Levothyroxine (L-T4) is recommended as lifelong replacement therapy for hypothyroidism. Recent clinical and experimental data support the addition of levotriiodothyronine (L-T3) treatment in some selected hypothyroid patients when their symptoms persist and their quality of life remains impaired despite adequate L-T4 monotherapy. An increase in L-T3 prescriptions has been recently observed in Italy due to availability of different L-T3 formulations, making it possible to clinicians to prescribe L-T3 alone or in combination with L-T4. The aim of the present position statement was to define the correct clinical indications, schedule, duration of treatment and contraindications of combined treatment with L-T4 and L-T3 in hypothyroid patients in an attempt to guide clinicians and to avoid potential adverse effects of overtreatment.
Keywords: Body weight; Clinical symptoms; Cognition; Deiodinases; Depression; Heart rate and patient preference for combined therapy; Hypothyroidism; L-Thyroxine; L-Triiodothyronine; Mood; Polymorphism in type 2 deiodinase gene; Quality of life; Replacement therapy; TSH-suppressive therapy; Thyroidectomized patients.