Department of Pediatrics, University of Bologna, Bologna, Italy.
J Pediatr. 2013 Jun;162(6):1264-9, 1269.e1-2. doi: 10.1016/j.jpeds.2012.11.070. Epub 2013 Jan 11.
To evaluate the effects of liquid (drops) and tablet formulations of levothyroxine in homogeneous groups of infants with congenital hypothyroidism (CH) as diagnosed through neonatal screening.
Forty-two consecutive infants with CH were subdivided into 2 groups consisting of infants with the severe or the moderate/mild form. For each form, the infants with CH were randomly assigned to receive liquid (group 1) or tablet (group 2) formulation. In all patients, thyroid function tests were performed before the beginning of therapy and at 15 and 30 days and at 3 and 6 months after the beginning of therapy.
In the severe form, after 15 days of treatment, serum thyrotropin (TSH) levels became normal in 8 of 9 patients in group 1 and in 5 of 9 patients in group 2; serum free triiodothyronine (fT3) levels were significantly higher in group 1 than in group 2; and serum fT4 levels were higher than the upper limit of the normal range in all patients in both groups. During the follow-up, there were significantly more patients with suppressed TSH concentrations in group 1 than in group 2. In the moderate/mild form, the patients of group 1 and group 2 showed median values of TSH, fT3, and fT4 that were not significantly different. No clinical or electrocardiographic signs of heart disease were found. There were no significant differences in the developmental quotient between group 1 and group 2 patients with severe and moderate/mild CH.
Our data seem to indicate that there is not complete bioequivalence between drops and tablets, especially in infants with severe CH.
评估经新生儿筛查诊断为先天性甲状腺功能减退症（CH）的同质婴儿中，左甲状腺素的液体（滴剂）和片剂制剂的效果。
42 名连续患有 CH 的婴儿分为 2 组，每组均由严重或中度/轻度形式的婴儿组成。对于每种形式，CH 婴儿均被随机分配接受液体（第 1 组）或片剂（第 2 组）制剂。在所有患者中，在开始治疗之前以及在开始治疗后 15 天、30 天和 3 个月、6 个月时进行甲状腺功能测试。
在严重形式中，在治疗后 15 天，第 1 组的 9 名患者中有 8 名，第 2 组的 9 名患者中有 5 名血清促甲状腺激素（TSH）水平恢复正常；第 1 组的游离三碘甲状腺原氨酸（fT3）水平明显高于第 2 组；两组所有患者的血清 fT4 水平均高于正常范围上限。在随访期间，第 1 组中 TSH 浓度受抑制的患者明显多于第 2 组。在中度/轻度形式中，第 1 组和第 2 组的患者 TSH、fT3 和 fT4 的中位数均无显著差异。未发现心脏疾病的临床或心电图迹象。严重和中度/轻度 CH 的第 1 组和第 2 组患者的发育商之间没有显著差异。
我们的数据似乎表明，滴剂和片剂之间没有完全的生物等效性，尤其是在严重 CH 的婴儿中。
