Cannabis Evidence Series What it is What it s not Acknowledgements: The evidence presented is from the Cannabis evidence series authored by the HTA unit at the University of Calgary and from Rapid response reports from CADTH PRODUCTION OF THIS DOCUMENT HAS BEEN MADE POSSIBLE BY A FINANCIAL CONTRIBUTION FROM ALBERTA HEALTH UNDER THE AUSPICES OF THE ALBERTA HEALTH TECHNOLOGIES DECISION PROCESS: THE ALBERTA MODEL FOR HEALTH TECHNOLOGY ASSESSMENT AND POLICY ANALYSIS. THE VIEWS EXPRESSED HEREIN DO NOT NECESSARILY REPRESENT THE OFFICIAL POLICY OF ALBERTA HEALTH. Courtesy istock CADTH is an independent, not-for-profit organization responsible for providing Canada's health care decision-makers with objective evidence to help make informed decisions about the optimal use of drugs, medical devices, diagnostics, and procedures in our health care system. Welcome and introductions Conflict disclosure Evidence-informed decision-making Local issues, context Available resources Clinical experience Evidenceinformed decisionmaking Best available scientific evidence Patient perspectives and values
Selective Cannabis Timeline 1923: Marijuana first criminalized in Canada 1972: Le Dain Commission recommends decriminalization 1996: Controlled Drugs and Substances Act 2001: Medical Marijuana legislation passed (MMAR) 2014: Medical Marijuana legislation revised (MMPR) 2015: Legalization part of the Federal Liberals platform 2016: Report from the Federal Task Force 2017: Bill C-45 The Cannabis Act (April 13) 2018: Implementation by Summer 2018 Current: Access to Cannabis for Medical Purposes Regulations (ACMPR) What is Cannabis? Cannabis is any preparation made from one of the Cannabis plants. Marijuana is from dried leaves of the cannabis plant There are over 70 known cannabinoids Each cannabinoid affects the body differently THC and CBD are the best known cannabinoids Adapted from Rebecca Haines-Saah, PhD, Assistant Profession, Community Health Sciences and O Brien Institute for Public Health http://www.leafscience.com/wpcontent/uploads/2014/06/indica-vs-sativa-02-06-191.jpg The Endocannabinoid system in the Nervous System Mark A. Ware adapted from presentation at U of C pre-course on Cannabis, April 2017 http://www.hc-sc.gc.ca/dhp-mps/alt_formats/pdf/marihuana/med/infoprof-eng.pdf
It is implicated in physiological and pathophysiological processes including: 1. Neural development 2. Inflammation 3. Appetite 4. Cardiovascular function 5. Digestion Immune function 6. Metabolism and energy homeostasis sis 8. Bone development and bone density 9. Synaptic plasticity and learning 10.Pain 11.Reproduction 12.Psychiatric disease 13.Psychomotor behaviour 14.Memory wake/sleep cycles 15.Regulation of stress and emotional states Photo Courtesy istock Photo Courtesy istock Use of medical cannabis Perceived impact of cannabis on physical and mental health compared to other substances University of Calgary Health Technology Assessment Unit. 2017. Cannabis evidence series: An evidence synthesis. University of Calgary Health Technology Assessment Unit. 2017. Cannabis evidence series: An evidence synthesis.
What does the evidence say? Evidence of the potential risks and benefits of the use of cannabis for therapeutic purposes is limited to mostly small, observational studies, and many of the effects are still unknown. What are the known adverse effects? Regular vs. intermittent use? High versus low dose THC Mode of administration Therapeutic Areas Conclusive (2) Substantial (1) Moderate (2) Limited (9) Insufficient (11) Chronic pain in adults Antiemetic's in chemothera py-induced nausea and vomiting Patientreported multiple sclerosis spasticity symptoms Short-term sleep outcomes Fibromyalgia chronic pain and multiple sclerosis -symptoms associated with dementia -intraocular pressure -Depressive symptoms -outcomes after a TBI -appetite and weight loss associated with HIV/AIDS -Tourette's -Anxiety -PTSD -cancers -ca associated anorexia -IBS symptoms -Epilepsy -Spinal cord injury spasticity -Parkinson s symptoms -Huntington's disease -Dystonia -Achieving abstinence in the use of addictive substances -Mental health concerns Our reality Cannabis will be legal by summer of 2018 Other jurisdictions Minimize harm, maximize benefit Variability Individual variability Plant variability Dose and delivery system variability Context variability Researcher variability Courtesy istock Mark A. Ware adapted from presentation at U of C pre-course on Cannabis. April, 2017
Health harms Why I might not have what she s having University of Calgary Health Technology Assessment Unit. 2017. Cannabis evidence series: An evidence synthesis. Interactions with other substances Reported adverse events The effects of cannabis can be increased if used with other substances, such as alcohol, blood thinners, nonsteroidal antiinflammatories, opioids, sleep medications, or other psychoactive drugs. Dizziness Dry mouth Nausea Fatigue Somnolence Euphoria Depression Diarrhea Disorientation Asthenia Anxiety Confusion Balance Hallucination Dyspnea Paranoia Seizures Impaired mental functioning Impaired motor skills Panic attacks https://janaburson.files.wordpress.com/2014/03/aaaapilsfighting.jpg?w=570
Health implications from second hand smoke Low blood pressure Rapid heart rate Worsening of seizures Weakened immune system Slowed digestion Drowsiness Worsening of existing lung conditions Respiratory problems Psychosis Cannabinoid hyperemesis syndrome Appears to be more mutagenic than tobacco smoke Some of the harmful chemicals found in tobacco smoke are also found in cannabis smoke. Exposure to second-hand cannabis smoke can cause a positive THC urine test and psychoactive effects in those passively exposed, with the extent of second-hand effect depending on the environment (ventilation) and dosages (amount of THC in smoked cannabis and number of cigarettes smoked). Addiction The addictive potential of cannabinoids is thought to be less than many other commonly abused prescription and illicit substances. But more evidence is needed. Risk factors for addictiveness include: early age of onset of cannabis use (under 25 years of age) high stress presence of comorbid mental disorders history of substance abuse experiencing a negative life event peer use Dependence The brain adapts to the presence of cannabinoids, which may lead to dependence and withdrawal if intake is stopped abruptly. Symptoms of withdrawal can include restlessness, irritability, agitation, hot flashes, sleep disturbance, nausea, and cramping.
Tolerance Sub-populations at an increased risk for harmful effects of Cannabis Chronic use of cannabis can result in a reduced response or tolerance to it. Tolerance does not always indicate an addiction to or dependence on cannabis. Pregnant Women Breastfeeding Women Children and Adolescents cannabinoids pass through the placenta and can slow the growth of a fetus. cannabinoids pass into breast milk and can slow the development of a baby. during developmental periods, the brain is more vulnerable to the long-term health effects of cannabis. At early age has been associated with reduced mental and emotional development. Psychosis Individuals with a personal or family history of psychosis: cannabis use may increase the risk of experiencing psychosis or a worsening in existing psychosis. Key points Cannabis will be legal what can we do? Stay tuned for evidence There is some evidence of benefit 1.Nausea and vomiting due to chemotherapy 2.Chronic Pain 3.Spasticity due to multiple sclerosis or paraplegia 4.Sleep disorder 5.Tourette Syndrome Thank you for your participation! www.cadth.ca Genevieve Chartrand, RN, Alberta Liaison Officer genevievec@cadth.ca Alexa Parry, MPH, Policy Advisor, Health Evidence and Policy, AH