PHARMACOKINETICS OF DOPAMINE IN INFANTS AND CHILDREN

Objective: We studied the pharmacokinetics of dopamine in hemodynamically stable children. Design: Prospective clinical trial. Setting: Pediatric ICU. Patients: Children (age 3 months to 13 yrs) recovering from cardiac surgery or shock. Intervention: Plasma dopamine concentrations were measured at the steady state or at termination of infusion using high-performance liquid chromatography. Results: The half-lives of distribution and elimination were 1.8 +/- 1.1 and 26 +/- 14 (SD) mins, respectively. The apparent volume of distribution was 2952 +/- 2332 mL/kg. The clearance rate was 454 +/- 900 mL/kg.min. Dopamine clearance was linearly related to dose only in patients who were also receiving dobutamine (r2 = .76, p < .05). Hepatic and renal dysfunction did not affect the pharmacokinetics of dopamine. Conclusions: A relationship between dopamine and dobutamine that affects the disposition of these two drugs may exist. The pharmacokinetics of dopamine are variable even in hemodynamically stable children. Hepatic or renal function does not adversely affect the pharmacokinetics of dopamine.