Risperidone in the treatment of dopamine-induced psychosis in Parkinson's disease: an open pilot trial.
OBJECTIVE
To evaluate the safety and efficacy of risperidone in patients with Parkinson's disease (PD) who are experiencing significant dopamine-induced psychosis.


METHODS
Seventeen patients (median age, 72 yrs) participated in this 12-week, open pilot study receiving 0.5 to 3 mg oral risperidone per day. Maintenance antiparkinsonian medication was continued throughout, although psychotropic medication was discontinued. EFFICACY RESULTS: Risperidone produced a substantial improvement in psychotic symptoms, shown on the mean total positive subscale score on the Positive and Negative Syndrome Scale (PANSS) by a 30% improvement (-3.1 decrease) after 1 week and a 66% improvement (-6.8 decrease) at end point. This improvement was most evident in the items delusions, hallucinatory behavior, and suspiciousness/persecution. Risperidone also achieved significant improvement from baseline in Clinical Global Impression (CGI)-severity and CGI-improvement (p < 0.001, Page test). Risperidone treatment did not adversely affect symptoms specific to Parkinson's disease, as assessed by the Unified Parkinson's Disease Rating Scale (UPDRS). SAFETY RESULTS: Sixteen patients reported at least one adverse event, but only two patients withdrew as a result of adverse events. No significant changes or clinically relevant abnormalities were observed in laboratory parameters or vital signs.


CONCLUSIONS
Short-term use of risperidone (mean dosage, 1.1 mg per day) improves the psychopathology of patients with PD who have dopamine-induced psychosis without adversely affecting the symptoms of PD. Higher doses and long-term use were not addressed in this study and may be precluded by extrapyramidal side effects.
Mohr
E
E
CroMedica Global Inc., Victoria, Canada.
Mendis
T
T
Hildebrand
K
K
De Deyn
P P
PP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000978:Antiparkinson Agents / Q000009:adverse effects*; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D001530:Belgium; D002170:Canada; D004298:Dopamine / Q000009:adverse effects*; D018492:Dopamine Antagonists / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000188:drug therapy*; D010865:Pilot Projects; D011569:Psychiatric Status Rating Scales; D011605:Psychoses, Substance-Induced / Q000188:drug therapy*; D018967:Risperidone / Q000627:therapeutic use*; D016896:Treatment Outcome
D000978:Antiparkinson Agents; D014150:Antipsychotic Agents; D018492:Dopamine Antagonists; D018967:Risperidone; D004298:Dopamine