Amiodarone induced thyroid dysfunction – Medicine MCQ
Wrong statement about amiodarone induced thyroid dysfunction:
A) Hypothyroidism occurs in iodine sufficient areas
B) Hyperthyroidism occurs in iodine deficient areas
C) Amiodarone can cause destructive thyroiditis
D) Amiodarone increases 5-deiodinase activity
Correct answer: D) Amiodarone increases 5-deiodinase activity
Structure of amiodarone (note the iodine atoms attached to the benzene ring in the middle)
Amiodarone induced thyroid dysfunction
- Amiodarone is a commonly used class III antiarrhythmic drug.
- It has a high iodine content.
- It can produce hypothyroidism in patients from iodine sufficient areas and hyperthyroidism in those from iodine deficient areas.
- It reduces 5-deiodinase activity and thereby decreases the conversion of T4 to T3.
- There is decreased generation of T3 and reduced clearance of rT3 (reverse T3), leading to accumulation of rT3.
- Destructive thyroiditis is the result of direct toxic effect of amiodarone and its metabolite on thyroid follicular cells.
Read more on amiodarone induced thyroid dysfunction: https://cardiophile.org/amiodarone-and-thyroid-dysfunction/
