There is a lot that’s still unknown about CBD, but some research indicates there are CBD drug interactions with certain prescriptions, like tacrolimus. The Portland Clinic pharmacy team offers important cautions for those thinking about trying cannabidiol, more commonly known as CBD. CBD, or cannabidiol, is a chemical compound just like any other substance on our beautiful planet. Just like any other compound, it has the potential to interact with other compounds, such as medications that metabolize in the same part of the body.
CBD drug interactions: Is CBD safe to take with prescription medications?
If you’ve visited a store that sells health and beauty products lately, you may have noticed that products containing CBD, or cannabidiol, seem to be all the rage. Oil, chocolate, supplements, even carbonated beverages, are filling up shelves—enticing shoppers with claims that using one of these products will cure insomnia, alleviate anxiety, reduce inflammation, or treat PTSD.
And shoppers are buying it, so to speak—one recent report indicated that CBD sales are expected to hit $16 billion by 2026, up from just over $1 billion in 2018. But what exactly is CBD, and is it safe for people who are using prescription medications? Before using it, it’s important to learn about the potential CBD drug interactions.
Is CBD marijuana?
While CBD is one of the active ingredients in marijuana, using CBD itself will not get you high (the component that does that is called tetrahydrocannabinol, or THC). CBD is really just a molecule within the hemp variety of the cannabis plant, and there is at least some anecdotal evidence and preliminary research suggesting that the extraction created from this molecule has some health benefits.
CBD is thought to act on certain receptors in your brain and other parts of the body, in ways that could relieve pain, or help certain health conditions, like childhood seizure disorders. However, as with any “natural” product, the fact that it comes from plants doesn’t automatically render it innocuous. For some people, particularly those taking certain prescription medications, using CBD is risky. It has anticoagulant effects that can thin blood; it can also modestly lower blood pressure. These effects could be dangerous for people with certain medical conditions.
“Herbal products are drugs,” says Rita Alloway, Pharm.D. , research professor of nephrology at the University of Cincinnati College of Medicine. “Just because [something] is herbal … doesn’t mean it can’t interact with any of the pharmaceutically manufactured drugs that you may be taking.”
Does CBD interact with medications?
Case in point: tacrolimus , an immunosuppressive medication used to prevent organ rejection in patients who have had heart, liver, or kidney transplants. CBD interferes with the metabolism of tacrolimus, according to research conducted by Dr. Alloway , who specializes in post-transplant immunosuppression. And because tacrolimus is a narrow therapeutic index drug (meaning the window between efficacy and toxicity is very small), this interference can lead to clinically significant negative outcomes (such as kidney problems or organ rejection), she says.
Are the concentrations in commercially available CBD high enough to cause this interaction? The evidence doesn’t really say one way or another. Dr. Alloway’s research involved a high dosage of CBD that wouldn’t be found in a retail product. However, it “highlights that a drug interaction is there,” she says. Plus, tacrolimus is metabolized in the body by a group of enzymes called cytochrome P450 and CBD is a known inhibitor of this process. What does that mean? If CBD inhibits the metabolism of tacrolimus, the patient can end up with too-high levels of tacrolimus in the body. In light of this, she urges anyone taking tacrolimus to speak with their transplant team before using CBD. Don’t get your hopes up, though—using herbal remedies, particularly those with potential interactions, is generally frowned upon by doctors looking after transplant recipients (including Dr. Alloway).
As for other drugs, well, most haven’t been studied yet. There is preliminary evidence that CBD could have a similar effect to grapefruit juice, impairing how your body metabolizes drugs, and raising serum levels of those medications in your body. And, because cytochrome P450 is responsible for the metabolism of numerous medications , proceed with caution before mixing any prescription pharmaceutical with CBD, Dr. Alloway says.
How about CBD’s therapeutic benefits?
Despite the not-so-great news about CBD for patients using tacrolimus, for some people, CBD is actually life-changing in a positive way. In 2018, for example, the CBD-derived medication Epidiolex received FDA approval for the treatment of Lennox-Gastaut syndrome and Dravet syndrome, two very rare and very severe forms of epilepsy.
But claims that CBD aids in the treatment of certain mental health and psychiatric conditions, don’t pass muster, says Roger McIntyre, MD , professor of psychiatry and pharmacology at the University of Toronto.
“There is no role right now for CBD in managing mental disorders that I [treat], such as depression, bipolar disorder … anxiety and ADHD,” he says. “We just don’t have the evidence that supports [it].”
Furthermore, most prescription medications used to manage these conditions are metabolized by cytochrome P450, making it entirely possible that CBD could interfere with—rather than enhance—treatment.
Dr. McIntrye, who co-authored a 2018 study that concluded that healthcare providers need more information about drug-drug interactions with CBD and psychotropic medication, says much of the information out there is confusing and contradictory. Therefore, he echoes Dr. Alloway’s statement that it is absolutely prudent that patients clear the use of CBD with their doctor before giving it a go.
“[The provider] knows the individual and knows what other treatments they may or may not be taking,” Dr. McIntyre explains. “They have a panoramic view of the patient’s medications, and would have [a better idea] of whether the patient is taking another medication that may have an interaction.”
