Current Therapeutic Cannabis Controversies and Clinical Trial Design Issues

Comparative Lipid Peroxidation and Apoptosis in Embryo-Larval Zebrafish Exposed to 3 Azole Fungicides, Tebuconazole, Propiconazole, and Myclobutanil, at Environmentally Relevant Concentrations

Azole fungicides have entered the aquatic environment through agricultural and residential runoff. In the present study, we compared the off-target toxicity of tebuconazole, propiconazole, and myclobutanil using embryo-larval zebrafish as a model. The aim of the present study was to investigate the relative toxicity of tebuconazole, propiconazole, and myclobutanil using multiple-level endpoints such as behavioral endpoints and enzymatic and molecular biomarkers associated with their mode of action. Zebrafish embryos were exposed to azoles at environmentally relevant and high concentrations, 0.3, 1.0, and 1000 µg/L, starting at 5 h postfertilization (hpf) up to 48 hpf, as well as 5 d postfertilization (dpf). Relative mRNA expressions of cytochrome P450 family 51 lanosterol-14α-demethylase, glutathione S-transferase, caspase 9, phosphoprotein p53, and BCL2-associated X protein were measured to assess toxicity attributable to fungicides at the mRNA level, whereas caspase 3/7 (apoptosis) and 3,4-methylene​dioxy​amphetamine (lipid peroxidation) levels were measured at the enzymatic level. Furthermore, mitochondrial dysfunction was measure through the Mito Stress test using the Seahorse XFe24 at 48 hpf. In addition, light to dark movement behavior was monitored at 5 dpf using Danio Vision® to understand adverse effects at the organismal level. There was no significant difference in the light to dark behavior with exposure to azoles compared to controls. The molecular biomarkers indicated that propiconazole and myclobutanil induced lipid peroxidation, oxidative stress, and potentially apoptosis at environmentally relevant concentrations (0.3 and 1 µg/L). The results from the mitochondrial respiration assay indicated a slight decrease in spare respiratory capacity with an acute exposure (48 hpf) to all 3 azoles at 1000 µg/L. Based on the present results, propiconazole and myclobutanil are acutely toxic compared to tebuconazole in aquatic organisms at environmentally relevant concentrations. Environ Toxicol Chem 2019;38:1455-1466. © 2019 SETAC.

Efficacy and safety of cannabidiol followed by an open label add-on of tetrahydrocannabinol for the treatment of chronic pain in patients with rheumatoid arthritis or ankylosing spondylitis: protocol for a multicentre, randomised, placebo-controlled study

INTRODUCTION

Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) are chronic, systemic, inflammatory diseases, primarily in the musculoskeletal system. Pain and fatigue are key symptoms of RA and AS. Treatment presents a clinical challenge for several reasons, including the progressive nature of the diseases and the involvement of multiple pain mechanisms. Moreover, side effects of pain treatment pose an implicit risk. Currently, no well-controlled studies have investigated how medical cannabis affects pain and cognitive functions in RA and AS. The present study aims to evaluate the efficacy and safety of medical cannabis in the treatment of persistent pain in patients with RA and AS with low disease activity.

METHODS AND ANALYSIS

A double-blinded, randomised, placebo-controlled study of cannabidiol (CBD), followed by an open label add-on of tetrahydrocannabinol (THC) with collection of clinical data and biological materials in RA and AS patients treated in routine care. The oral treatment with CBD in the experimental group is compared with placebo in a control group for 12 weeks, followed by an observational 12-week period with an open label add-on of THC in the primary CBD non-responders. Disease characteristics, psychological parameters, demographics, comorbidities, lifestyle factors, blood samples and serious adverse events are collected at baseline, after 12 and 24 weeks of treatment, and at a follow-up visit at 36 weeks. Data will be analysed in accordance with a predefined statistical analysis plan.

