There are some doubts about therapeutic effects of olanzapine and risperidone two antipsychotic drugs on behavioral disturbances in patients with Alzheimer's disease and concerns about safety have emerged. We assessed the effectiveness of these two atypical antipsychotic drugs in outpatients with Alzheimer's disease.

In this double-blind trial, 69 outpatients with Alzheimer's disease and psychosis, aggression, or agitation were randomly assigned to receive olanzapine (dose, 2.5- 7.5 mg per day) or risperidone (dose, 0.5-4.5 mg per day). Patients were followed for up to 10 weeks. The main outcomes were the scores of the Clinical Global Impression of Change (CGIC) scale and Brief Psychiatric Rating Scale (BPRS).

There were no significant differences among treatments with regard to improvement in risperidone and olanzapine group on the CGIC (3.2±4.3 vs. 3.5±5.8 & P Value=0.564) and BPRS scale (8.2±9.2.vs. 8.8±9.2 & P Value = 0.522) .Furthermore, although the number of patients who had left the study cause of side effects, was greater in risperidone group, sedation and headache are more common with olanzapine than risperidone.

Both risperidone and olanzapine might be useful and reasonable treatment for patients who suffering from behavioral disturbances due to psychosis in Alzheimer disease