Experience with low-dose replacement therapy in the initial management of severe pediatric acquired primary hypothyroidism.
Rapid hormonal replacement of children with severe primary hypothyroidism frequently results in irritability and poor concentration. To alleviate these problems we have been using initial low-dose thyroxine treatment, building up to a final dose in an incremental manner over 4 1/2 to 6 months. Because of concern this regimen may compromise growth, we reviewed our experience treating 14 children and adolescents. For the 10 patients with remaining growth potential, 5 to 7 month growth velocity from the onset of treatment was 8.5 +/- 1.9 cm/year (range 5.7-10.9), and 5 to 7 month growth velocity z-score 1.5 +/- 1.7 (range 0.2-4.9). For the entire group, the thyroxine dose required to normalize TSH was 1.6 +/- 0.74 microgram/kg (range 0.9-3.4) or 60.7 +/- 18.9 micrograms/m2 (range 37.5-97.7). Based on the 5 to 7 month z-score, we conclude that satisfactory growth can be achieved on this regimen despite biochemical hypothyroidism. Thyroxine doses required to induce initial euthyroidism are lower than previously proposed.
Department of Pediatrics, Medical College of Wisconsin, Milwaukee, USA.
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Slyper
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Swenerton
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D007037:Hypothyroidism / Q000188:drug therapy*; D008297:Male; D012189:Retrospective Studies; D013974:Thyroxine / Q000627:therapeutic use*
D013974:Thyroxine