The treatment of choice for correction of hypothyroidism is synthetic thyroxine (T4). For the vast majority of patients with hypothyroidism, we suggest not using combination T4-triiodothyronine (T3), Liothyronine therapy. T4-T3 therapy may improve symptoms in the rare subgroup of patients with a polymorphism in the type 2 deiodinase, which converts T4 to T3.
It is suggested that patients remain on the same formulation of T4 (If a switch from one manufacturer to another) is made by the pharmacy, and there is concern regarding equivalent efficacy of the preparations, serum thyroid-stimulating hormone (TSH) is measured 6 weeks after changing preparations to document that the serum TSH is still within the therapeutic target. The initial dose can be the full anticipated dose (1.6 mcg/kg/day) in young, healthy patients, but older patients should be started on a lower dose (25 to 50 mcg…
