title: Long-term 3,5,3'-triiodothyroacetic acid therapy in a child with hyperthyroidism caused by thyroid hormone resistance: pharmacological study and therapeutic recommendations.
abstract: BACKGROUND
  The effectiveness of short-term 3,5,3'-triiodothyroacetic acid (TRIAC) therapy for the treatment of hyperthyroidism caused by thyroid hormone resistance (RTH) has been documented. Here, we report a 3-year course of TRIAC therapy in an RTH boy, with a quantitative evaluation of the therapeutic effects and pharmacological study of TRIAC.
  
  
  METHODS
  The gene encoding the thyroid hormone receptor beta (THRB) of the patient carries a P453T mutation. During treatment with up to 3.0 mg TRIAC per day, reduction in the thyroid volume, resolution of supraventricular arrhythmia, and decrease in thyroid-stimulating hormone (TSH) and free-thyroxine (FT4) levels were achieved. In addition, attention-deficit hyperactivity disorder (ADHD) symptoms improved, with a concomitant decline in the ADHD Rating Scale score.
  
  
  CONCLUSIONS
  A TRIAC pharmacokinetic study, conducted using triiodothyronine level as a surrogate for TRIAC level, demonstrated that TRIAC disappears from the circulation rapidly and has a shorter duration of TSH secretion inhibitory effect in the RTH patient compared to that in the control subject. Studies of TSH and FT4 levels over a period of 3 years indicated that the TRIAC effect is dose dependent.
  
  
  CONCLUSIONS
  TRIAC was effective and safe in ameliorating the effects of hyperthyroidism and ADHD symptoms in a child with known genetic RTH. Further, it was demonstrated that TRIAC has a short half-life and functions dose dependently.
authors.affiliation: Department of Endocrinology and Metabolism, Kanagawa Children's Medical Center, Yokohama, Japan.
authors.forename: Rie
authors.initials: R
authors.lastname: Anzai
authors.forename: Masanori
authors.initials: M
authors.lastname: Adachi
authors.forename: Noriko
authors.initials: N
authors.lastname: Sho
authors.forename: Koji
authors.initials: K
authors.lastname: Muroya
authors.forename: Yumi
authors.initials: Y
authors.lastname: Asakura
authors.forename: Kazumichi
authors.initials: K
authors.lastname: Onigata
mesh_terms: D000293:Adolescent; D000328:Adult; D018880:Atrial Premature Complexes / Q000188:drug therapy; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy; D002648:Child; D002675:Child, Preschool; D005260:Female; D006207:Half-Life; D006801:Humans; D006980:Hyperthyroidism / Q000188:drug therapy*; D008297:Male; D037042:Thyroid Hormone Receptors beta / Q000235:genetics; D018382:Thyroid Hormone Resistance Syndrome / Q000188:drug therapy*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use
chemical_list: D037042:Thyroid Hormone Receptors beta; D014284:Triiodothyronine; C010642:3,3',5-triiodothyroacetic acid; D013972:Thyrotropin; D013974:Thyroxine