Starting October 17th, 2018, Canadians will be able to legally purchase and consume cannabis from a federally licensed producer, under the new Cannabis Act and provincial laws.
What are the risks and benefits of cannabis? Can medical cannabis help treat obstructive sleep apnea as some sources may claim? Join us in taking a closer look at the most relevant research on the uses of medical cannabis, and the effects of cannabis on sleep apnea.
A short history of Cannabis
Cannabis, or marijuana, is a plant-based (botanical) product suggested to have been used by humans over 5,000 years ago.1
It was a popular medical drug before the 1937 American Marihuana Tax Act, which removed it from the United States Pharmacopoeia and increased the popularity of opioids. Today, many people attribute the growing interest in medical cannabis to the opioid abuse crisis.
In the 1990’s scientists discovered the human endocannabinoid system which ties psychology, immunology, and neurology, and is known to affect some disorders and medical conditions.
Cannabinoid receptors are found in the nervous system, internal organs, connective tissues, glands, and immune cells throughout the body. The eCB system impacts our appetite, pain-sensation, mood, and memory when its receptors bind with internally produced cannabinoids, such as anandamide. 2
It has been proposed that eCB deficiency can cause a variety of conditions such as migraines, fibromyalgia, irritable bowel syndrome, while deficiencies in eCB signalling could be involved in the pathogenesis of depression. 3
How is Medical Cannabis used today?
|Cannabis for chronic pain||Cannabinoids can impact how pain is perceived, so it is often used to treat chronic pain. Clinical studies show that even if patients’ pain is not eliminated, cannabis helps them alter its perception so they can focus elsewhere.4|
|Cannabis for Cancer||Not enough evidence exists to prove that routine use of medicinal cannabis alleviates chemotherapy-related nausea and vomiting, but therapeutic agents based on THC - such as nabilone and dronabinol - are approved as antiemetics in the United States.5|
|Cannabis for Neurological Disorders||Cannabis was used as a treatment - mainly for headaches - in ancient China in 3,000 - 1,500 BC. Today, legal restrictions on the drug limit clinical data, but cannabis is thought to suppress seizures in epilepsy and improve spasticity and spasms/pain in multiple sclerosis.6|
|Cannabis for HIV/AIDS||In a study published in the Journal of Pain and Symptom Management, a large number of patients reported improved appetite (97%), muscle pain (94%), nausea (93%), anxiety (93%), nerve pain (90%), depression (86%), and paresthesia (85%). However, at the same time, many cannabis users (47%) reported associated memory deterioration.7|
Some cannabis users claim that it helps them fall asleep and sleep better.
While current studies are scarce, data collected in the 1970’s can help explain how cannabis affects sleep.
When low doses (4 to 20 mg) of THC cannabinoid were administered to regular cannabis users and non-users, REM sleep mildly decreased in both groups but deep sleep increased. Interestingly, this effect disappeared after repeated use.
Higher doses of THC (50 to 210 mg) decreased REM sleep and deep sleep in both groups but did not affect total sleep time. When THC was stopped, REM sleep somewhat rebounded but the overall sleep time was reduced, with longer time to fall asleep. 8
Early studies with animals demonstrated that synthetic cannabis extract dronabinol improved respiratory stability. As a result, recent studies in humans explored the potential use of dronabinol as an alternative treatment for sleep apnea.
However, dronabinol is not approved by the United States Food and Drug Administration (FDA) for the treatment of sleep apnea, and medical cannabis and synthetic extracts other than dronabinol have not been studied in patients with Obstructive Sleep Apnea.
According to the American Academy of Sleep Medicine (AASM) position statement April 16th 2018, “Avoid using medical marijuana to treat sleep apnea,” as the evidence is too limited to suggest that the synthetic medical cannabis extract dronabinol may improve respiratory stability and provide benefit to treat sleep apnea, while side effects such as somnolence related to treatment were reported in most patients. The long-term effects on other sleep quality measures, tolerability and safety are still unknown, and the composition of cannabinoids within medical cannabis is not regulated and varies significantly.
The diagnosis and effective treatment of Obstructive Sleep Apnea in adults is an urgent health priority. Positive airway pressure (PAP) therapy remains the most effective treatment for sleep apnea.
Obstructive Sleep Apnea should be excluded from the list of chronic medical conditions for state medical cannabis programs and people with sleep apnea should discuss their treatment options with a licensed medical provider at an accredited sleep facility. Further research is needed to understand the utility of medical cannabis extracts before recommending them as a treatment for sleep apnea.
1, 2, 3 Medicinal Cannabis: History, Pharmacology, And Implications for the Acute Care Setting, P&T® • March 2017 • Vol. 42 No. 3
4, 5, 6, 7 Medicinal Cannabis: The Evidence. Peter Reynolds, 27 th. February 2015. CLEAR Cannabis Law Reform. 42-46 Bethel Street. Norwich. https://www.bmj.com/sites/default/files/response_attachments/2015/03/Med...
8 “Cannabis and Sleep.” Psychology Today, Sussex Publishers, 6 Nov. 2012, www.psychologytoday.com/ca/blog/sleepless-in-america/201211/cannabis-and....