There are a growing number of people using medical cannabis for a variety health issues.  In fact, neuropathy sufferers are considered one of the patient groups who seem to find it find it most beneficial as it is very helpful in relieving neuropathic pain.  There are even cases where patients have titrated down their prescription medications, including opioids, to use significantly lower doses. Note: This should only be done under a doctors’ care. As a result, some medical cannabis advocates refer to it as an exit drug, a play a prior term for it – a gateway drug.  However, it does come with its own risks and cautions so if you are considering trying medical cannabis do your research to know if it is right for you.

More information on neuropathy and chronic pain can be found on the Government of Canada website: 4.6.2.2 Neuropathic pain or chronic non-cancer pain

Basics of Cannabis

Below are some basic facts about cannabinoids (the active ingredient in cannabis that has therapeutic properties) and the corresponding cannabinoid receptors in the body-the mechanism in our central and peripheral nervous systems that make them effective.   The following explains some cannabis terms and may help you to have an informed discussion with your doctor or staff at the cannabis clinic or education center.

There are more than 100 known cannabinoids and there are 3 main sources:

1. Phytocannabinoids are cannabinoids produced by the cannabis plant.
2. Endocannabinoids are ones produced naturally in the body (unrelated to phytocannabinoids).
3. Synthetic cannabinoids are produced in a laboratory and bind to cannabinoid receptors. Pharmaceutical cannabinoids: nabilone. Nabilone is a synthetic cannabinoid that resembles THC and is considered highly potent.  Nabiximols are normally provided in an oral spray form.  These are available in Canada and other countries via prescription.

In the body there are two sets of cannabinoid receptors:

1. CB1 Receptors are responsible for the psychoactive effects of cannabis. They are present in many areas of the brain and play a role in memory, mood, sleep, appetite and pain sensation. They react mostly with THC.(9)
2. CB2 Receptors react mostly with CBD and are responsible largely for the anti-inflammatory effects of cannabis. They are found in immune cells and throughout the rest of the body, and work to reduce inflammation. Inflammation is an immune response and is believed to be a factor in many diseases and conditions. ⁹

According to a German selective literature review, there is clear evidence that cannabinoids are useful as a treatment for many medical conditions.¹⁰ The known therapeutic properties of cannabis include:

• Analgesic – a drug for pain relief
• Antiemetic – a drug that provides anti-nausea relief
• Antispastic- relieves, prevents, or lowers the incidence of muscle spasms and seizures
• Antinflammatory – reduces inflammation
• Sedative – a drug used for its calming effect or sleep-inducing properties
• Neuroprotective – protects nerve cells from degenerating

The major components, phytocannabinoids, used for medical purposes are Delta 9-tetrahydrocannabinol (THC) & Cannabidiol (CBD).  CBD is a non-psychoactive phytocannabinoid component.  This is the same ingredient found in hemp.  CBD is an anti-inflammatory, neuroprotective, anti-anxiety/anti-panic, anti-epileptic, antipsychotic, and in some cases is used to manage symptoms of ADHD.  CBD also negates some of the affects of THC.  An owner of one of the larger medical cannabis clinics indicated in a presentation to the Calgary Neuropathy Association that the largest demographic of cannabis users is patients with chronic pain and the highest in demand are strains of CBD.  THC is the active ingredient that produces psychoactive effects.  It is also an analgesic, antiemetic, appetite stimulant and is effective for anti-spasticity.   High dose THC tends to make patients sleepy, so most people choose the low (or no) THC and higher CBD to remain functional in their daily lives.

Research Studies in Cannabis

There is still a lot of controversy around the use of medical cannabis for the treatment of neuropathic pain and other conditions.  However, in the last decade there has been a large uptake in research studies focused on Cannabis.  There is still much research necessary as results are often conflicting.

