Different Formulations of Levothyroxine for Treating Hypothyroidism: A Real-Life Study

Pierpaolo Trimboli; Lorenzo Scappaticcio; Annamaria De Bellis; Maria Ida Maiorino; Luisa Knappe; Katherine Esposito; Giuseppe Bellastella; Luca Giovanella

doi:10.1155/2020/4524759

Different Formulations of Levothyroxine for Treating Hypothyroidism: A Real-Life Study

Int J Endocrinol. 2020 Jan 20:2020:4524759. doi: 10.1155/2020/4524759. eCollection 2020.

Authors

Pierpaolo Trimboli¹, Lorenzo Scappaticcio², Annamaria De Bellis², Maria Ida Maiorino², Luisa Knappe¹, Katherine Esposito³, Giuseppe Bellastella², Luca Giovanella^{1

4}

Affiliations

¹ Clinic for Nuclear Medicine and Competence Centre for Thyroid Disease, Imaging Institute of Southern Switzerland, Ente Ospedaliero Cantonale, Bellinzona, Switzerland.
² Unit of Endocrinology and Metabolic Diseases, University of Campania "L. Vanvitelli", Naples, Italy.
³ Department of Advanced Medical and Surgical Sciences, University of Campania "L. Vanvitelli", Naples, Italy.
⁴ Clinic for Nuclear Medicine, University Hospital and University of Zurich, Zurich, Switzerland.

Abstract

Objective: Hypothyroid patients are treated by sodium levothyroxine (LT4). Tablet is the mostly used LT4 formulation, and the fasting regimen is required for the absorption of active principle. Also, gastrointestinal diseases and drugs may impair the LT4 bioavailability when tablet is used. Nonsolid LT4 formulations (i.e., liquid solution (LS) and soft gel (SG) capsule) were manufactured to overcome the limitations of LT4 tablet. This study was conceived to evaluate the performance of nonsolid LT4 formulations in a real-life scenario.

Methods: Two institutions participated in the study that was conducted in two phases (i.e., enrollment and re-evaluation). Adults with autoimmune or postsurgical hypothyroidism and on LT4 from a few months were selected. A nonparametric statistical analysis for paired or unpaired data was performed.

Results: 121 consecutive cases were included. At the enrollment phase, a 52% of patients took the therapy at least 30 min before breakfast with no difference between tablet and SG/LS users. TSH was 1.65 mIU/L (0.86-2.70) in patients on LT4 tablet and 1.70 mIU/L (1.10-2.17) in those on SG/LS (p=0.66). At the re-evaluation phase, among the patients using correct LT4 assumption, the TSH value was stable in the tablet group (p=0.66). At the re-evaluation phase, among the patients using correct LT4 assumption, the TSH value was stable in the tablet group (p=0.66). At the re-evaluation phase, among the patients using correct LT4 assumption, the TSH value was stable in the tablet group (p=0.66). At the re-evaluation phase, among the patients using correct LT4 assumption, the TSH value was stable in the tablet group (p=0.66). At the re-evaluation phase, among the patients using correct LT4 assumption, the TSH value was stable in the tablet group (.

Conclusion: The performance of nonsolid LT4 formulations is not influenced by correct or incorrect use of therapy. On the contrary, LT4 tablet does not guarantee euthyroidism when it is ingested without waiting for at least 30 minutes before breakfast. These new data, obtained in a real-life scenario, suggest that LT4 SG/LS should be regarded as first-line therapy for treating adults with newly diagnosed hypothyroidism.