Endocrine Abstracts

Levothyroxine (L-T4) is the mainstay of treatment of hypothyroidism. Marked elevation of thyrotropin (TSH) in patients on high replacement doses is rare and can result from malabsorption, drug interaction or poor compliance. The levothyroxine absorption test is required to distinguish these causes and has proved to be safe. This test measures the serum free thyroxine (FT4) response to 1 mg of oral L-T4 over 4–24 h.Clinical cases: Case no 1: A 28-yea...