Neurological toxicity associated with vidarabine (adenine arabinoside) therapy

Disorientation, myoclonic jerks, generalised rigidity and tremor developed in a young woman while on treatment with vidarabine for disseminated cutaneous varicella. Residua were still present 11 months later. She had normal renal function and was being treated with relatively low dose vidarabine therapy. A possible drug interaction with allopurinol is described.