Berberine Poisoning with Polymorphic Ventricular Tachycardia: A Case Report

INTRODUCTION: Natural supplements are readily available without a prescription and are not regulated by the United States Food and Drug Administration. The popularity of berberine, a bioactive compound used for centuries in traditional Chinese medicine, has surged due to its proposed benefits in glycemic control and cardiovascular health. However, use of berberine may lead to possible negative electrophysiologic changes. CASE REPORT: A 92-year-old male presented to the emergency department (ED) with chief complaints of tremors, urinary incontinence, and brief syncopal episodes that began approximately two weeks after starting berberine. In the ED he had multiple episodes of polymorphic ventricular tachycardia with pulselessness requiring immediate cardioversion, with a rapid return of spontaneous circulation between episodes. Amiodarone was started; however, despite this, he continued to have persistent episodes. Finally, the episodes resolved after starting lidocaine and isoproterenol in the intensive care unit. The patient's workup was notable for heart rate-corrected QT interval (QTc) prolongation (QTc 616 milliseconds (ms) [male reference range, QTc < 430 ms]) confirming the polymorphic ventricular tachycardia as torsades de pointes. His cardiac evaluation was otherwise normal, including a normal ejection fraction on a transthoracic echocardiogram. Withholding berberine and supportive management resulted in an improved QTc. On hospital day 3, the QTc was 454 ms. The patient had a short inpatient admission and was discharged without any further episodes. CONCLUSION: Berberine has numerous effects and is purported to have beneficial effects and cardioprotective properties. Due to induced bradycardia and QT prolongation, patients who take berberine can be vulnerable to life-threatening arrhythmias, such as the R-on-T phenomenon in our patient's case. Additional research on berberine is needed to better inform clinician-patient discussions about its use.