A recent study published in the Journal of the American Medical Association (JAMA) has found that a common blood pressure medication may increase the risk of serious bleeding in people with atrial fibrillation. Atrial fibrillation, the most common type of irregular heart rhythm, can lead to blood clots or stroke if untreated, according to the American Heart Association.
To manage atrial fibrillation and prevent complications, patients are often prescribed anti-clotting medications and medications to control heart rate. However, genetic differences can affect how individuals metabolize these medications, potentially leading to adverse effects. This concern was highlighted by Dr. Eli Zimmerman, associate professor in the Ken and Ruth Davee Department of Neurology’s Division of Stroke and Vascular Neurology, and a co-author of the study.
Dr. Zimmerman emphasized, “Genetic differences can impact how different people metabolize medications. This is particularly relevant when multiple medications used for the same condition, like atrial fibrillation, are impacted by these differences in metabolism. Our research group has looked at these differences and how they can cause negative effects.”
The study analyzed health records from Medicare beneficiaries aged 65 years or older with atrial fibrillation who started taking the anticoagulant medications apixaban or rivaroxaban, in addition to diltiazem or metoprolol, between 2012 and 2020. Diltiazem and metoprolol are medications that lower heart rate.
The findings revealed that patients receiving diltiazem were 20% more likely to experience bleeding-related hospitalization and death compared to those taking metoprolol. The risks were particularly high with higher doses of diltiazem. Notably, there were no significant differences in rates of stroke, systemic embolism, or hemorrhaging between the two groups.
“These findings are significant because they show that while there are some benefits to using diltiazem over metoprolol, and vice versa, differences in metabolism may introduce some increased risks of bleeding in those taking diltiazem,” Dr. Zimmerman explained.
Looking ahead, Dr. Zimmerman’s research group plans to continue investigating the underlying causes of different reactions to the same medications and explore potential methods for monitoring drug levels. “Next steps may include thinking about the need or the practicality of monitoring drug levels, which is our postulated mechanism of increased risk of bleeding,” he said.
The study, titled “Serious Bleeding in Patients With Atrial Fibrillation Using Diltiazem With Apixaban or Rivaroxaban,” provides critical insights into the complexities of medication management for atrial fibrillation patients and underscores the importance of personalized medicine based on genetic differences. For more information, refer to the full study by Wayne A. Ray et al. in JAMA (2024).