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 is that thyroid hormone replacement has a long-lasting effect because levothyroxine has a half-life of about a week. That means stopping or missing a single dose around the time of surgery won’t cause a rapid drop in thyroid hormone levels or an acute hypothyroid state. Therefore, it isn’t essential to take the dose exactly on the day of surgery, especially if the patient is NPO. The perioperative plan should aim to continue regular replacement as soon as feasible after surgery or resume it promptly to prevent hypothyroidism, rather than withholding it for weeks. Discontinuing for several weeks would create a risk of hypothyroidism and is not appropriate. In practice, thyroid status matters for perioperative hemodynamics and recovery, so the goal is continuity of therapy whenever possible, with adjustments only if the patient cannot take oral medication or if specific clinical factors require a different approach.