Amiodarone-Induced Hypothyroidism — RACP Adult Medicine MCQ

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ModerateEndocrinology & DiabetesAmiodarone-Induced HypothyroidismRACP Adult Medicine

A 58-year-old man presents with fatigue, weight gain, and constipation after treatment with amiodarone for atrial fibrillation 3 months ago. TSH is 45 mIU/L and free T4 is 6 pmol/L. What is the most appropriate management?

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Correct answer: A — Commence levothyroxine replacement

Amiodarone-induced hypothyroidism (AIH) is more common in iodine-sufficient populations like Australia. It results from the Wolff-Chaikoff effect (excess iodine inhibiting thyroid hormone synthesis). Management involves levothyroxine replacement. Amiodarone does NOT need to be ceased if clinically indicated for the arrhythmia, as hypothyroidism can be managed with levothyroxine titration.

Reference: eTG – 2025 – Endocrinology; AMH – 2025 – Amiodarone