariate analyses, logistic and linear multiple regression models of National Veterans Health Administration (VHA) data from Fiscal Year 2012. Results: Of the 234,181 (94% male) patients diagnosed with drug use disorders, 8.6% were diagnosed with co-occurring OUD and CUD; 33.3% with OUD only; 26.5% with CUD only; and 31.6% with other drug use disorders. Compared to the OUD only group (Mean = 4.8 (SD = 8.84)), the group with co-occurring OUD and CUD was associated with a lower number of opioid prescriptions (Mean = 3.79 (SD = 8.22)) (d = -0.16), but higher likelihood of inpatient psychiatric admission (RR = 1.95) and homelessness (RR = 1.52), and no significant difference in ED visits. Conclusions: These data highlight the need to further investigate whether the complex effects of cannabis use on patients with OUD are counterbalanced by potential benefits of reduced in opioid prescribing.

Herbal medicinal products or preparations for neuropathic pain

BACKGROUND

Neuropathic pain is a consequence of damage to the central nervous system (CNS), for example, cerebrovascular accident, multiple sclerosis or spinal cord injury, or peripheral nervous system (PNS), for example, painful diabetic neuropathy (PDN), postherpetic neuralgia (PHN), or surgery. Evidence suggests that people suffering from neuropathic pain are likely to seek alternative modes of pain relief such as herbal medicinal products due to adverse events brought about by current pharmacological agents used to treat neuropathic pain. This review includes studies in which participants were treated with herbal medicinal products (topically or ingested) who had experienced neuropathic pain for at least three months.

OBJECTIVES

To assess the analgesic efficacy and effectiveness of herbal medicinal products or preparations for neuropathic pain, and the adverse events associated with their use.

SEARCH METHODS

We searched CENTRAL and the Cochrane Database of Systematic Reviews, MEDLINE, Embase, CINAHL and AMED to March 2018. We identified additional studies from the reference lists of the retrieved papers. We also searched trials registries for ongoing trials and we contacted experts in the field for relevant data in terms of published, unpublished or ongoing studies.

SELECTION CRITERIA

We included randomised controlled trials (including cross-over designs) of double-blind design, assessing efficacy of herbal treatments for neuropathic pain compared to placebo, no intervention or any other active comparator. Participants were 18 years and above and had been suffering from one or more neuropathic pain conditions, for three months or more.We applied no restrictions to language or gender. We excluded studies monitoring effects of isolated, single chemicals derived from the plant or synthetic chemicals based on constituents of the plant, if they were not administered at a concentration naturally present within the plant.We excluded studies monitoring the effects of traditional Asian medicine and Cannabinoids as well as studies looking at headache or migraine as these treatments and conditions are addressed in distinct reviews.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently considered trials for inclusion, assessed risk of bias, and extracted data. We calculated the risk ratio (RR) and number needed to treat for an additional beneficial outcome (NNTB). The primary outcomes were participant-reported pain relief of 30%, or 50%, or greater, and participant-reported global impression of clinical change (PGIC). We also collected information on adverse events. We assessed evidence using GRADE and created a 'Summary of findings' table.

MAIN RESULTS

We included two studies (128 participants). Both diabetic neuropathy and non-diabetic neuropathic pain conditions were investigated across these two studies.Two herbal medicinal products, namely nutmeg (applied topically as a 125 mL spray for four weeks, containing mace oil 2%, nutmeg oil 14%, methyl salicylate 6%, menthol 6%, coconut oil and alcohol) and St John's wort (taken in capsule form containing 900 μg total hypericin each, taken three times daily, giving a total concentration of 2700 mg for five weeks). Both studies allowed the use of concurrent analgesia.Both reported at least one pain-related outcome but we could not carry out meta-analysis of effectiveness due to heterogeneity between the primary outcomes and could not draw any conclusions of effect. Other outcomes included PGIC, adverse events and withdrawals. There were no data for participant-reported pain relief of 50% or greater or PGIC (moderate and substantial) outcomes.When looking at participant-reported pain relief of 30% or greater over baseline, we observed no evidence of a difference (P = 0.64) in response to nutmeg versus placebo (RR 1.12, 95% confidence interval (CI) 0.69 to 1.85; 48.6% vs 43.2%). We downgraded the evidence for this outcome to very low quality.We observed no change between placebo and nutmeg treatment when looking at secondary pain outcomes. Visual analogue scale (VAS) scores for pain reduction (0 to 100, where 0 = no pain reduction), were 44 for both nutmeg and placebo with standard deviations of 21.5 and 26.5 respectively. There was no evidence of a difference (P = 0.09 to 0.33) in total pain score in response to St John's wort compared to placebo, as there was only a reduction of 1 point when looking at median differences in change from baseline on a 0 to 10-point numeric rating scale.There was a total of five withdrawals out of 91 participants (5%) in the treatment groups compared to six of 91 (6.5%) in the placebo groups, whilst adverse events were the same for both the treatment and placebo groups.We judged neither study as having a low risk of bias. We attributed risk of bias to small study size and incomplete outcome data leading to attrition bias. We downgraded the evidence to very low quality for all primary and secondary outcomes reported in this review. We downgraded the quality of the evidence twice due to very serious limitations in study quality (due to small study size and attrition bias) and downgraded a further level due to indirectness as the included studies only measured outcomes at short-term time points. The results from this review should be treated with scepticism as we have very little confidence in the effect estimate.

