Plasma levels of daunorubicin metabolites and the outcome of ANLL therapy.

Levels of plasma daunorubicin, daunorubicinol and aglycone metabolites were measured in 47 patients 3 h after daunorubicin was administered daily for three days as part of a cytosine arabinoside/daunorubicin remission induction regimen. High-pressure liquid chromatography with fluorescence detection was used for separation and quantitation of the drug and its metabolites. A wide range of plasma levels were observed regardless of the outcome of therapy. Patients who had high levels of the drug, or daunorubicinol on day 1 of therapy tended to have high levels on days 2 and 3 of the regimen. Three hours after the third daily dose of daunorubicin was administered, patients who would not enter remission had significantly higher levels of aglycone metabolites in plasma than did patients who entered remission. These data indicate that resistance to chemotherapeutic effects of daunorubicin may be connected with metabolism of the drug, especially with enhanced metabolism to aglycones.