Dobutamine pharmacokinetics and pharmacodynamics in pediatric intensive care patients.
OBJECTIVE
To evaluate the pharmacokinetics and pharmacodynamics of dobutamine in critically ill children.


METHODS
A prospective study of pediatric patients receiving continuous infusions of dobutamine in a stepwise format from 2.5 to 10.0 micrograms/kg/min.


METHODS
A pediatric critical care unit.


METHODS
Twelve children ranging in age from 1 month to 17 yrs with primary medical conditions.


METHODS
Plasma dobutamine concentrations and hemodynamic responses were measured at each infusion rate at steady state. Dose response data were analyzed to determine the threshold or minimum plasma dobutamine concentration necessary for discernible hemodynamic effects.


RESULTS
Dobutamine plasma clearance rates ranged from 40 to 130 mL/kg/min. Each patient presented a linear increase in the plasma dobutamine concentration at each infusion rate (r2 = .97, p less than .001). Plasma clearance rate vs. actual dobutamine concentration did not vary. Cardiac output, BP, and heart rate increased 30%, 17%, and 7%, respectively, at maximal dose. The dobutamine concentration thresholds for changes in cardiac output, BP, and heart rate were 13 +/- 6, 23 +/- 14, and 65 +/- 30 ng/mL, respectively.


CONCLUSIONS
There was no effect of plasma dobutamine concentration or infusion rate on plasma clearance rate. For this group of patients, over the range of the intravenous doses studied, dobutamine pharmacokinetics followed a first-order kinetic model. Threshold values for dobutamine usually show increases in cardiac output before changes in heart rate. These data demonstrate that dobutamine is an effective inotropic agent in critically ill pediatric patients and has minimal chronotropic action.
Habib
D M
DM
Harbor-UCLA Medical Center, UCLA School of Medicine, Torrance.
Padbury
J F
JF
Anas
N G
NG
Perkin
R M
RM
Minegar
C
C
D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight; D002140:California; D002302:Cardiac Output / Q000187:drug effects; D002675:Child, Preschool; D016638:Critical Illness; D004280:Dobutamine / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology; D004298:Dopamine / Q000097:blood; D004305:Dose-Response Relationship, Drug; D016903:Drug Monitoring; D004837:Epinephrine / Q000097:blood; D006339:Heart Rate / Q000187:drug effects; D006776:Hospitals, Pediatric; D006801:Humans; D007223:Infant; D007262:Infusions, Intravenous; D015278:Intensive Care Units, Pediatric; D008657:Metabolic Clearance Rate; D008962:Models, Theoretical; D009638:Norepinephrine / Q000097:blood; D011446:Prospective Studies
D004280:Dobutamine; D004298:Dopamine; D009638:Norepinephrine; D004837:Epinephrine