Central nervous system toxicity with fludarabine.

A serious delayed neurotoxicity marked by encephalopathy and cortical blindness has occurred in patients treated with fludarabine. This toxicity had only been reported in patients receiving high doses (ie, aplasia-inducing). We describe a similar subacute neurological deterioration occurring in two patients, including one who received only low doses of this agent. Neurologic vulnerability to low doses of fludarabine may be multifactorial and at present cannot be predicted. Continued caution in the use of this new antineoplastic agent is appropriate.