Concomitant methimazole-induced agranulocytosis and cholestatic jaundice in a young woman

A woman in her 30s presented to the emergency department with new-onset sore throat and fever. She had recently been diagnosed with Graves' disease 3 months prior. As a result, she was initiated on atenolol and methimazole for management. Her methimazole dosing had been stable at 15 mg daily for the month prior to presentation. Investigation revealed severe neutropenia and jaundice. She was found to have concomitant agranulocytosis and cholestatic jaundice secondary to methimazole.Methimazole was discontinued on admission and the patient received granulocyte colony-stimulating factor for an absolute neutrophil count (ANC) of zero. She was placed on broad-spectrum antibiotics and intravenous steroids for epiglottic and supraglottic oedema noted on bedside laryngoscopy. ANC and bilirubin improved over a 2-week hospital course. She was discharged on a temporary regimen of propranolol, dexamethasone and potassium iodide until she was able to undergo successful thyroidectomy for definitive management of Graves' disease outpatient.

Carbimazole-Induced Agranulocytosis in a Previously Stable Patient: A Case Report and Literature Review

Carbimazole-induced agranulocytosis is a rare condition. A 48-year-old female patient with a history of hyperthyroidism for several years presented with generalized fatigue and chest pain associated with palpitations; the patient was stable on carbimazole therapy. She was previously on carbimazole 15 mg once daily (OD) and, three months later, was reduced to 10 mg OD as symptoms were controlled. She was taking propranolol, and it was stopped as she was not having any palpitations. This time, however, she presented mainly with palpitations at night associated with chest pain and generalized fatigue ongoing for the last one week. Her laboratory results showed agranulocytosis with reduced white cell count and neutrophil count in the absence of any evidence of infection. Her carbimazole was stopped, and the patient was referred to ear, nose, and throat surgeons for consideration of thyroidectomy. The patient underwent subtotal thyroidectomy, and her symptoms resolved following surgery.