Cannabidiol (CBD) is commonly taken to relieve various symptoms and ailments ranging from sleep apnea to multiple sclerosis syndrome and schizophrenia. It helps stimulate the receptors in the endocannabinoid system (ECS), which regulate conditions such as pain, sleep, appetite, and mood.
CBD is noteworthy in that it provides a safe alternative to many prescription and over the counter medications. There is no known lethal dose of CBD, so users don't have to worry about accidentally overdosing because they took too much cannabis. However, all CBD users should know about the way it interacts with other drugs.
CBD and other cannabinoids often inhibit a family of liver enzymes called cytochrome P450. The cytochrome P450 helps metabolize, or break down, the vast majority of drugs we take including over 60% of medications on the market. CBD taken in high enough dosages will momentarily disable the body’s cytochrome P450 enzymes, therefore reducing the rate that they break down any drugs in your system. This, in turn, means that whatever drugs aren’t being broken down will stay in your body longer and their effects will be heightened.
The complete list of substances that cytochrome P450 interacts with is quite lengthy, but includes many well-known names such as ibuprofen, esomeprazole, and oxycodone. It also includes more recognizable substances such as caffeine and cocaine. CBD can be particularly dangerous when mixed with a risky drug like fentanyl or methadone as they will become exponentially more potent.
If you are taking one of the aforementioned drugs, consider taking a lower dosage due to the heightened effects that CBD creates. You can also consider taking an inducer, which increases the body’s metabolic rate and will help counteract the CBD’s suppression of P450. Common inducers include rifampicin, phenytoin, sulphonylureas, phenobarbital, and alcohol when taken chronically.
Patients are being treated for conditions such as cancer and epilepsy must be careful as having CBD in their system could potentially heighten their medications to dangerous levels. Luckily, there have been very few reports of cannabinoids having negative side effects with cancer patients going through chemotherapy and the cytoprotective properties of cannabinoids may help reduce some of the toxins from chemotherapy.
One 2015 study at Massachusetts General Hospital found that children who took CBD with their refractory epilepsy medication had higher blood plasma levels and higher long-term blood concentrations of clobazam and norclobazam. Most of the children had to reduce their intake of clobazam due to its side effects. Fortunately, the study concluded that “CBD is a safe and effective treatment of refractory epilepsy in patients receiving [clobazam].”
1 https://www.solcbd.com/pages/pharmaceutical-drug- interaction-with- cbd
3 https://www.projectcbd.org/science/cannabis-pharmacology/cbd- drug-interactions- role-cytochrome- p450
CBD is incredibly useful for treating a wide variety of ailments, but users should always take caution in how they use it due to the way it interacts with other drugs and medications. As usual, it is always best to consult your doctor or another medical professional before mixing CBD with another substance. If you are unsure of how much CBD or medication you should take, aim for lower doses first to make sure that the effects aren't too overwhelming.