Quetiapine Improves Symptoms of Parkinson's Disease

March 02, 2001

New York (MedscapeWire) Mar 2 — In patients with Parkinson's disease and psychosis who failed treatment with other atypical antipsychotic agents, quetiapine (Seroquel, AstraZeneca) improved both cognitive and psychotic symptoms. These results from a 6-month, open-label study were presented this week at the American Association for Geriatric Psychiatry (AAGP) meeting in San Francisco, California. Seroquel is indicated for the treatment of schizophrenia.

The single-center study examined the safety, tolerability, efficacy, and cognitive effects of quetiapine in 29 patients with psychosis associated with Parkinson's disease who had failed treatment with clozapine, risperidone, or olanzapine due to lack of efficacy, intolerable adverse effects, or noncompliance with blood monitoring. Patients received up to 400 mg/day of quetiapine, which was dosed according to clinical response and tolerability for up to 6 months.

Psychiatric assessments included the Brief Psychiatric Rating Scale (BPRS), the Clinical Global Impressions (CGI) Severity of Illness item, the Neuropsychiatric Inventory sum of delusions and hallucinations (NPI-2), and the Unified Parkinson's Disease Rating Scale (UPDRS) mental subscale and a modified Hoehn and Yahr assessment. Assessments for Parkinson's disease symptoms included the remaining UPDRS subscales.

Cognitive function was evaluated using measures of overall cognitive function, attention, and memory before and 6 months after the initiation of quetiapine therapy. Cognitive performance in the quetiapine group was compared with that of a control group of 12 nonpsychotic patients with Parkinson's disease, with a test-retest interval of approximately 1 year.

Study analyses revealed significant improvements in patients who received quetiapine in the BPRS, CGI, NPI-2, and the UPDRS mental subscale. UPDRS motor subscale showed modest initial improvement that was maintained throughout the trial.

Significant improvement in memory was observed in patients with Parkinson's disease and psychosis after 6 months of quetiapine therapy. When compared with the nonpsychotic control group, patients with Parkinson's disease and psychosis who received quetiapine treatment had statistically significant improvements across time in sustained attention and immediate and delayed memory. No significant group differences were observed for overall cognitive function or measures of simple attention.

"The results of this study are exciting for the countless families touched by this crippling disease because they indicate that quetiapine may offer hope for improving everyday cognitive functioning for patients with Parkinson's disease and psychosis," said Vicki J. Roberts, PhD, of Department of Neurology, at Emory University, Atlanta, Georgia, who conducted the study. "These results need to be further investigated in placebo-controlled trials."

Three patients withdrew from the study due to adverse events.

Parkinson's disease, a progressive disorder of the central nervous system, affects more than 1 million people in the United States. The disease is characterized by a decrease in spontaneous movements, gait difficulty, postural instability, rigidity, and tremor. Parkinson's disease is caused by the degeneration of the pigmented neurons in the substantia nigra of the brain, resulting in decreased dopamine availability.