Endocrinology Made Simple : Amiodarone Induced Thyroid Dysfunction

Amiodarone Induced Thyroid Dysfunction

Amiodarone causes thyroid dysfunction through its high iodine content.

Hypothyroidism is more common and is seen in 85 % cases.

Thyrotoxicosis occurs in 10 – 15 % cases.

Amiodarone induced thyrotoxicosis occurs by one of the following two ways:

1.Activation of Grave”s disease : Type 1 thyrotoxicosos

2.Destructive Thyroiditis : Type 2 Thyrotoxicosis

Grave”s disease induced by Amiodarone is generally treated with high dose thionamides: Methimazole and 

Propylthiouracil.

Perchlorate can be used to reduce further uptake by Thyroid gland.

Steroids are given for treatment of Type 2 Thyrotoxicosis.

Thyroid functions are monitored every 6 months in euthyroid patients on Amiodarone.

In patients with significant coronary artery disease or those who are elderly,a lower dose should be started.

Amiodarone induced Hypothroidism can cause fatigue as  a side effect.

Patients with Amiodarone induced Hypothyroidism should  be treated with levothyroxine to bring their TSH with in a normal range.

Other side effects of Amiodarone include:

Corneal deposits

Skin discoloration

Hepatotoxicity and

Pulmonary Fibrosis