Cannabinoids in Pain Management and Palliative Medicine

Neuropathic Pain in Cancer: What Are the Current Guidelines?

OPINION STATEMENT

Neuropathic cancer pain is experienced by 30-40% of patients with cancer. It significantly reduces quality of life and overall wellbeing for patients living with and beyond cancer. The underlying mechanisms of neuropathic pain in patients with cancer are complex and involve direct tumour involvement, nerve compression or infiltration, chemotherapy and/or radiotherapy-induced nerve damage, or post-surgical complications. It is crucial for healthcare professionals to assess and manage neuropathic cancer pain effectively. There is increasing recognition that standardisation of neuropathic pain assessment leads to tailored management and improved patient outcomes. Pain management strategies, including medication, interventional analgesia, physical and complementary therapy, can help alleviate neuropathic pain and improve the patient's comfort and quality of life.

Cannabis Sativa Oil Promotes Social Interaction and Ultrasonic Communication by Acting on Oxytocin Pathway

Objective: Cannabis sativa is the most used recreational drug worldwide. In recent years, there has been a growing interest in the potential therapeutic benefits of medicinal cannabis to treat a variety of psychiatric and neurological conditions. In particular, cannabidiol (CBD), a nonpsychoactive cannabis constituent, has been investigated for its potential prosocial effects on behavior, although the molecular mechanisms underlying this effect are still largely unknown. The aim of this study was to investigate the effect of a C. sativa oil CBD rich (CS oil) on social interaction and ultrasonic communication in mice. Study Design: Twenty-seven adult male mice (B6; 129P F2) were treated daily with vehicle or CS oil for 2 weeks. At Day 14, mice were tested for behavior (social interaction test and ultrasonic communication). Forty minutes before the behavioral tests, mice were exposed to intranasal treatment with vehicle or the oxytocin receptor antagonist, L-371,257. After behavioral tests, VH- and CS oil-treated mice were sacrificed, RNA was extracted from the hypothalamus and used for quantitative Real Time-PCR experiments. Results: We found that a 2-week treatment with the CS oil on mice exerted a prosocial effect associated with an increase in ultrasonic vocalizations. These effects were inhibited by pretreating mice with an oxytocin receptor antagonist. In addition, at the molecular level, we found that CS oil treatment caused a significant increase in oxytocin and a decrease in oxytocin receptor expression levels in the brain hypothalamus. Conclusion: Our results suggest that CS oil promotes social behavior by acting on oxytocin pathway.

Pierre M, Belle-Isle L, Gagnon M, Bevan S, Sanchez T, Arlt S, Monahan-Ellison M, O'Hara J, Boivin M, Costiniuk C. Clinical Practice Guidelines for Cannabis and Cannabinoid-Based Medicines in the Management of Chronic Pain and Co-Occurring Conditions

Background: One in five individuals live with chronic pain globally, which often co-occurs with sleep problems, anxiety, depression, and substance use disorders. Although these conditions are commonly managed with cannabinoid-based medicines (CBM), health care providers report lack of information on the risks, benefits, and appropriate use of CBM for therapeutic purposes. Aims: We present these clinical practice guidelines to help clinicians and patients navigate appropriate CBM use in the management of chronic pain and co-occurring conditions. Materials and Methods: We conducted a systematic review of studies investigating the use of CBM for the treatment of chronic pain. Articles were dually reviewed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Clinical recommendations were developed based on available evidence from the review. Values and preferences and practical tips have also been provided to support clinical application. The GRADE system was used to rate the strength of recommendations and quality of evidence. Results: From our literature search, 70 articles met inclusion criteria and were utilized in guideline development, including 19 systematic reviews and 51 original research studies. Research typically demonstrates moderate benefit of CBM in chronic pain management. There is also evidence for efficacy of CBM in the management of comorbidities, including sleep problems, anxiety, appetite suppression, and for managing symptoms in some chronic conditions associated with pain including HIV, multiple sclerosis, fibromyalgia, and arthritis. Conclusions: All patients considering CBM should be educated on risks and adverse events. Patients and clinicians should work collaboratively to identify appropriate dosing, titration, and administration routes for each individual. Systematic Review Registration: PROSPERO no. 135886.

