Effect of Blonanserin on Delirium in a Patient with Alzheimer Disease

A 67-year-old woman with Alzheimer's disease was administered 5 mg/day donepezil for approximately three years. The patient exhibited acute confusion, global impairment of cognition with disorientation, sleep disturbance, psychomotor agitation, hallucinations and delusions due to delirium at night. She was then administered 8 mg/day blonanserin for approximately one month in addition to donepezil. Blonanserin is an atypical antipsychotic that blocks the serotonin 5HT2A and dopamine D2 receptors. The delirium improved gradually with treatment, so the blonanserin dose was tapered to 4 mg/day over approximately two weeks. The delirium continued to improve without adverse events. The patient continues to receive 5 mg/day donepezil, and is able to live alone. The delirium she experienced may have been related to disturbances in neurotransmitter systems involving acetylcholine, serotonin, dopamine and gamma- aminobutyric acid. Blonanserin may improve the functioning of the serotonin and dopamine neurotransmitter systems, providing effective treatment for delirium in patients with Alzheimer's disease.