Despite the growing popularity of cannabis products, information is currently limited on how they may interact with other drugs. To resolve this issue, researchers from Pennsylvania State University have published a list of prescription medications that interact negatively with cannabis products.
Given the general lack of information on how cannabis interacts with drugs, co-author of the new research, Professor Kent Vrana, and his colleague Paul Kocis created a list of potential interactions between cannabis compounds and prescribed medications. In particular, they looked for cannabis-based drugs that affect the speed at which the body breaks down other drugs o competes for the same target. All in all, they evaluated several cannabinoids, including the popular cannabidiol (CBD) and tetrahydrocannabinol (THC), the psychoactive compound in cannabis.
For the analysis, they looked at the list of enzymes that process THC and CBD and compared it to prescribing information for common drugs. In doing so, they were able to identify overlaps between the two- known as drug-drug interactions. This meant they were then able to compile a list of 57 prescription medications that could be adversely affected by cannabinoid use.
Overall, the list contains several common medications, including antidepressants like amitriptyline and lofepramine, opioid pain medications like fentanyl, and blood thinners such as warfarin. In particular, the researchers warn that the list contains medicines with a narrow therapeutic index. Meaning that a small margin of increase in their activity could be toxic, they thus say that the possibility for cannabis to upregulate the effects of drugs poses some serious health concerns.
While many possible side effects of these drug-drug interactions include dizziness, confusion, and sedation, the authors also note that more serious issues, such as changes in heart rhythm and blood pressure, may occur. As such, the researchers recommend that doctors take into account a person’s use of cannabinoids before prescribing medications.