Rate of hallucinations and hospitalizations in PD: which medication is the best?

By Anna Shavers

(left to right) Dr. Melissa Armstrong, Dr. Joshua Brown, Dr. Golnoosh Alipour-Haris
(left to right) Dr. Melissa Armstrong, Dr. Joshua Brown, Dr. Golnoosh Alipour-Haris

Hallucinations and delusions from psychosis are not uncommon for people living with Parkinson’s disease (PD). According to the Parkinson’s Foundation, between 20-40% of people living with PD report hallucinations with the likelihood increasing as someone living with PD ages.

The only FDA-approved medication for hallucinations in Parkinson disease is pimavanserin (commonly sold under the name Nuplazid), a medication that the U.S. Food and Drug Administration (FDA) approved in 2016. 

After its approval, concerns were raised that pimavanserin might increase the risk of death in people using it. The FDA investigated and found no new or unexpected safety risks associated with using pimavanserin. Concerns have remained about pimavanserin safety. 

The other most commonly used medication for hallucinations in PD, an older medication called quetiapine (commonly sold under the name Seroquel), is not FDA-approved for the management of hallucinations. How much quetiapine helps hallucinations is also uncertain.

Recent research compared the risks of using pimavanserin in people living with PD and hallucinations to people using no medication for hallucinations at all. These results don’t necessarily help clinicians, though. 

“Sometimes hallucinations are mild, and we don’t need to treat them. But when hallucinations are a problem, the question isn’t whether or not to treat the hallucinations, but rather what medication to use,” said Melissa Armstrong, M.D., M.Sc., FAAN, associate professor in the Department of Neurology and movement disorders specialist at the Norman Fixel Institute for Neurological Diseases.

To better understand the safety considerations, researchers at the Norman Fixel Institute for Neurological Diseases at UF Health and the Center for Drug Evaluation & Safety at the University of Florida College of Pharmacy conducted a study comparing the occurrence of hospitalization and death between pimavanserin and quetiapine.

Led by Golnoosh Alipour-Haris, Pharm.D., M.S., graduate research assistant in the Center for Drug Evaluation and Safety, the research study identified new users of pimavanserin and quetiapine between 2016 and 2018. Data collected for comparison included the occurence of hospitalization and mortality (death) between users of pimavenserin and quetiapine.

“We found that the risk of hospitalization was lower among people with Parkinson’s disease psychosis who were prescribed pimavanserin compared to those who were prescribed quetiapine. The study did not find a significantdifference in mortality between the two groups,” said Dr. Alipour-Haris. “We hope this study will advance the field by providing clinically relevant information for patients and physicians about the relative safety of pimavanserin and quetiapine for the treatment of Parkinson’s disease psychosis.”

“This research takes the important step of comparing the two most commonly used medications for hallucinations in Parkinson’s disease. It is reassuring to know that when we need to treat hallucinations, the current study using data from people on Medicare found no increased risk of death in people prescribed pimavanserin,” said Dr. Armstrong, co-author on the study. “More research is needed to understand why hospitalization was lower in the group receiving pimavanserin.”

The research team included Golnoosh Alipour-Haris, Pharm.D., M.S., graduate research assistant in the Center for Drug Evaluation and Safety at the Department of Pharmaceutical Outcomes & Policy at the University of Florida College of PharmacyMelissa Armstrong, M.D., M.Sc., FAAN, associate professor in the Department of Neurology and movement disorders specialist at the Norman Fixel Institute for Neurological Diseases at UF Health; Joshua Brown, Pharm.D., Ph.D., M.S., associate professor in the Department of Pharmaceutical Outcomes & Policy at the University of Florida College of Pharmacy and Michael Okun, M.D., director of the Norman Fixel Institute for Neurological Diseases and chair and professor of the Department of Neurology.

Read the full study in the journal Movement Disorders Clinical Practice.