Whether it’s medicinal or recreational cannabinoid use, it’s wise to let your doctor know – particularly if you’re taking other medication. Here’s why.
As medical and adult use cannabis becomes legal in an increasing number of jurisdictions, this creates extra challenges for doctors. Among them is understanding how cannabinoids such as cannabidiol (CBD) or tetrahydrocannabinol (THC) may interact with other medications. And if a doctor doesn’t know a patient is using cannabinoids, there’s extra risk when prescribing.
It’s been known for some time that products containing cannabinoids may have impacts on the effects of some conventional prescription drugs, but finding this information has been difficult. Leading related research has been the USA’s Penn State College of Medicine. Penn State researchers initially compiled a list of 57 medications that may not function as intended when used with such products.
Since we first reported on this work in 2020, the research has continued and has evolved into the CANNabinoid Drug Interaction Review (CANN-DIR). This free-to-use and publicly accessible online tool seeks to increase awareness of possible drug interactions.
“Our emphasis with this tool is on patient safety,” says Paul Kocis, a clinical pharmacist at Penn State Health Milton S. Hershey Medical Center . “There really was no information about how CBD and THC might affect other medications, so we set out to fill a need that was not being met.”
An example of an interaction is marijuana use while a patient is taking warfarin, which is a blood thinner commonly used to treat and prevent clots. Marijuana reportedly has the potential to cause excessive bleeding in patients taking this medication.
“A lot of people aren’t aware of these potential interactions and that’s why we thought it was important to provide a tool like CANN-DIR, which can be easily used by both medical professionals and patients,” says Mr. Kocis. “It’s about enhancing safety for everyone.”
CANN-DIR is available in 11 languages, and according to Penn State is currently used in more than 80 countries around the world. It’s worth noting that when accessing the tool, selecting a “doctor” profile will usually provide a bit more information on interactions compared to accessing CANN-DIR under a patient profile.
