Is it possible to administer methotrexate intrathecally?
Yes. When methotrexate is administered intrathecally solutions without a preservative should be used. The maximum concentration for intrathecal administration is 1 mg/ml. In adults, the intrathecal dose of methotrexate should not exceed 15 mg. The therapy has to be evaluated on the basis of cerebrospinal fluid cytology. When methotrexate is given intrathecally plasma levels may be reached which may cause general toxicity (see SmPC).
