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cbd oil heart disease

Your Good Health: CBD oil risky for anyone on heart medication

January 3, 2019 06:02 AM


Dear Dr. Roach: I am a 49-year-old woman who had a massive heart attack in April of this year. My father died of a massive heart attack at 49 when I was three. I have four stents in three arteries and am on Brilinta, low-dose aspirin, blood-pressure medication, etc.

I have had essential tremor for all of my life, first noticing the tremors in middle school. The tremor is in my hands, making writing nearly impossible, and I have head bobs. I have an internal tremor that never stops.

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A previous practitioner prescribed a month’s trial of beta blockers several years ago. I noticed no relief with the tremor, but was physically ill for the first 30 minutes of the morning in the first two weeks of the trial. Recently, while doing some research, I found an online blog regarding essential tremor and CBD oil. Nearly all of the bloggers found some level of relief using this treatment.

If I choose to try CBD oil to assist with my tremor, is there a risk of it interfering with my heart and blood-pressure medications?


Cannabidiol, or CBD, is a nonpsychoactive substance found in cannabis, as opposed to tetrahydrocannabinol, or THC, the best-known psychoactive component.

CBD is typically sold as an oil, and has been receiving press as a potential treatment for a wide variety of medical issues. Many or most of these claims have no data to support them. Anecdotal reports, such as most blogs, are neither reliable nor scientific (and may or may not be true).

There is also an issue with proving the dosage and purity of products said to contain CBD.

However, in the case of essential tremor, there is some evidence: Studies in mice have shown benefit with CBD, although a single case report showed effectiveness of THC but not CBD in essential tremor.

The issue of drug interactions is a significant one. CBD inhibits two powerful pathways the body uses to detoxify drugs, the CPY3A4 and CYP2D6 systems. This is a serious issue for you. Ticagrelor (Brilinta), an anticoagulant, is metabolized by CYP3A4, as are some of the statin drugs usually prescribed to people with heart blockages.

The effect of the anticoagulant could be much higher than expected, leading to bleeding risk. Other commonly used heart medications are metabolized by CYP2D6, and the effect on these medications is unpredictable.

I can’t recommend CBD products given the medications you are taking, but would suggest you consider alternative treatments.

You might have read about deep brain stimulation and ultrasound, two powerful and effective treatments for people whose symptoms have not responded to standard treatments.

Dear Dr. Roach: This question is for my husband. How safe is drinking tea while on warfarin?

He has his INR checked monthly, and for the most part, it stays between 2 and 3.

He watches his vitamin K intake regularly. He has read conflicting stories about how tea interacts with warfarin by making INR levels high.


Tea comes in two major types: black tea, which is fermented, and green tea, which is not. Black tea has no known interactions with warfarin (Coumadin). Green tea contains small amounts of vitamin K, which could make the INR lower and the warfarin less effective. However, the effect is likely to be small. Further, if he drinks a consistent amount per day, his dose can be adjusted to reflect his vitamin K intake.

Dear Dr. Roach: I am a 49-year-old woman who had a massive heart attack in April of this year. My father died of a massive heart attack at 49 when I was three. I have four stents in three arteries . . .

Cannabis, heart disease and stroke

Cannabis has been legal for medicinal use in Canada since 2001. Since 2018, many cannabis products have been legal for recreational use, including dried cannabis, fresh cannabis, cannabis oil and cannabis seeds for cultivation. In 2019, cannabis edibles, topicals and extracts (including cannabis vape products) became legal.

There is currently little high-quality scientific evidence about the impact of recreational cannabis use on heart conditions and stroke.

  • Emerging evidence shows an increased risk for heart disease and stroke from the effects of cannabis on blood pressure, inflammation of the blood vessels and cardiac arrhythmias 1,2,3,4
  • Other reports link cannabis use with cardiovascular emergencies, including heart attack, arrhythmias, heart failure, stroke and cardiac arrest (cardiopulmonary arrest). 5,6,7
  • Some research shows that long-term or excessive use of cannabis, increases the risk for heart disease and stroke. 1,3,8
  • Respiratory illness and deaths in the United States have been linked to vape products, many of which are cannabis (THC) vaping products obtained through informal sources. 9

Heart & Stroke recommends reviewing the Lower-Risk Cannabis User Guidelines to assess the safest modes of cannabis use. Consumers should follow guidance and advisories from Health Canada related to vape products and if vaping cannabis, always obtain THC extracts for vaping from authorized dealers.

Recreational use of cannabis

If you are considering using cannabis for recreational purposes, read the Lower-Risk Cannabis Use Guidelines. However, the guidelines have not been updated since early 2019 and predate the surge in vaping-related lung illness throughout 2019. Heart & Stroke recommends that people follow the advice of health agencies – including the Centre for Disease Control (CDC) and Health Canada – with regards to the use of vape products. We also recommend that you speak to your healthcare provider about the effects of cannabis on your personal health – especially if you have a higher risk for heart disease and stroke.

Vape products and cannabis

There have been over 2,600 cases of vaping related respiratory illness in the US, including over 60 related deaths. 9 Several cases have emerged in Canada, without any deaths. The CDC has recently identified Vitamin E acetate (an additive in some THC vape products) as a chemical of concern in this outbreak and is warning e-cigarette users to avoid using THC products especially from informal sources. 9 The CDC has not yet ruled out other chemicals of concern. Heart & Stroke warns that vape devices of all kinds are not without harm.

Smoking cannabis is considered the most harmful for respiratory health and ingestion of cannabis is the least harmful. Vaping cannabis is somewhere in the middle in terms of level of harm. All modes of delivery have some level of overall health risk.

Heart & Stroke is working to ensure government regulations are in place to make sure young people are protected from vape products with nicotine or THC. These include:

  • warning labels
  • marketing restrictions
  • flavour ban
  • restricting sales to special vape shops
  • increasing the legal purchase age to 21 years of age
Cannabis for medical purposes for heart disease and stroke

Using cannabis products to help you with pain from heart disease and stroke is a personal decision. To get cannabis for medical purposes, you need a prescription from a healthcare provider. 10 There are discussions taking place about allowing Canadians access to cannabis health products for minor ailments (muscle soreness, pain relief) without a prescription. 11

Talk to your healthcare provider about the risks and benefits of using cannabis for medical purposes. While cannabis products are legal, Health Canada does not endorse, nor has it evaluated, the use of cannabis for medical purposes. 12

Gaps in research

Further research is needed into the short-term and long-term effect of cannabis on heart disease and stroke. Heart & Stroke encourages more research on the impact of recreational cannabis use and the medicinal benefits of cannabis products on heart disease and stroke.

More research is needed to understand the effects of cannabis on your heart and brain. Learn about cannabis, heart disease and stroke.