Drug Shows Promise in Treating Parkinson's Psychosis
Pimavanserin may have fewer side effects than current therapy, study suggests
After 43 days, patients taking pimavanserin showed a significant improvement on a scale of psychotic symptoms compared to those given a placebo -- 37 percent versus 14 percent.
However, this early study only provided short-term results, another expert pointed out.
Frances Weaver, director of the Center for Management of Complex Chronic Care at Hines VA Hospital, in Illinois, said although the trial was promising, more needs to be known about the long-term picture for this drug.
"The follow-up was only 43 days," she said. "It will be important to examine the long-term effects of this medication as psychosis is an ongoing problem which will likely require the patient to remain on medications for the rest of his life. Questions about long-term tolerability and effectiveness still need to be answered."
In addition to psychosis relief, the researchers reported other benefits of the drug. Patients taking pimavanserin slept better and the improvement in mental functioning also helped caregivers, who found it easier to care of their patients, Ballard said.
Motor symptoms of the people taking the drug didn't get worse, the study found.
Dr. Susan Fox, an associate professor of neurology at the University of Toronto, wrote an accompanying journal editorial about the new findings.
"Treating psychosis in Parkinson's disease is challenging because of side effects of current drugs -- especially potentially worsening Parkinson's disease motor symptoms. Pimavanserin offers an alternative without this risk," Fox said.
Pimavanserin was well tolerated and side effects were mild to moderate, and similar in the two groups. The most common side effects were urinary tract infections (12 percent for placebo versus 13 percent for pimavanserin) and falls (9 percent for placebo versus 11 percent for pimavanserin), the researchers found.
However, 10 patients stopped taking pimavanserin because of a side effect, compared with two patients in the placebo group, the authors noted.
According to Ballard, the U.S. Food and Drug Administration has invited a new drug application based on this trial, "so the decision regarding approval should probably be in 12 to 18 months," he said.