[Hormonal therapy of congenital hypothyroidism in childhood]

L-tiroxine (L-T4) substitutive therapy has been evaluated in a group of 15 hypothyroid children (6 males and 9 females), one to six years old. We have found a wide dosage range, being not possible to find any significant difference between ranges leading to normal and ranges leading to pathological findings, thus making impossible to suggest a reasonably safe dosage pro kg. of body weight. Increasing L-T4 dosage we have got a significant increase of FT4 levels, a significant decrease of TSH levels, but no variations of FT3 values, indicating an individual capability in regulating FT3 disposal. FT3 and TSH are the most valuable indexes of therapy adequacy, since their normality reflects an euthyroid status; we should achieve an individually adequate dose of L-T4, based on clinical judgment and hormonal findings.