Pimavanserin, a 5-HT2A inverse agonist, was commercially released in the United 
States in April 2016 for the treatment of Parkinson disease psychosis. No 
"naturalistic" treatment results have yet been published. Charts from the 
movement disorders clinic were reviewed for all patients who received this drug 
as treatment for psychosis associated with primary parkinsonism due to 
α-synucleinopathies. Data of 10 patients with idiopathic Parkinson disease, 
including 1 with a long history of schizophrenia, 4 with dementia with Lewy 
bodies, and 1 with multiple-system atrophy, were reviewed. There were no adverse 
events reported. Ten patients improved and continue on the drug, whereas 5 
stopped because of lack of benefit.