Cognitive effects of flumazenil in patients with Alzheimer's disease.

Intravenous flumazenil was administered to two patients with probable Alzheimer's disease. Neuropsychological tests were administered at baseline, immediately after drug administration, and at washout 3 hours later. Cognitive function was observed to decline in both patients with eventual return to baseline, which indicates an adverse effect of flumazenil. Tests of vigilance were most severely affected, which may have been related to an inverse agonistic effect of flumazenil in producing symptoms of anxiety.