US Cardiac Arrhythmia Case Could Stoke International CBD Safety Worries
Executive Summary
A patient admitted to a US emergency department after experiencing dizziness and fainting without warning is found to have been using a cocktail of herbal dietary supplements, including CBD and CBG. The case could fuel international worries about CBD's safety, for example in the EU, where novel food applications were recently put on hold by EFSA because of safety data gaps.
A study published in the official journal of the Heart Rhythm Society reports what may be the first recorded case of acute cardiovascular issues related to the use of cannabidiol and cannabigerol (CBD/CBG)-containing supplements, according to its authors.
The study notes the case of a 56-year-old woman who was recently admitted to a US emergency department after experiencing dizziness and fainting without warning.
She was diagnosed with a life-threatening cardiac arrhythmia after an electrocardiogram (ECG) showed short bouts of torsade de pointes – a specific type of abnormal heart rhythm originating in the ventricles that can lead to sudden cardiac death – and noticeably long intervals between her heart’s electronic recharge, measured by its QT interval.
“Her medical history was unremarkable,” noted the study's authors. “There was no familial history of sudden cardiac death.”
What was remarkable, however, was that the patient had been taking a cocktail of supplements to help her deal with a “stressful work-life balance,” according to the researchers.
She had been taking hemp oil supplements containing a total of 61mg/mL CBD and 1mg/mL CBG three or four times a day for the previous four months, as well as herbal supplements containing 250mg of berberine.
As part of her treatment, this supplements regime was stopped, resulting in a gradual decrease of the QT interval and normalization after five days.
The patient was discharged six days after hospitalization. At three months’ follow-up, she reported no new episodes of dizziness or syncope, with an ECG still showing a QT interval within normal range.
“Herbal supplements are gaining popularity and are available as OTC medicine. These products should be used with caution,” the study's authors warn, “as data concerning their effectiveness, toxicity, and potential for interactions are limited.”
“In addition, there are variations in the concentrations of the active substances. Therefore, the use of these supplements should not be taken lightly, dosing recommendations should be respected, and possible interactions with other medication or supplements should always be considered,” they add.
Fuel To The Fire?
The case may add fuel to fire of debates about CBD safety, for example in the EU and US.
The European Food Safety Authority, EFSA, recently put all CBD novel food applications on hold after its Novel Foods and Food Allergens panel concluded that there are “several hazards related to CBD intake” and that the “many data gaps on these health effects need filling before these evaluations can go ahead.”
While cardiovascular issues were not identified by the NDA as one of the hazards and related data gaps, liver damage, gastrointestinal issues, specifically diarrhea, and negative effects on pregnancy and reproductive organs were.
In conclusion, the NDA stated that the safety of CBD as a novel food “cannot currently be established.”
“The Panel has identified several hazards related to CBD intake and pointed out deficiencies in both the experimental animal and human data,” the NDA concludes.
“The data gaps and uncertainties identified in this statement need to be addressed by the applicants to provide the basis for the safety assessment of CBD as a NF.”
Safety In Question
In the US, the Food and Drug Administration recently stated that its scientific advisory board will be “utilizing cannabinoids as a case study,” during a meeting conducted online will consider challenges in evaluating the safety of “ingredients with predicted pharmacological activity” which are used in supplements and food.
The FDA has previously noted that the safety profile for products containing CBD or cannabis-derived compounds like CBG is still limited and has highlighted the need for additional data to address uncertainties and data gaps related to the ingredient. (Also see "Confidentiality For Proprietary Information Drives FDA Plan To Generate More CBD Safety Data" - HBW Insight, 5 Mar, 2020.) (Also see "Cultivating Cannabinoid Safety Data In US: Principles, Projects And Problems" - HBW Insight, 8 Jan, 2021.)
In the UK, the Food Standards Agency’s Advisory Committee on Novel Foods and Processes (ACNFP) also concluded that toxicological data is currently inadequate. (Also see "Existing CBD Safety Data Not Good Enough, Warns UK Novel Foods Committee" - HBW Insight, 3 Nov, 2020.)
Analyzing two CBD dossiers informally submitted to the regulator as a training exercise, the ACNFP found both the safety data submitted by the two applicants to be wanting.