The management of psychosis can be challenging in PD patients. Pimavanserin is the only approved medication for the treatment of PD psychosis.  It is an inverse agonist at the serotonin receptor and has no affinity to the dopamine receptors. Pimavanserin has been available for only 2.5 years and there is limited data on its safety and efficacy.

A retrospective chart review was performed from June 2016 through September 2018. The patients prescribed pimavanserin were identified and information such as age, concomitant medications, adverse events, discontinuation rate, disease duration, and mortality were collected.

Pimavanserin was prescribed for 127 patients; 107 of these patients used the drug and 20 never received the drug, with 20% dying prior to initiation. There were 71 males and 36 females with a mean age of 74.2 years, mean disease duration of11.7 years, and mean MoCA score of 18.8. Psychosis improved in 44% (n=47) and resolved in 9% (n=10). Pimavanserin was stopped in 18% (n=19) due to an adverse effect including edema, confusion, gait and balance problems, and worsening of hallucinations. A total of 30 patients died after the initiation of pimavanserin, however, only 16 (53%) were taking pimavanserin at the time of death. Therefore, the mortality rate was 20/100 patient years. The deceased group was older (mean age 78 years vs 73 years), had a longer disease duration (mean 13 years vs 11 years) and were more cognitively impaired (MoCA score 16.6 vs 19.7). A greater percentage of the deceased group were taking other antipsychotics with pimavanserin (20% vs. 15.6%). 

Pimavanserin improved psychosis in the majority of patients. There were a number of deaths in this cohort; however, nearly half occurred after discontinuation of the drug.