Severe confusion in a patient receiving electroconvulsive therapy and atenolol.

Atenolol is a beta-blocker antihypertensive agent that reportedly has little central nervous system action. A patient was given atenolol during a course of electroconvulsive therapy and developed an organic mental syndrome with paranoid delusions. The possible alteration of the permeability of the blood-brain barrier by electroconvulsive therapy may have enabled atenolol to cause this unusual side effect.