Does CBD interact with aspirin and other antiplatelets?

  • Aspirin can help some people lower their risk of a heart attack or stroke. However, the antiplatelet can also cause severe bleeding, according to an article published by the University of Michigan Health System (UMHS)(1).
  • Data from a 2012 study published in the British Journal of Clinical Pharmacology showed that CBD influenced platelet formation, which could support the ability of CBD to delay or prevent the development of cardiovascular disorders(2).
  • However, CBD can inhibit the cytochrome P450 (CYP450) system’s ability to metabolize certain drugs, leading to an overall increase in processing times(3).
  • In a study published by the American Society for Clinical Pharmacology and Therapeutics, researchers found that the effects of low-dose aspirin administration on CYP450 in healthy human subjects are enzyme-specific, meaning the effects depend on which type of enzymes(4).
  • Given that the specific effects of combining CBD with aspirin have not been established in any longitudinal scientific study conducted on humans, using the two substances together is not recommended.
  • Consulting with a trusted medical practitioner experienced with cannabis use is the best course of action for anyone looking to try CBD for the first time or include CBD in their current regimen.

Can CBD Be Taken with Aspirin?

Aspirin is typically used by a person to relieve minor pain and aches or to reduce fever. Veterinarians also often prescribe aspirin for dogs that are suffering from musculoskeletal or osteoarthritis inflammation.

But can people take aspirin and use CBD at the same time?

The cytochrome P450 enzyme system, which is found within the liver, is responsible for metabolizing (breaking down) potentially toxic compounds, including over 60% percent of any drugs consumed(5).

Certain substances can affect processing times within this system, making drugs metabolize faster or slower than they would on their own.

Cannabidiol can inhibit the cytochrome P450 system’s ability to metabolize certain drugs, leading to an overall increase in processing times(6).

In a study published by the American Society for Clinical Pharmacology and Therapeutics, researchers illustrated the effect of low-dose aspirin administration on the activity of cytochrome P450 (CYP) in healthy human subjects(7).

Researchers of the said study found that the effects of aspirin on the CYP450 system of enzymes depend on the specific type of enzyme under the CYP450 family of enzymes.

Given that the specific effects of combining CBD with aspirin have not been established in any scientific study, using the two substances together is not recommended.

Can Another Antiplatelet Be a Substitute for Aspirin So CBD Oil Can Be Taken?

Ticlopidine (marketed as Ticlid), an effective inhibitor of platelet formation, is indicated for patients who cannot take aspirin or in whom aspirin has not worked to prevent a thrombotic stroke(8).

A thrombotic stroke is one that is caused by thrombosis, the formation or presence of a blood clot within a blood vessel.

However, ticlopidine inhibits multiple CYP450 types of enzymes, as data from a study published in the British Journal of Clinical Pharmacology showed(9).

According to the research findings, the plasma concentrations and/or toxicity of drugs whose elimination pathways involve the different types of CYP450 enzymes increased when ticlopidine is concomitantly administered.

Thus, ticlopidine may also interact with CBD in the same way that aspirin does.

Given that the specific effects of combining CBD with aspirin have not been established with scientific evidence, using ticlopidine is also not recommended to use with CBD.

It is interesting to note, however, that bleeding time was significantly prolonged by aspirin alone and by ticlopidine alone.

However, the most significant prolongation was produced by aspirin plus ticlopidine, according to results of a study published by the American Heart Association(10).

The results of the study also demonstrated that the combination of aspirin and ticlopidine is a potent antiplatelet strategy.

Can CBD replace Aspirin?

There is no scientific data to establish CBD as a treatment option in the same way that people use aspirin. The two drugs may interact with the heart in different ways.

An article on aspirin risks and benefits by Mark Fendrick, M.D., published by the University of Michigan Institute for Healthcare Policy and Innovation.

In the said article, Fendrick says that aspirin interferes with the blood’s clotting action and reduces the clumping action of platelets, possibly preventing a heart attack(11).

Still, he cautions that it is not advisable to take aspirin tablets, hoping to prevent a heart attack, without a doctor’s supervision.

Is CBD a safer alternative to aspirin in preventing heart attack?

Data from a 2012 study published in the British Journal of Clinical Pharmacology showed that CBD influenced platelet formation, which could support the ability of CBD to delay or prevent the development of cardiovascular disorders(12).

However, the study was done on animal subjects. Whether the responses to CBD would translate into the human cardiovascular system remains to be established.

In another study, which was first published by JCI Insight in 2017, results showed that CBD could lower blood pressure, which could help prevent hypertensive heart disease(13).

The study was done on healthy volunteers, however. The researchers noted that further research is required to establish whether CBD has a role in the treatment of cardiovascular disorders.

New Guidelines for Aspirin Use

According to an October 2019 article published by the American College of Physicians, recent research based on a 2017 National Health Interview Survey has found that, in certain groups of people, there are few advantages and a higher risk of bleeding from daily aspirin use(14).

In response to the results of the survey, the American Heart Association and American College of Cardiology updated their guidelines in March of 2019.

The two agencies no longer recommend aspirin for the prevention of cardiovascular disease in adults aged 70 and above or for those with a higher risk of bleeding, like those with stomach (peptic) ulcers.

Thus, medical experts advise that people speak with their health care providers before taking aspirin daily.

Two Types of Blood Thinners: Which Type is Aspirin?

There are two primary types of blood thinners. Anticoagulants, like heparin or warfarin (Coumadin), slow down the aggregation or formation of clots.

On the other hand, antiplatelet drugs, like aspirin, inhibit blood cells (platelets) from clumping together to form a clot(15).

Aspirin as Nonsteroidal Anti-Inflammatory Drug (NSAID)

Nonsteroidal anti-inflammatory drugs (NSAIDs) reduce fever and inflammation and relieve pain. Examples of NSAIDs include aspirin, ibuprofen, and naproxen.

Aspirin, unlike other NSAIDs, can help certain people lower their risk of a heart attack or stroke. However, taking aspirin is not recommended for everyone as the antiplatelet can cause severe bleeding, according to an article published by the University of Michigan Health System (UMHS)(16).

The article says that people who are over 65 years old or who have existing kidney, heart, liver, stomach, or intestinal disease are at increased risk for complications.

How NSAIDs Work

NSAIDs work by blocking enzymes called COX-1 and COX-2. These enzymes produce prostaglandins, a group of compounds made by the cells in the body(17).

Prostaglandins made by COX-1 enzymes actuate platelets and protect the lining of stomach and intestines. Prostaglandins produced by COX-2 enzymes are generated in response to injury or infection, controlling inflammation.

Most NSAIDs work non-selectively on both enzymes. However, this lack of selectivity becomes an issue given that pain and inflammation relief from NSAIDs come from blocking COX-2. When COX-1 is also blocked, unwanted adverse side effects emerge.

Aspirin, an NSAID, functions by blocking the production of prostaglandins, the on-off switch in cells that control pain and inflammation. Thus, aspirin prevents mild inflammation and pain(18).

“To the consumer, aspirin is almost a miracle drug,” says Nimita Thekkepat, assistant professor of pharmacy at St. Louis College of Pharmacy. “It helps inflammation, fever, and it can save your life from a heart attack.”

However, while aspirin blocks the type of prostaglandins that trigger pain or lead to clotting and narrowing of the blood vessels and inflammation, the drug also blocks a different kind of prostaglandins that protect the stomach lining.

Aspirin belongs to a group of nonsteroidal anti-inflammatory drugs, or NSAIDs, that include ibuprofen (Motrin, Advil), naproxen (Aleve) and ketoprofen (Orudis).

Among these NSAIDs, aspirin induces the most irritation and the most toxic (painkiller) to the stomach, says Dr Richard Brasington, head of the Division of Rheumatology at Washington University School of Medicine.

Medical experts, like Brasington, warn against taking a variety of nonsteroidal anti-inflammatory drugs at the same time as they neutralize each other, making neither drugs perform well. The remedy is to wait several hours after taking one medicine before taking the next.

Blood Thinners and NSAIDs, A Bad Mix

NSAIDs impact the way platelets work and could impede with healthy blood clotting, which could increase the risk of bleeding, especially in the digestive tract, says cardiologist Dr Deepak L. Bhatt, a Harvard Medical School professor, in an article published by Harvard Health(19).

Bhatt also adds that taking NSAIDs together with blood thinners raises the bleeding risk even more.

Understanding CBD

Medical marijuana, sometimes referred to as medical cannabis, is a term for derivatives of the Cannabis sativa plant(20).

CBD (cannabidiol) and THC (tetrahydrocannabinol) are common cannabinoids that are natural constituents of cannabis plants, which include marijuana and hemp. Thus, CBD can either be a hemp or cannabis extract.

Marijuana contains much more THC than hemp, while hemp contains excellent quantities of CBD. THC induces a euphoric high, while CBD helps promote relaxation and calmness.

In a study published in the Cerebrum Journal, researchers explained that the endocannabinoid system (ECS), which is comprised of cannabinoid receptors, endocannabinoid molecules, and their metabolic enzymes, is crucial in maintaining homeostasis, or balance, amongst physiological functions(21).

CBD Oil or Hemp Oil?

The term “hemp oil” is sometimes used to refer to the CBD-rich product extracted from the hemp plant’s flowers and leaves, which is essentially CBD oil. However, the term is also used to refer to hemp seed oil that contains no CBD.

Although hemp seed oil is not CBD oil, which is extracted from the flowers and leaves of the plant, note that oil pressed from hemp seed does not contain CBD, THC, and plant cannabinoids(22).

CBD oil is available in different varieties, such as full-spectrum (oil derived from the whole plant), THC-free distillate, and CBD isolates.

Cannabis and Aspirin

In a 2013 study published in the Rambam Maimonides Medical Journal, it was shown that the ECS is involved in numerous body functions, including the modulation of pain and inflammation(23).

In a 2008 study published in the Journal of Therapeutics and Clinical Risk Management, author Ethan Russo found that Tetrahydrocannabinol (THC) has twenty times the anti-inflammatory potency of aspirin(24).

Results from his research also suggest that cannflavin A, a flavone unique to cannabis, inhibits PGE-2 thirty times more potently than aspirin, although further examinations are needed(25).

PGE-2 (Prostaglandin E2) is a bioactive lipid that elicits a wide range of biological effects associated with cancer and inflammation(26).

Flavones are a sub-group of flavonoids shown to exhibit anti-inflammatory, antidiabetic, anticancer, anti-thrombogenic (prevents blood clot), and neuroprotective activities through different mechanisms of action outside a living organism and in animal models(27).

Cannabidiol and CYP2D6

Cannabidiol, a major phytocannabinoid, is a potent atypical inhibitor for CYP2D6, according to a study published in the Drug Metabolism and Disposition Journal(28).

Phytocannabinoids are cannabinoids that occur naturally in the cannabis plant. Cannabinoids are closely-related compounds naturally found in cannabis, like CBD and THC.

In the said study, the researchers investigated the inhibitory impacts of the primary phytocannabinoids on the activity of human CYP2D6. The results indicated that CBD caused directly blocked CYP2D6 potency.

Drug to Drug Interactions

In a 2016 study published in the Epilepsia Journal, the authors found that repeated administration of CBD may induce CYP2B enzymes in animal subjects, which may have implications for people with epilepsy as antiepileptic drugs (AEDs), such as valproate and clobazam, are metabolized via these enzymes(29).

Still, the antiepileptic mechanisms of CBD have not been known. The researchers noted that there is a lack of data from longitudinal double-blind, randomized, controlled studies on the efficacy of pure CBD for any disorder.

Recently, the U.S. Food and Drug Administration (FDA) approved Epidiolex as the first-ever cannabis-derived medicine for Lennox-Gastaut Syndrome (LGS) and Dravet Syndrome (DS), the symptoms of which do not typically respond to anti-seizure medications(30).

While CBD is the active ingredient in Epidiolex, it also contains inactive ingredients that include dehydrated alcohol, sesame seed oil, strawberry flavor, and sucralose(31).

Aspirin and Beta Blockers

Aspirin blunts the vasodilation (widening of blood vessels) caused by both angiotensin-converting enzyme (ACE) inhibitors and beta blockers in hypertensive patients and in patients with heart failure. This conclusion was derived from a study that was published in the Journal of the American College of Cardiology(32).

The specific mechanisms that cause this interaction are unknown, and further studies are needed. Until conclusive evidence is available, it is not advisable to use aspirin in conjunction with beta blockers.

Aspirin and Warfarin

A 2017 study published in the Cannabis and Cannabinoid Research Journal analyzed CBD safety and side effects(33).

Researchers of the said study noted that while CBD can raise the levels of concentration of certain medications in the blood, its adverse side effects can sometimes outweigh the advantages.

Based on the results of the study, the authors indicated that CBD could cause a surge in the level of the anticoagulant (blood thinner), warfarin (Coumadin), by accentuating aspirin’s blood-thinning property.

Conclusion

Aspirin is part of a group of painkillers and fever reducers called non-steroidal anti-inflammatory drugs (NSAIDs).

Meanwhile, CBD’s broad utility for pain relief may be partly explained by its anti-inflammatory effects.