Does CBD Gummies Interact With Medications
If you’ve been thinking about trying cannabidiol — more commonly known as CBD — welcome to the rapidly growing club. Interest in CBD as a treatment for pain, insomnia, anxiety and other complaints has been rising steadily ever since Oregon and other states legalized cannabis (marijuana).
CBD is one of many natural chemical compounds found in cannabis, but unlike the plant’s other well-known chemical, THC, it has no psychoactive or mind-altering effects. Instead, CBD owes its popularity to its therapeutic effects. Before you try it, however, be aware that it carries potential risks, as well — especially if you take other medications or have liver problems.
To date, the only FDA-approved use of CBD is a prescription medication called Epidiolex, which treats seizure disorders. Other over-the-counter uses, while widely promoted, need further study to support their claims. These include the following:
With its naturally sedating effects, CBD is used by many people as a sleep aid.
Anxiety and depression
CBD has shown promising results for many people with these issues.
Pain and inflammation
Some patients with arthritis and cancer find CBD helpful in reducing these symptoms.
Much remains unknown about how CBD works, its therapeutic benefits and its safety. For your own safety, it’s important to be aware of the known risks. They include the following:
CBD liver harm
CBD can be harmful to the liver. People with liver impairment should be cautious or avoid it.
CBD medication interactions
Because of its effect on the liver and liver enzymes, CBD can interfere with many medications, either increasing their levels in the blood to potentially toxic levels, or decreasing levels and reducing their effectiveness. Certain seizure medications, antidepressants, muscle relaxers, and drugs that can suppress the central nervous system (such as benzodiazepines, sleeping pills and opioids), among many other medications, may have strong interactions.
It’s important to talk to your doctor or pharmacist before using CBD to make sure you’re not taking a medication that will interact badly with it.
CBD drowsiness and other side effects
Because CBD causes drowsiness on its own, it also increases the drowsiness caused by other medications, including antihistamines (such as Benadryl), benzodiazepines (Xanax, Ativan, Valium), antipsychotics, antidepressants and opioids, as well as alcohol and supplements such as kava, melatonin and St. John’s Wort.
CBD’s sedating effects are similar to alcohol, so it’s not a good idea to use it if you need to drive or to do anything that requires mental alertness. Other common side effects of CBD include diarrhea and changes in appetite and mood.
CBD safety and regulation
Over-the-counter CBD products are not regulated by the FDA. Although most are extensively tested, there is still a possibility of error (such as the mix-up reported last September in The Oregonian), so be wary that products might not be 100% CBD as labeled.
Considering CBD? Talk to your doctor or pharmacist first
If you have questions about how your medications will interact with CBD, reach out to your doctor or local pharmacist for help. Pharmacists are great resources and can help come up with alternative therapies if CBD is not a good option for you.
What Drugs Should Not Be Taken With CBD?
CBD, or cannabidiol, is a chemical compound just like any other substance on our beautiful planet. Just like any other compound, it has the potential to interact with other compounds, such as medications that metabolize in the same part of the body. There are a whopping 98 identified drug interactions just for caffeine, some of which stop the other drug from working completely. Even grapefruit can’t be eaten if you’re on certain prescription medications – which means it’s no surprise that CBD and some drugs just shouldn’t mix.
Fortunately, unlike caffeine and grapefruit, most of the potential interactions with CBD and other drugs have been identified as harmless or mild. In some cases, other drugs and CBD can work in combination with each other favorably instead of having adverse side effects. We always recommend speaking with a certified health professional or physician prior to taking CBD oil or adding it into your daily routine, especially if you are currently on or plan on taking prescription medications. Today, though, we’re going to cover some of the drugs that have been shown to interact with CBD in some way to look at which drugs should not be taken with CBD.
How CBD Might Interact with Other Drugs
We see a range of ways for how CBD interacts with other drugs, medications, and chemical compounds. Cannabidiol may potentially reduce the metabolism of other drugs that compete for the same enzyme as it does. Metabolized by the cytochrome enzymes CYP2C19 and CYP3A4 in the body, this can raise the blood levels of other medications that metabolize the same way, which would require your doctor to do a downward adjustment on your doses. It can inhibit CYP2D6, the enzyme targeted by risperidone and omeprazole medications. Likewise, it could reduce the metabolization of diclofenac and warfarin by inhibiting the hepatic enzyme, CYP2C9.
It was found to increase the bioavailability of Hexobarbital, a barbiturate derivative with sedative and hypnotic effects that’s often sold in both sodium salt and acid forms like Tobinal, Evipan, and Citopan. While cannabis may increase the potency or effectiveness of other drugs, close monitoring by your physician or a medical professional is important. Your dosage may need to be adjusted even if the drug interact is beneficial, so make sure you’re staying honest with your doctor if you’re interested in using CBD.
The CYP450 Enzyme
CBD interacts with more than one cytochrome enzyme, including one located primarily in the liver and brain that’s involved in helping the body process about 60% of the pharmaceuticals on the market right now.