AUTHORS' CONCLUSIONS

There was insufficient evidence to determine whether nutmeg or St John's wort has any meaningful efficacy in neuropathic pain conditions.The quality of the current evidence raises serious uncertainties about the estimates of effect observed, therefore, we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect.

Core Outcome Measures in Preclinical Assessment of Candidate Analgesics

All preclinical procedures for analgesic drug discovery involve two components: 1) a "pain stimulus" (the principal independent variable), which is delivered to an experimental subject with the intention of producing a pain state; and 2) a "pain behavior" (the principal dependent variable), which is measured as evidence of that pain state. Candidate analgesics are then evaluated for their effectiveness to reduce the pain behavior, and results are used to prioritize drugs for advancement to clinical testing. This review describes a taxonomy of preclinical procedures organized into an "antinociception matrix" by reference to their types of pain stimulus (noxious, inflammatory, neuropathic, disease related) and pain behavior (unconditioned, classically conditioned, operant conditioned). Particular emphasis is devoted to pain behaviors and the behavioral principals that govern their expression, pharmacological modulation, and preclinical-to-clinical translation. Strengths and weaknesses are compared and contrasted for procedures using each type of behavioral outcome measure, and the following four recommendations are offered to promote strategic use of these procedures for preclinical-to-clinical analgesic drug testing. First, attend to the degree of homology between preclinical and clinical outcome measures, and use preclinical procedures with behavioral outcome measures homologous to clinically relevant outcomes in humans. Second, use combinations of preclinical procedures with complementary strengths and weaknesses to optimize both sensitivity and selectivity of preclinical testing. Third, take advantage of failed clinical translation to identify drugs that can be back-translated preclinically as active negative controls. Finally, increase precision of procedure labels by indicating both the pain stimulus and the pain behavior in naming preclinical procedures.

Effect of cannabis use in people with chronic non-cancer pain prescribed opioids: findings from a 4-year prospective cohort study

BACKGROUND

Interest in the use of cannabis and cannabinoids to treat chronic non-cancer pain is increasing, because of their potential to reduce opioid dose requirements. We aimed to investigate cannabis use in people living with chronic non-cancer pain who had been prescribed opioids, including their reasons for use and perceived effectiveness of cannabis; associations between amount of cannabis use and pain, mental health, and opioid use; the effect of cannabis use on pain severity and interference over time; and potential opioid-sparing effects of cannabis.

METHODS

The Pain and Opioids IN Treatment study is a prospective, national, observational cohort of people with chronic non-cancer pain prescribed opioids. Participants were recruited through community pharmacies across Australia, completed baseline interviews, and were followed up with phone interviews or self-complete questionnaires yearly for 4 years. Recruitment took place from August 13, 2012, to April 8, 2014. Participants were asked about lifetime and past year chronic pain conditions, duration of chronic non-cancer pain, pain self-efficacy, whether pain was neuropathic, lifetime and past 12-month cannabis use, number of days cannabis was used in the past month, and current depression and generalised anxiety disorder. We also estimated daily oral morphine equivalent doses of opioids. We used logistic regression to investigate cross-sectional associations with frequency of cannabis use, and lagged mixed-effects models to examine temporal associations between cannabis use and outcomes.

