Atomoxetine-Induced Pheochromocytoma and Paraganglioma Crisis Managed With Veno-Arterial Extracorporeal Membrane Oxygenation

Pheochromocytoma and paragangliomas (PPGLs) crises can be triggered by various factors, including norepinephrine reuptake inhibitors used to treat attention deficit hyperactivity disorder (ADHD), which worsen symptoms in patients with PPGLs. Therefore, attention should be paid to the potential for serious adverse reactions in patients with PPGLs taking ADHD medications. A 21-year-old man presented to the emergency department with acute onset of severe respiratory and circulatory failure after initiating atomoxetine treatment. During preparation for hospital admission, his respiratory and circulatory status deteriorated, requiring emergency intubation and mechanical ventilation and transfer to our institution for further evaluation and treatment. Profuse sweating and sinus tachycardia were observed, and echocardiography revealed a significantly reduced ejection fraction. Contrast-enhanced computed tomography of the trunk revealed a 50 mm tumour anterior to the inferior vena cava and a 20 mm enhancing tumour in the left adrenal gland. Treatment with the α-blocker, phentolamine, was initiated on the grounds of cardiogenic shock induced by an endocrine disorder such as PPGLs. However, the patient developed bradycardia and hypotension, progressing to pulseless electrical activity (PEA), for which cardiopulmonary resuscitation (CPR) was initiated. After the administration of adrenaline (1 mg), a return of spontaneous circulation was achieved. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) was initiated to prevent further cardiac arrest. An intra-aortic balloon pump (IABP) was inserted to reduce the cardiac workload. Circulatory dynamics gradually stabilised, and treatment with VA-ECMO was discontinued on day 4 after admission as the ejection fraction improved to approximately 50%. On day 6, the patient was successfully extubated, respiratory support was discontinued, and he was discharged on day 25, confirming the diagnosis of PPGLs with no evidence of higher brain dysfunction. Outpatient management included dose adjustment of the α1-blocker, and he was readmitted for surgical removal of the tumour. The postoperative course was uneventful, with a notable improvement in ADHD symptoms. This case report highlights the importance of a multidisciplinary approach for the diagnosis and management of patients with symptoms suggesting psychiatric or endocrine disorders.