Nuplazid Side Effects May Increase Parkinson’s Disease Hallucination Risks, ISMP Report Warns

A relatively new antipsychotic medication, Nuplazid, was designed to reduce the risk of hallucinations and psychosis, but a new report warns that the medication may not be effective, and may even worsen those conditions for some patients. 

The Institute for Safe Medication Practices (ISMP) released its QuarterWatch report (PDF) last week, warning about safety signals linked to Nuplazid.

ISMP researchers found that in the first year the drug was on the market, the FDA received 2,236 adverse event reports involving Nuplazid problems among users.

The FDA approved Nuplazid (pimavanserin) for use in April 2016, as a treatment for hallucinations and psychosis in Parkinson’s disease patients. It was developed and manufactured by Acadia Pharmaceuticals. However, within the first year of the drug being prescribed to patients, the FDA received 487 reports of hallucinations linked to the drug, which ISMP researchers note were often observed by healthcare professionals who knew that hallucinations were a known Parkinson’s disease side effect.

The ISMP report indicates that the number of reports suggest that the drug may be ineffective for some patients at treating hallucinations, or may even worsen the problem in some cases.

The reports also included 333 reports specifically indicating that the drug was ineffective, 258 reports that patients suffered confusion after taking Nuplazid, and 244 reports of death. However, it is not clear that the deaths were actually caused by Nuplazid, and the patient population of the drug is generally 65 years or older, which is when the onset of the Parkison’s disease hallucinations typically begin.

The ISMP notes that the drug was rushed to the market with very little scientific study suggesting that its benefits outweighed its risks.

“It relied on a single clinical trial indicating a minimal treatment effect, used a measurement scale for symptoms that had not been validated, and succeeded only after three previous trials had failed to demonstrate a benefit,” ISMP researchers noted. “Further, the agency’s medical reviewer recommended against approval and was overruled. He noted that although other psychiatric drugs were often approved on limited evidence of benefit, in the case of pimavanserin treatment more than doubled the risk of death and/or serious adverse events in its pivotal trial.”

The ISMP indicates that it reached out to Acadia Pharmaceuticals about its findings. The company defended the drug, saying that one of the reasons for the large number of adverse event reports was because there was extensive contact between the company, healthcare professionals and patients, suggesting that doctors and patients were more likely to make an adverse event report due to this contact than with most other drugs.

It is commonly believed that only about 10% of adverse drug events are reported to the FDA. Acadia Pharmaceuticals is indicating that in the case of Nuplazid, that percentage is higher due to the company’s outreach to patients and doctors.