Review of Literature

Drug interactions


Journal of Clinical Medicine. 2019; 8(7):989.

Article name

Potential Adverse Drug Events and Drug–Drug Interactions with Medical and Consumer Cannabidiol (CBD) Use


Brown JD, Winterstein AG.

Understanding the Risks: CBD Use and Potential Drug Interactions

The use of Cannabidiol (CBD), a compound found in cannabis, is becoming increasingly common in medical treatments and consumer products. However, this widespread use raises important questions about the potential adverse effects and interactions CBD could have with other drugs. This study, conducted by researchers from the University of Florida, aims to shed light on these potential risks.

Understanding the Study

This is a review study, meaning the researchers analyzed existing data and research rather than conducting their own experiments. The authors, based at the Center for Drug Evaluation & Safety and the Department of Epidemiology at the University of Florida, focused on the potential for adverse drug events (ADEs) and drug-drug interactions (DDIs) with CBD use.

Main Findings

  • Nearly half of CBD users experienced ADEs, which displayed a general dose-response relationship.
  • Common ADEs include transaminase elevations, sedation, sleep disturbances, infection, and anemia.
  • The potential for DDIs with commonly used medication is high due to CBD effects on common biological targets implicated in drug metabolism and excretion.

Specific interactions

Drug Interaction with CBD
Clobazam Increased systemic exposures of clobazam and norclobazam
Rifampicin Decreased maximum concentration of CBD
Ketoconazole Increased bioavailability of CBD
Omeprazole No changes in the pharmacokinetics of CBD
Topiramate, Rufinamide, Zonisamide, Eslicarbazepine Increased concentrations of these drugs
Acetaminophen, Ibuprofen Potential for increased concentrations due to inhibition of UGT1A9 and UGT2B7
Glyburide, Imatinib, Methotrexate, Mitoxantrone, Nitrofurantoin,Prazosin, Statins, Dipyridamole Potential for increased concentrations due to inhibition of BCRP
Paclitaxel, Digoxin, Statins, Telmisartan, Glyburide, Ketoconazole, Rosiglitazone, Celecoxib Potential for increased concentrations due to inhibition of BSEP


The researchers reviewed prescribing information for federally approved products containing CBD. They extracted and summarized data on ADEs and DDIs. The study did not involve direct interaction with human or animal subjects, but rather was an analysis of existing data.

Potential Implications

The findings of this study suggest that CBD use may come with a higher risk of adverse drug events and interactions than previously thought. This is particularly important for patients with complex conditions and treatment regimens, as well as for the growing number of consumers using CBD products.


As a review study, the findings are limited by the quality and scope of the existing research that was analyzed. More research is needed to fully understand the potential risks associated with CBD use.


While CBD has potential therapeutic benefits, it's important for patients, consumers, and healthcare providers to be aware of the potential safety issues and risks of adverse drug events and interactions. More research is needed to further understand these risks and develop guidelines for safe CBD use.

For more details, you can read the full study here.

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