The Effect of Psychotropic Agents on Sick Sinus Syndrome: A Case Report

Sick sinus syndrome (SSS) presents significant challenges in psychiatric medication management because of the potential for worsening cardiac conduction and interactions with antiarrhythmic therapy. A 35-year-old woman with generalized anxiety disorder (GAD) and insomnia was treated with bupropion, hydroxyzine, melatonin, and intermittent quetiapine, alongside comorbid SSS and supraventricular tachycardia managed post-ablation with metoprolol. A review of her regimen identified several cardiac safety concerns: quetiapine's potential interference with flecainide, hydroxyzine-associated QT prolongation, and bupropion's CYP2D6 inhibition that could increase flecainide levels. Management prioritized minimizing arrhythmogenic risk by discontinuing quetiapine, restricting hydroxyzine to low doses, and continuing melatonin, supplemented by stress testing and reassessment of psychotropic options. This case highlights the importance of careful psychotropic selection in patients with SSS, favoring lower-risk agents, such as mirtazapine, which is one of the safest among several possible alternatives, while maintaining close ECG monitoring and coordinated cardiology and psychiatry collaboration to reduce drug-drug interactions and optimize safety.