This article was written and vetted for scientific accuracy by Dr. Omer Rashid
If you are looking to use CBD products to alleviate any medical problems that you are experiencing then prior information about its drug-drug interactions is vital. This knowledge about how CBD can impact other drugs in the body system will not only save you from any unwanted issues but will also help you to extract more benefits out of your CBD use.
CBD, also known as cannabidiol, is one of the most significant constituents of cannabis. Unlike cannabis (marijuana), CBD on its own does not cause euphoria or dependence. Also, The World Health Organization states that there have been no reports of any health-related issues as far as pure CBD is concerned. While pure CBD has no warnings associated with it, CBD products that have additional constituents need to be carefully analyzed before use. You should also be cautious if you are already on other drugs or you have been prescribed medications recently to avoid any possible adverse CBD drug interactions. And one way of staying risk-free is keeping your doctor in the loop about your current use of CBD or your prospective intent to use CBD.
As a rule of thumb, I would recommend you to go for CBD oils that are high in cultivar whole-plant extracts and have little or no impurities. CBD oil extracted from high cultivar strains of the cannabis plant have negligible levels of Tetrahydrocannabinol (THC) as compared to other strains. THC is the constituent of cannabis that imparts euphoria and may also result in some side effects.
CBD interactions with Medications
For all the things we ingest, metabolism starts in the stomach. But the most crucial metabolic phase of 60 percent of the drugs that we use takes place in the liver. This means that the liver is the organ responsible for making the active ingredients of these drugs available in the bloodstream. Once these metabolized active ingredients are able to travel through the blood, they can then reach the numerous organ tissues in an efficacious form. Being the usual metabolic center for the drugs, the liver also helps in eliminating the unwanted drug byproducts that are produced because of the chemical reactions taking place in the liver. These byproducts are transformed by the liver into a form that makes it easier for the body system to flush out.
The liver has a set of enzymes (CYPs) that help it metabolize various substances. However, some specific substances can engage these enzymes and hamper their ability to metabolize other drugs. This increases the concentration of the non-metabolized drugs in the body, which can make a person experience adverse effects. CBD is also one of those substances that can potentially interact with the CYPs resulting in a degradation of the metabolism process of some drugs.
However, CBD products such as CBD oils that are taken sublingually enter the bloodstream without encountering the liver and its chemical reactions. So there are no drug interactions with CBD oil in such cases. But if you are ingesting CBD oil then it may lead to CBD oil drug interactions due to the involvement of the liver. Most of the research that has been done so far to find out the effects of CBD oil on the liver involves mice. And the mice were exposed to a much higher dose as compared to what humans would normally consume.
Studies were also conducted on mice to find the effects of CBD oil on kidneys and no evidence of any adverse effects could be found. The studies actually revealed some beneficial effects of CBD on kidneys such as prevention of a particular type of nephrotoxicity.
Drugs not Compatible with CBD
CBD is generally well tolerated and the adverse effects that have been reported are only due to its interaction with other drugs. These other drugs can be the existing medications or other substances that might be mixed with CBD.
The primary concern with CBD drug interactions is that it can result in raising the levels of certain drugs in the body system — resulting in toxicity or amplified side effects. Therefore, It’s important to talk about those medications first that are widely used and have the potential to cause harm on a larger scale.
Drugs like Xanax or Ativan, termed benzodiazepines, are widely prescribed to treat anxiety.
CBD can elevate the concentrations of these drugs in the body, which can amplify the sedative effects of these drugs — so be wary of that. Increased drowsiness may also be experienced while using CBD with some supplements such as St. John’s wort, kava, and melatonin. A high state of drowsiness can lead to accidental falls and road accidents.
CBD can also increase the levels of warfarin, a blood thinner sold under the brand name Coumadin, and this can result in excessive bleeding. People who are on warfarin should talk to their doctors about their CBD use. The doctor would either adjust the dose or advise you to halt your CBD use.
A thyroid medication named levothyroxine has also been found to be unsafe for use in conjunction with CBD.
Anti-epileptics such as Clobazam are widely used to treat seizures in children. CBD is also considered an effective treatment of seizures in children and if both CBD and Clobazam are being used simultaneously, it can increase clobazam levels causing an overdose of the drug. CBD use alongside epileptics should be avoided in general.
If you are on cholesterol medicines, also known as statins, you should be aware that CBD can increase the levels of these drugs in the body. CBD can increase the accumulation of atorvastatin (Lipitor) and simvastatin (Zocor) in the body system which can have dangerous effects.
You can experience a decrease in your appetite if you are taking CBD with a stimulant such as Adderall. And you may experience diarrhea if you are taking CBD with heartburn drugs like Prilosec and diabetes drugs such as metformin.
There are several other kinds of medicines that CBD is not recommended with. Thanks to the grapefruit rule it can be easier for you to identify these medicines. Grapefruit rule refers to the grapefruit warning, which means that if you consume grapefruit along with a particular drug, you are likely to have a higher concentration of that drug in the body. Grapefruit drug interactions work the same way as CBD, which means that they too interfere with the CYPs enzymes to raise the levels of certain drugs. So the grapefruit rule implies that if you find a grapefruit warning on a drug — it is also a CBD warning. Please note that this is a general rule of thumb and does not account for all possible scenarios.
According to the FDA, drugs such as steroids and corticosteroids (budesonide sold as Uceris and Entocort UC), heart rhythm medications (amiodarone sold as Nexterone and Pacerone, high blood pressure medications (nifedipine sold as Adalat CC and Procardia), organ transplant rejection drugs (cyclosporine sold as Neoral and Sandimmune), and some antihistamines (fexofenadine sold as Allegra) are all on the grapefruit warning spectrum. So avoid them while using CBD.
Also, drugs such as bronchodilators, antidepressants, antipsychotics, antihistamines (Benadryl), some NSAIDs (Advil and Aleve), and certain antibiotics (clarithromycin and erythromycin) are prone to CBD drug interactions.
Rule of thumb
The grapefruit rule is a great tool to help you stay safe from any CBD incompatibilities — so always look for those grapefruit warnings on drug labels. Also, try to consult your doctor whenever you can.