OBJECTIVES: I. Determine the safety and efficacy of daunorubicin and cytarabine by continuous infusion and PSC 833 in patients over age 56 with newly diagnosed acute myeloid leukemia. II. Determine the frequency and severity of toxicities of this regimen in these patients. III. Determine the frequency and prognosis of functional and phenotypic P-glycoprotein expression, cytogenetics, and pharmacokinetics in this population.