Pimavanserin, a novel antipsychotic for management of Parkinson's disease psychosis.

INTRODUCTION: Parkinson's disease psychosis (PDP) may develop in up to 60% of Parkinson's patients and is associated with increased morbidity and mortality. It also correlates with depression and dementia, and can contribute to caregiver stress and burnout. Pimavanserin is the first FDA approved drug for the treatment of hallucinations and delusions associated with PDP. Areas covered: For this review, a MEDLINE literature search (via PubMed) and information provided by ACADIA Pharmaceuticals were used. This review will discuss the pathophysiology and current management of PDP. In addition, this review will focus on the rationales behind the development of pimavanserin, mechanism of action, pharmacokinetics, pharmacodynamics, and the clinical trials evaluating the efficacy and safety of pimavanserin. Last, the review will address the drug's package insert warning. Expert commentary: Pimavanserin, a 5HT2A receptor inverse agonist, is the first FDA approved drug for the treatment of PDP which has been shown to reduce psychosis in PD through its unique mechanism of action. Pimavanserin, does not worsen PD motor symptoms and has an acceptable safety profile. The development of pimavanserin as an antipsychotic opened a new therapeutic avenue in the treatment of PDP as well as targeting psychosis in other disorders such as Alzheimer's disease.