Medical Marijuana Drug Interactions: A Maryland Cannabis Doctor’s Perspective

Medical Marijuana Drug Interactions Maryland

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In 2014, Maryland legalized medical cannabis and on December 1st, 2017, for the first time EVER, Maryland medical cannabis patients were allowed to legally purchase marijuana from a state approved medical cannabis dispensary!!

Since February 2016, Green Health Docs has seen and certified over 3000 patients, in 6 locations, for the Maryland Medical Marijuana Program and finally patients are getting access to this wonderful medication.

Many patients come to Green Health Docs looking to reduce the amount and/or dosage of their current prescription medications. This is understandable since most medications have the potential for harmful side effects, especially with prolonged use and when combined with other medications.

Even over-the-counter pain medications like ibuprofen (Motrin) can cause stomach ulcers or increased bleeding if overused. Despite all the medical benefits of cannabis, there are many drugs that it can’t replace. Blood pressure medication, blood thinners, antidepressants, anxiolytics, seizure medications and chemotherapeutics are examples of common medications that should be continued in conjunction with medical marijuana.  

Luckily the effects of marijuana itself are pretty benign, and that will be a topic for another blog post.  But what about the effects of marijuana in conjunction with these common types of medications?

The Biggest Risks of Medical Marijuana Use

Most of the cannabis-drug interactions can be traced back to liver metabolism. Our livers have important Cytochrome P450 enzymes (abbreviated CYP450) that metabolize the vast majority of drugs that we take. Cannabinoids like THC and CBD are also metabolized by these enzymes.  

The effectiveness of your CYP450 enzymes can be altered by other medications, and in the case of cannabis, this can cause your other medications to get metabolized more slowly. As a result, your prescriptions will remain in your system longer and at higher levels than intended, which can sometimes cause unwanted side effects.

This usually only occurs at very high doses though, and CBD appears to be the main culprit. Cannabis is just a plant but it can still be deadly.

Side Effects and Signs of Drug-Cannabis Interactions

Side Effects and Signs of Drug-Cannabis Interactions

The vast majority of patients do not experience side effects when taking cannabis in conjunction with other common medications, but given the lack of clinical trials on cannabis, it is wise for patients to be aware of some possible drug-cannabis interactions. It’s extremely important to watch for side effects when using blood thinners like Eliquis, Xarelto, and Coumadin.  

Be wary of cuts that bleed too long, increased bruising, increased nosebleeds, or blood in your stool or vomit.  For blood pressure medications like Carvedilol, Hydrochlorothiazide, Lisinopril and Valsartan watch for low heart rate, fatigue or reduced blood pressure approaching 90/60.  Antidepressants, anxiolytics, seizure medications and chemotherapy medications all have their own specific side effects that may become pronounced by cannabis use as well.

Cannabis also has possible interactions with medications that are not related to liver metabolism. Some case studies have shown that cannabis combined with SSRI antidepressant medications like Zoloft and Prozac can induce hypomania (elevated mood with symptoms such as racing thoughts, decreased sleep, grandiose thoughts, and talkativeness).

Sedatives and anti-anxiety medications may have their effects amplified by cannabis use as well. However, there are not enough rigorous studies to warrant avoiding concurrent cannabis use completely.  People have been using cannabis legally and illegally in combination with their prescription drug regimens for decades and there has yet to be much cause for concern for the general public.

A Few Important Facts about Cannabis Metabolism

A Few Important Facts about Cannabis Metabolism

Your age, route of administration/ingestion and the health of your liver are examples of factors that can determine whether the current dose of cannabis you use is safe with your other medications. Genetics also play an important role, as it does for most medications. The genetics of your drug transporters could affect how much THC is able to cross your blood-brain barrier.  

Furthermore, everyone’s cells have different concentrations of the CB1 and CB2 receptors that cannabinoids activate. Some people also have variations in their CYP450 enzymes which make them less effective at metabolizing cannabinoids so that low doses of cannabis have more powerful effects on them.

If you do notice that cannabis is affecting your medications and causing serious side effects, it’s recommended that you cease cannabis use and notify your medication prescriber as soon as possible in case doses need to be adjusted.

If the side effects are minor, there are a few things you can adjust to prevent them from reoccurring. You can cut back on edibles since orally administered cannabis is more heavily metabolized by the liver. You can also reduce your CBD intake since research shows it more drastically affects CYP450 liver metabolism than THC at higher doses.

What Should You Know about the THC and CBD Content of Your Medication?

Medical Marijuana - Maryland Medical Cannabis Commission

Try to stagger your prescription drugs and your cannabis use to give time for your body to metabolize each separately. If all of those things fail you may have to either lower your cannabis dose or use a lower dose of your medications while using cannabis.

By far, the vast majority of patients do not notice any major side effects as a result of cannabis interfering with drug liver metabolism. Nonetheless it’s important to use common sense if you are new to cannabis or if you are starting a new prescription medication.

Lastly, try to be aware of the THC and CBD content of your medication if you are trying new strains or if you are trying a different route of administration. Keep the cannabis risks in mind so you can fully enjoy all the medical benefits this amazing plant can offer.


About the Author:

Dr. Evan Edwards is a medical cannabis expert and practices as a physician with Green Health Docs. Dr. Edwards was the first doctor in the Green Health group of providers and as such has seen more Maryland cannabis patients than almost any other provider in the state of Maryland. Believing the potential of this plant to heal many, Dr. Edwards enjoys providing this option for patients and loves seeing the improvements cannabis has made in the lives of his patients.  

Green Health Docs has 6 locations statewide – Cumberland, Hagerstown, Frederick, Rockville, Waldorf and Baltimore – and certifies patients all over Maryland for the Medical Cannabis Program.  

If you are looking to become a legal Maryland marijuana patient, contact Green Health Docs at 240-356-1000 and we will walk you through everything!

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7 comments on “Medical Marijuana Drug Interactions: A Maryland Cannabis Doctor’s Perspective

  1. Hello,
    I heard that you run seminars on the education of how to use the paraphernalia once a patient has the product. Can you tell me if and when you would be holding such a seminar.

    1. Thank you for reaching out! We use to hold seminars and maybe starting them back up in the future, but if you ever have questions you can reach us at 240-356-1000 or come into any of our 6 locations and our staff would be more than happy to assist you!

      Best, Green Health Doc’s

  2. The locations in the state of Maryland are great for the people that are in need of the medication. Will share this information to others that might not know of all the places that serve people in need.

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