Effects of Parenteral Nutritional Regimens on Oxidative Drug Metabolism

Abstract

To determine whether the caloric source of i.v. nutrition can influence oxidative drug metabolizing capacity, antipyrine metabolism was studied in 6 healthy volunteers, who were taking no food or liquid by mouth, after they were administered an i.v. nutritional regimen of 5% dextrose, 440 kcal/day, for 4 days, and after they were switched to an essentially isocaloric i.v. nutritional regimen of amino acids (Aminosyn 3.5%) for 1 day. The change in i.v. nutritional regimen resulted in a 21% decrease in mean half-life (range: 3-32%), a 20% decrease in mean area under the concentration-time curve (range: 4-42%) and a 24% increase in mean metabolic clearance rate (range: 2-71%) for antipyrine. Apparently, the change from i.v. dextrose to i.v. amino acids for only 1 day produced in all subjects an increase in antipyrine metabolism. There was marked variability in the responsiveness of the different subjects to the change in i.v. caloric source.