While research on the health benefits of cannabidiol piles up, do we know if it is safe? According to a recent study Germany, the answer is yes.
Building on previous research
With a focus on clinical studies and cannabidiol’s potential to interact with other drugs, researchers Kerstin Iffland and Franjo Grotenhermen from the nova-Institute undertook a review of the available research, including relevant animal studies, in order to assess the safety of cannabidiol. Their findings were published in the journal ‘Cannabis and Cannabinoid Research.’
The study primarily builds on the findings of Mateus Machado Bergamaschi’s comprehensive survey from 2011 which found CBD to be safe in humans and animals. This new paper backed up those findings, with the authors concluding that “this review could substantiate and expand the findings of Bergamaschi et al. about CBD’s favorable safety profile.”
The spotlight on Cannabidiol
Although THC has garnered much of the attention surrounding the therapeutic uses of cannabis, in recent years, it’s CBD that has found itself in the spotlight due to its lack of psychoactivity and numerous beneficial pharmacological effects. CBD has now been shown to have anxiolytic, anti-inflammatory, antiemetic, antipsychotic, and neuroprotective properties.
The review even goes so far as to say that, based on current research, CBD is a potentially beneficial treatment for heroin addiction, seizures, psychosis, cancer, and anxiety. CBD’s immunomodulatory properties also mean it could play a role in the treatment of various diseases such as multiple sclerosis, arthritis, and diabetes. The authors do note, however, that human studies on these conditions with pure CBD are still lacking.
Studies also indicate that CBD has no adverse physiological effect on blood pressure, heart rate, body temperature. Moreover, psychological and psychomotor functions are not adversely affected, while the same holds true for gastrointestinal transit, food intake, and absence of toxicity for non-transformed cells, the authors note.
Cannabidiol is well tolerated
Chronic use and high doses of CBD have repeatedly shown to be well tolerated by humans, with no neurological, psychiatric, or clinical adverse effects. This is also true for mice. In one study, 60 mg/kg of CBD was given to mice three times per week for 12 weeks with no adverse effects.
Nevertheless, the study did point out that some side effects have been reported with the use of CBD, but these are mainly in vitro or in animal studies. They include alterations of cell viability, reduced fertilization capacity, and inhibition of hepatic drug metabolism and drug transporters. Of course, more studies have to be conducted to see if these effects also occur in humans. Some studies also found that CBD’s acute anti-anxiety effects in animals were reversed after chronic administration.
Can Cannabidiol interact with other drugs?
The review does present evidence that CBD can in fact interact with some drugs, including medications metabolized by enzymes belonging to the cytochrome P450 family. The P450 enzyme group is responsible for metabolizing many commonly used medications, such as ibuprofen, naproxen, acetaminophen, codeine, caffeine, Xanax (alprazolam), and Lipitor (atorvastatin).
The review also found evidence that CBD may inhibit the enzymes CYP2D6 and CYP2C9, which, in turn, can potentially slow down the metabolization of drugs like omeprazole, risperidone, warfarin, and diclofenac. In one human study, CBD was also found to interact with isozymes CYP3A4 and CYP2C19, resulting in an increase in bioavailability of the antiepileptic drug clobazam, making it more effective at a lower dose and allowing patients to effectively manage seizures while reducing their dose of the antiepileptic drug.
Additionally, a number of in vitro studies were quoted in which CBD was found to inhibit the ABC transporters P glycoprotein and Breast Cancer Resistance Protein, possibly preventing some anticancer drugs from binding to transporters.
These findings suggest, therefore, that considerations must be taken when CBD is administered alongside other drugs. The authors acknowledge that more research on CBD and its safety profile is paramount.
What’s next for Cannabidiol research?
In their conclusion, Iffland and Grotenhermen expound on the need for various areas of CBD research to be extended. They advise that more studies on the side effects of chronic CBD administration need to be conducted; more participants need to be included in future clinical trials; and that there needs to be more studies and research evaluating CBD’s effect on hormones.
So, while the study does confirm the previously held belief that CBD is very safe, even in high doses, and that it offers a plethora of medicinal value, there are still gaps in our knowledge that need to be addressed in order for CBD to realize its potential.