[Effects of quetiapine at low doses on psychosis motor disability and stress of the caregiver in patients with Parkinson's disease].

INTRODUCTION

Quetiapine is a novel neuroleptic drug with pharmacological properties close to clozapine, the most effective drug in the management of psychotic symptoms in patients with Parkinson s disease (PD). Unlike clozapine, however, quetiapine does not induce agranulocytosis and therefore no haematologic controls are required.

OBJECTIVES

To assess tolerability and effectiveness of low dose quetiapine on psychotic symptoms, sleep disturbances and stress of the caregiver in PD patients with dopaminomimetic psychosis.

PATIENTS AND METHODS

We carried out a 16 week, prospective, open label study on the effects of quetiapine in 7 consecutive PD patients with psychosis. A ceiling dose was arbitrarily established at 25 mg/d. Antiparkinsonian medication remained unchanged throughout the study. Motor symptoms were assessed with UPDRS motor subscale portion, Schwab England scale, and Hoehn Yahr diseases staging. The effects on hallucinations and paranoia, sleep disorder, and stress in the caregiver were scored separately, aside from a global score on the Neuropsychiatric Inventory (NPI). Global impression of both, investigators and caregiver was obtained at study conclusion. A patient died from unrelated causes.

RESULTS

Under a mean quetiapine dose of 24.9 mg/d (12.5 37.2) motor impairment during on periods remained unchanged, both according to patients and caregiver whereas mean UPDRS motor score remained unchanged (35.5 4.5 versus 32.8 5.2). Levodopa induced dyskinesias disappeared in the single patient with this complication. Improvement occurred in mean NPI global score, as well as subscores for hallucinations and paranoia, and caregiver stress. In over half the patients, effectiveness was scored as very good or good both by examiners and caregivers. A confusional episode occurred in one patient under 25 mg/d but readily resolved while maintaining the benefit following dose reduction to 12.5 mg.

CONCLUSION

Quetiapine at low doses appears a useful alternative for psychotic symptoms, sleep disorders and stress of the caregiver in patients with PD