SAT-LB83 Amiodarone Induced Myxedema Coma

Introduction Amiodarone is widely used as a rhythm-conversion agent in atrial fibrillation. It’s low negative inotropic activity and low risk of ventricular arrhythmia makes it an advantageous agent for atrial arrhythmia. One of the major limiting factors in the use of amiodarone can be its thyroid toxicity leading to thyroid-dysfunction; ranging from thyrotoxicosis to myxedema coma. Myxedema coma, although rare, is a deadly complication of hypothyroidism with a mortality rate as high as 60%. It is considered an endocrinologic emergency that requires prompt attention and treatment. We present a case of myxedema coma in the setting of chronic amiodarone intake. Case Presentation A 75-year-old female with a past medical history significant for atrial fibrillation, hypothyroidism, end stage renal disease from diabetic nephropathy on hemodialysis, Hepatitis C, hypertension, and hyperlipidemia was admitted to the hospital for evaluation of generalized weakness. Her medications included amiodarone 200mg/day among others. The next day, the rapid response team was called when the patient became hypotensive, bradycardic and unresponsive. She was transferred to the ICU and intubated immediately. On exam, her skin was dry and cold. Her laboratory findings revealed a markedly elevated TSH level of 185uIU/mL. Her most recent TSH level was 9.044uIU/mL from a year back. Other laboratory tests revealed WBC count of 9.0k/mm cu, hemoglobin 13.7 g/dL, platelet count 48 k/mm cu. A diagnosis of myxedema coma was made based on her presentation and lab findings. The patient was started on intravenous levothyroxine 100mg daily with intravenous hydrocortisone 100mg every 8 hours. T4 levels were 0.38ng/dL, T3 levels were 1.83pg/mL and TPO antibodies were negative. A decision was made not to administer intravenous T3 because of the patient’s advanced age and underlying atrial fibrillation. Over the course of the hospitalization, the patient was showing signs of clinical improvement and attempts were being made to wean her off the ventilator. However, later she died due to hemorrhagic shock. Conclusion Myxedema coma may manifest nonspecifically as lethargy and altered mental status and can present without the more specific symptoms of skin changes or myxedematous soft tissue changes. It is therefore, very important for physicians to consider myxedema coma as one of the differential diagnoses in patients on amiodarone with underlying thyroid disease. Administering amiodarone for elderly patients with underlying thyroid problems warrants attention to polypharmacy. The treatment guidelines for myxedema coma are yet to be established. While intravenous levothyroxine with intravenous hydrocortisone remains the mainstay of therapy, there are no consensus on T3 administration.