The following lists conclusions of studies and reviews on Cannabis-Based Medicines (CBM) for pain:

•  Efficacy of Cannabis-Based Medicines for Pain Management: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
  • Conclusions: “The current systematic review suggests that CBMs might be effective for chronic pain treatment, based on limited evidence, primarily for neuropathic pain (NP) patients. Additionally, GI AEs occurred more frequently when CBMs were administered via oral/oromucosal routes than by inhalation.”⁴
• Cannabis constituent synergy in a mouse neuropathic pain model.
  • Conclusions: “These findings demonstrate that CBD synergistically enhances the pain-relieving actions of THC in an animal neuropathic painmodel, but has little impact on the THC-induced side effects. This suggests that low dose THC:CBD combination treatment has potential in the treatment of neuropathic pain.”⁵
•  The Endogenous Cannabinoid System: A Budding Source of Targets for Treating Inflammatory and Neuropathic Pain
  • Conclusions: “Notably, cannabinoid receptor agonists as well as inhibitors of endocannabinoid-regulating enzymes fatty acid amide hydrolase and monoacylglycerol lipase produce reliable antinociceptive effects, and offer opioid-sparing antinociceptive effects in myriad preclinical inflammatory and neuropathic pain Emerging clinical studies show that ‘medicinal’ cannabis or cannabinoid-based medications relieve pain in human diseases, such as cancer, multiple sclerosis, and fibromyalgia.”6

Additionally, the American Cancer Society as indicated it has potential in treatment of some forms of cancer.  “More recently, scientists reported that THC and other cannabinoids such as CBD slow growth and/or cause death in certain types of cancer cells growing in laboratory dishes. Some animal studies also suggest certain cannabinoids may slow growth and reduce spread of some forms of cancer.”  It should be noted that this is only true for some cancers.  For hormonal cancers THC makes the tumor grow more aggressively.  On the same web page the society also states, “A few studies have found that inhaled (smoked or vaporized) marijuana can be helpful treatment of neuropathic pain(pain caused by damaged nerves).” ⁷

Not all studies produce positive conclusions. See the section on Cautions.

Cautions

There has not been a lot of research done on the long-term effects of medical cannabis and of course there are legal issues to consider as well.  Some things to consider are listed below:

1. Do not drive or operate machinery, if you are using a strain containing THC you are considered impaired.
2. Do not travel with medical cannabis to the United States. The US Border Patrol may refuse you entry into the United States if they suspect you have used cannabis in the past. Even having a medical cannabis registration card is enough for you to be refused.
3. While cannabis is generally thought to be non-addictive, there is some who believe 10% of users may become addicted.
4. Approximately 10% of people do not have the cannabinoid receptors and so cannabis as no effect (or benefit) for them.
5. Cannabis should not be used by people with severe personality disorders or psychoses.
6. Cannabis is not advised to be used by people under the age of 18.
7. “Several longitudinal cohort studies have shown a statistical association between psychotic illness and self-reported cannabis use. However, the results are difficult to interpret due to methodological problems, particularly the unknown reliability of self-reported data. It has not been possible to establish a causal relationship in either direction, because of these methodological limitations.”¹  “There is considerable evidence that in individuals with an established psychotic disorder such as schizophrenia, exposure to cannabis can exacerbate symptoms, trigger relapse, and worsen the course of the illness. Only a very small proportion of the general population exposed to cannabis develop a psychotic illness.”2
8. “Chronic inflammatory and precancerous changes in the airways have been demonstrated in cannabis smokers, and the most recent case-control study shows an increased risk of airways cancer that is proportional to the amount of cannabis use.” ³
9. Cannabis is not advised for people with:
   • Severe cardiovascular diseases as a side effect can be tachycardia (abnormally rapid heart rate)
   • Hepatitis C as it may accelerate the development of cirrhosis (scarring of the liver)
   • Some hormonal cancers (it may make the tumor grow more aggressively)
   • Addictive Disorders
10. Cannabis is also well known to have the following side effects:
    • Euphoria
    • A reduction in psychomotor and cognitive performance
    • Memory Impairment
    • Distorted perception of the passage of time

How to’s of Cannabis

While cannabis is showing great promise for easing patient’s suffering, particularly for neuropathic pain, ensure you educate yourself on the cautions and risks of cannabis use (see above).  When starting a new strain start with small doses and slowly increase the amount to learn how you are affected.

Most specialized clinics have cannabis specialists you can speak to and ask questions throughout your treatment.  They help you decide on the best strains for your situation and what the different producer/distributors provide.  Note, on the rare situations where are able to obtain a prescription from your own family physician it is likely they only deal with one producer/distributor, so your choices are limited.  If you want to change or have the options provided by different producers it will be necessary to connect with one of the specialized clinics and see their physician. There is no risk of toxicity when combining opioids and medical cannabis, however consult a doctor or clinic that includes education in the use of cannabis for therapeutic purposes as part of their offerings to achieve the best results.