Patients' perspectives on prescription cannabinoid therapies: a cross-sectional, exploratory, anonymous, one-time web-based survey among German patients

Introduction

Since cannabinoids were partially legalized as prescription medicines in Germany in 2017, they are mostly used when conventional therapies do not suffice. Ambiguities remain regarding use, benefits and risks. This web-based survey explored the perspectives of patients whose experiences are not well enough known to date.

Methods

In an anonymous, exploratory, cross-sectional, one-time web-based observational study, participants receiving cannabinoid therapy on prescription documented aspects of their medical history, diagnoses, attitudes toward cannabinoids, physical symptoms, and emotional states. Participants completed the questionnaires twice here: first regarding the time of the survey and then, retrospectively, for the time before their cannabinoid therapy. Participants were recruited in a stratified manner in three German federal states.

Results

N = 216 participants (48.1% female, aged 51.8 ± 14.0) completed the survey, most of which (72%, n = 155) reported pain as their main reason for cannabinoid therapy. When comparing the current state with the retrospectively assessed state, participants reported greater satisfaction with their overall medical therapy (TSQM II: +47.9 ± 36.5, p < 0.001); improved well-being (WHO-5: +7.8 ± 5.9, p < 0.001) and fewer problems in PROMIS subscales (all p < 0.001). Patients suffering primarily from pain (72%, n = 155) reported a reduction of daily pain (NRS: -3.2 ± 2.0, p < 0.001), while participants suffering mainly from spasticity (8%, n = 17) stated decreased muscle spasticity (MSSS: -1.5 ± 0.6, p < 0.001) and better physical mobility (-0.8 ± 0.8, p < 0.001). Data suggests clinically relevant effects for most scores. Participants' attitudes toward cannabinoids (on a 5-point scale) improved (+1.1 ± 1.1, p < 0.001). Most patients (n = 146, 69%) did not report major difficulties with the cannabinoid prescription process, while (n = 27; 19%) had their cannabinoid therapy changed due to side effects.

Discussion

Most participants experienced their therapy with cannabinoids as more effective than their previous therapy. There are extensive limitations to this cross-sectional study: the originally intended representativeness of the dataset was not reached, partly due to the SARS-CoV-2 pandemic; the sample has a larger proportion of privately insured and self-paying patients. Results does not suggest that cannabinoid patients belong to a particular clientele. Effect sizes observed for pain reduction, quality of life, social participation, and other outcomes suggest a therapeutic potential, particularly in the treatment of chronic pain.

Cell death induction and intracellular vesicle formation in human colorectal cancer cells treated with Δ9-Tetrahydrocannabinol

BACKGROUND

Δ9-Tetrahydrocannabinol (Δ9-THC) is a principal psychoactive extract of Cannabis sativa and has been traditionally used as palliative medicine for neuropathic pain. Cannabidiol (CBD), an extract of hemp species, has recently attracted increased attention as a cancer treatment, but Δ9-THC is also requiring explored pharmacological application.

OBJECTIVE

This study evaluated the pharmacological effects of Δ9-THC in two human colorectal cancer cell lines. We investigated whether Δ9-THC treatment induces cell death in human colorectal cancer cells.

METHODS

We performed an MTT assay to determine the pharmacological concentration of Δ9-THC. Annxein V and Western blot analysis confirmed that Δ9-THC induced apoptosis in colorectal cancer cells. Metabolic activity was evaluated using MitoTracker staining and ATP determination. We investigated vesicle formation by Δ9-THC treatment using GW9662, known as a PPARγ inhibitor.

RESULTS

The MTT assay showed that treatment with 40 μM Δ9-THC and above inhibited the proliferation of colorectal cancer cells. Multiple intracytoplasmic vesicles were detected upon microscopic observation, and fluorescence-activated cell sorting analysis showed cell death via G1 arrest. Δ9-THC treatment increased the expression of cell death marker proteins, including p53, cleaved PARP-1, RIP1, and RIP3, suggesting that Δ9-THC induced the death of colorectal cancer cells. Δ9-THC treatment also reduced ATP production via changes in Bax and Bcl-2. Δ9-THC regulated intracytoplasmic vesicle formation by modulating the expression of PPARγ and clathrin, adding that antiproliferative activity of Δ9-THC was also affected.

