Controlled clinical trial of combined triiodothyronine and thyroxine in the treatment of hypothyroidism

Abstract

A -double-blind crossover trial of a combined preparation of triiodothyronine and thyroxine (1:4 ratio) compared with thyroxine alone was conducted with 99 patients previously stabilized on. thyroxine as treatment for hypothyroidism. Four patients were excluded during the trial and eight afterwards owing to gross deficiencies in taking the tablets. Of the remaining 87 patients 42 (48%) had no -preference for either medication, 29 (33%) preferred thyroxine alone, and 16 (18%) the combination. A high incidence of unpleasant symptoms was experienced during the two months' treatment with the combined preparation. The serum protein-bound iodine levels were lowered (mean reduction 1.8 mug./100 ml.) on the combination, but the labelled T(3)-resin sponge uptake values were not altered and remained in the normal range. on both treatments.