Pulsed intravenous methylprednisolone combined with oral steroids as a treatment for poorly responsive type 2 amiodarone-induced thyrotoxicosis

Objectives: Amiodarone-induced thyrotoxicosis (AIT) affects up to 3% of tre ated patients. Type 2 AIT (AIT2) is a destructive thyroiditis and is usually treated with medium-high oral doses of prednisone. As AIT may worsen the underlying heart disease, a rapid control of thyroid functi on is desirable. We aimed to determine whether a combined intravenous methylprednisolone (IVMP) pulses therapy associated to prednisone in the interpulse period can represent an efficient and safe alternative to urgent total t hyroidectomy in patients with AIT2 not responsive to prednisone alone. Design and methods: Patients presenting with a severe AIT2 studied in a tertiary r eferral Center from August 2018 to April 2019. We included four patients requiring a rapid improve ment of thyroid function for their underlying cardiac disorders. The baseline doses of oral prednisone (range: 5-12.5 mg/day) and IVMP (range: 250-500 twice a week) were determined according to the severity of the thyrotoxicosis and were titrated based on clinical response. Results: Combined treatment was effective in all patients in the prompt restoration of euthyroidism and no major adverse events were reported during the follow-up. In all cases, FT4 and FT3 levels normalized at 3-5 weeks of treatment. A permanent hypothyroidism was observed in one patient, 3 months after the discontinuation of treatment. Conclusions: We report for the first time that the combined intravenous and oral steroid therapy is effective in patients with AIT2. The treatment is well tolerated and leads to a rapid improvement of thyroid function, avoiding urgent total thyroidectomy and favoring a quick functional recovery and reha bilitation of cardiac patients.