cytarabine is often given by continuous intravenous infusion, which follows a biphasic elimination – initial fast clearance rate followed by a slower rate of the analog. cytarabine is transported into the cell primarily by hent-1. it is then monophosphorylated by deoxycytidine kinase and eventually cytarabine-5´-triphosphate, which is the active metabolite being incorporated into dna during dna synthesis.