FINDINGS

1514 participants completed the baseline interview and were included in the study from Aug 20, 2012, to April 14, 2014. Cannabis use was common, and by 4-year follow-up, 295 (24%) participants had used cannabis for pain. Interest in using cannabis for pain increased from 364 (33%) participants (at baseline) to 723 (60%) participants (at 4 years). At 4-year follow-up, compared with people with no cannabis use, we found that participants who used cannabis had a greater pain severity score (risk ratio 1·14, 95% CI 1·01-1·29, for less frequent cannabis use; and 1·17, 1·03-1·32, for daily or near-daily cannabis use), greater pain interference score (1·21, 1·09-1·35; and 1·14, 1·03-1·26), lower pain self-efficacy scores (0·97, 0·96-1·00; and 0·98, 0·96-1·00), and greater generalised anxiety disorder severity scores (1·07, 1·03-1·12; and 1·10, 1·06-1·15). We found no evidence of a temporal relationship between cannabis use and pain severity or pain interference, and no evidence that cannabis use reduced prescribed opioid use or increased rates of opioid discontinuation.

INTERPRETATION

Cannabis use was common in people with chronic non-cancer pain who had been prescribed opioids, but we found no evidence that cannabis use improved patient outcomes. People who used cannabis had greater pain and lower self-efficacy in managing pain, and there was no evidence that cannabis use reduced pain severity or interference or exerted an opioid-sparing effect. As cannabis use for medicinal purposes increases globally, it is important that large well designed clinical trials, which include people with complex comorbidities, are conducted to determine the efficacy of cannabis for chronic non-cancer pain.

FUNDING

National Health and Medical Research Council and the Australian Government.

[Cannabis and cannabinoids-easier access, hype and disappointment : What has been confirmed in therapy?]

BACKGROUND

Cannabis products are being increasingly liberalized all over the world and there is a huge interest in cannabis-based medicine.

OBJECTIVES

Presentation of current studies on the efficacy of different cannabis-based medicine for the treatment of various diseases CURRENT DATA: In German pharmaceutical legislation, nabiximols is approved for the treatment of moderate to severe therapy-resistant spasticity in multiple sclerosis and nabilone is approved for the treatment of therapy-resistant chemotherapy-associated nausea and vomiting. In case of therapy failure cannabinoids, as part of an individual therapeutic attempt, may be considered for the treatment of chronic pain (neuropathic pain, cancer pain, non-neuropathic noncancer pain), cachexia in human immunodeficiency virus as well as for Dravet and Lennox-Gastaut syndrome. From the authors' perspective there is not enough evidence for the use in chemotherapy-associated nausea and vomiting and chronic non-neuropathic pain.

CONCLUSIONS

Currently, a wide use of cannabinoids does not seem probable in the near future. Further studies involving more patients and evaluating long-term effects are necessary.

The Association between Cannabis Product Characteristics and Symptom Relief

Federal barriers and logistical challenges have hindered measurement of the real time effects from the types of cannabis products used medically by millions of patients in vivo. Between 06/06/2016 and 03/05/2018, 3,341 people completed 19,910 self- administrated cannabis sessions using the mobile device software, ReleafApp to record: type of cannabis product (dried whole natural Cannabis flower, concentrate, edible, tincture, topical), combustion method (joint, pipe, vaporization), Cannabis subspecies (C. indica and C. sativa), and major cannabinoid contents (tetrahydrocannabinol, THC; and cannabidiol, CBD), along with real-time ratings of health symptom severity levels, prior-to and immediately following administration, and reported side effects. A fixed effects panel regression approach was used to model the within-user effects of different product characteristics. Patients showed an average symptom improvement of 3.5 (SD = 2.6) on an 11-point scale across the 27 measured symptom categories. Dried flower was the most commonly used product and generally associated with greater symptom relief than other types of products. Across product characteristics, only higher THC levels were independently associated with greater symptom relief and prevalence of positive and negative side effects. In contrast, CBD potency levels were generally not associated with significant symptom changes or experienced side effects.

A Review of Cannabis in Chronic Kidney Disease Symptom Management

PURPOSE OF REVIEW

Physical and psychological symptom burden in patients with advanced chronic kidney disease (CKD) is significantly debilitating; yet, it is often inadequately treated. Legalization of cannabis in Canada may attract increasing interest from patients for its medical use in refractory symptom management, but its indications and long-term adverse health impacts are poorly established, creating a challenge for clinicians to support its use. In this review, we summarize key clinical studies and the level of evidence for nonsynthetic cannabinoids in the treatment of common symptoms encountered in advanced stages of CKD, including chronic pain, nausea and vomiting, anorexia, pruritus, and insomnia.

