Treating Hypothyroidism with Thyroxine/Triiodothyronine Combination Therapy in Denmark: Following Guidelines or Following Trends?

Background: Five to ten percent of patients with hypothyroidism describe persistent symptoms despite being biochemically well regulated on levothyroxine (L-T₄). Thyroxine (T₄)/triiodothyronine (T₃) combination therapy [L-T₄/liothyronine (L-T₃) or desiccated thyroid] are still regarded as experimental with no evidence of superior effect on persistent symptoms according to meta-analyses. However, some randomized controlled trials have demonstrated patients' preference for T₄/T₃ combination therapy as compared to L-T₄ monotherapy. In 2013, attention to combination therapy increased in Denmark after a patient published a book describing her experiences with hypothyroidism and treatment. Objective: To investigate current Danish trends in the use of T₄/T₃ combination therapy. Methods: We used an Internet-based questionnaire, distributed as a link via two Danish patient fora. Further, information was obtained from the Division of Pharmacies and Reimbursement at the Danish Health and Medicines Authority and from the only pharmacy in Denmark producing desiccated thyroid and L-T₃ tablets. Results: A total of 384 patients answered the questionnaire, and 293 responders were included. Sixty-nine percent of the responders had six or more symptoms, and 84% reported a treatment effect. Forty-four percent of the responders received their prescriptions from general practitioners; 50% received desiccated thyroid and 28% reported that they adjust their dose themselves. Responders followed by general practitioners more frequently received desiccated thyroid and adjusted their dose themselves. Conclusions: Increased media focus has changed the prescription pattern of thyroid hormones; European guidelines on T₄/T₃ combination therapy are not always followed in Denmark and many patients adjust their medication themselves and may therefore be at risk of overtreatment.