How long to take cytarabine sodium for effect depends on the specific condition of the patient and cannot be generalized. Sodium cytarabine is mainly used for the treatment of neurological sequelae caused by craniocerebral injury and cerebrovascular accident. This drug can improve the patient’s brain circulation to a certain extent, reduce the brain blood flow resistance, increase the brain blood supply, promote brain substance metabolism, thus promoting brain function recovery. If the patient’s condition is mild, the effect can usually be seen within 2-3 days of taking the medicine. However, if the patient’s condition is severe, the effect time will be relatively longer, and it is usually recommended to take the medication for 1 month, i.e. a course of treatment, followed by a follow-up consultation and guidance from a neurologist for the next step. During the medication period, patients should follow the doctor’s instructions and should not increase or decrease the dose of medication, nor should they extend or shorten the duration of medication or change the usage to avoid affecting the recovery.