ETHICS AND DISSEMINATION

The Danish Ethics Committee (S-20170217), the Danish Medicines Agency (S-2018010018) and the Danish Data Protection Agency approved the protocol. The project is registered in the European Clinical Trials Database (EudraCT 2017-004226-15). All participants will give written informed consent to participate prior to any study-related procedures. The results will be presented at international conferences and published in peer-reviewed journals.

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.

Adverse outcome pathway of developmental neurotoxicity resulting from prenatal exposures to cannabis contaminated with organophosphate pesticide residues

There is growing concern that increased use of medical and recreational cannabis may result in increased exposure to contaminants on the cannabis, such as pesticides. Several states are moving towards implementing robust regulation of the sales, cultivation, and manufacture of cannabis products. However, there are challenges with creating health-protective regulations in an industry that, to date, has been largely unregulated. The focus of this publication is a theoretical examination of what may happen when women are exposed pre-conceptually or during pregnancy to cannabis contaminated with pesticides. We propose an adverse outcome pathway of concomitant prenatal exposure to cannabinoids and the organophosphate pesticide chlorpyrifos by curating what we consider to be the key events at the molecular, cellular, and tissue levels that result in developmental neurotoxicity. The implications of this adverse outcome pathway underscore the need to elucidate the potential developmental neurotoxicity that may result from prenatal exposure to pesticide-contaminated cannabis.

A survey of the attitudes, beliefs and knowledge about medical cannabis among primary care providers

Background

Healthcare providers play a critical role in facilitating patient access to medical cannabis. However, previous surveys suggest only a minority of providers believe that medical cannabis confers benefits to patients. Significant new knowledge about the potential benefits and harms of medical cannabis has recently emerged. Understanding current attitudes and beliefs of providers may provide insight into the ongoing challenges they face as states expand access to medical cannabis.

Methods

We conducted an electronic survey of primary care providers in a large Minnesota-based healthcare system between January 23 and February 5, 2018. We obtained information about provider characteristics, attitudes and beliefs about medical cannabis, provider comfort level in answering patient questions about medical cannabis, and whether providers were interested in receiving additional education.

Results

Sixty-two providers completed the survey (response rate 31%; 62/199). Seventy-six percent of respondents were physicians and the average age was 46.3 years. A majority of providers believed (“strongly agree” or “somewhat agree”) that medical cannabis was a legitimate medical therapy (58.1%) and 38.7% believed that providers should be offering to patients for managing medical conditions. A majority (> 50%) of providers believed that medical cannabis was helpful for treating the qualifying medical conditions of cancer, terminal illness, and intractable pain. A majority of providers did not know if medical cannabis was effective for managing nearly one-half of the other state designated qualifying medical conditions. Few believed that medical cannabis improved quality of life domains. Over one-third of providers believed that medical cannabis interacted with medical therapies. One-half of providers were not ready to or did not want to answer patient questions about medical cannabis, and the majority of providers wanted to learn more about it.

Conclusions

Healthcare providers generally believe that medical cannabis is a legitimate medical therapy. Provider knowledge gaps about the effectiveness of medical cannabis for state designated qualifying conditions need to be addressed, and accurate information about the potential for drug interactions needs to be disseminated to address provider concerns. Clinical trial data about how medical cannabis improves patient quality of life domains is desperately needed as this information can impact clinical decision-making.

Electronic supplementary material

The online version of this article (10.1186/s12875-019-0906-y) contains supplementary material, which is available to authorized users.

