Effects of docarpamine on hemodynamics after open heart surgery in children.

Docarpamine is a dopamine prodrug which has been selected from a large number of dopamine derivatives in order to develop an orally effective dopamine. The pharmacokinetics after oral administration of docarpamine have not yet been studied in children undergoing open heart surgery. This study examined the effects of docarpamine on hemodynamics and evaluated its safety in 11 children undergoing open heart surgery for congenital heart disease. This study began when the patientOs postoperative condition was stabilized by continuous dopamine infusion into the vein at a rate of 5 micro g/kg/min. The patients were administered 40 mg/kg of docarpamine every 8 hours, and hemodynamics were measured every 4 hours for 16 hours after the initial docarpamine administration. Immediately after the initial docarpamine administration, the dose of dopamine was reduced to 3 micro g/kg/min. Infusion of dopamine was stopped 8 hours after the initial docarpamine administration. Systemic systolic and diastolic blood pressure and heart rate showed no significant changes. Mean right atrial pressure decreased 4 hours after docarpamine administration. Mixed venous oxygen saturation and mean velocity of circumferential fiber shortening increased significantly after docarpamine administration. No significant changes were observed in urine volume. All patients could be weaned from dopamine within 8 hours. No changes were observed in ECG, and no arrhythmia-inducing action was noted. Our study indicates that 40 mg/kg oral doses of docarpamine produce plasma dopamine concentration equivalent to those of a 3 to 5 micro g/kg/min dopamine infusion. Our data suggest that docarpamine is a safe and effective drug for children who have undergone open heart surgery.