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how does cbd oil interact with other medications

Does CBD Interact with Other Medications?

In a nation where prescription drug use is rampant, the issue of med interactions is sure to rear its head. Big Pharma introduces new prescription drugs to the market annually. And there are thousands available. The Government’s recent National Health Survey found that approximately 20% of American adults take 3+ drugs. Some FDA experts believe a massive percentage use at least two.

Research by JAMA Internal Medicine found that 36% of seniors use at least five drugs or supplements! Because of this, 15% of seniors are at risk of significant drug interactions. Sometimes, a physician prescribes a cocktail of medication to a patient. The goal is to create beneficial interactions that enhance the effect of drugs. Sadly, there are occasions where the doctor gets it wrong, and patients become ill or even die.

Logically, the more drugs you take, the higher the risk of a drug interaction. Incredibly, there is a 15% chance if you take two medications. Consequently, the risk increases to 40% for five drugs, and 80% for seven drugs! It is of greatest concern for seniors due to their extensive usage of prescription medications.

A growing number of people use CBD to try and combat the symptoms of medical conditions. Popular uses for the compound include as a means of reducing epileptic seizures, and to reduce anxiety. While the cannabinoid has a good safety profile, there is the question of CBD interactions.

In this article, we explore the issue in greater depth.

How CBD Interacts with Drugs and Medication

CBD drug interactions are more prevalent than you think. The most common one relates to Cytochrome P450 (CYP 450) enzymes. Up to 60% of all medications on the market get broken down by this class of enzyme. Let’s check out a few more medical interactions featuring cannabidiol.

CBD & CYP 450 Enzymes

The reason why CBD causes so many potential drug interactions is down to its effect on the CYP 450 enzyme. You find it in the liver, and it’s responsible for metabolizing possible toxic compounds. This class of enzymes metabolizes up to 60% of pharmaceutical drugs. When determining the right doses of drugs, physicians make their calculations based on the CYP 450 enzymes. They decide how long it takes for a certain drug to pass through the system.

At sufficient doses, CBD temporarily deactivates CYP 450 enzymes. This process has a significant impact on how we metabolize drugs. According to preclinical research, the CYP 450 class of enzymes metabolize CBD. However, cannabidiol becomes a competitive inhibitor and stops the enzymes from metabolizing other compounds.

The extent of CBD’s effect on CYP 450 depends on how tightly it binds to the active site of the enzyme before and after oxidation. This action varies according to the CBD dose, the form of administration, and the unique attributes of the user. CBD won’t affect CYP 450 when taken in small doses.

A report from 2013 looked at GW Pharmaceuticals’ Sativex, a sublingual spray containing CBD and THC. It found no interaction when patients used 40mg of CBD. However, a later clinical trial discovered that just 25mg of orally administered CBD was enough to block an anti-epileptic drug’s metabolization.

In summation, CBD inhibits the CYP 450 system of enzymes. When the proteins can’t perform their function, too much of a drug enters the liver. It flows to the bloodstream unprocessed. It subsequently increases the risk of having dangerously high levels of drugs in your system. Given the rate of opioid overdose deaths, it is an essential piece of information.

Grapefruit & Drugs

Those who have used medication in the past are probably aware of the ‘grapefruit’ warning that appears on certain drugs. In this instance, you are not supposed to eat grapefruit when using the medication due to a possible negative interaction. This is because grapefruit contains furanocoumarins. These compounds bind with and neutralize, CYP 450 enzymes. As with CBD, it causes excessive levels of a drug to get into the bloodstream.

CBD is arguably even more of an issue than grapefruit because it binds in several parts of the liver and gut. In contrast, grapefruit primarily impacts enzymes within your small intestine. After CBD inhibits an enzyme, it can take days for its function to return to baseline levels.

A study by Yamaori S., published in Drug Metabolism and Disposition in November 2011, looked at CBD’s effects on CYP2D6. The researchers found that cannabidiol was also a potent inhibitor of CYP3A4. Both enzymes affect drugs such as antidepressants, antihistamines, and statins.

The enzymes inhibited by CBD and grapefruit potentially break down a vast range of OTC drugs as well. In theory, a low dose of medicine could become a high dose if not broken down correctly. A high dose could turn into an overdose. There is a particular risk with drugs that have a narrow therapeutic window.


CBD lowers blood pressure and reduces anxiety, just like beta-blockers. Indeed, both options produce a variety of similar results, and CBD oil potentially carries fewer side effects. However, take both together and you may experience a rapid drop in blood pressure. As a result, you could feel dizzy, weak, and lethargic. In some instances, you could faint or go into shock.


CBD also inhibits the system that metabolizes a high percentage of SSRIs, antipsychotics, and tricyclic antidepressants. In theory, using cannabidiol with any of these drugs could interfere in how they are metabolized.

Blood Thinners

If you take certain blood thinners with CBD, they are potentially subject to prolonged activity and an increased effect. Moreover, cannabidiol could increase the levels of medication in your blood. This process enhances the risk of adverse side effects.


Individuals use metformin to manage diabetes. Early research indicates that CBD’s anti-inflammatory properties could also aid patients with diabetes. However, the cannabinoid could counter metformin’s effect of lowering blood sugar.

Hydrocodone/Paracetamol Interactions

Research into how hydrocodone interacts with CBD is limited. However, mixing this powerful drug with cannabis could suppress your central nervous system to dangerous levels.

At present, there is no known CBD interaction with paracetamol. Next, let’s check out the drugs you should avoid when using CBD.

What Drugs Should You Not Take With CBD?