CONCLUSION

In conclusion, Δ9-THC regulated two functional mechanisms, intracellular vesicle formation and cell death. These findings can help to determine how cannabinoids can be used most effectively to improve the efficacy of cancer treatment.

Effect of Cannabidiol on Cyclooxygenase Type 1 and 2 Expression and Function in Human Neutrophils

Introduction: In this study, the effects of the cannabinoid CBD were assessed on cyclooxygenase (COX)-1 and COX-2 expression and activity in resting and activated human neutrophils (polymorphonuclear [PMN] leukocytes). Methods: COX expression was measured at the mRNA levels, whereas COX activity was assessed by enzyme-linked immunosorbent assay measurement of prostaglandin (PG)E2. In vitro experiments in a standard commercial acellular assay of COX-1/COX-2 activity completed the study. Results: Results show that CBD profoundly inhibits expression of COX-1 and COX-2 mRNA in activated PMN, however, without any significant consequences for PGE2 production. CBD, however, was able to induce a slight but significant direct inhibition of COX-2 in the acellular model. Conclusion: The effects of CBD occur in the μM concentration range, which is attained in humans with therapeutic doses of the drug, suggesting the clinical relevance of these findings.

Review: Cannabinoids as Medicinals

PURPOSE OF REVIEW

There have been many debates, discussions, and published writings about the therapeutic value of cannabis plant and the hundreds of cannabinoids it contains. Many states and countries have attempted, are attempting, or have already passed bills to allow legal use of cannabinoids, especially cannabidiol (CBD), as medicines to treat a wide range of clinical conditions without having been approved by a regulatory body. Therefore, by using PubMed and Google Scholar databases, we have reviewed published papers during the past 30 years on cannabinoids as medicines and comment on whether there is sufficient clinical evidence from well-designed clinical studies and trials to support the use of CBD or any other cannabinoids as medicines.

RECENT FINDINGS

Current research shows that CBD and other cannabinoids currently are not ready for formal indications as medicines to treat a wide range of clinical conditions as promoted except for several exceptions including limited use of CBD for treating two rare forms of epilepsy in young children and CBD in combination with THC for treating multiple-sclerosis-associated spasticity.

SUMMARY

Research indicates that CBD and several other cannabinoids have potential to treat multiple clinical conditions, but more preclinical, and clinical studies and clinical trials, which follow regulatory guidelines, are needed to formally recommend CBD and other cannabinoids as medicines.

The use of medical cannabis in pediatric palliative care: a case series

BACKGROUND

Medical cannabis may be a useful tool for managing treatment-resistant epilepsy and chronic pain, which affect many patients in pediatric palliative care (PPC); however, little evidence is available in this setting.

CASE PRESENTATION

We aimed to describe a clinical experience in a setting where high-level evidence may not be obtained. We report our clinical experience in a pediatric palliative care department in Italy. Caregivers reported changes in intensity and frequency of pain and epilepsy events. Six patients received a titrated plant extract of cannabis sativa for 1 year. Only mild and transient adverse events occurred: drowsiness, euphoria, restlessness and tachycardia; the resolution was either spontaneous or obtained by modifying the administration schedule. Treatment was never discontinued. No overdoses occurred. All patients experienced seizures during the pre-treatment observation period, and obtained a reduction in seizure frequency, although with variable extent while receiving cannabis. In addition, a benefit on pain was observed, based on the caregiver's evaluation, and a reduction of analgesic use.

CONCLUSION

Our experience suggests that a titrated plant extract preparation of medical cannabis may be useful to control treatment-resistant pain and epilepsy in PPC patients.

Cannabidiol: Knowledge, Beliefs, and Experiences of Patients With Cancer

BACKGROUND

Cannabidiol (CBD) is purported to work for a variety of therapeutic indications. Interest in CBD products has significantly increased as patients with cancer seek ways to improve symptom control and quality of life.

OBJECTIVES

The purpose of this study was to explore patients' knowledge of and experience with CBD.

