Pimavanserin (Nuplazid), a drug used to treat symptoms of psychosis related to Parkinson's disease, has just been approved by the US Food and Drug Administration (FDA).
Citing results from a phase 3 drug trial that showed a marked reduction in hallucinations, delusions, and behavior changes in those who took pimavanserin for six weeks, the FDA granted the new antipsychotic a breakthrough therapy designation. The designation is part of a program designed to speed the development and review of drugs for serious conditions, based on preliminary evidence that the drug is substantially better than available therapies. In addition to its effectiveness, pimavanserin did not worsen motor symptoms, including shaking and tremor.
A Different Mechanism
Most traditional antipsychotics block dopamine, a neurotransmitter that regulates movement and is in short supply in people with Parkinson's disease. When dopamine is blocked, motor symptoms such as tremors and rigidity worsen. Pimavanserin, on the other hand, targets the serotonin receptor, says Michael S. Okun, MD, FAAN, Adelaide Lackner professor and chairman of neurology at the University of Florida and national medical director of the National Parkinson Foundation. "Since pimavanserin uses a serotonin pathway, it does not have the associated side effects of a typical dopamine-blocking drug."
A New Option
The new drug provides another option for people with Parkinson's disease-related psychosis who have been unable to take other antipsychotic medications to control their symptoms. "The big need for the Parkinson's disease community has been to develop a drug that controls hallucinations but does not worsen the motor symptoms," says Dr. Okun. "Pimavanserin may potentially fill that need for select patients." Side effects are considered mild to moderate and not significant and included urinary tract infections and falls.
Incidence of Psychosis
As many as 50 percent of people with Parkinson's disease experience symptoms of psychosis—seeing or hearing things that aren't there (hallucinations) and/or having false beliefs (delusions)—at some point during the course of their illness, according to the FDA. Eventually, these symptoms can become so severe that people with the disease can't "relate to loved ones or take appropriate care of themselves," according to the FDA's press release.
For more about hallucinations associated with Parkinson's disease, as well as other tips to manage psychotic behavior, visit bit.ly/HelpforHallucinations.