Pimavanserin tartrate: a 5-HT2A inverse agonist with potential for treating various neuropsychiatric disorders

Background: Pimavanserin tartrate is the first 5-HT2A inverse agonist to enter clinical trials as a treatment for L-dopa-induced psychosis in Parkinson's disease and for augmentation of low-dose risperidone treatment in schizophrenia. Pimavanserin is also being evaluated as a possible anti-insomnia drug. Objective: To discuss the potential of pimavanserin to fill multiple therapeutic needs. Methods: The problems with currently approved antipsychotics and sleep agents are explored to highlight how pimavanserin might address some longstanding issues in the treatment of psychosis and insomnia. Results/conclusions: In Phase II clinical trials, pimavanserin seemed to be safe, well-tolerated and efficacious in treating L-dopa-induced psychosis without worsening motor symptoms. Pimavanserin also potentiated the therapeutic effects of low-dose risperidone, reduced haloperidol-induced akathisia, and increased slow-wave sleep in older individuals.