Definition

A liposomal intrathecal formulation of the antimetabolite cytarabine. As an S-phase-specific antimetabolite, cytarabine is phosphorylated by deoxycytidine kinase to a triphosphate form which competes with thymidine for incorporation into DNA; the incorporation of cytarabine triphosphate into DNA appears to inhibit DNA polymerase and so DNA synthesis, resulting in cell death.