In that article, we wrote that CBD could potentially decrease the activity of the liver metabolizing enzyme CYP3A4, which is responsible for the metabolism of Lipitor.
The result of CYP3A4 inhibition by CBD could potentially increase concentrations of Lipitor in the body, increasing the risk of side effects such as stomach cramping, diarrhea or even the more serious ones, like rhabdomyolysis (the breakdown of muscle).
Unfortunately, since the time we wrote that article, we still don't know much more about how CBD could affect Lipitor as there have been no studies that have specifically evaluated this potential interaction.
Nevertheless, there have been some additional studies on CBD interactions which give us more insight. This is discussed below
CBD Interaction With CYP3A4
More often than not, it is difficult to find thorough drug interaction information on over the counter supplements and herbal products.
Fortunately, when it comes to CBD (cannabidiol), it is not only available over the counter, but is an FDA approved active ingredient in the prescription product Epidiolex, which is approved for the treatment of rare seizure disorders.
Since CBD is available in prescription products, we have more evidence than usual on how it could potentially interact with other drugs.
As mentioned above, we are concerned about how Epidiolex could affect CYP3A4, which is the liver enzyme principally responsible for the metabolism of Lipitor.
The prescribing information for Epidiolex (CBD) does not give any indication that it either inhibits or induces (i.e. increases activity) of CYP3A4.
In fact, since CBD itself is metabolized by CYP3A4, it only warns against using drugs known to inhibit or induce that enzyme since they could potentially influence the effectiveness of CBD.
Older studies (ones completed in the early 2010's) showed that CBD had the potential to inhibit CYP3A4, and therefore, there was some concern administering with other drugs that were metabolized by the enzyme (like Lipitor).
However, more recent studies suggest that while CBD can inhibit CYP3A4, the doses required for such inhibition are extremely high, higher than a dose that anyone would feasibly take.
CBD With Lipitor
As stated above, there have been no studies looking specifically at an interaction between CBD and Lipitor.
An interaction could be inferred based on studies that show that CBD can inhibit CYP3A4, but human studies are lacking and most animal or laboratory studies show that only very high doses of CBD result in any sort of clinically significant effect.
Additionally, the prescribing information for Epidiolex, the prescription CBD product, does not state that it can potentially affect CYP3A4 substrate drugs, like Lipitor.
There is far more data available stating that other drugs that inhibit or induce CYP3A4 affect CBD concentrations, not the other way around.
So overall, it appears that the risk of an interaction between CBD and Lipitor is low, but it should not be ruled out. It is unlikely that you will need a dose adjustment of either drug but as always, you should speak with your doctor about CBD use with other drugs prior to combining them.
Other CBD Interactions
Even though there doesn't appear to be a high risk of a Lipitor interaction, it is important to consider how CBD could interact with other drugs.
CBD does have well-documented interactions with several others, including:
Aside from drug interactions, there may be other issues taking CBD with certain drugs.
For example, studies show that taking CBD with valproate, a commonly used drug for seizures, can increase liver enzymes.
Until we have more information and studies on CBD interactions and its effects on the body, always be sure to talk to your doctor prior to use so you can be appropriately monitored for side effects and efficacy.
SummaryThe majority of data from studies suggest that there is a low risk of an interaction between Lipitor and CBD (cannabidiol). Although CBD may inhibit CYP3A4, the enzyme responsible for Lipitor metabolism, it likely only occurs at doses higher than what is generally taken.
- Epidiolex Approval FDA Announcement:
- Prescribing Information Epidiolex
- PubMed Potent inhibition of human cytochrome P450 3A isoforms by cannabidiol: Role of phenolic hydroxyl groups in the resorcinol moiety.
- PubMed An Update on Safety and Side Effects of Cannabidiol: A Review of Clinical Data and Relevant Animal Studies.
- PubMed Human Metabolites of Cannabidiol: A Review on Their Formation, Biological Activity, and Relevance in Therapy.
- PubMed An interaction between warfarin and cannabidiol, a case report.
- PubMed Interactions between cannabidiol and commonly used antiepileptic drugs.