8288 Navigating Diagnostic Challenges of Amiodarone Induced Thyrotoxicosis in a Psychiatrically Complex Patient within a Community Hospital Setting

Abstract Disclosure: M.S. Shah: None. K.P. Sanu: None. S. Humayon: None. R. Chawla: None. N.K. Bains: None. This case delves into the intricate diagnostic and therapeutic journey of a 64-year-old male who presented to a community hospital with psychosis. Medical history was pertinent for ventricular arrhythmias treated with amiodarone 400 mg once daily, bipolar disorder with medication non-compliance and heart failure with reduced ejection fraction status post automatic implantable cardioverter-defibrillator placement. Collaboration with the patient's family revealed a history of repeated hospitalizations for similar presentations as well as recent weight loss. The challenge lay in distinguishing between manic episodes and other potential underlying medical causes. The patient's recent weight loss and amiodarone use prompted a thyroid panel, revealing a TSH of 0.01 mlU/L (n = 0.27 to 4.20 mIU/L), free T4 of 7.77ng/dL (n = 0.93 to 1.70 ng/dL), and free T3 of 7.51ng/dL (n = 2.00 to 4.40 pg/mL). Inadequate facilities for a radioactive iodine uptake (RAIU) scan and thyroid doppler ultrasound heightened the diagnostic challenge, making the history and physical exam pivotal in steering the course of this patient's care. The Burch-Wartofsky score was found to be elevated at 30 due to delirium and abdominal pain reported in the emergency department. Amiodarone use for over two years with no prior history of thyroid dysfunction, along with the absence of a goiter or thyroid antibodies suggestive of Graves disease heightened the suspicion for amiodarone-induced thyrotoxicosis type 2 (AIT type 2). Due to the lack of RAIU scan and thyroid ultrasound to better differentiate between AIT type 1 and type 2, the patient was treated with methimazole and prednisone along with an antipsychotic medication regimen. The discontinuation of antipsychotic medications became necessary due to QTc prolongation and subsequent defibrillator discharge. The patient's further improvement without psychiatric medications highlighted the success of the tailored treatment strategy, emphasizing the importance of accurate diagnosis in patients with psychiatric comorbidities. The patient’s relatively rapid clinical response also aids in differentiating AIT type 1 from type 2. This case brings awareness to the importance of a comprehensive history and physical exam, particularly in the setting of a community hospital with limited diagnostic resources. Despite the inability to obtain history directly from the patient and having diagnostic constraints, the judicious use of available resources and clinical acumen led to the diagnosis of Amiodarone-induced thyrotoxicosis type 2. Clinicians should keep a broad differential to avoid confirmation bias in treating psychiatric patients with a complex medical history. This case serves as a testament to the importance of a holistic approach to patient care and the need for ongoing advancements in diagnostic capabilities within community healthcare settings. Presentation: 6/2/2024