Medicinal Cannabis-Potential Drug Interactions

The endocannabinoids system (ECS) has garnered considerable interest as a potential therapeutic target in various carcinomas and cancer-related conditions alongside neurodegenerative diseases. Cannabinoids are implemented in several physiological processes such as appetite stimulation, energy balance, pain modulation and the control of chemotherapy-induced nausea and vomiting (CINV). However, pharmacokinetics and pharmacodynamics interactions could be perceived in drug combinations, so in this short review we tried to shed light on the potential drug interactions of medicinal cannabis. Hitherto, few data have been provided to the healthcare practitioners about the drug–drug interactions of cannabinoids with other prescription medications. In general, cannabinoids are usually well tolerated, but bidirectional effects may be expected with concomitant administered agents via affected membrane transporters (Glycoprotein p, breast cancer resistance proteins, and multidrug resistance proteins) and metabolizing enzymes (Cytochrome P450 and UDP-glucuronosyltransferases). Caution should be undertaken to closely monitor the responses of cannabis users with certain drugs to guard their safety, especially for the elderly and people with chronic diseases or kidney and liver conditions.

Oral Ingestion of Cannabis sativa: Risks, Benefits, and Effects on Malaria-Infected Hosts

Background: The emergence of a multidrug-resistant strain of Plasmodium falciparum (Pf Pailin) raises concern about malaria control strategies. Unfortunately, the role(s) of natural plants/remedies in curtailing malaria catastrophe remains uncertain. The claims of potential antimalarial activity of Cannabis sativa in vivo have not been well established nor the consequences defined. This study was, therefore, designed to evaluate the effects of whole cannabis consumption on malaria-infected host.

Methods: Thirty mice were inoculated with dose of 1×10⁷ chloroquine-resistant Plasmodium berghei ANKA-infected erythrocyte and divided into six treatment groups. Cannabis diet formulations were prepared based on weighted percentages of dried cannabis and standard mice diet and the study animals were fed ad libitum. Chemosuppression of parasitemia, survival rates, parasite clearance, and recrudescence time were evaluated. Histopathological studies were performed on the prefrontal cortex (PFC) and hippocampus of the animals after 14 days' consumption of cannabis diet formulation by naive mice.

Results: There was a significant difference (p<0.05) in the day-4 chemosuppression of parasitemia between the animals that were fed C. sativa and chloroquine relative to the untreated controls. There was also a significant difference in the survival rate (p<0.05) of animals fed C. sativa diet (40%, 20%, 10%, and 1%) in contrast to control animals on standard mice diet. A parasite clearance time of 2.18±0.4 was recorded in the chloroquine treatment group, whereas recrudescence in chloroquine group occurred on day 7. There were slight histomorphological changes in the PFC and cell densities of the dentate gyrus of the hippocampus of animals that were fed C. sativa.

Conclusions:C. sativa displayed mild antimalarial activity in vivo. There was evident reduction in symptomatic manifestation of malaria disease, though unrelated to levels of parasitemia. This disease tolerance status may be beneficial, but may also constitute a transmission burden through asymptomatic carriage of parasites by habitual cannabis users.

Prevalence and Sociodemographic Correlates of Adolescent Use and Polyuse of Combustible, Vaporized, and Edible Cannabis Products

IMPORTANCE

Cannabis legalization and commercialization have introduced novel alternative cannabis products, including edible and vaporized cannabis that might appeal to youth and be associated with polyuse (ie, use of ≥2 different products).

OBJECTIVE

To investigate the prevalence, patterns, and sociodemographic correlates of cannabis product use across combustible, edible, and vaporized administration methods, including polyuse of cannabis via multiple administration methods.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional survey study included 10th-grade students from 10 Los Angeles, California, area high schools from January 2 through October 6, 2015. Students were recruited from respondents in the Happiness and Health Study, an ongoing prospective cohort study in the 10 high schools. Students not in school during administration of the pencil-and-paper survey completed abbreviated surveys by telephone, internet, or mail. Data were analyzed from July 17, 2017, through July 12, 2018.

EXPOSURES

Self-reported sex, race/ethnicity, and socioeconomic status (SES). Students with high SES had parents who attained college or a higher educational level and were ineligible for free or subsidized lunch; those with low SES had parents with lower educational attainment or were eligible for free or subsidized lunch.

MAIN OUTCOMES AND MEASURES

Self-report of ever use (yes or no) and past 30-day use (yes or no) status and frequency of use (days in past 30 days) of combustible, edible, and vaporized cannabis.

