A comparison of two schedules of cytosine arabinoside used in combination with adriamycin and 6-thioguanine in the treatment of acute myelogenous leukemia.

The most effective schedule of cytosine arabinoside (Ara-C) administration remains controversial and is further confused by the use of combination chemotherapy. Two remission induction regimens comprising adriamycin, Ara-C, and 6-thioguanine have been compared in patients with acute myelogenous leukemia. Administration of Ara-C by continuous intravenous infusion resulted in faster clearing of leukemic blasts from the peripheral blood and bone marrow than after administration of the same dose by twice daily intravenous injection. Myelosuppression and gastrointestinal toxicity were, however, more pronounced when Ara-C was given by infusion. The complete remission rate was higher in the patients treated with intravenous infusions. It is too early to assess the duration of remission in the infusion study; however, despite the relatively low remission rate, 80% of patients under the age of 60 in the intravenous bolus study remain in remission with a minimum follow-up of two years.