---
title: Compare pimavanserin and quetiapine effectiveness
nct_id: NCT05590637
phase: PHASE4
status: RECRUITING
sponsor: The University of Texas Health Science Center at San Antonio
study_type: INTERVENTIONAL
canonical_url: "https://parkinsonspathways.com/trial/NCT05590637"
clinicaltrials_gov: "https://clinicaltrials.gov/study/NCT05590637"
last_fetched: "2026-05-10T14:07:12.416Z"
source: "Parkinson's Pathways (curated)"
---
# Compare pimavanserin and quetiapine effectiveness

**Goal (in five words):** Compare pimavanserin and quetiapine effectiveness

**Official Title:** A Pragmatic Randomized Trial Comparing Antipsychotics in Lewy Body Disease

**Trial ID:** [NCT05590637](https://clinicaltrials.gov/study/NCT05590637)

## Key Facts

- **Phase:** PHASE4
- **Status:** RECRUITING
- **Study Type:** INTERVENTIONAL
- **Sponsor:** The University of Texas Health Science Center at San Antonio
- **Target Enrollment:** 94 participants
- **Start Date:** 2022-04-22
- **Completion Date:** 2026-08
- **Conditions:** Parkinson's Disease Psychosis, Dementia With Lewy Bodies
- **Interventions:** Pimavanserin, Quetiapine
- **Intervention Types:** DRUG

## Summary For Families

They're comparing two antipsychotics to see which better controls hallucinations and delusions in people with Parkinson's disease psychosis or dementia with Lewy bodies, while keeping an eye on safety and effects on movement. One drug, pimavanserin, blocks serotonin 5‑HT2A receptors and treats psychosis without blocking dopamine receptors, so it is less likely to worsen Parkinsonian movement or interfere with levodopa; the other, quetiapine, is an atypical antipsychotic that blocks dopamine and serotonin receptors, which can calm psychosis but may cause sedation or motor side effects. The trial enrolls neurology clinic patients at UT Health San Antonio who have PD psychosis or DLB and need to start an antipsychotic, are not already on one, have a caregiver able to complete symptom questionnaires, and have a prescriber comfortable prescribing and managing either medication.

## Eligibility

- **Sex:** ALL

### Full Criteria

```
Inclusion Criteria:

* Patients seen in the neurology clinic at UT Health San Antonio
* Diagnosed with psychosis due to PD or DLB
* Requiring initiation of an antipsychotic medication
* Clinical equipoise between quetiapine and pimavanserin must exist
* The prescribing provider must be comfortable prescribing and managing both quetiapine and pimavanserin

Exclusion Criteria:

* Medical contraindication to either medication
* Caregiver unavailable to complete NPI-Q
* Currently taking an antipsychotic medication
* Prescribing provider unwilling to manage either medication
```

## Locations (2)

- University Health System, San Antonio, Texas, United States _(29.4241, -98.4936)_
  - Sarah Horn, MD — (CONTACT) — 210-450-0500 — horns@uthscsa.edu
  - Carolyn Paiz, BS — (CONTACT) — 210-450-8830 — paizc@uthscsa.edu
- UT Health Science Center - San Antonio, San Antonio, Texas, United States _(29.4241, -98.4936)_
  - Carolyn Paiz — (CONTACT) — 210-450-8830 — paizc@uthscsa.edu
  - Sarah Horn, MD — (PRINCIPAL_INVESTIGATOR)

## Central Contacts

- Carolyn Paiz, BS — (CONTACT) — 210-450-8830 — paizc@uthscsa.edu

---

*Canonical: https://parkinsonspathways.com/trial/NCT05590637*  
*HTML version: https://parkinsonspathways.com/trial/NCT05590637*  
*Source data: https://clinicaltrials.gov/study/NCT05590637*