Drugs that May Interact with CBD

Cannabidiol is a safe, non-intoxicating, and non-addictive cannabis compound with significant therapeutic attributes, but CBD-drug interactions may be problematic in some cases. When THC or any other foreign compound enters the body, it is metabolized.

CBD and the Cytochrome P-450 Enzyme System

Research has clearly shown that cannabidiol, or CBD, has the potential to effectively treat many different ailments by manipulating the endocannabinoid system with very few unintended effects.

However, some of cannabidiol’s side effects can be dangerous if they are not properly understood. One such effect is the inhibition of the cytochrome P-450 enzyme system.

What is the Cytochrome P-450 System?

The cytochrome P-450 enzyme system is a system within the liver that is responsible for metabolizing 90 percent of the drugs you consume. According to Davis’s Drug Guide, this system contains more than 50 enzymes that process and eliminate toxins.

Why Does it Matter?

In order to determine appropriate dosages of medications, doctors make calculations using the average amount of time it takes for various drugs to be processed by this system.

If only one drug is being processed and the system is generally healthy, these averages are usually correct.

However, certain drugs have the ability to affect processing times within the cytochrome P-450 system, thus making other drugs metabolize faster or slower than they would have on their own. 

Similarly, if the system is unhealthy because of liver problems or other pre-existing conditions, drugs may not metabolize as they should.

Cannabidiol in the Cytochrome P-450 System
Cannabidiol can inhibit the cytochrome P-450 system’s ability to metabolize certain drugs, which leads to an overall increase in processing times. 

This leads to higher levels of the drug in your system at one time, which can cause unwanted side effects and even overdose. Thus, if you are taking a drug affected by cannabidiol, you may need a dosage adjustment in order to take both drugs safely.

Drugs that Interact with Cannabidiol (CBD)
Any drug metabolized by cytochrome P-450 enzymes could potentially interact with cannabidiol. 

According to the Indiana University Department of Medicine, drugs known to use the cytochrome 
P-450 system include:

  • Steroids 
  • HMG CoA reductase inhibitors 
  • Calcium channel blockers 
  • Antihistamines 
  • Prokinetics 
  • HIV antivirals 
  • Immune modulators 
  • Benzodiazepines 
  • Anti-arrythmics 
  • Antibiotics 
  • Anesthetics 
  • Anti-psychotics 
  • Anti-depressants 
  • Anti-epileptics 
  • Beta blockers 
  • PPIs 
  • NSAIDs 
  • Angiotension II blockers 
  • Oral hypoglycemic agents 
  • Sulfonylureas
Keep in mind that this list does not necessarily contain every medication that could be affected by cannabidiol.

Likewise, not every medication in each of the categories listed will cause an interaction. 

For this reason, you should consult with a medical professional before taking any combination of drugs at the same time, as alternative medications or dosage adjustments may be required. 

If you are worried that you P-450 enzyme system may not be functioning properly, physicians can test the system to ensure that the medications you take are metabolizing as expected.

CA total of 565 drugs (3598 brand and generic names) are known to interact with cannabis.

There are:
  • 7 major drug interactions (31 brand and generic names)
  • 558 moderate drug interactions (3567 brand and generic names)