METHODS

A panel of oncology nurse practitioners, an oncologist, and oncology pharmacy specialists developed a survey to capture information about patient knowledge and use of CBD. The initial survey was pilot tested and further refined, resulting in the final item survey. The final survey was administered to 100 participants undergoing or having completed cancer treatment and being followed in a supportive oncology care clinic at a large academic medical center.

FINDINGS

Most patients learned about CBD through a family member or friend. The majority of patients had never tried CBD. The most common reported indications were pain, anxiety, and nausea. Of those who had not tried CBD, the most common reasons included lack of knowledge about CBD and providers not recommending CBD.

Cannabidiol as a Treatment for Chronic Pain: A Survey of Patients' Perspectives and Attitudes

INTRODUCTION

Cannabis products have become easily available and accessible after decriminalization of cannabis for recreational and medicinal use in many states. Cannabidiol (CBD) has been of increasing interest to patients and is being used to self-medicate a variety of ailments. However, very limited information is available to patients and providers to form an educated opinion regarding its indicated use to treat the many conditions this substance has been implied to be helpful for. The aim of this survey was to learn about participants' attitudes and views towards cannabis-based medicine (CBM) with a focus on perception of "CBD" and its potential role for pain management.

MATERIALS AND METHODS

We recruited survey participants from seven pain management clinics in Southern California to learn about their knowledge, beliefs, and personal experience with CBD products. After Institutional Review Board (IRB) review, an internet survey platform was utilized to administer the survey online.

RESULTS

A total of 253 participants answered the survey. Participants were 45.4 ± 13.8 (Mean ± SD) years of age, the majority identified as white (56.1%), had an annual household income of less than $20,000, and were primarily insured by Medicare (22.5%) or Medicaid (43.9%). Among participants, 62.0% reported trying a CBD product [including products containing delta-9-tetrahydrocannabinol (THC)]. The majority responded that these products have helped their pain (59.0%) and allowed them to reduce their pain medications (67.6%), including opioids (53.7%). They reported believing that CBD was a good treatment option (71.1%), not harmful (74.9%), and not addictive (65.3%). About half of participants (51.9%) report that they would be more comfortable with their physician prescribing CBD products. The overall attitude and experience of participants regarding CBD is reported as positive, while 91.9% of people expressed a desire to learn more about it.

SUMMARY

In summary, most participants expressed a positive attitude about CBD products as a treatment option, reported positive outcomes when used for multiple different conditions, and would prefer to obtain information about and prescription for CBD from their physicians.

Cannabinoid Use in Musculoskeletal Illness: a Review of the Current Evidence

PURPOSE OF REVIEW

The use of cannabinoids has increased since legalization of recreational and medical use in the USA. It is likely that many orthopaedic patients consume cannabinoid products during the traumatic or perioperative period. The purpose of this study was to investigate the pre-clinical data evaluating the mechanism of action of cannabidiol (CBD) and Δ9-Tetrahydrocannabinol (Δ9-THC) and to evaluate the current clinical data on the use of cannabinoids in musculoskeletal illness.

RECENT FINDINGS

Recent pre-clinical studies have demonstrated that cannabinoid use and the endocannabinoid system (ECS) has an important role in bone healing and bone homeostasis. There is data that suggests that the use of cannabidiol (CBD) may increase bone healing, whereas the use of Δ9-Tetrahydrocannabinol (Δ9-THC), the major psychoactive ingredient in marijuana, likely inhibits bone metabolism and repair. The clinical implications and consumption of marijuana by orthopaedic patients have not been thoroughly evaluated. Studies have demonstrated concern for negative cardiovascular and psychiatric effects caused by marijuana use, but have not yet elucidated outcomes in the orthopaedic literature. With the recent increase in advertising of CBD products and legalization of marijuana, it is likely that many orthopaedic patients are consuming cannabinoid products. The clinical implications and consumption of these products are unclear. We need more robust and well-designed clinical studies prior to making further recommendations to our patients on the consumption of these products.

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.

