Cellular and plasma kinetics of daunorubicin by two methods of administration in a patient with acute leukemia

Leukemic cell and plasma concentrations of daunorubicin were examined serially in a patient with acute lymphoblastic leukemia following administration of the drug by two different regimens: A an iv bolus dose of 50 mg/m ², and regimen B a loading dose of 15 mg/m ² followed by 35 mg/m ² infused over 4 hours. Peak plasma levels were four times higher after regimen A than B, whereas leukemic cell concentrations were not significantly different. No difference in acute toxicity or therapeutic efficacy was seen after either method of administration. However, we have demonstrated that peak plasma levels of daunorubicin can be reduced by continuous infusion without significantly altering target tissue concentrations.