Pimavanserin vs. Quetiapine for Treatment of Parkinson's Psychosis

Inclusion Criteria:

• Veteran

• Age 40 years or older

• Diagnosis of Parkinson's Disease consistent with UK Parkinson's Disease SocietyBrain Bank Clinical Diagnostic Criteria

• Psychosis [with Neuropsychiatric Inventory (NPI) hallucinations (B) or delusions (A)score 4 or greater]

• Stable dose of PD medications for at least 2 weeks

• If on an acetylcholinesterase inhibitor (AChEI) initially prescribed at least 3months prior and stable dose (no dose or medication change) for past month

• Informed other must provide informed consent and agree to attend all study visits.The informed other must be at least 18 years of age and have regular contact withthe patient (on average at least 4 days per week and at least 2 hours per day, or atleast 3 days per week and at least 4 hours per day, that is with patient) viain-person, video, or telephone

• English-speaking

INFORMED OTHER

• Age 18 years or older

• Must have regular contact with the patient (on average at least 4 days per week, andat least 2 hours per day, or at least 3 days per week and at least 4 hours pr day,that is with patient) via in-person, video, or telephone

• Agree to attend all study visits

• Be able to provide informed consent

• English-speaking

Exclusion Criteria:

• Psychosis symptoms severe enough to preclude enrollment in a clinical trial andrequire prompt clinical care instead

• Treatment with quetiapine >50 mg/day or pimavanserin in the past 3 months, orquetiapine 50 mg/day or another antipsychotic in the past week prior to studyrandomization

• Deep brain stimulation (DBS) surgery within 3 months or has had stimulatoradjustments in the previous 2 weeks

• History of a psychotic disorder prior to PD, including bipolar disorder,schizophrenia, schizoaffective disorder, and major depressive disorder withpsychotic features, if it is thought to be the cause of the current psychosissymptoms

• Suspected atypical parkinsonian disorder or dementia with Lewy bodies (DLB)

• Psychosis secondary to other toxic or metabolic disorder

• History of long QT syndrome

• Documented chart evidence indicating persistent hypoglycemia, hypokalemia,hypomagnesemia that would put patient at increased risk for QTc prolongation.

• History of ventricular arrhythmias, except when treated with an implantablecardioverter defibrillator (ICD) or pacemaker, or untreated or unstable atrialfibrillation/flutter

• Currently taking medications that are moderate or strong CYP3A4 inducers or strongCYP3A4 inhibitors

• Concomitant use of drugs that prolong the QTc interval with a known risk of Torsadesde Pointes

• Comorbid medical condition determined too severe by Site Investigator to allowparticipation in clinical trial

• Failure to tolerate quetiapine or pimavanserin previously

• Severe cognitive impairment (MoCA score <5)

• Nursing home placement at screening or planned placement during the study, unlessapproved by study Co-Chairs. Approval will depend upon nursing facility agreement toreceive, return, and administer medications or allow participant to self-administerstudy medications; appropriate IO availability; and transportation availability forstudy visits.

• Currently enrolled in another therapeutic or interventional study

• Pregnant, or a female of child-bearing potential who is unwilling to use a reliableform of contraception