What Drugs Should Not Be Taken With CBD | Complete Guide

pills spread in a question mark

Because of possible interactions between certain medications and cannabidiol (CBD) that could change the concentration of substances within the body, reducing their effectiveness or elevating their levels and producing side effects, you must be aware of what drugs should not be taken with CBD to ensure your safety.

Even if you are using a high-quality CBD oil and follow dosage guidelines carefully, the cannabidiol could still influence the rate at which the drug is metabolized, leading to either high blood concentrations or decreased effectiveness. 

Understanding CBD Drug Interactions

Every day, research uncovers more information about how exactly CBD affects the metabolism of certain medications, but there is still much to learn. 

What we do know is that CBD has the ability to either increase the concentration levels of certain medications, which could lead to adverse effects and faster elimination from the body, or decrease the concentration levels, resulting in diminished effectiveness. 

Additionally, CBD can increase the side effects of some medications, particularly those with side effects similar to those associated with CBD.

A general rule to follow is that if you are advised to avoid grapefruit in any form while taking a prescription, you should avoid taking CBD with it as well. This is because, like CBD, grapefruit can impact how the CYP450 enzyme system works, particularly the CYP3A4 isoform.

You should always check with your doctor before adding CBD to your wellness routine, particularly if you are on any prescription medications. 

CBD Can Affect How Certain Drugs Are Processed

Studies have shown that CBD is metabolized by the CYP450 enzyme system, which includes CYP2C9, CYP2C19, CYP3A4, UGT1A9, UGT2B7, CYP2C8, CYP1A2, CYP2B6, CYP2D6, CYP2C8, CYP2E1, CYP3A, and CYP3A4 enzymes.

Approximately 60% of prescription medications are also metabolized by these enzymes. It is thought that CBD and certain medications sometimes “compete” for the enzymes, though there is still much to learn about how exactly this occurs. 

CBD can either inhibit or induce these enzymes, affecting how quickly or slowly some medications are metabolized. This leads to altered concentrations of the drug within the body, which, in turn, impacts the drug’s effectiveness.

Some Drugs Can Affect How CBD Is Processed

Like CBD, some medications also inhibit or speed up the work of enzymes in the liver. This can impact how cannabidiol is processed and made available to the endocannabinoid system. 

When enzymes are inhibited by medications, there may be increased levels of CBD in the system due to decreased enzymatic activity, but when enzymes are induced, cannabidiol is processed at a higher rate due to increased enzymatic activity, which reduces its bioavailability, leading to a shorter duration of effectiveness.

Overlapping Side Effects With CBD and Certain Medications

Side effects of CBD are relatively rare and typically mild. These include drowsiness, fatigue, dry mouth, irritability, lightheadedness due to a temporary drop in blood pressure, and digestive upset. 

When taking CBD alongside medications (or supplements) with similar effects, you not only double your chances of experiencing these side effects, but you also run the risk of increasing the severity of any resulting effects.

Drugs to be especially cautious of in regards to side effects when mixed with CBD include alcohol, antidepressants, opioids, antihistamines, benzodiazepines, and antipsychotics.

How You Take CBD Affects the Degree of Interaction

Taking CBD oil sublingually (placing and holding the oil under your tongue) and vaping CBD produce the fastest effects because the cannabidiol is directly absorbed into the bloodstream, where it soon reaches the liver for metabolization. 

CBD gummies, capsules and other edibles go through your digestive system, where they are partially broken down before reaching your bloodstream. This leads to lower concentrations of CBD, which mean a lower risk of drug interactions within the liver. 

CBD applied topically does not reach the bloodstream in large enough amounts to warrant concern regarding drug interference. 

What Drugs Should Not Be Taken With CBD

With more than 20,000 prescription drugs available currently, figuring out which ones are safe to use with CBD is not easy. The following list is by no means comprehensive, but it should give you a general idea of which medications are not considered compatible with CBD for safety reasons.

Drugs Used To Treat Epilepsy

CBD shows great promise in preventing seizures caused by certain conditions in some people, and, currently, the only CBD medication approved by the FDA, Epidiolex, is for controlling seizures.