RESULTS

The sample included 3177 tenth-grade students (93.5% of study enrollees); among these students, 1715 (54.0%) were girls and the mean (SD) age was 16.1 (0.4) years. Among those with available demographic data, respondents were diverse in race/ethnicity (537 [17.2%] Asian; 149 [4.8%] black; 1510 [48.3%] Hispanic; 507 [16.2%] white; 207 [6.6%] multiethnic/multiracial; and 216 [6.9%] other) and included 1654 (60.1%) with a low SES. Prevalence of ever use was highest for combustible products (993 [31.3%]), followed by edible (676 [21.3%]) and vaporized (333 [10.5%]) products. A similar pattern was found for past 30-day use (426 [13.4%] for combustible, 249 [7.8%] for edible, and 156 [4.9%] for vaporized cannabis). Among participants who reported using cannabis in the past 30 days, mean frequency of use of combustible cannabis was higher by 2.65 days (95% CI, 1.40-3.91 days, P = .001) than the mean frequency of use for edible cannabis and 1.75 days higher (95% CI, 0.59-2.90 days, P = .003) than frequency of use for vaporized cannabis. Most cannabis users (665 [61.7%]) used multiple administration methods, and 260 (8.2%) used all 3 methods. Boys had higher prevalence of ever use for vaporized (170 [11.6%] vs 163 [9.5%]) but not combustible (459 [31.4%] vs 534 [31.1%]) or edible (303 [20.7%] vs 373 [21.7%]) cannabis. Respondents with low SES had higher prevalence of ever use for combustible (614 [37.1%] vs 242 [22.0%]) and edible (408 [24.7%] vs 166 [15.1%]) but not vaporized (186 [11.2%] vs 93 [8.5%]) cannabis.

CONCLUSIONS AND RELEVANCE

Among 10th-grade students in Los Angeles, use of cannabis via alternative administration methods was of appreciable prevalence, predominately reported in conjunction with other cannabis products and unequally distributed across sociodemographic strata. Prevention programs and regulatory restrictions addressing the spectrum of cannabis products might benefit pediatric public health.

Cannabis contaminants: sources, distribution, human toxicity and pharmacologic effects

There has been a resurgence in interest and use of the cannabis plant for medical purposes. However, an in-depth understanding of plant contaminants and toxin effects on stability of plant compounds and human bioavailability is needed. This systematic review aims to assess current understanding of the contaminants of cannabis and their effect on human health, leading to the identification of knowledge gaps for future investigation. A systematic search of seven indexed biological and biomedical databases and the Cochrane library was undertaken from inception up to December 2017. A qualitative synthesis of filtered results was undertaken after independent assessment for eligibility by two reviewers. The common cannabis contaminants include microbes, heavy metals and pesticides. Their direct human toxicity is poorly quantified but include infection, carcinogenicity, reproductive and developmental impacts. Cannabis dosing formulations and administration routes affect the transformation and bioavailability of contaminants. There may be important pharmacokinetic interactions between the alkaloid active ingredients of cannabis (i.e. phytocannabinoids) and contaminants but these are not yet identified nor quantified. There is significant paucity in the literature describing the prevalence and human impact of cannabis contaminants. Advances in the availability of cannabis globally warrant further research in this area, particularly when being used for patients.