Given the likely safety profile of the cannabinoid, there are a surprising number of CBD drug interactions. As you will see later, it has a lot to do with the CYP 450 enzymes. As a consequence, there are possible CBD oil drug interactions with the following:

  • Steroids
  • PPIs
  • NSAIDs
  • Oral hypoglycemic agents
  • Anti-epileptics
  • Benzodiazepines
  • HIV antivirals
  • Prokinetics
  • Antihistamines
  • Calcium channel blockers
  • Immune modulators
  • Sulfonylureas

The above is not a full list of all possible drugs impacted by CBD. Also, not every medication within the above categories causes an interaction. As a result, we recommend consulting with a medical professional before trying CBD oil.

What Medications Does CBD Interfere with?

CBD oil interactions occur with drugs that are also metabolized in the body by CYP 450 enzymes, CYP3A4, and CYP2C19. The United States Department of Health has created a list of medicines that are possibly subject to CBD oil interaction.

Here is a list of drugs that cause a medication interaction when used with CBD:

  • Calcium Channel Blockers: Tiazac, Norvasc, and Cardizem.
  • Tricyclic Antidepressants: Amitriptyline, doxepin, and protriptyline.
  • A Variety of Antipsychotics
  • Sildenafil: Viagra, Levitra, and Cialis.
  • Benzodiazepines: Valium, Xanax, and Klonopin.
  • Antihistamines: Allegra, Benadryl, and Xrytec.
  • HIV/AIDS Medications
  • Opioids: Oxycodone and codeine.

Does CBD Oil Interact with Antidepressants?

Yes! Be wary when using CBD oil and antidepressants together. According to the National Alliance on Mental Illness, up to 20% of American adults live with a mental illness. NBC News reported that 17% of US residents take a form of psychiatric medication. Antidepressants are the most widely prescribed.

Peter Grinspoon of Harvard Medical School, says that in general, you can use CBD supplements with antidepressants safely. However, he cites some concerns. For one thing, the CBD market remains unregulated. As a result, you must get your CBD from a reputable supplier.

The other primary concern is the lack of clinical evidence. Grinspoon asserts that CBD has hypothetical drug interactions. However, we don’t know if they are clinically significant. He continued by pointing out how CBD inhibits two central enzyme systems and discussed the grapefruit issue.

Grinspoon looked at CBD and SSRIs. He notes that CBD inhibits the system that metabolizes this form of drug. If you are taking psychiatric medication, the last thing you need is interference in how it is metabolized. Nonetheless, Grinspoon confidently stated that most harmful CBD interactions are theoretical. He said that CBD had a minimal side effect profile. Grinspoon also hasn’t heard of ‘clinical decompensation’ issues due to the addition of CBD.

Interaction Between CBD and Chemotherapy Drugs

You must also show caution when undergoing chemotherapy treatment. A growing number of patients use cannabidiol to manage symptoms such as vomiting and nausea. Common chemotherapy drugs include Paraplatin, Doxorubicin, and Ellence.

An inadequate amount of a drug means it won’t provide relief. However, too much could lead to toxicity. Because of this, it is a fine line between therapeutic benefits and harmful side effects. Doctors use the CYP 450 to calculate suitable doses. If the enzyme system is inhibited, it makes their job a lot more complicated. This is what happens when you add CBD to the mix. Therefore, the cannabinoid could cause excessive concentrations of the drug to enter the bloodstream, with toxic results.

Consult a Doctor Regarding CBD Medication Interaction

Drug-drug interactions occur when two medications react with one another. As a result, medication interaction is a grave matter. In some cases, the drug has less of an effect. In other instances, too much of the medicine gets into the system. Certain combinations are dangerous. For example, mixing a sedative with an antihistamine could significantly slow your reactions. Suddenly, driving a vehicle or operating heavy machinery are actions fraught with peril.

Research suggests that there are CBD oil interactions with a wide variety of drugs. It all relates to how cannabidiol inhibits the CYP 450 class of enzymes. These are responsible for the metabolization of over half the drugs on the market.

Ideally, you will get in contact with a physician before using CBD if you are on other drugs. In most cases, you should not use cannabidiol with any medicines that carry a ‘grapefruit’ warning. While there is no evidence of a high risk, it is better to be safe than sorry!

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Can you take cbd when you take beta blocker. Using cbd hopefully to help with seizures!

Amy Passarelli

CBD is yes an incredibly safe and therapeutic medication, but I would say that always consult your doctor when you are mixing two things together at the same time. Also in case of any emergency, your doc would then know as to why it happened and would be able to manage it in a more appropriate manner.


I take many inhalers and oxygen, will CBD oil cause any problems or should
I just go off all of them and only need to take CBD oil.


Researchers have found that CBD inhibits the enzymes CYP3A4 and CYP2D6. These are both major metabolizing enzymes for our body, which means CBD has the potential to interact with many substances.

Mary Stevens

To me CBD has never interacted of interfered with other forms of medication. I have tried it with antibiotics, with weed, with multivitamins, it works well for me without any side effects always.


I am trying to get off Ativan as I’m so nervous I cry in despair.
I cut from 3 to 2 a day and it’s so hard. Cbd helps but it takes allot to counterattack my severe nervousness. Thank you for this article. God knows we try to get off these meds that doctors feed to us so they can keep us in bondage to them as they sip of the highlife. This world is ready for a change to help the innocent be freed from big pharma for good. Lord help us all

Diane Keets

Thank you for this. I am sadly on a very large amount of meds, all of which are different and probably some shouldn’t be used together. I would love to try CBD for my depression, but worry it will end badly.