ESPE Abstracts (2018) 89 P-P1-253

Long Term Comparison between Liquid and Tablet Formulations of L-Thyroxine (L-T4) in the Treatment of Congenital Hypothyroidism (CH)

Maria Cristina Vigonea, Rita Ortolanob, Gaia Vincenzia, Clara Pozzia, Micol Rattia, Valentina Assirellib, Sofia Vissanib, Paolo Cavarzerec, Alessandro Mussad, Roberto Gastaldie, Raffaella Di Masef, Maria Elisabeth Streetg, Jessica Trombatoreh, Giovanna Weberi & Alessandra Cassiob

aVita-Salute San Raffaele University, IRCSS San Raffele, Department of Pediatrics, MIlano, Italy; bS.Orsola-Malpighi University Hospital, Pediatric Unit, Center for Rare Endocrine Diseases (CARENDO BO), Bologna, Italy; cPediatric Department, Universitary Hospital of Verona, Verona, Italy; dTorino University, Department of Pediatrics, Torino, Italy; eGiannina Gaslini Children’s Hospital, Genova, Italy, Genova, Italy; fDepartment of Pediatrics, AOUF Federico II, Napoli, Italy; gDepartment of Paediatrics, AUSL Reggio Emilia-IRCCS, Reggio Emilia, Italy; hMessina University, Department of Pediatrics, Messina, Italy; iVita- Salute San Raffaele University, IRCSS San Raffele, Department of Pediatrics, MIlano, Italy

Introduction: Few studies have been published comparing the liquid and tablet formulations of L-T4 in pediatric patients, with a short follow-up period. Both formulations seemed to produce a rapid normalization of thyroid fuction with a tendency of a greater TSH inhibition in children taking the L-T4 liquid drops. The aim of our study is to compare the long-term effectiveness and saftey of both liquid and tablet L-T4 therapy in CH patients up to 3 years old via a multicenter study.

Methods: 276 children affected with CH identified by neonatal screening were included in this study: 129 treated with liquid formulation (Group A) and 147 treated with tablets (Group B). Birth data, TSH and FT4 values and L-T4 dose were collected at 15 days, 1-3-6-12-24-36 months. The liquid formulation contains ethanol as an excipient: to further evaluate its influence on childrens’ cognitive development, we evaluated the patients’ Developmental Quotient (DQ) at 1 and 3 years of age.

Results: There was no significant difference in birth weight and length, gestational age, TSH and FT4 at diagnosis, and etiology of CH between groups A and B. Group A began therapy with a median dose of 11.02 mcg/kg/die (range 3.5–15.67) and group B with 11.13 mcg/kg/die (range 4.6–15) (P=0.052; α=0.006). There was no significant difference between L-T4 dose, TSH and FT4 serum levels at 15 days, 1-3-6-12-24-36 months. The median DQ at 1 and 3 years of age was 101 (range 50–135) and 104 (range 88–133) in group A, and 108.5 (range 74–127) and 110 (range 72–125) in group B, without a significant difference between the two groups (P=0.045 at 1 year; P=0.19 at 3 years; α=0.025).

Conclusions: These data confirm that both liquid and tablet formulations are efficient in treating CH and TSH inhibition never occurred when using the liquid formulation. No negative effects in cognitive development were observed in the patients treated with liquid drops.