Pimavanserin vs. Quetiapine for Treatment of Parkinson's Psychosis

Condition(s) studied

Investigational drug(s) / intervention(s)

Pimavanserin: Fixed-dose Pimavanserin - Pimavanserin is a new antipsychotic agent, and pure 5HT-2A inverse agonist, that was approved by the FDA recently (2016) for the treatment of PDP. It is the only FDA-approved medication for PDP, but is still not the first-line AP used in PD. All participants assigned to pimavanserin will receive the FDA-approved dose of 34 mg (equivalent to 40 mg pimavanserin tartrate) daily without titration up or down; however, because pimavanserin is blinded to quetiapine, participants will undergo sham titration based on tolerability (i.e., overall adverse event profile) and efficacy (i.e., improvement in severity of psychosis).

Quetiapine: Flexible-dose Quetiapine - Quetiapine, which is a mixed serotonin and dopamine receptor antagonist, is by far the most commonly used AP for PDP. However, scientific evidence for the efficacy of quetiapine in PDP is almost non-existent as most of the studies were underpowered, had high drop-out rates, and possibly underdosed quetiapine. Quetiapine immediate and extended release will be titrated as shown: Baseline visit Quetiapine: 25 mg IR QHS, All participants must be up-titrated to 50 mg/day Week 1 call Quetiapine: 50 mg XR QHS, Up-titration to 50 mg Week 3 visit Quetiapine: 100 mg XR QHS, Up-titration as appropriate Week 5 visit Quetiapine: 150 mg XR QHS, Up- or down-titration as appropriate Week 6 call Quetiapine: 200 mg XR QHS, Up- or down-titration as appropriate

Study summary

Patients with Parkinson's disease (PD) sometimes experience symptoms affecting their movement, such as slowness, tremor, stiffness, and balance or walking problems. Many patients also have other symptoms not related to movement, called non-motor symptoms, which may affect one's mood or emotions, memory or thinking, or cause one to see or hear things that aren't real (hallucinations) or believe things that aren't true (delusions). Hallucinations or delusions, together called psychosis, occur in up to 60% of PD patients at some point in time. Parkinson's disease psychosis can sometimes be associated with decreased quality of life, increased nursing home placement, increased rate of death, and greater caregiver burden. There are approximately 50,000 Veterans with Parkinson's disease receiving care in the VA, and up to 30,000 (60%) of them will experience psychosis at some point in time.

Quetiapine is an antipsychotic drug approved by the Food and Drug Administration (FDA) that is the most commonly used medication to treat PD psychosis, but more studies are needed to determine if it works for this condition and is also well tolerated and safe. Pimavanserin is a newer antipsychotic drug approved by the Food and Drug Administration (FDA) specifically to treat PD psychosis, but more studies are needed to determine if it works and its safety.

The purpose of this research is to gather additional information on the safety and effectiveness of both Quetiapine and Pimavanserin. By doing this study, the investigators hope to learn which of these medications is the most effective course of treatment for people with PD psychosis.

Enrollment is open to Veterans nationwide, see your VA provider about the possibility of being referred to one of the study's Hub sites. This can be done through contact from your provider to the study's NSC (Tamara Boney at 267-303-9829).

Eligibility

Primary outcome measure(s)

• CGI-I Psychosis — 8 Weeks
  The Clinical Global Impressions (CGI) scale is a brief, well-established research rating tool used to quantify and track patient progress and treatment response over time. The CGI comprises two measures, one of which is Improvement (CGI-I) from the initiation of treatment. It is scored 1 to 7. The CGI-I is used to assess how much the patient's illness has improved or worsened relative to baseline when the intervention was started (1-Very much improved, 2-Much improved, 3-Minimally improved, 4-No change, 5-Minimally worse, 6-Much worse, 7-Very much worse). The CGI-I can also be used to assess specific domains, including psychosis (this study's primary outcome) and parkinsonism (a secondary outcome). During the 8 weeks, the CGI-I (for psychosis, hereafter simply referred to as the CGI-I) will be administered to all participants at 3 weeks, 5 weeks, and 8 weeks following a CGI-I baseline interview to assess clinical improvement in psychosis.

Trial sites (24)

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