Which statement about levothyroxine management around surgery is correct?

Which statement about levothyroxine management around surgery is correct?

• A. Essential to take before surgery
• B. Not very important to take levothyroxine on the day of surgery because its half-life is about 1 week.
• C. Should be discontinued for several weeks before surgery
• D. Has no relevance to perioperative planning

Answer: (B)

The key idea here is that levothyroxine works with a relatively long half-life, about a week. Because of that, thyroid hormone levels don’t plunge after just one missed dose. In the perioperative period, missing the morning pill on surgery day is unlikely to cause an acute thyroid crisis or major instability, since stores of hormone remain in the body and continue to support metabolism for several days. That’s why this statement captures the practical point: the day-of-surgery dose is not always critical, provided the patient can resume therapy as soon as feasible and the overall thyroid status is being maintained.

In contrast, stopping levothyroxine for weeks before surgery would risk hypothyroidism and its complications, so that other choice is not appropriate. Saying it has no relevance to perioperative planning ignores the role thyroid status plays in cardiovascular response and healing, so that choice isn’t accurate either. Finally, claiming it is essential to take before surgery overstates the immediacy of thyroid hormone needs on the day of surgery given the long half-life.