title: Nonlinear dobutamine pharmacokinetics in a pediatric population.
abstract: OBJECTIVE
  To evaluate a linear kinetic model for dobutamine clearance.
  
  
  METHODS
  A prospective evaluation of pediatric patients receiving continuous infusions of dobutamine at varying doses.
  
  
  METHODS
  A pediatric critical care unit.
  
  
  METHODS
  Twelve patients age 2 days to 9 yrs and weighing 2.7 to 33 kg who required vasopressor therapy. Infusion rates for dobutamine ranged from 2 to 15 micrograms/kg.min.
  
  
  RESULTS
  Serum concentrations varied from 6.4 to 347 ng/mL (21 to 1151 nmol/L). Concentration was found to increase with dose. However, the relationship of clearance to steady-state concentration had a negative slope. Values for clearance varied from 32 to 625 mL/kg.min. Multiple analysis of variance on age, weight, and co-infused dopamine showed that these factors did not influence the relationship of clearance to steady-state concentration. Analysis to show an underlying model failed to differentiate Michaelis-Menten from nonlinear binding or mixed models on the basis of these data.
  
  
  CONCLUSIONS
  Dobutamine pharmacokinetics do not appear to follow a simple linear model. Based on the current data, neither age nor the added infusion of dopamine affects the clearance of dobutamine.
authors.affiliation: University of Utah, Primary Children's Medical Center, Salt Lake City 84113.
authors.forename: W
authors.initials: W
authors.lastname: Banner
authors.forename: D D
authors.initials: DD
authors.lastname: Vernon
authors.forename: S D
authors.initials: SD
authors.lastname: Minton
authors.forename: J M
authors.initials: JM
authors.lastname: Dean
mesh_terms: D000367:Age Factors; D001835:Body Weight; D002648:Child; D002675:Child, Preschool; D004280:Dobutamine / Q000008:administration & dosage / Q000378:metabolism / Q000493:pharmacokinetics*; D004298:Dopamine / Q000008:administration & dosage / Q000378:metabolism / Q000493:pharmacokinetics; D004359:Drug Therapy, Combination; D005069:Evaluation Studies as Topic; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007262:Infusions, Intravenous; D016014:Linear Models; D008657:Metabolic Clearance Rate; D008956:Models, Chemical; D011446:Prospective Studies; D011485:Protein Binding; D015203:Reproducibility of Results
chemical_list: D004280:Dobutamine; D004298:Dopamine