Long-term outcome of quetiapine use for psychosis among parkinsonian patients

To evaluate the long‐term efficacy and tolerability of quetiapine for psychosis among parkinsonian patients, a retrospective analysis of all parkinsonian patients taking quetiapine for psychosis in a single movement disorders center was carried out. Demographic data, including type and severity of psychosis, presence of dementia, treatment response, before and after Unified Parkinson's Disease Rating Scale (UPDRS)‐motor scores and Hoehn and Yahr (H&Y) scale were obtained. One hundred six parkinsonian patients with a mean age of 76.6 years were on an average levodopa (L‐dopa) dose of 415 mg/d. Seventy‐eight of 106 (74%) remained on quetiapine for a mean duration of 15 months at an average dose of 60 mg per day. Eighty‐seven (82%) patients had partial or complete resolution of their psychosis whereas 19 (18%) patients had no improvement on quetiapine. Motor worsening was noted in 34 (32%) patients but was uncommonly sufficient to warrant quetiapine discontinuation. More quetiapine non‐responders were noted to be demented, delusional, and experienced threatening psychosis but only the presence of dementia remained significant on multivariate analysis (OR = 11.6; 95% CI = 1.4–92.9). Also, patients who developed motor worsening while on quetiapine tended to be more demented (P = 0.07). © 2003 Movement Disorder Society