Antidepressants and Beta Blockers Increase Risk for Bradycardia and Low Blood Pressure
New evidence shows interactions between antidepressants and beta blockers may amplify side effects, urging careful monitoring and alternative prescribing strategies.
A new analysis presented at HYP 2025 found that combining certain antidepressants (SSRIs, SNRIs, bupropion, duloxetine) with CYP2D6-metabolized beta blockers significantly increases drug exposure, lowers systolic blood pressure by up to 20%, and raises bradycardia risk by 25%.
Study Details
Depression and hypertension often coexist, making the concurrent use of antidepressants and beta blockers common. Researchers systematically reviewed drug interaction data from 65 adults with both conditions. The goal was to understand how antidepressants affect the pharmacokinetics of beta blockers.
Methodology
The team conducted a meta-analysis of clinical data on plasma drug concentrations, clearance, and pharmacokinetic markers such as area under the curve (AUC), maximum serum concentration (Cmax), and half-life. Patients in the review were taking SSRIs, SNRIs, bupropion, or duloxetine alongside different beta blockers.
Key Findings
Blood Pressure: Combination therapy led to a 15–20% reduction in systolic BP.
Heart Rate: Patients had a 25% higher risk of bradycardia.
Drug Exposure: For CYP2D6-dependent beta blockers (like nebivolol), AUC rose 2.5-fold, Cmax nearly doubled, and half-life extended by ~2x.
Safer Options: Atenolol and nadolol, which are less dependent on CYP2D6 metabolism, showed no significant interaction with antidepressants.
Implications for Practice
For patients with both depression and hypertension, clinicians should:
Monitor closely for bradycardia and hypotension when prescribing SSRIs/SNRIs with beta blockers.
Consider dose adjustments for CYP2D6-metabolized beta blockers.
Switch to alternatives such as atenolol or nadolol when interactions are suspected.
Coordinate care between cardiology and psychiatry teams to prevent adverse outcomes.
While this study was limited by its small sample size and review-based design, it underscores the importance of anticipating drug–drug interactions in real-world practice. Larger prospective studies will be critical for confirming these findings.