In congenital hypothyroidism, an initial L-thyroxine dose of 10-12 μg/kg/day is sufficient and sometimes excessive based on thyroid tests 1 month later

Priya Vaidyanathan, Meenal Pathak, Paul B. Kaplowitz

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12 Citations (Scopus)

Abstract

Background: Current guidelines recommend an initial L-thyroxine (L-T4) dose of 10-15 μg/kg/day for the treatment of congenital hypothyroidism (CH). We analyzed our data for the treatment outcome at 1 month after we noted a frequent overtreatment even at the lower end of this dose range. Methods: A 3-year chart review of 55 patients with confirmed CH was performed. The patients were divided to three groups based on L-T4 dose: Group 1 (6-9.9 μg/kg), Group 2 (10-11.9 μg/kg), and Group 3 (12-15 μg/kg). Over-treatment was defined as T4> 16 μg/dL/free T4>2.3 ng/dL ± thyroid-stimulating hormone (TSH) < 0.5 μIU/L and undertreatment was defined as TSH> 6 μIU/L at 1 month. Results: At 1 month, 45.8%, 37.5%, and 16.6% in Group 1, 30%, 55%, and 15% in Group 2, and 0%, 75%, and 25% in Group 3 had target labs, overtreatment, and undertreat-ment, respectively. Conclusions: An initial L-T4 dose of 10-11.9 μg/kg for TSH> 100 μIU/L and 8-10 μg/kg for TSH<100 μIU/L at diagnosis met and often exceeded the target thyroid levels at 1 month. More frequent overtreatment was seen when > 12 μg/kg was given.

Original languageEnglish (US)
Pages (from-to)849-852
Number of pages4
JournalJournal of Pediatric Endocrinology and Metabolism
Volume25
Issue number9-10
DOIs
StatePublished - Oct 1 2012

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Congenital Hypothyroidism
Thyrotropin
Thyroxine
Thyroid Gland
Guidelines
Therapeutics
Medical Overuse

All Science Journal Classification (ASJC) codes

  • Pediatrics, Perinatology, and Child Health
  • Endocrinology, Diabetes and Metabolism
  • Endocrinology

Cite this

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title = "In congenital hypothyroidism, an initial L-thyroxine dose of 10-12 μg/kg/day is sufficient and sometimes excessive based on thyroid tests 1 month later",
abstract = "Background: Current guidelines recommend an initial L-thyroxine (L-T4) dose of 10-15 μg/kg/day for the treatment of congenital hypothyroidism (CH). We analyzed our data for the treatment outcome at 1 month after we noted a frequent overtreatment even at the lower end of this dose range. Methods: A 3-year chart review of 55 patients with confirmed CH was performed. The patients were divided to three groups based on L-T4 dose: Group 1 (6-9.9 μg/kg), Group 2 (10-11.9 μg/kg), and Group 3 (12-15 μg/kg). Over-treatment was defined as T4> 16 μg/dL/free T4>2.3 ng/dL ± thyroid-stimulating hormone (TSH) < 0.5 μIU/L and undertreatment was defined as TSH> 6 μIU/L at 1 month. Results: At 1 month, 45.8{\%}, 37.5{\%}, and 16.6{\%} in Group 1, 30{\%}, 55{\%}, and 15{\%} in Group 2, and 0{\%}, 75{\%}, and 25{\%} in Group 3 had target labs, overtreatment, and undertreat-ment, respectively. Conclusions: An initial L-T4 dose of 10-11.9 μg/kg for TSH> 100 μIU/L and 8-10 μg/kg for TSH<100 μIU/L at diagnosis met and often exceeded the target thyroid levels at 1 month. More frequent overtreatment was seen when > 12 μg/kg was given.",
author = "Priya Vaidyanathan and Meenal Pathak and Kaplowitz, {Paul B.}",
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TY - JOUR

T1 - In congenital hypothyroidism, an initial L-thyroxine dose of 10-12 μg/kg/day is sufficient and sometimes excessive based on thyroid tests 1 month later

AU - Vaidyanathan, Priya

AU - Pathak, Meenal

AU - Kaplowitz, Paul B.

PY - 2012/10/1

Y1 - 2012/10/1

N2 - Background: Current guidelines recommend an initial L-thyroxine (L-T4) dose of 10-15 μg/kg/day for the treatment of congenital hypothyroidism (CH). We analyzed our data for the treatment outcome at 1 month after we noted a frequent overtreatment even at the lower end of this dose range. Methods: A 3-year chart review of 55 patients with confirmed CH was performed. The patients were divided to three groups based on L-T4 dose: Group 1 (6-9.9 μg/kg), Group 2 (10-11.9 μg/kg), and Group 3 (12-15 μg/kg). Over-treatment was defined as T4> 16 μg/dL/free T4>2.3 ng/dL ± thyroid-stimulating hormone (TSH) < 0.5 μIU/L and undertreatment was defined as TSH> 6 μIU/L at 1 month. Results: At 1 month, 45.8%, 37.5%, and 16.6% in Group 1, 30%, 55%, and 15% in Group 2, and 0%, 75%, and 25% in Group 3 had target labs, overtreatment, and undertreat-ment, respectively. Conclusions: An initial L-T4 dose of 10-11.9 μg/kg for TSH> 100 μIU/L and 8-10 μg/kg for TSH<100 μIU/L at diagnosis met and often exceeded the target thyroid levels at 1 month. More frequent overtreatment was seen when > 12 μg/kg was given.

AB - Background: Current guidelines recommend an initial L-thyroxine (L-T4) dose of 10-15 μg/kg/day for the treatment of congenital hypothyroidism (CH). We analyzed our data for the treatment outcome at 1 month after we noted a frequent overtreatment even at the lower end of this dose range. Methods: A 3-year chart review of 55 patients with confirmed CH was performed. The patients were divided to three groups based on L-T4 dose: Group 1 (6-9.9 μg/kg), Group 2 (10-11.9 μg/kg), and Group 3 (12-15 μg/kg). Over-treatment was defined as T4> 16 μg/dL/free T4>2.3 ng/dL ± thyroid-stimulating hormone (TSH) < 0.5 μIU/L and undertreatment was defined as TSH> 6 μIU/L at 1 month. Results: At 1 month, 45.8%, 37.5%, and 16.6% in Group 1, 30%, 55%, and 15% in Group 2, and 0%, 75%, and 25% in Group 3 had target labs, overtreatment, and undertreat-ment, respectively. Conclusions: An initial L-T4 dose of 10-11.9 μg/kg for TSH> 100 μIU/L and 8-10 μg/kg for TSH<100 μIU/L at diagnosis met and often exceeded the target thyroid levels at 1 month. More frequent overtreatment was seen when > 12 μg/kg was given.

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