What happens if a patient with a total thyroidectomy misses levothyroxine (T4) therapy for several weeks?

From the Research

Effects of Missing Levothyroxine Therapy

• If a patient with a total thyroidectomy misses levothyroxine (T4) therapy for several weeks, they may experience symptoms of hypothyroidism, such as fatigue, weight gain, and cold intolerance 1, 2.
• The time required to achieve euthyroidism after thyroidectomy can be prolonged, with a median of 116 days and one dose adjustment, and some patients may require multiple dose adjustments 3.
• Missing T4 therapy can lead to an increase in thyroid-stimulating hormone (TSH) levels, which can take several weeks to normalize after therapy is resumed 4, 5.
• Patients who have undergone total thyroidectomy may require TSH-suppressive doses of levothyroxine to achieve preoperative native serum triiodothyronine levels 5.

Factors Affecting Levothyroxine Therapy

• Iron supplementation and multivitamin with mineral supplementation have been associated with prolonged dose adjustment of levothyroxine therapy after thyroidectomy 3.
• The formulation of levothyroxine, whether liquid or tablet, can affect the effectiveness of therapy, with liquid formulation showing better control of TSH levels in some studies 4.
• Individual factors, such as age, gender, and preoperative thyroid disease, do not independently predict prolonged dose adjustment of levothyroxine therapy after thyroidectomy 3.