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CBD and inappropriate drug interactions?

The assumption that CBD will not interact with drugs because it is not psychoactive is a potentially dangerous misconception. The widespread recognition of the difference between CBD and high-THC cannabis marks a positive development in medicine, but this development has also served to extend that assumption.

You won't really feel high and so-called "high" after taking CBD, but it's good to know that CBD crosses the blood-brain barrier, which means it affects the brain. In fact, CBD directly affects the central nervous system in a way that slightly alters mood and perception, which technically removes its non-psychoactive label. It would be more appropriate to use the term non-intoxicant.

It may sound like verbiage, but once you understand that CBD is a non-intoxicant that nevertheless produces a number of physiological changes, you realise that you also need to consider that CBD can interact with various drugs and sometimes even fundamentally alter their effects. In almost all cases, this change concerns the rate of metabolism of the drugs.

In this text, we will explain exactly how CBD interacts with drugs, which drugs are involved and how best to manage these interactions

The mechanism by which CBD affects drug metabolism is fairly straightforward

According to a 2019 research article published in the Journal of Clinical Medicine, CBD is a known inhibitor of a group of liver enzymes called cytochrome P450 enzymes.

Cytochrome P450 enzymes, which are responsible for the production and breakdown of a wide range of substances such as steroid-based hormones and fats, maintain a healthy balance of vital molecules in all of our cells.

This class of enzymes also breaks down the compounds contained in prescription drugs, allowing our bodies to feel their effects for a specified period of time and at a specified level of intensity. Because CBD inhibits the production of cytochrome P450 enzymes to some degree, there is an interaction that impairs drug metabolism.

Lower concentrations of these cytochrome enzymes mean that prescription drugs work more strongly for longer periods of time because they are not broken down as quickly. A small but growing body of research in this area has not yet produced any clear data regarding the strength of this effect. However, many substances (about 2/3 of all types of prescription drugs) have been identified that may be affected by CBD in this way.

Drugs interacting with CBD

  • CYP3A4
  • CYP2D6
  • Antihistamines
  • Antipsychotics
  • Antiretrovirals
  • Beta blockers
  • Benzodiazepines
  • Opioids
  • Calcium channel blockers
  • Cyclosporine
  • Tricyclic antidepressants
  • Haloperidol
  • Macrolides
  • Sildenafil (and other PDE-5 inhibitors)
  • Some statins (atorvastatin and simvastatin, but not pravastatin or rosuvastatin)


A report from the Washington, D.C., Department of Health that discusses hemp and CBD drug interactions lists two specific cytochrome enzymes that CBD inhibits. For clarification, both of these enzymes are part of the aforementioned cytochrome P450 category, but are individually identified by a mix of letters and numbers: CYP3A4 and CYP2D6. Although these are not the only enzymes inhibited by CBD, these two are the most significant in terms of drug interactions with a wide range of common drugs.

The report states that CYP3A4 is responsible for the breakdown of antihistamines, some statins, calcium channel blockers, and several other classes of drugs. CYP2D6 is used by the body to metabolize antidepressants, beta-blockers, opioid painkillers and again several other classes of drugs. The above study explains that when these enzymes are inhibited, serum concentrations of the above drugs rise for a longer period of time than in people who took these drugs without CBD.

The specific medications that CBD interacts with are too numerous to list in one article, but if you are aware of what type of medication you are taking, i.e. antihistamine or opioid painkiller, you can determine whether or not an interaction is likely.

This list provides examples of medications and substances, broken down by type, that may interact with CBD:

  • Benadryl (antihistamine)
  • Codeine (opioid)
  • Metoprolol (beta blocker)
  • Zoloft (antidepressant)
  • Lipitor (statin)
  • Alcohol

As always, it is imperative that you consult your physician if you have any questions about possible interactions of CBD with medications you are currently taking or plan to take. This indirect enzymatic pathway is not the only way CBD interacts with drugs, as it can directly target a number of receptors as an agonist or antagonist, meaning it either promotes or limits the receptor's action.

However, these effects have not yet been thoroughly explored and would likely be equally secondary to enzyme-inhibiting effects in terms of relevance to healthcare users. However, one such case that is particularly interesting and highly relevant to many of us involves the relationship between CBD and alcohol.

CBD and alcohol

The results of a study involving ten people, published in the journal Psychopharmacology, point to a nuanced and potentially useful interaction between CBD and alcohol. Participants in the experimental group were given both alcoholic beverages and CBD, and after consumption were tested for motor performance (finger tapping test), psychomotor skills and other indicators of toxicity.

Compared to the placebo group, the CBD group showed significantly lower blood alcohol levels. However, the study states that there were "few differences observed between the pharmacological effects of the two states of drunkenness," suggesting that the anti-toxicity effect of CBD in alcohol consumption did not affect motor performance. Essentially, this suggests that CBD doesn't make you seem less drunk in terms of motor control of the body, but it may act as a buffer to lower blood alcohol levels.


Using known interactions to make smarter healthcare decisions

Even if you suspect that CBD will interact with medications you plan to take or are currently taking, a consultation with your doctor may reveal that you don't necessarily need to get off CBD altogether. This is because the interactions described above are not "synergistic", i.e. they do not increase the potentially dangerous effectiveness and side effects caused by combining certain types of chemical compounds, such as alcohol and opioid painkillers.

In some cases, the patient may be advised to keep CBD doses low and either increase them in very small increments or not at all. For this reason, we recommend that people taking medication use CBD oils and gum with lower concentrations.

Key points to remember

As always, the more you research and prepare, the better equipped you will be to handle potential CBD-medication interactions.

The most important things to remember in this scenario are:

CBD has the potential to interact with a wide variety of drugs in a way that primarily affects their absorption into the body (metabolism). The best way to determine if you can take CBD and medications at the same time is to consult with your prescribing physician.To help you manage CBD interactions with medications, use CBD products that make it easy to set low doses and adjust in small increments. If you follow these steps while talking openly with your doctor, you can greatly reduce the risk of adverse reactions.



Every brand has a responsibility to its customers. Hemnia is dedicated to natural remedies and a harmonious lifestyle. We like to write about these things and share our good experiences. In addition to verified quality and correct, understandable descriptions for our products, we have a duty to make you aware of what we can and cannot be held responsible for. The goal is your safety and we fully respect that.

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