Non-inferiority of liquid thyroxine in comparison to tablets formulation in the treatment of children with congenital hypothyroidism.

Objectives: The aim of the current prospective randomized control study was to assess efficacy, safety, and non-inferiority of a new liquid L-thyroxine formulation dissolved in glycerol and water (T4 drops, produced by a Greek pharmaceutical Company, Uni-Pharma, Athens, Greece) in comparison to the standard Tablets form (T4 tablets, Uni-Pharma, Athens, Greece) in the substitutive treatment of children with congenital hypothyroidism (CH).

Methods: Thirty-nine children with CH, aged 3-12 years old, were enrolled in the study, after parental Informed Consent has been obtained, while three patients were lost from follow-up. At baseline, all participants had normal thyroid-stimulating hormone (TSH) and Free T4 values. Patients were randomly subdivided according to the assigned treatment in Group A (n=17)-Tablet Form and Group B (n=19)-Liquid Form. TSH and Free T4 levels were evaluated at 0, 2, 4, and 6 months.

Results: TSH values showed a statistically significant difference (p=0.017) between groups only at six months (Group A having higher TSH levels than Group B, albeit within the normal range), while Free T4 levels had no statistical difference throughout the six month study period and were always within the normal range. Moreover, dose adjustments were more frequent in Group A (p=0.038) during the six months. Liquid L-thyroxine substitutive treatment exhibited no statistically significant adverse effects in comparison to the widely used tablets.

Conclusions: Levothyroxine (LT4) as liquid solution formulation is safe and noninferior to the widely used L-thyroxine Tablets, with less need for dose adjustment, and can therefore be safely used in the treatment of children with CH.