Prolonged delirium with propanolol.

Propanolol use can result in a severe toxic psychosis. In this case, mild perceptual errors progressed eventually to a severe confusional state over a period of 6 months. Life threatening cardiac symptoms forced the continuation of propanolol until the bundle of His was surgically severed. Despite the prolonged delirium, the patient showed complete clearing of sensorium within 2 weeks after cessation of the drug. The differential diagnosis of delirium in the cardiac patient needs to include consideration of propanolol use.