Abstract
The kinetics and distribution of methotrexate in intraventricular fluid were studied in a patient with central nervous system leukemia after drug administration by intravenous infusion, indwelling intraventricular subcutaneous reservoir (Ommaya).
Methotrexate administered by Ommaya reservoir, at a dose of 15 mg/M2, rapidly distributed in the subarachnoid space. The peak ventricular concentration of methotrexate was 2.54±0.9×10-4M, and remained in 10-6M level for 72 hours with a half-life of 10.5 hours. During an intravenous 6 hour-infusion at a dose of 750∼1,500 mg/M2 and 2,250∼3,000 mg/M2, the ventricular cerebrospinal-fluid concentration of methotrexate rose to 7.55±1.33×10-7M and 2.35±0.89×10-6M, respectively.
The patient was achieved CNS-remission following 6 doses of intraventricular methotrexate (15 mg/M2/dose) and hydrocortisone (50 mg/M2/dose), and maintained with intraventricular chemotherapy every 6 weeks. Over eighteen months after Ommaya reservoir insertion the patient has been still in CNS-remission.
Our data suggested that intraventricular chemotherapy via Ommaya reservoir has improved significantly for CNS-leukemia with monitoring methotrexate concentration in the cerebrospinal fluid.
