Reverse Takotsubo Cardiomyopathy Caused by Repeated Guanfacine Overdose.

BACKGROUND: Guanfacine, an α2A receptor agonist, is prescribed to reduce cerebral neural activity in patients with attention-deficit hyperactivity disorder. CASE SUMMARY: We present the case of a 15-year-old girl who overdosed on extended-release guanfacine 3 times. This resulted in 2 episodes of reverse takotsubo cardiomyopathy with respiratory failure requiring mechanical ventilation, followed by late QT prolongation and spontaneous recovery. DISCUSSION: The prominent characteristic of this case was the blood guanfacine concentration-dependent development of reverse takotsubo cardiomyopathy, providing insights into the underlying mechanisms. TAKE-HOME MESSAGES: An overdose of guanfacine, a medication used for treating attention-deficit hyperactivity disorder, can result in reverse takotsubo cardiomyopathy in a blood concentration-dependent manner. The cardiopulmonary time course of an extended-release guanfacine overdose spans approximately 2 weeks, with early critical respiratory failure, reverse takotsubo cardiomyopathy, and late QT prolongation.