Can one take CBD with Zofran, and are there any interactions that should cause some concerns? Find out how CBD can help with nausea, vomiting, and other health issues.

Is it Safe to Combine CBD and Zofran?

Zofran is an antiemetic (anti-nausea) medication that works by blocking the neurotransmitter serotonin from binding to its receptors. Inhibiting the activity of serotonin has been established to reduce nausea and vomiting in clinical studies of both animals and humans.

Zofran is potentially dangerous to take CBD while on a Zofran prescription. While CYP2D6 and CYP3A4 metabolize Zofran, CBD blocks both of these enzymes, which results in an increased amount of Zofran that enters the bloodstream. Thus, CBD may also slow down the body’s ability to clear the antiemetic drug from one’s system. 

Having the drug in one’s system for an extended period could also lead to life-threatening or fatal side effects, such as serotonin syndrome. Serotonin syndrome happens when one takes medications that cause high levels of the chemical serotonin to accumulate in the body. Symptoms of serotonin syndrome include muscle rigidity, diarrhea, headache, and heavy sweating. 

Meanwhile, a study published in the British Journal of Clinical Pharmacology showed the effect of combining a cannabis-based medicine with standard antiemetic therapy, such as Zofran. Results indicated that the drug combination was well tolerated, and it provided more protection against delayed chemo-induced nausea. 

Mostly, the patients in the study were able to use less Zofran gradually. They felt better within a period of three to five days after chemotherapy, as compared to taking Zofran alone. The non-psychoactive cannabinoid CBD interacts with serotonin release receptors and has been shown to help alleviate nausea and vomiting. However, the study was only done on a few patients, and not all cancer types were represented. Thus, more extensive clinical trials are necessary to validate the initial results.

There have been reports from some people taking CBD that it has helped them lessen their use of conventional anti-nausea medications like Zofran. Still, combining CBD and Zofran may pose risks. One should never combine CBD and Zofran without the express knowledge, advice, and strict supervision of a medical professional.

How Zofran Helps with Nausea and Vomiting?

Zofran is used to help treat nausea and vomiting in surgical patients and those undergoing cancer treatment with chemotherapy. It is sometimes prescribed to treat severe nausea and vomiting in pregnant women as well, although the U.S. Food and Drug Administration (FDA) has not approved Zofran for this purpose.

Zofran works by inhibiting the activity of a neurotransmitter, a chemical that relays messages within and between nerve cells. As an antagonist, Zofran prevents the neurotransmitter from binding to its receptors. The result of inhibiting the binding of serotonin to its receptors has been shown to alleviate nausea and vomiting.    

Before starting a Zofran therapy, one should inform his or her doctor if there is a personal or family history of Long QT syndrome. The term Long QT refers to an abnormal pattern seen on an EKG (electrocardiogram). LQTS is a heart rhythm disorder and can cause sudden and uncontrollable arrhythmias (problems with irregular heartbeat).

A 32-mg intravenous dose of Zofran may affect QT interval prolongation, which may result in abnormal and potentially fatal heart arrhythmia. Serious side effects of Zofran include blurred vision or temporary vision loss lasting from a few minutes to several hours. Slow heart rate, difficulty in breathing, shivering, anxiety, and agitation may also be experienced. 

People who take Zofran may also feel like they might faint, or they would urinate less than usual, if at all. Zofran may also impair one’s cognitive function, judgment, or reactions. Thus, when these side effects manifest, one should stop taking Zofran and consult with a doctor immediately.

Can CBD Help with Nausea and Vomiting?

There have been no clinical studies on humans to examine the properties of CBD by itself to regulate nausea and vomiting. However, a study found that a mixture with a ratio of equal parts of CBD and THC was very effective at treating nausea and vomiting. Meanwhile, some animal studies have shown promising results for using CBD alone to help alleviate these conditions.

Anandamide, a fatty acid neurotransmitter, directly impacts nausea and vomiting, as high levels of anandamide seem to help improve symptoms. Experts believe that CBD helps to stop the body from metabolizing anandamide. Thus, anandamide levels in the brain increase.

Managing Nausea and Vomiting with Cannabis

Cannabis can provide relief to patients who experience nausea as a result of chemotherapy, radiation, or other recognizable reasons. Tetrahydrocannabinol (THC), cannabidiol (CBD), and cannabidiolic acid (CBDA) all show potential benefits both in research labs and in the homes of patients experienced with cannabis. 

Cannabis use for nausea and vomiting due to chemotherapy or radiation is recognized by some physicians who do not otherwise recommend cannabis. Cannabis is a natural, effective, and well-tolerated by most people. Still, patients should know where their medicine is grown and prepared, and use only third-party lab-tested cannabis that is free of contaminants.

It is best to consult with a healthcare provider before taking CBD oil if one is currently taking any prescription medications. Besides helping one decide whether CBD is safe to take, a medical professional can also offer some advice regarding appropriate CBD dosing that would not cause any adverse effects. A safe way to commence one’s CBD therapy is with a low dose of CBD and only moving to high doses gradually until the desired effect is achieved.

CBD Clinicals is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Learn more