Evidence map›Paper›PMID 42729706›Full record

ArticleClinical parkinsonism & related disorders2026

Treatment-resistant Parkinson's disease psychosis responding to xanomeline-trospium: A case report.

Andrew Farah, Karen Timbrook-Dillow, Heather Garrison

Abstract readCase Reports
In one paragraph

Article in Clinical parkinsonism & related disorders, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

3 authors.

Andrew FarahHigh Point University, High Point, North Carolina 27268, USA.
Karen Timbrook-DillowHigh Point University, High Point, North Carolina 27268, USA.
Heather GarrisonHigh Point University, High Point, North Carolina 27268, USA.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

We report the case of an 83-year-old male with Parkinsonism and severe psychosis characterized by persistent daytime and nighttime hallucinations associated with marked fear and distress. His psychosis failed to respond to therapeutic trials of quetiapine, brexpiprazole, and pimavanserin. He was referred specifically for a trial of clozapine therapy, which the patient and caregiver declined due to its risk profile. Treatment with xanomeline-trospium was initiated at 50/20 mg twice daily and resulted in substantial improvement, including resolution of nighttime hallucinations within two weeks. He further achieved a near complete resolution of psychotic symptoms within three weeks of a dose escalation to 100/20 mg twice daily. To our knowledge, this is the first published case of Parkinson's disease psychosis successfully treated with xanomeline-trospium, a novel M1/M4 muscarinic receptor agonist-based therapy. The patient's psychosis proved refractory to three pharmacologically distinct therapies-quetiapine, a low-affinity, rapidly dissociating dopamine D2 receptor antagonist; brexpiprazole, a dopamine D2 partial agonist; and pimavanserin, a selective 5-HT2A receptor inverse agonist-before improving with xanomeline-trospium, whose antipsychotic effects are mediated through central M1/M4 muscarinic receptor agonism. This case supports the further investigation of muscarinic receptor agonism as a therapeutic strategy for Parkinson's disease psychosis.

Indexed as

HallucinationsMuscarinic receptor agonistsParkinson's disease psychosis (PDP)Xanomeline-trospium

Identifiers

PMID42729706
PMCPMC13563583

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Registered trials

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