Congenital hypothyroidism treatment in infants: a comparative study between liquid and tablet formulations of levothyroxine

Horm Res Paediatr. 2014;81(1):50-4. doi: 10.1159/000356047. Epub 2013 Nov 12.


Aims: To compare the effects of liquid and tablet formulations of levothyroxine (L-T4) in 78 newborns with congenital hypothyroidism (CH).

Methods: 39 patients received liquid L-T4 (group A) and 39 patients received tablets (group B). Thyroid-stimulating hormone (TSH) and free thyroxine (fT4) were measured and L-T4 dose recorded at onset of therapy and during the first year of treatment. Developmental quotient (DQ) was assessed by Griffiths' mental development scales at 12 months of age.

Results: Gestational age, birth weight, screening TSH, etiology and severity of CH, age at onset of therapy and median initial L-T4 dose were similar in both groups. fT4 concentration normalized before 10 days of treatment in all patients. Normalization of TSH concentration was achieved after 7-10 days of therapy in 87% of group A patients and in 82% of group B patients. Group A patients had significantly lower TSH values compared with those of group B at 7-10 days (p = 0.05) and 6-8 months (p = 0.043) of treatment, despite similar L-T4 dose and fT4 concentration. Mean DQ scores were within normal range in all patients.

Conclusion: We confirmed the efficacy and safety of both formulations. The TSH inhibition trend when using liquid L-T4 may be linked to a higher absorption in comparison to the tablets.

Publication types

  • Comparative Study

MeSH terms

  • Birth Weight
  • Child Development / drug effects
  • Cognition / drug effects
  • Congenital Hypothyroidism / blood
  • Congenital Hypothyroidism / drug therapy*
  • Humans
  • Infant
  • Locomotion / drug effects
  • Retrospective Studies
  • Suspensions
  • Tablets
  • Thyroid Function Tests
  • Thyrotropin / blood
  • Thyroxine / administration & dosage*


  • Suspensions
  • Tablets
  • Thyrotropin
  • Thyroxine