The Intricate Influence of the Placebo Effect on Medical Cannabis and Cannabinoids

The botanical drug cannabis flos (inflorescence of Cannabis sativa L.) has a unique popular status as being a potent recreational drug and bona fide universal remedy (panacea). Generally, cannabinoids exert therapeutic effects in a broad range of pathophysiologies related to inflammation, pain, metabolic and stress-related conditions in preclinical animal models. However, the translation of such data to humans still lacks an evidence-based foundation. Motivated by the booming cannabis manufacturing industry and the increasing worldwide self-therapy by patients, there are cumulative accounts about broad therapeutic effects of cannabis and legal cannabinoids like cannabidiol (CBD) beyond statistical evidence. The numerous affirming anecdotal reports by patients pose a challenge to physicians and legal authorities. Moreover, the lack of standardization of cannabis products and widely missing randomized double-blind placebo-controlled clinical trials largely hinder the scientific assessment of medical cannabis in humans. Given the recent insight that the endocannabinoid system is mediating, at least in part, a placebo effect, psychoactive cannabis and cannabinoids could exert complex neuropharmacological actions. As discussed in this commentary, the meaning response may play a role in the broad palliative and therapeutic effects of medical cannabis unprecedented by other phytopharmaceuticals.

A Twitter-based survey on marijuana concentrate use

AIMS

The purpose of this paper is to analyze characteristics of marijuana concentrate users, describe patterns and reasons of use, and identify factors associated with daily use of concentrates among U.S.-based cannabis users recruited via a Twitter-based online survey.

METHODS

An anonymous Web-based survey was conducted in June 2017 with 687 U.S.-based cannabis users recruited via Twitter-based ads. The survey included questions about state of residence, socio-demographic characteristics, and cannabis use including marijuana concentrates. Multiple logistic regression analyses were conducted to identify characteristics associated with lifetime and daily use of marijuana concentrates.

RESULTS

Almost 60% of respondents were male, 86% were white, and the mean age was 43.0 years. About 48% reported marijuana concentrate use. After adjusting for multiple testing, significant predictors of concentrate use included: living in "recreational" (AOR = 2.04; adj. p = .042) or "medical, less restrictive" (AOR = 1.74; adj. p = .030) states, being younger (AOR = 0.97, adj. p = .008), and daily herbal cannabis use (AOR = 2.57, adj. p = .008). Out of 329 marijuana concentrate users, about 13% (n = 44) reported daily/near daily use. Significant predictors of daily concentrate use included: living in recreational states (AOR = 3.59, adj. p = .020) and using concentrates for therapeutic purposes (AOR = 4.34, adj. p = .020).

CONCLUSIONS

Living in states with more liberal marijuana policies is associated with greater likelihood of marijuana concentrate use and with more frequent use. Characteristics of daily users, in particular, patterns of therapeutic use warrant further research with community-recruited samples.

Cannabis, from plant to pill

The therapeutic application of cannabis is attracting substantial public and clinical interest. The cannabis plant has been described as a veritable 'treasure trove', producing more than 100 different cannabinoids, although the focus to date has been on the psychoactive molecule delta-9-tetraydrocannabinol (THC) and cannabidiol (CBD). Other numerous secondary metabolites of cannabis, the terpenes, some of which share the common intermediary geranyl diphosphate (GPP) with the cannabinoids, are hypothesized to contribute synergistically to their therapeutic benefits, an attribute that has been described as the 'entourage effect'. The effective delivery of such a complex multicomponent pharmaceutical relies upon the stable genetic background and standardized growth of the plant material, particularly if the raw botanical product in the form of the dried pistillate inflorescence (flos) is the source. Following supercritical CO₂ extraction of the inflorescence (and possibly bracts), the secondary metabolites can be blended to provide a specific ratio of major cannabinoids (THC : CBD) or individual cannabinoids can be isolated, purified and supplied as the pharmaceutical. Intensive breeding strategies will provide novel cultivars of cannabis possessing elevated levels of specific cannabinoids or other secondary metabolites.

