A child is to receive intrathecal methotrexate (Folex) for treatment of meningeal leukemia. For which reason would intrathecal administration be selected
A．The child has very poor veins and is unable to receive drugs IV.
B．This drug would be destroyed by gastric acid and so it can't be given by mouth.
C．This drug is poorly transported across the blood-brain barrier, so it's administered intrathecally.
D．Because the drug is rapidly absorbed if given IM, adverse effects may appear more quickly.
参考答案：C
解析：Because the IV route doesn't allow chemotherapeutic agents to reach all areas invaded by leukemic cells, this medication is administered intrathecally to ensure the entire body receives treatment. Although this medication may be given by mouth, IM, or IV, these routes would be inappropriate in this situation.