title: Two- to three-fold increase in blood tacrolimus (FK506) levels during diarrhea in liver-transplanted children.
abstract: BACKGROUND
  The diagnosis and treatment of diarrhea in liver transplant recipients often pose a challenge owing to the variety of infectious and non-infectious causes. However, diagnosis is principally focused on ruling out an infectious etiology. Tacrolimus, an immunosuppressive agent generally used after liver transplantation, is absorbed mainly from the duodenum through the upper jejunum. It can be assumed that metabolism of the drug will be influenced by diarrhea.
  
  
  METHODS
  Four liver transplant recipients who developed an episode of acute gastroenteritis. Infectious etiology was confirmed; trough tacrolimus levels were measured before, during and after gastroenteritis.
  
  
  RESULTS
  All patients presented a two- to three-fold increase in blood tacrolimus levels after the onset of gastroenteritis.
  
  
  CONCLUSIONS
  Until the role played by the intestine in the metabolism of tacrolimus is fully understood, it is prudent to recommend early dose reduction of tacrolimus and careful monitoring of trough levels during diarrheal disorders of any nature in pediatric liver-transplanted patients.
authors.affiliation: Pediatric ICU Service, Hospital Vall d'Hebron, Barcelona, Spain. jiglesias.hmi@cs.vhebron.es
authors.forename: Juan Iglesias
authors.initials: JI
authors.lastname: Berengue
authors.forename: Jesús Alberto
authors.initials: JA
authors.lastname: López-Espinosa
authors.forename: Juan
authors.initials: J
authors.lastname: Ortega-López
authors.forename: Luz
authors.initials: L
authors.lastname: Sánchez-Sánchez
authors.forename: Patricia
authors.initials: P
authors.lastname: Castilla-Valdes
authors.forename: Marino
authors.initials: M
authors.lastname: Asensio-Llorente
authors.forename: Carlos
authors.initials: C
authors.lastname: Margarit-Creixell
mesh_terms: D000208:Acute Disease; D002675:Child, Preschool; D003967:Diarrhea / Q000097:blood* / Q000209:etiology; D005260:Female; D005759:Gastroenteritis / Q000097:blood* / Q000150:complications; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use; D007223:Infant; D007413:Intestinal Mucosa / Q000378:metabolism; D016031:Liver Transplantation; D008297:Male; D011183:Postoperative Complications / Q000097:blood* / Q000209:etiology; D016559:Tacrolimus / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use
chemical_list: D007166:Immunosuppressive Agents; D016559:Tacrolimus