The medicinal and recreational use of the plant Cannabis sativa dates back thousands of years, as there is evidence the plant was used in Ancient Egypt, China, India and Persia to treat epilepsy. Later attempts to isolate the active ingredients of cannabis, have found over 100 cannabinoids, including cannabinol (CBN) and tetrahydrocannabinol (THC).
Cannabis was also described by ancient peoples as “the drug that takes away the mind”, referring to what we now understand as the psychoactive properties, attributed to THC. While THC is known for its psychoactive effects, it has also been found to be an effective pain killer and antioxidant, as well as an effective treatment in preventing and alleviating nausea. Other research has found cannabinoids to have antitumoral and anticonvulsive properties. Together, these findings have led researchers to investigate the effectiveness of cannabinoids in treating epilepsy, HIV, multiple sclerosis, chronic and acute pain, nausea, vomiting, and weight loss, as well as tumors in breast cancer, prostate cancer, lung cancer, and melanoma.
The effects of medical cannabis, and its THC and CBD components, vary depending on the strain, formula, dose, patient characteristics, and method of administration. For example, different strains of cannabis have varying levels of THC and CBD, and some formulas of medical cannabis, designed for those patients wanting to avoid any psychoactive effects, have no THC at all.
Doses of THC are defined as low when they are less than 7 mg, medium when between 7–18 mg, and high dose if there is more than 18 mg of THC in the formulation. Research suggests that patients may develop increased tolerance to THC within as little as 4 days, and because THC accumulates in the brain and fat stores, effects in the brain last longer than other physiological effects.
Inhalation – Vaporization is the preferred method of administrating medical cannabis. The effects of cannabinoids through inhalation reach peak levels in under 10 minutes, and the cannabinoids are not broken down as they would be in the digestive process. However, it is also important to be aware that smoking cannabis is not recommended, as the smoke inhaled during the process contains most of the same harmful chemicals and toxins as tobacco smoke, such as arsenic, benzene, cadmium, formaldehyde and lead, as well as ammonia, carbon monoxide, hydrogen cyanide, and tar.
Oral consumption – Oral consumption of medical cannabis is typically administered in the form of cannabis oils, and their formulas may or may not include THC. Oral consumption is a popular choice for those who do not want the psychoactive effects of THC. However, cannabinoids can be broken down and metabolised by stomach acid, and therefore, it is a less effective method of delivering the drug than inhalation, demonstrating peak levels typically between 60 and 120 minutes after administration, although peak levels have been shown to be delayed as long as 4 hours. Alternatively, oral sprays have been shown to be slightly more effective than other methods of oral administration.
Three cannabis derived drugs have been approved in Canada: dronabinol, nabilone, and nabiximols.
Dronabinol and nabilone have been shown to relieve nausea and vomiting associated with cancer therapies, and anorexia and weight loss associated with immune deficiency syndrome, as well as pain and muscle spasticity.
Nabilone has been shown to be effective in managing pain, and has been used with diabetic neuropathy among patients with upper motor neuron disease and spinal cord injury.
Nabiximols are offered as an oral spray to relieve muscle spasticity and neuropathic pain among patients with multiple sclerosis, as well as intractable cancer pain.
Other uses for medicinal cannabis include:
- Childhood‐onset epilepsy
- Chronic pain
- Postoperative pain and nausea
- Rheumatoid arthritis
- Neuropathic pain
- Improved sleep quality
The addictiveness of cannabis remains controversial, as not all studies use the same parameters or criteria. Also, because medical cannabis has varying and lower levels of THC than is found in non-medicinal strains, data from non-medicinal studies may not be indicative of rates of abuse and dependence for medical cannabis. Addictions and usage disorders are complex, and involve behavioral, psychological as well as physiological factors. Usage disorder may be mild, moderate, or severe, and broadly relate to the recurrent use of drugs or alcohol causing various kinds of impairment or health problems, or inability to function at work or school.
It is recommended that individuals interested in medical cannabis consult their physicians regarding the risks of different strains and formulas of medical cannabis.
The Human Endocannabinoid System
Our bodies include receptors, which are areas in cell membranes that respond to specific stimulus, such as heat, light, neurotransmitters, hormones, etc., and then transmit signals to other nerves. An interest in understanding the body’s endocannabinoid system, which includes endogenous (meaning originating within the organism- in this case the human body) cannabinoids and cannabinoid receptors, as well as enzymes that synthesise and break down endocannabinoids, led to the discovery of the G protein-coupled receptors (GPCRs), CB1 and CB2, which help to activate physiological responses to CBD and THC.
High concentrations of CB1 receptors are found in the neocortex, which governs higher thinking capabilities, such as sensory perception, cognition, spatial reasoning and language, and in the hippocampus, which is associated with short-term, long-term and spatial memory, as well as the cerebellum and basal ganglia, which are associated with motor coordination and activity. High levels of CB1 receptors are also found in the hypothalamus and limbic cortex, which are associated with appetite and sedation, and the spinal cord. Additionally, lower concentrations of CB1 receptors can be found in the spleen and white blood cells, associated with the immune system, and endocrine glands, which govern hormone production, as well as in the reproductive, gastrointestinal and urinary tracts. Alternatively, the majority of CB2 receptors are found on white blood cells, and in the spleen and tonsils.
