Under the authority of subsection 41(1) of the WC Act, WorkSafeNB may provide medical aid that it considers necessary as a result of a worker’s work-related injury. Using this authority, WorkSafeNB has determined when cannabis for medical purposes will be authorized as treatment for workplace injuries or occupational diseases.
According to Health Canada, cannabis is not an approved therapeutic drug in Canada and does not endorse the use of medical cannabis. At present, while pointing to some potential therapeutic benefits, the scientific evidence does not establish the safety and efficacy of medicinal cannabis, to the extent required by the Food and Drug Regulations for marketed drugs in Canada. After a review of the evidence, including reviewing the report “The health effects of cannabis and cannabinoids: The current state of evidence and recommendations for research” from the National Academies of Sciences, Engineering, and Medicine, medicinal cannabis is generally not a WorkSafeNB approved treatment, and will only be approved for these specific medical circumstances:
- Symptoms encountered in palliative/end of life care setting;
- Nausea and vomiting while receiving chemotherapy as part of treatment for cancer;
- Loss of appetite of injured workers receiving cancer treatment or with AIDS;
- Spasms and spasticity resulting from central nervous system injury;
- Chronic neuropathic pain; and
- Harm reduction.
As medical evidence evolves, other conditions may be considered by the Chief Medical Officer.
- WorkSafeNB manages, monitors, and controls the use of medicinal cannabis by:
- Outlining the process for approval;
- Providing expectations for the management of authorizations; and
- Determining monitoring requirements and conditions for suspending payments.
- The requirement of a full risk assessment and monitoring for medicinal cannabis applies to spasms and spasticity resulting from central nervous system injury, chronic neuropathic pain and harm reduction. A full risk assessment and monitoring is not required for palliative/end of life care, nausea and vomiting from chemotherapy and loss of appetite of injured workers receiving cancer treatment or with AIDS.
- Medicinal cannabis will only be considered for spasms and spasticity directly resulting from a compensable central nervous system injury when other treatment options have failed or are not appropriate. Prior to approval to treat spasms and spasticity resulting from central nervous system injury, a trial pharmaceutical cannabinoid must be completed and found to be ineffective.
- Medicinal cannabis will only be considered for chronic neuropathic pain, that is chronic pain resulting from injury to the nervous system, when all other treatment options have failed or are not appropriate, and only under the following circumstances:
- There is an objectively identified neuropathic pain source;
- The neuropathic pain source is directly attributable to the compensable condition; and
- The pain source is managed in accordance with the principles of the Canadian Pain Society (CPS) which provides a four tier treatment guideline for prescribing medication. Medicinal cannabis is a third-tier treatment and may only be considered when there has been a trial of at least two agents listed on tier 1 or tier 2 for a reasonable period of time, usually a minimum of 12 weeks for each agent, and these agents have been found to be ineffective.
- Medicinal cannabis may also be considered for harm reduction when the injured worker is on a dosage amount of opioids over the maximum daily dose as recommended in Policy 25-012 Medical Aid – Opioids with a high risk profile for death from respiratory depression or other significant harmful consequences.
- In cases of harm reduction, continued approval for medicinal cannabis will be contingent upon:
- Enrollment in a supervised harm reduction management program, including a signed therapeutic agreement between the health care provider and the injured worker;
- Sustained reduction in the amount of opioids being prescribed for the worker towards dosages in line with the WorkSafeNB opioid policy; or sustained reduction in the amount of other substances with risk of dependency such as benzodiazepines; and
- Completion of the WorkSafeNB Opioid Review Process handbook in the case of opioid reduction.
- A full risk assessment must include:
- A documented review of medical indications and contraindications;
- A documented review of the potential occupational and work site risks and potential impact on the work environment and co-workers; and
- A documented evidence based review of the potential impact on the individual’s ability to perform safety sensitive tasks in the workplace, including operating a motor vehicle or equipment.
- The authorization requirements are:
- Cannabis must be supplied by a federally licensed producer;
- Consistent with the recommendation of the Council of Chief Medical Officers of Health from the Public Health Agency of Canada (2019), and the guiding principle of treatment doing more good than harm, the delivery mode must not involve smoking or vaping;
- For the symptoms from injuries and occupational diseases that require monitoring and risk assessments, prior to approval for the use of medicinal cannabis, the injured worker must have completed a trial of at least 12 weeks on a pharmaceutical cannabinoid with a minimum of two functional assessments;
- The daily dosage should start at the lowest possible quantity to improve or maintain function, with the maximum daily dosage limited to three (3) grams or less. Requests for higher dosages will only be considered when the authorizing physician can provide substantiated evidence, as outlined under Policy 25-014 Medical Aid Decisions, to support the additional dosage. The physician must also demonstrate that the additional dosage does not harm or impair the injured worker, or delay their return to work; and
- The authorization must be for CBD rich medicinal cannabis, the maximum THC content being less than one percent (1%), (as THC is the component that causes impairment). Higher THC content may be considered if there are exceptional medical circumstances, with supporting evidence, as outlined under Policy 25-014 Medical Aid Decisions, provided by the authorizing physician of the benefit of additional THC and evidence that the increase will not cause harm to or impair the injured worker, or delay a return to work.
