Blood concentrations of dopexamine in patients during and after orthotopic liver transplantation

Blood concentrations of dopexamine were measured in five female patients during and after orthotopic liver transplantation. Each patient received a continuous infusion of the drug (2 micrograms kg-1 min-1), starting at induction of anaesthesia and finishing 48 h afterwards. Blood concentrations of dopexamine increased rapidly at the start of the infusion, to a mean (range) value of 64 (40-150) ng ml-1 after 20 min. Blood concentrations of dopexamine increased further during the anhepatic period of surgery, to 236 (180-410) ng ml-1. On reperfusion of the donor liver, concentrations of dopexamine decreased rapidly, reaching similar values to the maximum seen during the dissection period. Steady-state was not reached during either the dissection or anhepatic periods. From 1-2 h after revascularisation the mean (range) steady-state concentration was 85 (69-102) ng ml-1 corresponding to a mean (range) clearance of 24 (20-29) ml min-1 kg -1. These results suggest that the liver plays a significant role in the clearance of dopexamine.