Cannabinoid receptors regulate the release of cytokines (small proteins that help to regulate immune response), and have become a target for scientists examining their anti-inflammatory and immunosuppressive activity. While research is limited, preclinical trials have found antitumoral effects in several cancers, including breast cancer, prostate cancer, lung cancer, and melanoma. Aside from its psychoactive effect, THC has also been found to have analgesic, antiemetic, and antioxidant properties. Additionally, CBD has been found to have anxiolytic, antipsychotic and anticonvulsive properties.
Cannabis as a Schedule 1 drug
Drugs in Canada and the U.S. are regulated according to schedules: 1 through V111 in Canada, and 1 through V in the United States. Substances are given a Schedule 1 listing if they are believed to have a high potential for abuse, no accepted medicinal purpose, and are deemed a high safety risk under medical supervision. Because it has been a Schedule I controlled drug, its availability for research has been extremely limited, as is the amount of data accumulated. Also, research with cannabis contains THC ranging from 0.001% to 13%, and no cannabis with high CBD content has been available for research. Nonetheless, the medicinal properties of cannabis have been studied for treating nausea, pain, anorexia and weight loss, seizures, spasticity, and glaucoma, particularly with cancer patients, and patients with HIV, epilepsy, and multiple sclerosis.
Potential harmful effects
Smoking any substance has negative health effects. Smoked cannabis contains carcinogens, and therefore, has the potential to cause cancer. As well, smoking cannabis can damage the large airways and increase symptoms of chronic bronchitis. Vaporization is the preferred method of administrating medical cannabis, followed by oral consumption.
Also, cannabis use has been shown to reduce memory, attention, cognition, judgment, balance, reaction time, tracking, and motor function, especially within the first hour of use. However, differences in cognitive functioning are greatly dependent on frequency and duration of use. Additionally, despite the fact that some people report that cannabis helps with depression and anxiety, cannabis is also associated with increased risk of anxiety, depression, paranoia, hallucinations, disorientation, and other psychotic symptoms. Moreover, studies show increased risk and incidence of heart disease, suicide, earlier-onset schizophrenia and other psychoses with cannabis use. Studies also show that cannabis use during pregnancy increases the risk of stillbirth, as well as adverse neurobehavioral effects. Other studies show that long‐term recreational cannabis use is associated with reduced luteinizing hormone, follicle-stimulating hormone, prolactin, and growth hormone. Finally, Cannabis may have adverse reactions with alcohol and other drugs.
Below you will find some of our frequently asked questions about medical cannabis. If your question is not answered, please feel free to contact us!
The most common mild adverse effects associated with cannabis are, dizziness, vomiting, urinary tract infection, and allergic reaction. More severe reactions reported include anxiety, paranoia, hallucinations, disorientation, and other psychotic symptoms.
Individuals must obtain permission in a medical document from a health practitioner to gain access to a licensed producer.
You are allowed to have a maximum 30-day supply of medical cannabis or up to 150 grams.
Individuals who have obtained the medical documentation from a health practitioner to use cannabis can apply to Health Canada to grow a predetermined number of plants (or appoint someone to grow the plants for them) based on the amount authorized by the health care practitioner and the average supply of a plant under specific growing conditions.
Canadian Air Transport Authority has provided specific guidelines for individuals traveling within Canada:
- Cannabis products should be kept in their original containers
- Individuals must have their Health Canada registration Certificate
- Cannabis products should be packed in carry-on luggage
- As well, screening officers must call police to verify the documents. In the event police are not available to verify the documentation, the passenger’s information is recorded and given to local authorities. Canadian Air Transport Authority recommends that passengers contact airports in advance to travelling.
More than 600 Canadians are reportedly in foreign jails due to drug-related offences.
When you travel internationally, you must know and obey the laws of the country you travel to. Many countries have extremely severe penalties, including death, for the possession and use of illegal drugs, regardless of whether the drug is legal in Canada or not. Your Canadian citizenship will not offer immunity for such penalties. Additionally, you may be refused entry into a country if you have previously used a drug that is deemed illegal that country.
No, Canada’s Criminal Code states that it is illegal to operate any motor vehicle or vessel, or to assist in the operation of a motor vehicle or vessel while being under the influence of alcohol or a drug.The use of medical cannabis falls under the same human rights legislation as any other prescription drug, which states that an employer must attempt to accommodate an employee’s condition. However, occupational health and safety legislation must also be considered. The employer must complete an accommodation evaluation to determine whether or not the effects of medical cannabis are compatible or interfere with any or all of the tasks required by the job. An employer may be able to tailor a position accordingly, or may conclude that, for safety reasons, the employee is unable to continue in the current position (e.g. operating heavy machinery).
The use of medical cannabis falls under the same human rights legislation as any other prescription drug, which states that an employer must attempt to accommodate an employee’s condition. However, occupational health and safety legislation must also be considered. The employer must complete an accommodation evaluation to determine whether or not the effects of medical cannabis are compatible or interfere with any or all of the tasks required by the job. An employer may be able to tailor a position accordingly, or may conclude that, for safety reasons, the employee is unable to continue in the current position (e.g. operating heavy machinery).