- A treatment monitoring questionnaire and a functional questionnaire should be completed every 12 weeks prior to renewal of the authorization for medicinal cannabis. After one year of monitoring, if the dosage has remained the same and there is improvement or continued maintenance of improvement in function, the authorization can be reviewed annually. Any changes in dosage or decline in function would require a return to 12 week approval and monitoring.
- WorkSafeNB may suspend or discontinue payment for authorized medicinal cannabis when, in its opinion, there is:
- No resulting improvement in symptoms;
- Evidence that clinically meaningful improvement in function has not been achieved or maintained;
- Harm or impediment to the worker’s recovery, improvement in function, and/or return to work;
- Evidence that the authorization is being used in a manner not intended by the authorizer;
- Evidence that the authorization is being used in combination with continued unreduced use of opioids or benzodiazepines; or
- Serious side effects or other risks.
National Academies of Sciences, Engineering, and Medicine. 2017. The health effects of cannabis and cannabinoids: The current state of evidence and recommendations for research. Washington, DC: The National Academies Press. dbi: 10.17226/24625.
Lucas, Philippe, Rationale for cannabis-based interventions in the opioid overdose crisis. Harm Reduction Journal, 18 August 2017.
College of Family Physicians of Canada Authorizing Dried Cannabis for Chronic Pain or Anxiety: Preliminary Guidance from the College of Family Physicians of Canada. Mississauga, ON: College of Family Physicians of Canada; 2014.
Moulin DE, Boulanger A, Clark AJ, Clarke H, Dao T, Finley GA, Furlan A, Gilron I, Gordon A, Morley-Forster PK, Sessle BJ. Pharmacological management of chronic neuropathic pain: revised consensus statement from the Canadian Pain Society. Pain Research and Management. 2014;19 (6):328-35.
The Canadian Consortium for Investigation of Cannabinoids Checklist for the Medical Assessment of the Patient Asking about Medical Cannabis (initial medical assessment; and follow up)
The Short Form (SF36) Health Survey
Statement from the Council of Chief Medical Officers of Health on vaping in Canada (October 11,2019)
Cannabinoids – chemical compounds that are found in cannabis plants including being secreted by cannabis flowers, (e.g. THC and CBD) and act on cannabinoid receptors.
Cannabis dried/or Herbal Marijuana – refers to medicinal cannabis that has been harvested and subjected to any drying process, is normally inhaled or ingested. Does not have a DIN number (Adapted from Health Canada).
Cannabis Oil – refers to a medicinal cannabis extract that has been dissolved in oil, which can be ingested or used to make other forms. Does not have a DIN number (Adapted from Health Canada).
CBD – refers to cannabidiol, another major constituent of the cannabis plant which, reportedly, has no intoxicating effects.
College of Family Physicians of Canada (CFPC) – a professional association which is the legal certifying body for the practice of family medicine in Canada.
Canadian Pain Society (CPS) – is a chapter of the International Association for the Study of Pain. The CPS is a society of scientists and health professionals who have a vested interest in pain research and management.
Chronic neuropathic pain - Chronic pain resulting from injury to the nervous system.
Medical Cannabis – refers to both dried and oil forms of cannabis authorized to treat a medical condition. The term should be used rather than marijuana and medical marijuana. The term represents the non-pharmaceutical form of medicinal cannabis. Medicinal cannabis products do not have a drug identification number (DIN).
Pharmaceutical Cannabinoids – refers to approved cannabinoids, which are produced in a controlled pharmaceutical manufacturing environment with standard dosages and various formulations and with various routes of administration. Pharmaceutical cannabinoids have each been allocated a drug identification number (DIN). Similar to other prescription medication with a DIN, pharmaceutical cannabinoids will be approved with the use of formularies. Examples are Nabilone (Cesament) and Nabiximols (Sativex). Sativex is also a phytocannabinoid in that it is a herbal extract in oral-mucosal spray in a 1:1 ratio of THC:CBD and also has other microcannabinoids. Term is interchangeable with pharmaceutical marijuana.
THC – refers to tetrahydrocannabinol, a chemical that is an active component in cannabis and the primary psychoactive compound in cannabis.