Practical considerations in medical cannabis administration and dosing

Cannabis has been employed medicinally throughout history, but its recent legal prohibition, biochemical complexity and variability, quality control issues, previous dearth of appropriately powered randomised controlled trials, and lack of pertinent education have conspired to leave clinicians in the dark as to how to advise patients pursuing such treatment. With the advent of pharmaceutical cannabis-based medicines (Sativex/nabiximols and Epidiolex), and liberalisation of access in certain nations, this ignorance of cannabis pharmacology and therapeutics has become untenable. In this article, the authors endeavour to present concise data on cannabis pharmacology related to tetrahydrocannabinol (THC), cannabidiol (CBD) et al., methods of administration (smoking, vaporisation, oral), and dosing recommendations. Adverse events of cannabis medicine pertain primarily to THC, whose total daily dose-equivalent should generally be limited to 30mg/day or less, preferably in conjunction with CBD, to avoid psychoactive sequelae and development of tolerance. CBD, in contrast to THC, is less potent, and may require much higher doses for its adjunctive benefits on pain, inflammation, and attenuation of THC-associated anxiety and tachycardia. Dose initiation should commence at modest levels, and titration of any cannabis preparation should be undertaken slowly over a period of as much as two weeks. Suggestions are offered on cannabis-drug interactions, patient monitoring, and standards of care, while special cases for cannabis therapeutics are addressed: epilepsy, cancer palliation and primary treatment, chronic pain, use in the elderly, Parkinson disease, paediatrics, with concomitant opioids, and in relation to driving and hazardous activities.

Medical Cannabis: The Oncology Nurse's Role in Patient Education About the Effects of Marijuana on Cancer Palliation

BACKGROUND

Cannabis, also known as marijuana, is legal either medicinally or recreationally in 29 states and the District of Columbia, with a majority of the U.S. adult population now living in states where cannabis is legal for medicinal use. As an advocate for patient autonomy and informed choice, the oncology nurse has an ethical responsibility to educate patients about and support their use of cannabis for palliation.
.

OBJECTIVES

This article aims to discuss the human endocannabinoid system as a basis for better understanding the palliative and curative nature of cannabis as a medicine, as well as review cannabis delivery methods and the emerging role of the oncology nurse in this realm.
.

METHODS

This article examines the literature and uses a theoretical-conceptual method to explore the oncology nurse's role in supporting the use of medicinal cannabis by patients with cancer. 
.

FINDINGS

The oncology nurse can play a pivotal role in supporting patients' use of cannabis for palliation.

Cannabinoids Modulate Neuronal Activity and Cancer by CB1 and CB2 Receptor-Independent Mechanisms

Cannabinoids include the active constituents of Cannabis or are molecules that mimic the structure and/or function of these Cannabis-derived molecules. Cannabinoids produce many of their cellular and organ system effects by interacting with the well-characterized CB1 and CB2 receptors. However, it has become clear that not all effects of cannabinoid drugs are attributable to their interaction with CB1 and CB2 receptors. Evidence now demonstrates that cannabinoid agents produce effects by modulating activity of the entire array of cellular macromolecules targeted by other drug classes, including: other receptor types; ion channels; transporters; enzymes, and protein- and non-protein cellular structures. This review summarizes evidence for these interactions in the CNS and in cancer, and is organized according to the cellular targets involved. The CNS represents a well-studied area and cancer is emerging in terms of understanding mechanisms by which cannabinoids modulate their activity. Considering the CNS and cancer together allow identification of non-cannabinoid receptor targets that are shared and divergent in both systems. This comparative approach allows the identified targets to be compared and contrasted, suggesting potential new areas of investigation. It also provides insight into the diverse sources of efficacy employed by this interesting class of drugs. Obtaining a comprehensive understanding of the diverse mechanisms of cannabinoid action may lead to the design and development of therapeutic agents with greater efficacy and specificity for their cellular targets.

User characteristics and effect profile of Butane Hash Oil: An extremely high-potency cannabis concentrate

BACKGROUND

Recent reports suggest an increase in use of extremely potent cannabis concentrates such as Butane Hash Oil (BHO) in some developed countries. The aims of this study were to examine the characteristics of BHO users and the effect profiles of BHO.

DESIGN

Anonymous online survey in over 20 countries in 2014 and 2015. Participants aged 18 years or older were recruited through onward promotion and online social networks. The overall sample size was 181,870. In this sample, 46% (N=83,867) reported using some form of cannabis in the past year, and 3% reported BHO use (n=5922).

