Acute encephalopathy attributed to 5-FU.

Acute encephalopathy attributable to 5-fluorouracil (5-FU) is rare. A patient experienced this reaction associated with a continuous 5-FU infusion. The etiology of the event remains uncertain, but it is generally reversible and does not preclude retreatment with 5-FU at reduced dosages. Steroids and thiamine may expedite neurologic recovery.