However, when non-prescription CBD is combined with drugs used to treat epilepsy, such as brivaracetam, clobazam, eslicarbazepine, lamotrigine, stiripentol, rufinamide, topiramate, valproic acid, zonisamide, phenobarbital and phenytoin, this could lead to liver damage and toxicity. 

Antidepressants

Because of CBD’s ability to inhibit liver enzymes, taking cannabidiol while on prescription medicine to treat depression can lead to elevated concentrations of the drug within the body as the liver isn’t able to process the drug as it normally would. This could lead to negative and potentially dangerous side effects. 

Medications that fall within this category include sertraline (Zoloft), escitalopram (Lexapro), fluoxetine (Prozac), and other Selective Serotonin Reuptake Inhibitors (SSRIs).

Blood Pressure Medications

Because cannabidiol has been shown to reduce blood pressure in some individuals, taking CBD while on medication to treat hypertension can be dangerous. This is because both CBD and high blood pressure medications work to lower blood pressure, so you would be essentially doubling your dose, which could lead to dangerously low blood pressure. 

Unless your doctor instructs otherwise, do not take CBD if you are taking diuretics, beta-blockers, ACE inhibitors,angiotensin II receptor blockers, calcium channel blockers, alpha blockers, alpha-2 receptor agonists, combined alpha and beta-blockers, or vasodilators.

Benzodiazepines

Benzodiazepines are mild sedatives used to treat insomnia, stress, anxiety, and sometimes seizures. CBD also has mild sedative properties, so taking the two together could significantly increase feelings of sedation. 

It’s not just overlapping side effects that pose potential problems here. CBD can inhibit the enzymes responsible for processing benzodiazepines, which could lead to increased levels of the drug in your body. This could accelerate or intensify the normal effects of the drug in a dangerous way. 

The potential dangers apply to all benzodiazepines, including Xanax, Librium, Valium, Ativan, diazepam, and clonazepam.

Opioids

Opioids are not limited to heroin and fentanyl. Codeine, morphine, oxycodone, hydrocodone, and many other medicines prescribed for pain also fall in the opioid class. 

Promising studies indicate that, one day, CBD might be useful in treating opioid addiction, but when it comes to combining cannabidiol with prescription opioids, experts advise against it.

Both CBD and opioids can cause increased sleepiness, lethargy, and sedative effects. Combining these substances could lead to greatly increased side effects, which could impact your ability to function normally and even result in slower breathing and heart rate. 

Blood Thinners

Commonly prescribed blood thinners include warfarin, apixaban (Eliquis), rivaroxaban (Xarelto),  dabigatran (Pradaxa), edoxaban (Savaysa), fondaparinux (Arixtra), enoxaparin (Lovenox), and dalteparin (Fragmin).

Taking CBD with blood thinner medications that are metabolized by the CYP450 enzymes, whether they are antiplatelets or anticoagulants, can be risky. Because CBD can impact the metabolic rate of blood thinners, either an increased chance of bleeding or a reduction in the medication’s effectiveness can result. 

Immunosuppressants

Immunosuppressants, such as tacrolimus, cyclosporine, mTOR inhibitors, and adalimumab (Humira), help prevent your immune system from attacking healthy cells. 

CBD could affect how these drugs are metabolized, which could cause negative side effects, toxicity, and an increased risk of severe infection.

Proton Pump Inhibitors

Proton pump inhibitors are used to reduce the amount of stomach acid produced. Common PPIs include omeprazole (Prilosec), esomeprazole (Nexium), lansoprazole (Prevacid), pantoprazole (Protonix), rabeprazole (AcipHex), and dexlansoprazole (Dexilant). 

Using CBD in conjunction with PPIs can increase the chances of side effects, such nausea and diarrhea, and possibly cause the drug to be less effective.

Antibiotics and Antifungals

Because antibiotics and antifungals are processed by the same enzymes that are responsible for metabolizing CBD, taking them together is not wise. 