[Diabetic polyneuropathy]

Approximately one of three people with diabetes is affected by distal symmetric sensorimotor polyneuropathy (DSPN) which is associated with marked impairment in quality of life due to partly excruciating neuropathic pain on the one hand and painless foot ulcers on the other hand. The prevalence of painful DSPN may reach up to one quarter of patients with diabetes, while DSPN may be asymptomatic in up to half of the patients affected. Regrettably, DSPN still remains underdiagnosed. Typical neuropathic symptoms include pain, paresthesias and numbness particularly in the feet and calves. The management of DSPN includes three cornerstones: (1) lifestyle modification, causal treatment aimed at near-normoglycemia and multifactorial cardiovascular risk intervention, (2) pathogenesis-derived treatment and (3) symptomatic treatment of neuropathic pain. Multimodal pain treatment should not only aim at pain relief, but also allow for improvement in quality of sleep, mobility, and general quality of life.

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.

[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.

[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.

Molecular Basis of Cancer Pain Management: An Updated Review

Pain can have a significantly negative impact on the quality of life of patients. Therefore, patients may resort to analgesics to relieve the pain. The struggle to manage pain in cancer patients effectively and safely has long been an issue in medicine. Analgesics are the mainstay treatment for pain management as they act through various methods on the peripheral and central pain pathways. However, the variability in the patient genotypes may influence a drug response and adverse drug effects that follow through. This review summarizes the observed effects of analgesics on UDP-glucuronosyl (UGT) 2B7 isoenzyme, cytochrome P450 (CYP) 2D6, μ-opioid receptor μ 1 (OPRM1), efflux transporter P-glycoprotein (P-gp) and ATP-binding cassette B1 ABCB1/multiple drug resistance 1 (MDR1) polymorphisms on the mechanism of action of these drugs in managing pain in cancer. Furthermore, this review article also discusses the responses and adverse effects caused by analgesic drugs in cancer pain management, due to the inter-individual variability in their genomes.

Effectiveness and tolerability of THC:CBD oromucosal spray as add-on measure in patients with severe chronic pain: analysis of 12-week open-label real-world data provided by the German Pain e-Registry

Objective: To evaluate effectiveness, tolerability and safety of an oromucosal spray containing Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), as add-on treatment in patients with severe chronic pain (SCP).

Methods: Exploratory analysis of anonymized 12-week routine/open-label data provided by the German Pain e-Registry (GPR) on adult SCP patients treated with THC:CBD oromucosal spray in 2017.

Results: Among those 30.228 cases documented in the GPR in 2017, 800 (2.6%; 57% female, mean ± SD age: 46.3±9.7 years) received a treatment with THC:CBD. All patients fulfilled the legislative preconditions for a treatment with cannabis as medicine as defined by the German Act Amending Narcotics and Other Regulations. THC:CBD-treatment was followed by an aggregated nine-factor symptom relief (ASR-9) improvement at end of week 12 vs baseline of 39.0±26.5% (95%-CI: 36.9–41.1, median: 42, range −41 to 85). A full ASR-9 response (ie, a 50%-improvement in all 9 factors) was found for 123 patients (15.4%), while 488 patients (56.0%) presented with an ≥50% improvement in at least 5 of 9 ASR factors. With a 54.9±17.2% (median: 56%, range: −6 to 85) improvement was significantly superior in the neuropathic pain subgroup (n=497, 62.1%) vs those with mixed (n=249, 31.1%; ASR-9: 18.2±12.0, median: 19, range: −12 to 42%) or nociceptive pain (n=54, 6.8%; ASR-9: −11.9±10.5, median: −11, range: −41% to 12%; p<0.001 for each). 159 patients (19.9%) reported at least one of 206 TEAEs, most of them of mild intensity (n=81.6%). Most frequently reported TEAEs were increased appetite (n=50, 6.3%) and dysgeusia (n=23, 2.9%). TEAE-related discontinuations were reported for 32 patients (4.0%). 113 (14.1%) patients discontinued due to inadequate pain relief, most of them with nociceptive pain (n=40, 74.1%), least with neuropathic pain (n=1, 0.2%; p<0.001).

Conclusion: THC:CBD oromucosal spray proved to be an effective and well-tolerated add-on treatment for patients with elsewhere refractory chronic pain – especially of neuropathic origin.

[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.

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.

Association of Cannabinoid Administration With Experimental Pain in Healthy Adults: A Systematic Review and Meta-analysis

Importance

Cannabinoid drugs are widely used as analgesics, but experimental pain studies have produced mixed findings. The analgesic properties of cannabinoids remain unclear.

