Successful treatment of intrathecal methotrexate overdose with folinic acid rescue: a case report

A 7-y-old boy with acute lymphoblastic leukaemia (ALL) received 600 mg of i .v. methotrexate (MTX) over 2 h, followed by triple intrathecal therapy (TI T) with cytosine arabinoside 30 mg, methylprednisolone 10 mg and MTX 300 mg (instead of the prescribed 12 mg). Ninety minutes later the patient develo ped headache, loss of consciousness and generalized hypertonia. He was tran sferred to the Intensive Care Unit, intubated and treated with phenobarbita l. Three hours after the TIT, the levogyrus form of folinic acid (equivalen t to double doses of the racemic product) was started i.v. at a dose of 100 mg every 3 h for 24 h,and every 6 h in the following 24 h. Cerebrospinal f luid was examined and was found normal. The patient subsequently remained i n normal neurological status. The favourable outcome in our case suggests t hat folinic acid rescue may be adequate to prevent sequelae in patients who undergo intrathecal MTX overdoses up to 300 mg.