MEASUREMENTS

Participants reported their use of 7 types of cannabis in the past 12 months, the source of their cannabis, reasons for use, use of other illegal substances, and lifetime diagnosis for depression, anxiety and psychosis. Participants were asked to rate subjective effects of BHO and high potency herbal cannabis.

FINDINGS

Participants who reported a lifetime diagnosis of depression (OR=1.15, p=0.003), anxiety (OR=1.72, p<0.001), and a larger number of substance use (OR=1.29, p<0.001) were more likely to use BHO than only using high potency herbal cannabis. BHO users also reported stronger negative effects and less positive effects when using BHO than high potency herbal cannabis (p<0.001) CONCLUSION: Mental health problems and other illicit drug use were associated with use of BHO. BHO was reported to have stronger negative and weaker positive effects than high potency herbal cannabis.

Cannabinoids and Pain: Sites and Mechanisms of Action

The endocannabinoid system, consisting of the cannabinoid₁ receptor (CB₁R) and cannabinoid₂ receptor (CB₂R), endogenous cannabinoid ligands (endocannabinoids), and metabolizing enzymes, is present throughout the pain pathways. Endocannabinoids, phytocannabinoids, and synthetic cannabinoid receptor agonists have antinociceptive effects in animal models of acute, inflammatory, and neuropathic pain. CB₁R and CB₂R located at peripheral, spinal, or supraspinal sites are important targets mediating these antinociceptive effects. The mechanisms underlying the analgesic effects of cannabinoids likely include inhibition of presynaptic neurotransmitter and neuropeptide release, modulation of postsynaptic neuronal excitability, activation of the descending inhibitory pain pathway, and reductions in neuroinflammatory signaling. Strategies to dissociate the psychoactive effects of cannabinoids from their analgesic effects have focused on peripherally restricted CB₁R agonists, CB₂R agonists, inhibitors of endocannabinoid catabolism or uptake, and modulation of other non-CB₁R/non-CB₂R targets of cannabinoids including TRPV1, GPR55, and PPARs. The large body of preclinical evidence in support of cannabinoids as potential analgesic agents is supported by clinical studies demonstrating their efficacy across a variety of pain disorders.

The current status of artisanal cannabis for the treatment of epilepsy in the United States

The widespread patient use of artisanal cannabis preparations has preceded quality validation of cannabis use for epilepsy. Neurologists and cannabinoid specialists are increasingly in a position to monitor and guide the use of herbal cannabis in epilepsy patients. We report the retrospective data on efficacy and adverse effects of artisanal cannabis in Patients with medically refractory epilepsy with mixed etiologies in Washington State, California, and Maine. Clinical considerations, including potential risks and benefits, challenges related to artisanal preparations, and cannabinoid dosing, are discussed.

RESULTS

Of 272 combined patients from Washington State and California, 37 (14%) found cannabis ineffective at reducing seizures, 29 (15%) experienced a 1-25% reduction in seizures, 60 (18%) experienced a 26-50% reduction in seizures, 45 (17%) experienced a 51-75% reduction in seizures, 75 (28%) experienced a 76-99% reduction in seizures, and 26 (10%) experienced a complete clinical response. Overall, adverse effects were mild and infrequent, and beneficial side effects such as increased alertness were reported. The majority of patients used cannabidiol (CBD)-enriched artisanal formulas, some with the addition of delta-9-tetrahydrocannabinol (THC) and tetrahydrocannabinolic acid (THCA). Four case reports are included that illustrate clinical responses at doses <0.1mg/kg/day, biphasic dose-response effects, the use of THCA for seizure prevention, the use of THC for seizure rescue, and the synergy of cannabinoids and terpenoids in artisanal preparations. This article is part of a Special Issue entitled "Cannabinoids and Epilepsy".