Evaluating pimavanserin tartrate as a treatment in Parkinson’s disease

Introduction Pimavanserin is an efficacious, atypical neuroleptic. It ameliorates the frequency and severity of hallucinations and delusions in patients with Parkinson's disease with psychosis. Most antipsychotic drugs directly block dopamine receptors and thus worsen motor behavior. In contrast pimavanserin reduces the activity of excitatory serotonin receptor subtypes. They stimulate dopaminergic pathways in the mesolimbic system. As a result onset of psychosis may occur particularly in patients on a chronic dopamine substituting treatment regimen, like in Parkinson's disease.