Interactions of cannabis (CBD/THC) with medications
How do medications and cannabis interact?
Cannabis use is also set to be legalized in Germany. That's on the new federal government's agenda. It is well known that marijuana and hashish are widely used even without legalization. So we want to get ahead of this and draw attention to possible interactions.
Interactions between cannabis (CBD/THC) and medications: CBD and THC are the two best-known active compounds among more than a hundred
cannabinoids in the hemp plant
One example already known is an interaction with the "blood thinner" Marcumar and its generics products with the same active ingredient but a different name. Using cannabis during Marcumar therapy can increase the risk of bleeding. This can be dangerous because, as Marcumar patients know, bleeding while taking Marcumar can be hard to stop. This applies not only to external bleeding but also, for example, to bleeding in the gastrointestinal tract. A similar interaction with cannabis is also possible for another group of blood-thinning medications, the direct oral anticoagulants (DOACs) such as Pradaxa (dabigatran), Xarelto (rivaroxaban) and Eliquis (apixaban).
The opposite can occur when blood-thinning is achieved with Plavix (clopidogrel). In this case, the antithrombotic (blood-thinning) effect can be reduced. So using cannabis can increase the risk that blood clots will form.
Similar interactions are described or at least suspected for a large number of other medications. We used the example of blood thinners because this is well documented and because blood thinners are often prescribed for cardiovascular diseases for example after heart attacks and strokes.
To make sure your high doesn't turn into a problem, please don't hesitate to ask your pharmacist about possible interactions with your medications if you plan to use cannabis.
Sources:
This article comes from BloodPressureDB – the leading app since 2011 that helps hundreds of thousands monitor their blood pressure every day.
Our content is based on carefully researched, evidence-based data and is continuously updated (as of 07/2025).
Author Sabine Croci is a qualified medical assistant with many years of experience in internal medicine and cardiology practices as well as in outpatient care, and has led BloodPressureDB's specialist editorial team since 2015. Thanks to her extensive additional qualifications as a paramedic, first responder and in various therapy and emergency areas, she provides solid, practical and reliably reviewed information.
Author Sabine Croci is a qualified medical assistant with many years of experience in internal medicine and cardiology practices as well as in outpatient care, and has led BloodPressureDB's specialist editorial team since 2015. Thanks to her extensive additional qualifications as a paramedic, first responder and in various therapy and emergency areas, she provides solid, practical and reliably reviewed information.
We hope you found the article helpful. For good blood pressure control, it's important to take your medications correctly. Our app BloodPressureDB will gladly remind you when to take them.
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