Objective

To conduct a systematic review and meta-analysis of the association between cannabinoid drug administration and experimental pain outcomes in studies of healthy adults.

Design, Setting, and Participants

A systematic search of PubMed, EMBASE, MEDLINE, PsycINFO, and CINAHL was conducted from the inception of each database to September 30, 2017. Studies were eligible for inclusion if they met criteria, including healthy participants and an experimentally controlled administration of any cannabinoid preparation in a quantified dose. Studies that used participants with chronic pain were excluded. Data extracted included study characteristics, cannabinoid types and doses, sex composition, and outcomes. Study quality was assessed using a validity measure previously established in published reviews. Random-effects meta-analyses were used to pool data and generate summary estimates.

Main Outcomes and Measures

Experimental pain threshold, pain tolerance, pain intensity, pain unpleasantness, and mechanical hyperalgesia.

Results

Eighteen placebo-controlled studies (with 442 participants) were identified. Of the 442 participants, 233 (52.7%) were male and 209 (47.3%) were female. For sample ages, 13 (72%) of the 18 studies reported a mean sample age (26.65 years), 4 (22%) reported a range, and 1 (6%) reported a median value. The search yielded sufficient data to analyze 18 pain threshold comparisons, 22 pain intensity comparisons, 9 pain unpleasantness comparisons, 13 pain tolerance comparisons, and 9 mechanical hyperalgesia comparisons. Cannabinoid administration was associated with small increases in pain threshold (Hedges g = 0.186; 95% CI, 0.054-0.318; P = .006), small to medium increases in pain tolerance (Hedges g = 0.225; 95% CI, 0.015-0.436; P = .04), and a small to medium reduction in the unpleasantness of ongoing experimental pain (Hedges g = 0.288; 95% CI, 0.104-0.472; P = .002). Cannabinoid administration was not reliably associated with a decrease in experimental pain intensity (Hedges g = 0.017; 95% CI, -0.120 to 0.154; P = .81) or mechanical hyperalgesia (Hedges g = 0.093; 95% CI, -0.059 to 0.244; P = .23). The mean quality rating across studies was good.

Conclusions and Relevance

Cannabinoid drugs may prevent the onset of pain by producing small increases in pain thresholds but may not reduce the intensity of experimental pain already being experienced; instead, cannabinoids may make experimental pain feel less unpleasant and more tolerable, suggesting an influence on affective processes. Cannabis-induced improvements in pain-related negative affect may underlie the widely held belief that cannabis relieves pain.

Personal experience and attitudes of pain medicine specialists in Israel regarding the medical use of cannabis for chronic pain

Introduction

The scientific study of the role of cannabis in pain medicine still lags far behind the growing use driven by public approval. Accumulated clinical experience is therefore an important source of knowledge. However, no study to date has targeted physicians who actually use cannabis in their daily practice.

Methods

Registered, active, board-certified pain specialists in Israel (n=79) were asked to complete a Web-based survey. The survey was developed using the Qualtrics Online Survey Software. Questions were formulated as multiple-choice questions, and these addressed three areas of interest: 1) doctors’ personal experience; 2) the role of cannabis in pain medicine; and 3) cannabis medicalization and legalization.

Results

Sixty-four percent of all practicing pain specialists in Israel responded. Almost all prescribe cannabis. Among them, 63% find cannabis moderately to highly effective, 56% have encountered mild or no side effects, and only 5% perceive it as significantly harmful. Common indications are neuropathic pain (65%), oncological pain (50%), arthralgias (25%), and any intractable pain (29%). Leading contraindications are schizophrenia (76%), pregnancy/breastfeeding (65%), and age <18 years (59%). Only 12% rated cannabis as more hazardous than opiates. On a personal note, 45% prefer cannabis for themselves or a family member. Lastly, 54% would like to see cannabis legalized in Israel.

Conclusion

In this survey, pain clinicians experienced in prescribing cannabis over prolonged periods view it as an effective and relatively safe treatment for chronic pain, based on their own experience. Their responses suggest a possible change of paradigm from using cannabis as the last resort.