Endocrine Abstracts

Introduction

The use of antithyroid drugs is associated rarely with severe hepatotoxicity. Recently, due to several cases reported in the literature, acute pancreatitis was added as a severe potential adverse effect induced by methimazole. The physiopathology of methimazole induced pancreatitis is not fully understood (intrinsic toxicity or idiosyncratic drug reaction were proposed as possible mechanisms). If adverse effects occur and no other treatment options are available (other antithyroid agent, radioiodine therapy), the rapid correction of hyperthyroidism can be obtained by surgery (thyroidectomy).

Case presentation

A 69-year-old woman was diagnosed with Graves’ disease in January 2021, with severe thyrotoxicosis, without ophthalmic involvement. The patient started methimazole treatment with high doses (30 mg/day) gradually tapered over the following weeks. Three weeks later she presented to the Emergency Department with severe abdominal pain, nausea, vomiting, inappetence, palpitations, and sweating. She had no fever and was negative for coronavirus (RT-PCR test). She reported no history of hypertriglyceridemia, alcohol or other medication. The laboratory tests confirmed acute pancreatitis (serum lipase was elevated 6 times the upper limit of normal) and liver dysfunction (transaminases were elevated 10 times the upper limit). Alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT) and total bilirubin were significantly increased. All the imagistic investigations (abdominal ultrasound, computed tomography, echoendoscopy) confirmed the diagnosis of acute pancreatitis, without signs of gallstones or tumors. Thyroid ultrasound revealed normal thyroid volume (15 ml), marked hypoechoic parenchyma, increased vascularization. The hormonal data showed a very suppressed TSH associated with normal FT3 and slightly increased FT4. Methimazole was interrupted and Propranolol was administered in high doses (80 mg/day). After i.v. fluids, pain medication and proton pump inhibitor administration, patient’s condition improved. After five days, transaminases, lipase, ALP and GGT levels decreased significantly. On the sixth day, the repeated RT-PCR for COVID 19 was positive. She was transferred to the special COVID 19 Department, where she was evaluated (thoracic CT showed only minor lesions, with “ground-glass” appearance affecting less than 10% of the lungs) and treated with i.v. perfusions, pain medication, anti-inflammatory drugs, heparine and propranolol. Radioactive iodine therapy was unavailable. On the same day she underwent emergency total thyroidectomy, without any complications. She was discharged after 6 days, on oral anticoagulants and levothyroxine.

Conclusion

As severe thyrotoxicosis may be associated with more serious complications from COVID-19, urgent thyroidectomy is a valid option in patients with severe adverse effects to antithyroid drugs (pancreatitis).