title: Nationwide surveillance of circulatory collapse associated with levothyroxine administration in very-low-birthweight infants in Japan.
abstract: BACKGROUND
  Although the administration of levothyroxine sodium (LT4) to premature infants had been considered safe, several cases of late-onset circulatory collapse (LCC) following the administration of LT4 in very-low-birth-weight (VLBW) infants have been reported in Japan since 2008. This study was performed to investigate the incidence of LCC associated with the administration of LT4 to VLBW infants.
  
  
  METHODS
  A questionnaire regarding LCC with or without an association with LT4 administration in VLBW infants from 2006 to 2008, was sent to 212 hospitals belonging to the Japan Neonatologist Association.
  
  
  RESULTS
  Data of 8727 VLBW infants were analyzed, and 46 cases of LCC associated with the administration of LT4 were reported in this surveillance. Especially, an analysis for infants weighing between 1000 and 1499 g at birth revealed that the incidence of LCC with the administration of LT4 was higher than that of those without LT4.
  
  
  CONCLUSIONS
  LT4 is widely used for infants, including VLBW infants, and no major complications have been reported. However, our study revealed that more than a few cases of LCC were associated with the administration of LT4 in VLBW infants. In conclusion, careful attention is necessary when initiating the administration of LT4 to VLBW infants.
authors: Department of Pediatrics, Graduate School of Medicine, Kyoto University, Kyoto, Japan. masahiko@kuhp.kyoto-u.ac.jp
authors: Masahiko
authors: M
authors: Kawai
authors: Satoshi
authors: S
authors: Kusuda
authors: Kazutoshi
authors: K
authors: Cho
authors: Reiko
authors: R
authors: Horikawa
authors: Fumihiko
authors: F
authors: Takizawa
authors: Makoto
authors: M
authors: Ono
authors: Tetsuo
authors: T
authors: Hattori
authors: Makoto
authors: M
authors: Oshiro
mesh_terms: D000311:Adrenal Glands / Q000187:drug effects; D003409:Congenital Hypothyroidism / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D007564:Japan / Q000453:epidemiology; D008297:Male; D011159:Population Surveillance; D012189:Retrospective Studies; D012769:Shock / Q000139:chemically induced*; D013960:Thyroid Function Tests; D013974:Thyroxine / Q000009:adverse effects* / Q000097:blood*; D013997:Time Factors
chemical_list: D013974:Thyroxine