A Case Report on Methimazole-Induced Severe Hypothyroidism

Severe, uncorrected hypothyroidism can result in a dangerous hypometabolic state leading to myxedema crisis, a rare but life-threatening illness. Myxedema crisis is a clinical diagnosis. The treatment for severe hypothyroidism and myxedema crisis is multifaceted, centered around thyroid hormone replacement, identification and treatment of precipitating factors, and intricate supportive care. Even with early and aggressive treatment, the myxedema crisis carries a high mortality rate. We present a case of iatrogenic hypothyroidism with severe features in a patient concurrently taking methimazole and amiodarone. This case illustrates the need for a high index of suspicion for patients on treatment for hyperthyroidism with any inciting event. The complexity of this case was rooted in polypharmacy, specialized care for numerous comorbidities complicated by significant strain on ED resources and personnel due to a global pandemic, resulting in severe complications. This case brings to light the need for immediate and appropriate treatment and critical care consultation for admission to a unit with an advanced level of care, as is the case for all patients with concern for severe hypothyroidism or myxedema crisis.