CBD can inhibit the enzymes, which could lead to high concentrations of your medicine in the bloodstream, but the medications could also impact the metabolism of CBD, which could cause higher levels to circulate within your body and increase the chance of side effects.

Chemotherapy Drugs

While preliminary research indicates that CBD is helpful in fighting cancer and alleviating symptoms associated with chemotherapy drugs, the possibility of CBD to affect the metabolism of these drugs still exists. This could cause drug concentration levels to rise to potentially toxic levels.

Until more is known about how CBD affects chemotherapy medications, combining the two is not worth the risk unless your doctor thinks otherwise.

Statins

Using CBD while on cholesterol-lowering statin drugs, such as atorvastatin (Lipitor),

fluvastatin (Lescol), lovastatin (Mevacor), pitavastatin (Livalo), and simvastatin (Zocor), can cause an increased risk of side effects and liver damage.

Like CBD, statins can cause drowsiness and digestive upset, so taking these together is not recommended.

Taking CBD With OTC Drugs and Supplements

You might assume that taking CBD with common over-the-counter drugs and health supplements is safe, but that is not quite accurate. 

While adverse effects are not likely to be life threatening, CBD can interfere with the way certain drugs and supplements work, making them less effective and potentially causing increased side effects.

Tylenol, for example, can damage the liver over time. Taking it with CBD increases this chance. Many OTC drugs and supplements have a list of side effects that coincide with those of CBD, such as drowsiness, stomach upset, diarrhea, lightheadedness, and mild sedation. 

When you combine CBD with a medicine or supplement with similar side effects, you greatly increase the likelihood of these side effects and possibly increase their severity as well. 

Other Potential Side Effects

In addition to possible drug interactions, CBD can also potentially cause several other side effects. In some instances, taking cannabidiol could result in dry mouth, fatigue, drowsiness, lightheadedness, irritability, and digestive issues such as nausea and diarrhea.

These side effects are usually mild in nature and resolve on their own once you stop taking CBD or as your body adjusts to the CBD in your system. 

If you have any concerning reactions after taking CBD, stop dosing, and consult your doctor right away, especially if you experience dizziness or lightheadedness as this could indicate a dramatic drop in blood pressure.

Closing Thoughts

It’s completely understandable if you’re still unsure if your prescription medicine is safe to take with CBD. After all, not many of us know exactly which one of our many enzymes is responsible for breaking down the medicines we take routinely, and scientists are still studying the possible effects and reactions that can occur when CBD and prescription drugs are combined. 

The safest route to take is to obtain clearance from your doctor before adding CBD to your daily routine, even if you think you have a firm grasp of what drugs should not be taken with CBD. 

Why take chances with low-quality CBD? Spruce CBD oil is made with lab-grade full-spectrum CBD and 100% natural ingredients. Each batch is thoroughly tested by a third party for purity and potency to ensure a quality that is simply unmatched!

Frequently Asked Questions

What medications are not safe with CBD?
Taking CBD with medications that are processed by the CYP450 enzyme system could result in dangerously high drug concentration levels in your bloodstream, leading to adverse effects. 

CBD also has the ability to increase the speed at which some drugs are metabolized, leading to reduced effectiveness. 

When should you not use CBD?
You should not use CBD if you are pregnant or breastfeeding, taking prescription medications that are metabolized by CYP450 enzymes, or when consuming alcohol or recreational drugs. 

If you are new to CBD, avoid activities that require alertness, such as driving, until you know how your body responds.

What supplements should not be taken with CBD oil?
While it is considered safe to take common vitamins and supplements while using CBD, supplements with side effects similar to those of CBD, such as drowsiness, drop in blood pressure, and fatigue, should be avoided as effects could be intensified to the point of being dangerous.

Does CBD oil affect your liver or kidneys?
Currently, CBD oil is not thought to harm your kidneys, especially when used responsibly. Some studies indicate that cannabidiol may protect your liver from fatty liver disease. However, those taking excessively high doses of CBD for a long period of time have a slightly elevated risk of liver toxicity. 

Read also: