Does cannabis harm patients with bleeding disorders?

Uwe’s Answer: A bleeding disorder is a medical condition where the blood’s ability to clot is impaired, leading to excessive bleeding or bruising. This can result from defects in blood vessels, platelets, or clotting factors. Common bleeding disorders include hemophilia, von Willebrand disease, and platelet function disorders. Symptoms may include frequent nosebleeds, heavy menstrual bleeding, prolonged bleeding from cuts, and easy bruising. Management typically involves medication to enhance clotting or replace deficient clotting factors.

The Endocannabinoid System and the Blood

Research has shown that the endocannabinoid system (ECS) plays a significant role in blood cell development and function. For instance, endocannabinoid receptors are expressed in several types of blood cells, including platelets, macrophages, mast cells, B-cells, T-cells, megakaryocytes, or erythrocytes. As such, they may represent a novel target system to treat a diverse group of blood disorders.¹ However, most research on this topic is still in its infancy, with only a few pre-clinical trials to guide an informed and discerning treatment path forward.

Endocannabinoids (AEA): The body’s endocannabinoids, anandamide (AEA) and 2-arachidonoylglycerol (2-AG), have been shown to speed platelet aggregation in the blood.

• AEA significantly accelerated thrombus (blood clot) growth in test animals.²
• 2-AG (and virodhamine) induce platelet aggregation in the laboratory.³

If confirmed in human trials, this effect may be harnessed to help patients with bleeding or clotting disorders (e.g., coagulopathy).

The reader may find it instructive to note that Yoga,⁴ a modulator of the eCBome, has been shown to increase AEA and 2-AG levels by more than 70% (for more information on the eCBome and respective modulators, click here).

Phytocannabinoids (THC): Tetrahydrocannabinol, the predominant psychoactive cannabis constituent, can interfere with platelet function and clotting, which could be detrimental to patients with bleeding disorders. Research indicates that THC can reduce platelet aggregation, which is critical to the clotting process, potentially leading to platelet dysfunction without significantly affecting clotting times.⁵

Phytocannabinoids (CBD): Pre-clinical data showed that CBD neither increased nor reduced the activation of platelets.⁶ CBD does not appear to have any significant effects on blood clotting. However, it can interact with blood thinners such as warfarin direct oral anticoagulants by inhibiting certain metabolizing enzymes, increasing the risk of bleeding complications. To learn more, consider looking at a case series involving the co-administration of CBD and oral blood thinners.⁷

Patients using cannabis products should consult healthcare providers to monitor and adjust their treatment regimens carefully. For instance, one case study found that reducing warfarin by 30% while co-administering CBD to control epileptic seizures was sufficient in this patient to prevent clotting-related adverse effects.⁸ However, it is essential to realize that the co-administration of cannabinoids with blood thinners must be monitored carefully to ensure optimal patient outcomes.

In summary:

• The understanding of the use of cannabinoids in the treatment context of bleeding disorders is in its pre-clinical phase.
• The ECS is involved in the synthesis and function of the blood.
• Endocannabinoids are involved in the clotting process.
• THC can reduce platelet aggregation, which is critical to the clotting process. As such, it could be detrimental to patients with clotting disorders.
• CBD does not appear to inhibit clotting.
• CBD inhibits enzymes that break down common pharmaceutical drugs for treating blood disorders.

Endnotes:

1. Sharma DS, Paddibhatla I, Raghuwanshi S, Malleswarapu M, Sangeeth A, Kovuru N, Dahariya S, Gautam DK, Pallepati A, Gutti RK. Endocannabinoid system: Role in blood cell development, neuroimmune interactions and associated disorders. J Neuroimmunol. 2021 Apr 15;353:577501.
2. Grambow E, Strüder D, Klar E, Hinz B, Vollmar B. Differential effects of endogenous, phyto and synthetic cannabinoids on thrombogenesis and platelet activity. Biofactors. 2016 Nov 12;42(6):581-590.
3. Brantl SA, Khandoga AL, Siess W. Mechanism of platelet activation induced by endocannabinoids in blood and plasma. Platelets. 2014;25(3):151-61.
4. Sadhasivam S, Alankar S, Maturi R, Vishnubhotla RV, Mudigonda M, Pawale D, Narayanan S, Hariri S, Ram C, Chang T, Renschler J, Eckert G, Subramaniam B. Inner Engineering Practices and Advanced 4-day Isha Yoga Retreat Are Associated with Cannabimimetic Effects with Increased Endocannabinoids and Short-Term and Sustained Improvement in Mental Health: A Prospective Observational Study of Meditators. Evid Based Complement Alternat Med. 2020 Jun 5;2020:8438272.
5. Reitsma SE, Lakshmanan HHS, Johnson J, Pang J, Parra-Izquierdo I, Melrose AR, Choi J, Anderson DEJ, Hinds MT, Stevens JF, Aslan JE, McCarty OJT, Lo JO. Chronic edible dosing of Δ9-tetrahydrocannabinol (THC) in nonhuman primates reduces systemic platelet activity and function. Am J Physiol Cell Physiol. 2022 Mar 1;322(3):C370-C381.
6. Grambow E, Strüder D, Klar E, Hinz B, Vollmar B. Differential effects of endogenous, phyto and synthetic cannabinoids on thrombogenesis and platelet activity. Biofactors. 2016 Nov 12;42(6):581-590.
7. Paduch M, Thomason AR. Potential Drug Interactions Between Cannabinoids and Its Derivatives and Oral Anticoagulants. Hosp Pharm. 2022 Feb;57(1):188-192.
8. Grayson L, Vines B, Nichol K, Szaflarski JP; UAB CBD Program. An interaction between warfarin and cannabidiol, a case report. Epilepsy Behav Case Rep. 2017 Oct 12;9:10-11.