In short, cannabidiol has the potential to interact with a lot of medications just from this enzyme alone.
In fact, here are some of the drugs that have been shown to use the CYP450 enzyme system in our bodies:
· Oral hypoglycemic agents
· Calcium channel blockers
By interacting or saturating this enzyme system, CBD could potentially prevent other drugs from accessing the same enzyme. This causes those medications to build up in the bloodstream instead, which simply makes the drug more potent. However, it could also prevent medication from having a timely effect or releasing into the bloodstream when it’s expected to. On the bright side, just using CBD oil or another CBD product doesn’t mean that your CYP450 enzyme system is affected. Those results came from observing consistently high doses of CBD.
The lower dosages that come in a CBD oil tincture bottle will likely not cause the same extreme effects. We still need more research before we can find the exact dose of CBD required to make any significant difference for a drug interaction. As a rule of thumb, it’s safe to assume that the risk of drug interaction increases the more CBD you take in a daily sitting.
Serum Concentration Increase
CBD may cause an increase the amount of medication in your blood, otherwise known as serum concentrations, according to the District of Columbia’s Department of Health. Just like grapefruit, this means it may interact with beta blockers, calcium channel blockers, antiretrovirals, antihistamines, and antidepressants. Allergy pills, blood pressure medication, and even cholesterol drugs may absorb differently due to CBD blocking the liver enzyme it’s trying to metabolize through.
Again, this is only found in very high doses of CBD, some of which are stronger than an entire standard bottle of a CBD oil tincture. Low amounts of CBD such as standard serving sizes throughout the day don’t appear to affect how your body is processing other medicine (though a doctor’s second opinion is always recommended).
Timing Might be Everything
While you need to discuss with your physician the schedule for taking your drugs, some research suggests that the timing of when you take other medications and CBD might play a huge role in CBD’s interaction with those drugs. The goal is to reduce the workload of the liver. Medication that metabolizes in the liver enzymes are already causing the liver to perform its bodily function. However, all drugs have a half-life, and it doesn’t stay in your liver once it has been metabolized. You just have to wait long enough for the enzymes in your liver to regain a sufficient level of their function before using CBD oil. Drug interactions between CBD and other liver enzyme metabolizing medications may diminish after waiting a couple hours between taking your prescription medication and taking the cannabidiol. Your chances of a drug interaction could be lower by trying CBD throughout different times of the day.
Everyone processes CBD and other drugs differently, so you may experience different interactions than others or have little to no reaction even when you take medication in combination with cannabidiol. Heavily influenced by our body size, age, genetics, and sensitivity to chemical compounds, the effect medication will have and how our bodies will process it can vary greatly. This is just one of the reasons you want to speak with a certified health professional if you’re taking other medication to make sure it doesn’t interfere with a daily serving or more of cannabidiol.
The CBD Product You Choose Matters
There are a tremendous variety of CBD products available now – from CBD oil tinctures, to soft chews, to topicals, we see new products released every day for the industry. The way you decide to use CBD will contribute greatly to how it interacts with any medication you’re on. How much cannabidiol gets into the bloodstream varies from method to method.
For example, applying a topical CBD cream to a target area on the body, or maybe over a muscle spasm, means that the cannabidiol is only interacting with the CB receptors on the skin. The amount of CBD absorbed into the bloodstream topically is likely negligible, making it one of the safest options if you want to use CBD but don’t want it to interact with a more important prescription medication you’re taking. You can also ingest the cannabidiol directly through a CBD oil tincture, soft chew, or other edible product.
This reduces how much and how fast the CBD hits the bloodstream, taking the long route through the gastrointestinal system before heading to the liver to reach those important liver enzymes we keep talking about. Using this method to consume your CBD, you still lessen some of the CBD that’s absorbed into the enzymes in the liver. CBD oil sublingually is the second-best way to get the most effective dose possible. Swishing it around in your mouth, through your teeth, and substantially under your tongue will allow it to hit the highest surface count of capillaries. This is a direct route to your bloodstream, so you can expect the effects to hit the fastest and most effectively, lasting around the same amount of time as an edible might. While this is one of the best ways to get the most out of a CBD oil bottle, it also runs the chance of causing the CBD to interact most severely with any other medication.
The most direct route, an IV is the only way to get the CBD anymore directly into your bloodstream. However, you can also vape or smoke the product; some CBD oil formulas can even be used for both vaping and sublingual doses.
Don’t mix substances without receiving medical advice from a doctor first. We love seeing how many people have found the effectiveness of CBD daily, but your health is the most important factor. We use CBD to promote general wellness, so we want to be upfront about anything that substance might interact with.
Whether you’re taking your prescribed medications or you’re new to cannabidiol, speak with a certified health professional before you take your first serving. Alternatively, you can also check out our lab reports to feel more confident about the lack of contaminants and pollutants and accuracy of the cannabinoid content level we report. You can also check out the FAQ section for any other CBD related answers you are looking for.
In the meantime, we hope this answers any questions you had about how cannabidiol metabolizes in the body, how CBD interacts with other medications or prescription drugs, and, ultimately, which drugs should not be taken with CBD.