SOURCES OF INFORMATION

Medline and Embase.

METHODS

A search was conducted in MEDLINE and EMBASE (inception to March 1, 2018) on cannabis and CKD symptoms of interest, complemented with a manual review of bibliographies. Studies that examined synthetic cannabinoids that are manufactured to mimic the effects of ∆9-tetrahydrocannabinol such as dronabinol, levonantradol, nabilone, and ajulemic acid were excluded. We focused on studies with higher level of evidence where available, and quality of studies was graded based on the Oxford Centre for Evidence-based Medicine Levels of Evidence (1a to 5).

FINDINGS

Based on studies conducted in patients without renal impairment, those treated with nonsynthetic cannabinoids were 43% to 300% more likely to report a ≥30% reduction in chronic neuropathic pain compared with placebo. However, there is currently insufficient evidence to recommend nonsynthetic cannabinoids for other medical indications, although preliminary investigation into topical endocannabinoids for uremia-induced pruritus in end-stage renal disease is promising. Finally, any benefits of cannabis may be offset by potential harms in the form of cognitive impairment, increased risk of mortality post-myocardial infarction, orthostatic hypotension, respiratory irritation, and malignancies (with smoked cannabis).

LIMITATIONS

Nonsynthetic cannabinoid preparations were highly variable between studies, sample sizes were small, and study durations were short. Due to an absence of studies conducted in CKD, recommendations were primarily extrapolated from the general population.

IMPLICATIONS

Until further studies are conducted, the role of nonsynthetic cannabinoids for symptom management in patients with CKD should be limited to the treatment of chronic neuropathic pain. Clinicians need to be cognizant that nonsynthetic cannabinoid preparations, particularly smoked cannabis, can pose significant health risks and these must be cautiously weighed against the limited substantiated therapeutic benefits of cannabis in patients with CKD.

Is cannabidiol the ideal drug to treat non-motor Parkinson's disease symptoms?

Parkinson's disease (PD) is a chronic neurodegenerative disorder characterized by motor symptoms such as bradykinesia, rest tremor, postural disturbances, and rigidity. PD is also characterized by non-motor symptoms such as sleep disturbances, cognitive deficits, and psychiatric disorders such as psychosis, depression, and anxiety. The pharmacological treatment for these symptoms is limited in efficacy and induce significant adverse reactions, highlighting the need for better treatment options. Cannabidiol (CBD) is a phytocannabinoid devoid of the euphoriant and cognitive effects of tetrahydrocannabinol, and preclinical and preliminary clinical studies suggest that this compound has therapeutic effect in non-motor symptoms of PD. In the present text, we review the clinical studies of cannabinoids in PD and the preclinical and clinical studies specifically on CBD. We found four randomized controlled trials (RCTs) involving the administration of agonists/antagonists of the cannabinoid 1 receptor, showing that these compounds were well tolerated, but only one study found positive results (reductions on levodopa-induced dyskinesia). We found seven preclinical models of PD using CBD, with six studies showing a neuroprotective effect of CBD. We found three trials involving CBD and PD: an open-label study, a case series, and an RCT. CBD was well tolerated, and all three studies reported significant therapeutic effects in non-motor symptoms (psychosis, rapid eye movement sleep behaviour disorder, daily activities, and stigma). However, sample sizes were small and CBD treatment was short (up to 6 weeks). Large-scale RCTs are needed to try to replicate these results and to assess the long-term safety of CBD.

Understanding the evidence for medical cannabis and cannabis-based medicines for the treatment of chronic non-cancer pain

The use of medical cannabis and cannabis-based medicines has received increasing interest in recent years; with a corresponding surge in the number of studies and reviews conducted in the field. Despite this growth in evidence, the findings and conclusions of these studies have been inconsistent. In this paper, we outline the current evidence for medical cannabis and cannabis-based medicines in the treatment and management of chronic non-cancer pain. We discuss limitations of the current evidence, including limitations of randomised control trials in the field, limits on generalisability of previous findings and common issues such as problems with measurements of dose and type of cannabinoids. We discuss future directions for medicinal cannabinoid research, including addressing limitations in trial design; developing frameworks to monitor for use disorder and other unintended outcomes; and considering endpoints other than 30% or 50% reductions in pain severity.