Marijuana became legal for adult recreational use in Canada on Oct 17th, as I’m sure you’ve heard on the news. The Canadian Government’s goal is to control use, eliminate the illegal trade, prevent use in minors and, of course, collect taxes.
But I’d like to talk about the other side of marijuana -- medicinal use. In Canada, marijuana use for medicinal purposes has been legal for 17 years but it’s only supplied through government sources, essentially mail order. Pharmacies are still not permitted to distribute or help clients with this medication and many doctors do not prescribe it, and this has lead to a fracturing of the usual medication system designed to prevent drug interactions and problems.
Another downside, besides the inconvenience of mail order, has been the stigma of using what was, until now, an illegal substance. I know of patients who would have benefitted from it, according to current studies, but were afraid to try a medication that had been described to them as a “drug of abuse”, worried they might become “addicted” while their doctor prescribed opioids or other prescription drugs instead.
Medical uses of marijuana
While marijuana is currently not a first-choice treatment for any condition, scientific evidence has shown it works for chronic pain, nausea and vomiting caused by chemotherapy, spasms caused by MS, and treatment-resistant epilepsy. There is also discussion around the possibility it may help decrease the opioid problem, now at crisis level in many countries, by substituting marijuana for this more dangerous class of medications. I know of patients who have successfully made the change from opioids to marijuana and now experience good or better pain relief with fewer side effects.
There are many active components in marijuana, known as cannabinoids -- at least 113, according to official Health Canada information, and as many as 400 different ones, according to other references. The two most active cannabinoids are THC (tetrahydrocannabinol) and CBD (cannabidiol). Most medicinal marijuana contains more CBD, the chemical that is active for pain and reducing muscle spasms) and less THC (which creates the “high”). Products can now be produced that contain virtually no THC for medicinal use. These products are considered safer than opioids and have fewer side effects than anti-inflammatory analgesics (known as NSAIDS).
Currently healthcare professionals are divided regarding whether access to medical marijuana should be integrated into the current medicine supply system. Many are not well educated on its actions and side effects, as they have had little or no contact with medical marijuana. Your doctor and pharmacists may not be able to advise you whether you would benefit from this medication unless they have taken the initiative to educate themselves. Currently there is little incentive for pharmacist to become involved, as they are not permitted to help even clients with legal permission to use marijuana. Last year, a young pharmacist lost her licence temporarily for helping one of these clients solve a problem with his medical marijuana -- a tragedy, in my opinion.
Is it OK to self-medicate?
With marijuana now available for recreational use, it has also become available for patients who may decide to self-medicate. This is certainly not an ideal situation When something is affecting your health, it's always best to get a proper diagnosis and discuss treatment options with your doctor or nurse practitioner. Like any medication, medical marijuana use needs to be monitored, to ensure it will be used in the safest manner possible, at the correct dose, in the ideal formulation, and that interactions with other medications or diseases will be avoided.
For example, smoking marijuana has all the same risks of lung problems that smoking tobacco does, and would aggravate lung diseases like asthma. While occasional recreational smoking may run lesser risk, smoking marijuana every day for medicinal use is understood to be as dangerous as a tobacco habit. Inhaling marijuana gives quick onset of effects (within seconds to minutes) but the effects do not last as long (usually 2 to 4 hours), requiring frequent dosing. Other forms, such as oral (swallowed) or sublingual (placed under the tongue) can last up to 12 hours, making them more suitable for medication use for patients with chronic diseases.
Can marijuana be habit-forming?
Humans produce their own cannabinoids, just like we produce our own opioids, and these drugs work by attaching to receptors in our brains for the substances we normally produce. When this happens, our brains change to compensate for the extra stimulation from the introduced drug. When these drugs are stopped, it can take some time for the brain to revert back to its usual function and this results in withdrawal effects that are generally opposite to the effect of the drug.
Opioids, for example, cause drowsiness and reduce the perception of pain. When opioids are stopped abruptly after longer-term high-dose use, people often have difficulty sleeping, may develop anxiety and could become hypersensitive to pain. While the brain changes with marijuana seem to be less persistent than those that occur with opioids, resulting in less withdrawal symptoms that with opioids, these can occur after long-term high-dose use. Marijuana withdrawal can result in nausea, anxiety and sleeplessness. Tapering the dose is recommended to avoid withdrawal effects when stopping long-term use, the same as with any medication that affects brain receptors, such as antidepressants, anti-anxiety medications, antipsychotic drugs and opioid analgesics. Further research still needs to be done to identify risks and benefits of long term use for chronic diseases.
In summary, there is still much to learn about marijuana, both for medical and recreational use. Legalization of the substance will encourage more research, reduce stigma for those using it for medicinal purposes, and encourage learning on the part of healthcare professionals. Our best hope, on the medicinal side, is that marijuana may help to reduce deaths and addictions to opioids from both medical and illicit sources while becoming an effective and safer treatment for a range of medical conditions.
References and further reading:
Now that cannabis is legal, let’s use it to tackle the opioid crisis, The Conversation
Cannabis in Canada, Health Canada
