title: The in vitro anticoagulant effect of rivaroxaban in children.
abstract: BACKGROUND
  Current anticoagulation therapy in children is less than ideal, requiring regular venous monitoring and dosing adjustments. Limitations associated with conventional anticoagulants have prompted the development of novel drugs that specifically target key proteins in the coagulation system. Rivaroxaban is the first oral, direct Factor Xa inhibitor available for the prevention of venous thromboembolism in adults. Its predictable pharmacokinetic profile, high oral bioavailability and once-daily dosing make rivaroxaban an optimal anticoagulant that warrants investigation in children. The aim of this study was to investigate the age-related anticoagulant effect of rivaroxaban in vitro.
  
  
  METHODS
  Age-specific plasma pools were created (i.e. 28 days-23 months, 2-6, 7-11, 12-16 years and adults) and spiked with increasing concentrations of rivaroxaban (0-500 ng/ml). Commercially available PT, APTT and anti-Factor Xa assays, as well as sub-sampling thrombin generation assays, were used to measure rivaroxaban effect.
  
  
  RESULTS
  The results of this study indicate that there are no significant differences in rivaroxaban effect across the age groups in vitro.
  
  
  CONCLUSIONS
  In vivo studies are required to confirm the consistency of dose-response across the paediatric age groups.
authors.affiliation: Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Victoria 3052, Australia.
authors.forename: C
authors.initials: C
authors.lastname: Attard
authors.forename: P
authors.initials: P
authors.lastname: Monagle
authors.forename: D
authors.initials: D
authors.lastname: Kubitza
authors.forename: V
authors.initials: V
authors.lastname: Ignjatovic
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000925:Anticoagulants / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D065427:Factor Xa Inhibitors; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009025:Morpholines / Q000494:pharmacology*; D000069552:Rivaroxaban; D013876:Thiophenes / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D000925:Anticoagulants; D065427:Factor Xa Inhibitors; D009025:Morpholines; D013876:Thiophenes; D000069552:Rivaroxaban