Timing of Thyroxine Dose Adjustment in Hypothyroid Patients: When are TSH Levels Stable?
Author(s): Kohler S, Senn O, Saleh L, Wass JAH and Ch SchmidKohler S, Senn O, Saleh L, Wass JAH and Ch Schmid
Background: Serum TSH is the target hormone by which adequate thyroid hormone supply can easily be monitored in patients with primary hypothyroidism. It is however controversial when TSH should be measured before thyroxine dose adjustments are made: 4 to 8 weeks are recommended. We looked at the time required to reach stable TSH levels in hypothyroid patients. Methods: We studied patients with newly diagnosed hypothyroidism (TSH >10 mU/l and fT4 <12.3 pmol/l). Treatment was initiated with thyroxine 50 μg/d if there was a history of cardiac disease and 100 μg/d otherwise. Blood pressure, weight and TSH, fT4, fT3, cystatin C and creatinine were measured once a week. Thyroxine dose was increased by 25 μg every 8 weeks until TSH normalised. Results: 12 patients with a mean TSH at baseline of 57.6 mU/l (range 11.3–151.8 mU/l) gave informed consent. They were followed f.. View More»