Which strain option is best for me?

Every person’s cannabinoid receptor system is different. Each patient needs to set out on a journey to find the best strain for their body and for what they are trying to treat. This may mean different strains for different purposes.  Some may help with getting to sleep others may make a person feel more rested in the morning.  Another strain may be used for treating anxiety during the day.  To find the strain or strains that works best for an individual, they must try different strains for each purpose to narrow down the one that works best for them. This can be an extensive and expensive process.

The question of how much to take is often confusing for new patients.  It is generally recommended that patients track the amount used and the results it produced. As well, it is recommended that patients start low and grow their dose.  As mentioned above, regulation and testing ensure each strain’s potency is consistent.  This allows the patient to develop their own dosing protocol based on their own experience.

Methods of Administration

 

Ingestion

Distributors provide an oral syringe with ingestible/edible oil so you are able to accurately measure each dose.  The desired dosage is measured into the syringe, placed under the tongue and swallowed.  The taste is no worse or better than smoking, however it has none of the additional risks that come with smoking. It takes anywhere between 1 hour to 1 ½ hours to begin to feel the effects and 2-4 hours for the full effect. The effects also last as long as 8 hours.

Edible products (baked goods and candy) are not currently available in Canada for purchase.  Individuals can make their own products by infusing butter or oils with cannabis and then using the infused butter/oil in baking or other cooking. Specialized infuser machines can be purchased however it can also be done in a pot on the stove or in a crockpot.

Making edibles takes practice and the levels of THC or CBD may not be consistent.  You’ll need to keep careful track of the amounts of cannabis you use in the infusing process and the amount of infuse product you add to your edible good.

Some education clinics offer infusing and cooking classes.

 Smoking

While this is the most well known method, it is also not recommended as together with the cannabinoids you are also inhaling many harmful by-products. Long term use of smoking cannabis introduces the risk of serious effects on throat and lungs.  This method does however provide quick absorption and relief.  Smoking is your choice reduce the negative impacts by using a bong (a glass ‘pipe’ that contains water to cool the smoke).

Topical

There are a lot of cannabinoid receptors spread on the skin’s nerve fibers and cells.  So, its fortunate that THC and CBD are absorbed easily into the skin.  Topical creams, oils, balms and gels provide an easy way to apply directly to a specific area and are used for treatment of arthritis and other localized pain. Relief is said to be within minutes and the effects last about 1 to 2 hours.

Topicals are not currently sold in Canada, however after legalization, its expected they’ll become readily available.  In the mean time, patients can develop their own, however this is a fair amount of work.  A second option is to purchase hemp topical products as they may also contain CBD.  Check the labels.

 Vaporizing

Vaporizing is like using e-cigarettes and is preferable over smoking for getting fast results, usually within 15 minutes without the harsh effects to throat and lungs.  Vaporizing heats the cannabis to the temperature needed to release and activate the cannabinoids, but does not ignite it.  Vaporizing cannabis using e-cigarettes or vaporizing equipment has not been studied for the long-term side effects, so use of this method is at your own risk. There is an upfront cost to purchase vaporizing equipment, usually in the order of $150 to $200.  Vaporizing also provides more cannabinoids to the system than smoking, so in the long term it is more cost effective.

Cannabis in Canada

Medical Cannabis has been legal in Canada since 2001 and in 2013 the Canadian government considerably improved its access.  The Federal Government wanted to provide safe consistent access to medical cannabis and so Health Canada created the Access to Cannabis for Medical Purposes Regulations (ACMPR), providing patients legal access to licenced producers.

Licenced producers are companies regulated by Health Canada and permitted to grow and sell medically prescribed cannabis.  Health Canada provides a list of licenced producers on their website: authorized-licensed-producers-medical-purposes. The number of licenced producers in Canada as grown from approximately 25 in 2015 to over 60 today (2017).  Of the 60+ registered producers/distributors, only one is organically grown.