CBD’s antioxidative and anti-inflammatory properties may help lower risk factors that can lead to heart disease, like high blood pressure, as a 2017 study suggests(34).

Still, despite CBD’s potential therapeutic benefits, taking it together with aspirin is not recommended. Neither is it advised to use CBD products in any form (gummies, tincture, vape, or topical) with other antiplatelet prescription drugs. Although using aspirin and CBD may each have its advantages, it also comes with risks. As studies mentioned above demonstrate, the risks may outweigh the health benefits.


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  13. Khalid A. Jadoon, Garry D. Tan, and Saoirse E. O’Sullivan. A single dose of cannabidiol reduces blood pressure in healthy volunteers in a randomized crossover study. JCI Insight. 2017;2(11):e93760. https://doi.org/10.1172/jci.insight.93760. Retrieved from https://insight.jci.org/articles/view/93760#FN.
  14. Colin W. O’Brien, MD; Stephen P. Juraschek, MD, PhD; Christina C. Wee, MD, MPH. (2019, October 15). Prevalence of Aspirin Use for Primary Prevention of Cardiovascular Disease in the United States: Results From the 2017 National Health Interview Survey. Retrieved from https://annals.org/aim/article-abstract/2738925/prevalence-aspirin-use-primary-prevention-cardiovascular-disease-united-states-results.
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  17. Bonni Goldstein, MD On August 15, 2018 (Updated On May 6, 2019). Trade in Your Ibuprofen for Cannabis. Retrieved from https://www.projectcbd.org/wellness/trade-your-ibuprofen-cannabis.
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  19. Harvard Health Publishing. Updated: December 16, 2019Published: October, 2013. Bad mix: Blood thinners and NSAIDs. Retrieved from https://www.health.harvard.edu/diseases-and-conditions/bad-mix-blood-thinners-and-nsaids.
  20. Mayo Clinic.(2019, Nov. 27). Medical marijuana. Retrieved from https://www.mayoclinic.org/healthy-lifestyle/consumer-health/in-depth/medical-marijuana/art-20137855.
  21. Alger BE. Getting high on the endocannabinoid system. Cerebrum. 2013;2013:14. Published 2013 Nov 1.
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  27. Jane Higdon, Ph.D. (2005). Flavonoids. Retrieved from https://lpi.oregonstate.edu/mic/dietary-factors/phytochemicals/flavonoids.
  28. Satoshi Yamaori, Yasuka Okamoto, Ikuo Yamamoto and Kazuhito Watanabe. Cannabidiol, a Major Phytocannabinoid, As a Potent Atypical Inhibitor for CYP2D6. Drug Metabolism and Disposition November 2011, 39 (11) 2049-2056; DOI: https://doi.org/10.1124/dmd.111.041384.
  29. Devinsky O, Cilio MR, Cross H, et al. Cannabidiol: pharmacology and potential therapeutic role in epilepsy and other neuropsychiatric disorders. Epilepsia. 2014;55(6):791–802. doi:10.1111/epi.12631.
  30. U.S. Food and Drug Administration (FDA). (2018, June 25). FDA approves first drug comprised of an active ingredient derived from marijuana to treat rare, severe forms of epilepsy. Retrieved from https://www.fda.gov/news-events/press-announcements/fda-approves-first-drug-comprised-active-ingredient-derived-marijuana-treat-rare-severe-forms.
  31. David C. Steinberg, FRAPS, Steinberg & Associates, Inc. Cannabidiol (CBD) The Coming Crisis. Retrieved from https://www.fda.gov/media/128536/download.
  32. JoAnn Lindenfeld, Alastair D Robertson, Brian D Lowes, Michael R Bristow. Journal of the American College of Cardiology. (2001 Dec). Aspirin impairs reverse myocardial remodeling in patients with heart failure treated with beta-blockers. DOI: 10.1016/S0735-1097(01)01641-2.
  33. Iffland K, Grotenhermen F. An Update on Safety and Side Effects of Cannabidiol: A Review of Clinical Data and Relevant Animal Studies. Cannabis Cannabinoid Res. 2017;2(1):139–154. Published 2017 Jun 1. doi:10.1089/can.2016.0034.
  34. Jadoon KA, Tan GD, O’Sullivan SE. A single dose of cannabidiol reduces blood pressure in healthy volunteers in a randomized crossover study. JCI Insight. 2017;2(12):e93760. Published 2017 Jun 15. doi:10.1172/jci.insight.93760.
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