HOW: USING MEDICINAL CANNABIS
Once a prescription is received, a patient might still have a lot of questions about what to expect from medicinal cannabis. Learn more about how medicinal cannabis is used.
How much or what dosage of medicinal cannabis should I take?
The ideal dosage of medicinal cannabis should be always determined by your treating physician, as he/she is in the best position to instruct you about what better serves your concrete medical condition. As a general rule, the optimal dose is the lowest dose that can control your symptoms without side effects. To accomplish this objective, your physician may ask you to start with a low dose and to up-titrate according to a proposed titration scheme. This may allow for better tolerability. Different patients may require or tolerate different doses.
Is there a recommended starting dose for medicinal cannabis?
Your treating physician will be able to recommend the best starting dose for your medicinal cannabis product. It may vary according to the symptoms to treat, the type of product, your previous experience with cannabinoids, and your concrete medical condition.
Usually, an initial oral daily dose with a THC-containing product should be started in the evening with between 1.25mg and 2.5mg THC.1 For patients in need of inhaled medicinal cannabis, there is a greater variability based on the deepness or type of inhalation, although a general starting point can be between 25mg and 100mg of inhaled dried flower.2 Your physician will instruct you what better suits your concrete medical condition.
How long after taking medicinal cannabis can I expect an effect?
This is hard to say because it depends on many factors. Cannabis that is inhaled enters the bloodstream quickly. The peak effects of inhaled cannabis can be felt as quickly as 5 to 10 minutes. Those effects usually last between 2 and 4 hours. On the other hand, cannabis that is ingested can take up to 2 or 3 hours to reach peak effect, however the effect could last for 6 to 12 hours.1
Should I take medicinal cannabis with or without food?
You can safely take oral medicinal cannabis on an empty or full stomach. However, the amount of food you have recently consumed can influence the quantity of cannabinoids that is absorbed.3 The general recommendation is to take your medicinal cannabis product under the same conditions in order to maintain stable absorption of the cannabinoids. Your physician will be able to better recommend what is most suitable for your concrete medical condition.
Do I have to smoke medicinal cannabis?
No. In fact, smoking is not recommended.1,2 There are many ways to inhale or ingest medicinal cannabis. For example, as an alternate to smoking, medicinal cannabis can be inhaled through a vaporizer. A vaporizer is not only safer, since you will not inhale a product resulting from the combustion of the dried flower, but also more accurate from a dosing standpoint.
Is there a recommendation on how to inhale medicinal cannabis?
You can use a vaporizer.3 Each vaporizer has its own specific setup, but the basic steps should include:
- Warming up the vaporizer.
- Grinding the medicinal cannabis flowers (if not already).
- Loading the vaporizer chamber with the ground flowers.
- Adjusting the temperature to 190ºC or higher.3
- When the vaporizer is ready, inhaling on the mouthpiece for 5 seconds.4
- Holding the vapor in the lungs for 10 seconds.4
- Exhaling and waiting for 10 to 20 minutes between inhalations, if required.
What is a vaporizer?
A vaporizer is a device that heats medicinal cannabis in the form of dried flowers. It uses a lower temperature than an open flame, so a vaporizer allows patients to inhale cannabis in vapor form, rather than smoke. Inhalation allows cannabinoids within the plant to be volatilized with heat, enter the bloodstream, and reach the brain more quickly via inhalation, thereby providing fast-acting relief of symptoms. In addition, vaporization avoids combustion and reduces the presence of potentially harmful irritants that may be contained in cannabis smoke.
Which form of medicinal cannabis should I take?
That is up to you and your physician. Generally, medicinal cannabis that is intended for inhalation acts more quickly and lasts a shorter period, so it is more appropriate for episodic acute symptoms. In contrast, medicinal cannabis intended for oral use usually takes a longer time to act, but then lasts for a longer period, so it is more appropriate for chronic conditions. Your physician will decide if and what type of medicinal cannabis product is suitable for your medical condition.
Is there a risk of potential interactions with my current medications?
There is a potential for interactions between medications. You should make sure to ask your physician or pharmacist about potential interactions with existing medications.
If I am taking medicinal cannabis should I stop taking my other medications?
You should only stop taking existing medications if you are advised to do so by your physician.
If I begin taking medicinal cannabis, will I be able to stop taking my opioid prescription?
Medicinal cannabis offers some of the same therapeutic benefits as opioids, however it is only recommended as an adjuvant therapy. Therefore, you should not stop taking any current medication unless you are advised to do so by your physician.
Can I drive when I am taking medicinal cannabis?
Like many other medications, medicinal cannabis can influence your ability to stay alert, drive, or operate heavy machinery.2,3 You should understand how your medicinal cannabis product and dosage affects your ability to function and stay alert prior to driving, operating machinery, or engaging in other dangerous activities. You should avoid driving until you reach a stable dosage for 5 to 7 days.2
You should be familiar with the legal amount of THC before driving. You should wait at least 3 hours after inhalation of medicinal cannabis, or up to 8 hours if psychotropic effects are experienced. Conversely, you should wait at least 6 hours after oral ingestion of medicinal cannabis, or up to 8 hours if psychotropic effects are experienced.2
Can I travel with medicinal cannabis?
Cannabis is authorized for medicinal use in some countries, but not all of them. However, each country may have different rules or limitations on the quantity, type, and strength of medicinal cannabis that is legal for medicinal use. To bring medicinal cannabis into another country, you may be required to fill out paperwork prior to your visit. For example, your physician can provide a certificate according to Article 75 of the Schengen Implementing Convention if you are travelling up to 30 days in one of the countries of the Schengen Implementing Convention.5 Otherwise, the transport of medicinal cannabis across an international border could be illegal. You should contact the embassy of the country you would like to visit so that you can learn how to travel legally with your medicinal cannabis. If you are travelling by air, you should also reach out to the airline to understand their policy on cannabis transportation.
Can I pass a drug test if I take medicinal cannabis?
If you inhale or ingest medicinal cannabis, there is no guarantee that you will pass a drug test. If you have THC in your system, there is a chance that you may fail a drug test. You should check the details of the drug test and if authorized medicinal use of cannabis is allowed.
How do I deal with family members who are unsupportive about medicinal cannabis?
When a family member has an issue with your decision to use medicinal cannabis, it is important to have an open conversation. You are likely much more informed about medicinal cannabis and need to help educate your family. You should try to calmly explain how it benefits you and your medical condition, and why you decided to take it. At the same time, you should listen to your family’s concerns and address them openly.
- MacCallum CA, Russo EB. Practical considerations in medical cannabis administration and dosing. Eur J Intern Med. 2018 Mar;49: 12-9.
- Häuser W, Finn DP, Kalso E, et al. European Pain Federation (EFIC) position paper on appropriate use of cannabis-based medicines and medical cannabis for chronic pain management. Eur J Pain. 2018 Oct;22(9): 1547-64.
- Health Canada. Information for Health Care Professionals: Cannabis and the cannabinoids. October 2018. ISBN: 978-0-660-27828-5.
- Wilsey B, Marcotte T, Deutsch R, Gouaux B, Sakai S, Donaghe H. Low-dose vaporized cannabis significantly improves neuropathic pain. J Pain. 2013 Feb;14(2): 136-48.
- Representatives of the Governments of the Member States of the European Union. The Schengen acquis - Decision of the Executive Committee of 22 December 1994 on the certificate provided for in Article 75 to carry narcotic drugs and psychotropic substances (SCH/Com-ex (94) 28 rev). Accessed December 21, 2021: https://op.europa.eu/en/publication-detail/-/publication/19331bf1-1a3a-4b09-a01a-882be71e6f20/language-en