Cannabis is still listed as a schedule 1 narcotic in Canada.  This means it requires a prescription in triplicate together with quarterly follow up appointments with the prescribing physician.  Despite its schedule 1 status it is getting progressively more accepted by the medical community and its use is spreading quickly.  More information can be found on the Government Of Canada Website: Consumer Information – Cannabis (Marihuana, marijuana).

Insurance Coverage

There are some insurance companies who will cover cannabis on a case by case basis, check with your insurance provider.  Canadians are also able to claim their cannabis prescription on their taxes.

Canada’s  Process for Patients

You require an actual appointment with a physician to determine if it is an option for your specific medical situation.  It doesn’t need to be your own physician however, in fact many general practitioner (GP) physicians will not provide a prescription. Instead, there are specialized clinics where a patient can see a physician to get a prescription and be connected with one or more producers/distributors. These clinics deal only with your cannabis needs, you remain with your GP for all other concerns. You can also self-refer to these clinics by simply calling or going on-line to book an appointment. In Canada, there are some clinics that do not charge for this appointment, however some do, so check around before booking.

An official medical document is needed to prove your need.  This document is submitted by the physician (with a practice id) to the licenced provider of your choosing.  Your medical document will include a maximum number of grams you are permitted per day.  By law distributors are not permitted to send more than 30 times your daily limit at a time (i.e. 30 days worth).

You select the distributor, but there are things you need to know before choosing which to order from. Things like: what they provide; their delivery times; products they specialize in; which ones have first time patient incentives; and, which ones have better financial assistance programs. Many producers offer financial assistance programs dependant on income.

At the time of this writing, prices range from $3.00/g for ‘budget bud’ to $15.00/g for niche products.  Producers are not able to market directly to the patients, they are required to market through education centres run by the clinics.  Some clinics specialize in certain strains; for example: not all producers have a high CBD strain.

Once the distributor has your medical document the you can place an order online.  The distributor then ships the product to you via Canada Post.

 

Production Regulations

According to Canadian regulations, producers cannot use pesticides or herbicides.  They are required to go through 3 tests for each harvest.  Health Canada takes a lot from every harvest from every single strain the producer grows. As well, there is in-house testing and third-party testing.  The lot must pass all three tests and if it does not the entire harvest is destroyed. Another purpose of testing is to ensure the strain you buy one month is the same the next month and, so you are sure the dosage they used previously will be the same dosage to use the next time.

References:

1. Adverse effects of cannabis; Abstract on Pub Med – Authors: none Listed; Prescrire Int. 2011 Jan;20(112):18-23. Review.  https://www.ncbi.nlm.nih.gov/pubmed/21462790
2. Cannabinoids and psychosis; Authors: Sewell RA, Ranganathan M, D’Souza DC. – Int Rev Psychiatry. 2009 Apr;21(2):152-62. doi: 1080/09540260902782802.https://www.ncbi.nlm.nih.gov/pubmed/19367509
3. Adverse effects of cannabis on health: an update of the literature since 1996.; Abstract on Pub Med – Authors: Kalant H – Prog Neuropsychopharmacol Biol Psychiatry. 2004 Aug;28(5):849-63.
4. Efficacy of Cannabis-Based Medicines for Pain Management: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.; Abstract on Pub Med – Authors: Aviram J, Samuelly-Leichtag G. – Pain2017 Sep;20(6):E755-E796. https://www.ncbi.nlm.nih.gov/pubmed/28934780
5. Cannabis constituent synergy in a mouse neuropathic pain model.; Abstract on PubMed – Authors: Casey SL, Atwal N, Vaughan CW. – Pain. 2017 Sep 1. doi: 10.1097/j.pain.0000000000001051. [Epub ahead of print]
6. The Endogenous Cannabinoid System: A Budding Source of Targets for Treating Inflammatory and Neuropathic Pain.; Abstract on Pub Med – Authors: Donvito G, Nass S², Wilkerson JL, Curry ZA, Schurman LD, Kinsey SG, Lichtman AH.
7. http://www.cancer.org/treatment/treatmentsandsideeffects/physicalsideeffects/chemotherapyeffects/marijuana-and-cancer
8. Presentation by Steve Fader, owner of Natural Health Services to the Calgary Neuropathy Association.
9. http://naturalhealthservices.ca/wp-content/uploads/2017/05/Medical-Cannabis.pdf
10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3442177/