Rivastigmine may improve certain behavioral symptoms associated with Alzheimer's disease such as delusions and hallucinations and may delay the need for an antipsychotic agent, according to 2 poster presentations at the 11th Annual Congress of the International Psychogeriatric Association.

"Behavioral symptoms such as agitation, aggression, and paranoia present enormous burdens on caregivers and often lead to a decision to institutionalize a patient," explained Jeffrey Cummings, M.D., presenter of the study regarding behavioral symptoms. "My data suggest that treatments such as rivastigmine (Exelon) may reduce specific disruptive behaviors, which is important because of the significant impact these symptoms have on patients and caregivers alike. This is in addition to demonstrated benefits in cognitive performance, global functioning, and activities of daily living."

The study led by Cummings evaluated the effects of rivastigmine on neuropsychiatric and behavioral disturbances in 173 nursing home residents with Alzheimer's disease. It was a retrospective analysis of a 26-week, prospective open-label study that involved 13 primary-care centers in the U.S. and 29 nursing homes.

Of the 173 total patients, 77 percent had at least 1 behavioral symptom at baseline as measured by the Neuropsychiatric Inventory-Nursing Home scale. After 26 weeks of treatment with rivastigmine, 59 percent of these people (92 patients) showed improvement in psychiatric and behavioral symptom scores. Of the patients who showed symptom improvement, 49 percent demonstrated a reduction in collective psychiatric and behavioral symptoms of greater than 30 percent.

Of the 12 neuropsychiatric disturbances documented in baseline evaluations, treatment produced a statistically significant improvement in 8 disturbances in at least some of the affected patients: delusions, hallucinations, agitation, apathy/indifference, irritability, aberrant motor behavior, night-time behavior, and appetite/eating change.

In the second study, researchers retrospectively analyzed insurance claims data to assess the effect of treatment with the cholinesterase inhibitor on the time to first antipsychotic drug prescription. The investigators compared patients with Alzheimer's disease who received rivastigmine with those who did not receive treatment with it or a similar agent during the 18-month period preceding the analysis. No patients who received an antipsychotic treatment during the18 months prior to the study date were included. The researchers identified 978 eligible patients and assigned them to 1 of 2 study groups: patients treated with rivastigmine (370 people) and patients who were not treated with a cholinesterase inhibitor (608 people).

Patients treated with rivastigmine during the 18 months prior to the study date were 60 percent less likely to receive an antipsychotic agent compared with the patients who were not treated with a cholinesterase inhibitor, a statistically significant difference after adjustments for factors such as age and gender. By the end of the observation period (median duration, 395 days), 10 percent (38 patients) in the rivastigmine group had been prescribed an antipsychotic medication compared with 25 percent (150 patients) in the untreated group.