Professional and Linguistic Assessments Board (PLAB) Practice Exam

What is the primary treatment for thyroid storm?

1. Levothyroxine

2. Radioactive iodine

3. PTU

4. Beta-blockers

The correct answer is: PTU

The primary treatment for thyroid storm primarily focuses on rapidly controlling the excessive thyroid hormone levels and managing the acute symptoms of the condition. Propylthiouracil (PTU) is particularly effective because it inhibits the synthesis of thyroid hormones by blocking the enzyme thyroperoxidase which is involved in the production of T3 and T4 in the thyroid gland. Additionally, PTU also decreases the conversion of T4 to T3, the more active form of the hormone, providing a more comprehensive approach in reducing thyroid hormone levels during a thyroid storm. While beta-blockers play a significant role in alleviating the cardiovascular symptoms associated with thyroid storm, such as tachycardia, they do not address the underlying cause of hormone overproduction. Other treatments, like levothyroxine and radioactive iodine, are not effective for managing thyroid storm since levothyroxine is a synthetic thyroid hormone, and radioactive iodine is used for hyperthyroidism management but not in acute scenarios. Therefore, the choice of PTU aligns with the need to rapidly control thyroid hormone production and mitigate the severity of thyroid storm.