- Patients with a history of severe toxicity related to receiving conventional dose cytarabine in first line treatment (approximately 100mg/m2/d for <7 days) are excluded. Patients who experienced unacceptable toxicities while receiving high dose cytarabine (approximately 3000mg/m2 for 6 doses) will not be treated again with the same regimen, but could be randomized to treatment with conventional dose cytarabine regimens where the risk of major toxicity is less.