How Does CBD Interact with Other Medications?

Research has shown that Cannabidiol (CBD) has the potential to treat various medical conditions by manipulating the endocannabinoid system (ECS), with very few unintended effects. CBD is a safe, non-intoxicating, and non-addictive cannabis compound with significant therapeutic attributes, but CBD-drug interactions may be problematic in some cases.

The CBD interaction with medications can be caused by the effect of the inhibition or deactivation of the cytochrome P450 (CYP) enzyme system with high CBD doses. CYP is the system principally found in the liver that is responsible for metabolizing many drugs that patients consume.  A large dose of CBD can cause CYP enzymes to become temporarily inactive. When those enzymes are inactive, it becomes much harder for processing certain drugs. In fact, basically any drug that is metabolized by CYP enzymes has the potential to interact with CBD.  The result is an increase of the medication level of effect by decreasing the drug metabolism.

Preclinical research shows that CBD is metabolized by CYP enzymes while functioning as a competitive inhibitor of the same liver enzymes. By occupying the site of enzymatic activity, CBD displaces its chemical competitors and prevents CYP enzymes from metabolizing other compounds. The extent to which CBD behaves as a competitive inhibitor of CYP depends on how tightly CBD binds to the active site of the metabolic enzyme before and after oxidation. This can change greatly, depending on CBD administration, dose, the unique attributes of the individual taking this medication, and whether isolated CBD is used. If the dosage of CBD is low, it will have no noticeable effect on CYP enzyme activity, but CBD may still exert other effects. There is no clearly established cut-off dose in which CBD does not interact with other drugs. Therefore, the recommendation of “start low and go slow” with initial CBD use will lessen the potential of drug interactions.

The following drug groups are metabolized by the cytochrome P450 enzyme system with the potential of prolonged medication effect with high dose administration of CBD:

-Steroids

-HMG CoA reductase inhibitors

-Calcium channel blockers

-Antihistamines

-Prokinetics

-HIV antivirals

-Immune modulators

-Benzodiazepines

-Antiarrhythmics

-Antibiotics

-Anesthetics

-Antipsychotics

-Antidepressants

-Anti-epileptics

-Beta blockers

-PPIs

-NSAIDs

-Angiotension II blockers

-Oral hypoglycemic agents

-Sulfonylureas

-Buprenorphines

Below is a drug interaction checker website for any medications.  Use the word ‘cannabidiol’ (CBD) to check interactions of medications with CBD.  

Drug Interaction Checker - Medscape.com