Levothyroxine Distribution and Pharmacokinetics

Pregnancy Considerations

• Levothyroxine dosage requirements increase during early pregnancy, necessitating dose adjustments for proper fetal neurologic development, as recommended by the Centers for Disease Control and Prevention, based on MMWR Recommendations and Reports 1

Steady-State Levels

• The American Association of Clinical Endocrinologists recommends waiting 4-6 weeks after dose changes before reassessing thyroid function tests, due to the time required to achieve steady-state levels, with a moderate strength of evidence 2