A 64-year-old man on long-term amiodarone develops thyrotoxicosis. The thyroid is mildly tender, there is no orbitopathy, colour flow Doppler shows absent vascularity, and interleukin-6 levels are markedly raised. Which treatment is most appropriate first-line?

• A Carbimazole alone, continuing amiodarone unchanged
• B Immediate total thyroidectomy
• C Potassium perchlorate combined with carbimazole
• D Glucocorticoids such as prednisolone ✓

Explanation

Absent Doppler flow, thyroid tenderness and high interleukin-6 identify amiodarone-induced thyrotoxicosis type 2, a destructive thyroiditis releasing preformed hormone. It responds to glucocorticoids, whereas type 1 is iodine-induced excess synthesis in an abnormal gland and needs thionamides, sometimes with perchlorate. The two forms can coexist, but pure type 2 with no goitre or increased vascularity is treated with steroids first, reserving surgery for refractory cases.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.