A caution has been issued to individuals using a combination of two commonly prescribed medications, as their effects can lead to a potentially fatal heart condition. In the UK, approximately 8.6 million people take antidepressants, while over 50 million are prescribed beta blockers for various conditions like anxiety and heart issues.
Recent research has revealed that when these two medications are combined, there is an increased risk of dangerously low blood pressure and abnormally slow heart rate. The study focused on individuals taking beta blockers along with SSRIs or SNRIs, which are popular types of antidepressants such as fluoxetine, sertraline, venlafaxine, duloxetine, and bupropion.
The study pinpointed beta blockers like metoprolol, carvedilol, and nebivolol as posing the highest risk. These drugs are typically metabolized in the liver by an enzyme called CYP2D6, but certain antidepressants inhibit this enzyme, causing a dangerous accumulation of the medications in the body.
Combining these medications was found to potentially reduce blood pressure by up to 20% and increase the risk of a slow heart rate by 25%. Low blood pressure can lead to symptoms ranging from dizziness to organ failure, while a slow heart rate can result in cardiac arrest. These findings were presented at the American Heart Association’s Hypertension Scientific Sessions 2025.
Lead researcher Dr. Inshal Jawed emphasized the need for caution when prescribing beta blockers metabolized by CYP2D6 alongside SSRIs or other CYP2D6 inhibitors. Adjusting the dosage and closely monitoring patients are crucial steps, and using beta blockers that are less dependent on liver metabolism may be a safer option.
Further investigation is warranted according to Dr. Jawed. Symptoms to be vigilant for include dizziness, blurred vision, nausea, fainting, confusion, chest pain, extreme fatigue, shortness of breath, and difficulty concentrating.