Exchange of cerebrospinal fluid in accidental intrathecal overdose of cytarabine.

Intrathecal cytarabine (cytosine arabinoside) is included in many protocols for the treatment of acute lymphoblastic leukaemia of childhood. We report here the accidental administration of 200mg cytarabine intrathecally to a 4-year-old boy with CNS relapse. After the overdose the patient had dilated pupils during the first hour. One month later an unsteady gait and mild intention tremor in the hands were noted. By the exchange of cerebrospinal fluid with isotonic saline started 1 hour after overdose through a lumbar needle, about 27% of the administered dose was recovered. The estimated recovery in view of the time elapsed between overdose and start/end of the exchange procedure was 36%. This indicates that this procedure is of value in managing patients with heavy overdose of intrathecal cytarabine in hospitals without neurosurgical facilities.