The U.S. Food and Drug Administration (FDA) approved pimavanserin, the first drug approved to treat psychosis in patients with Parkinson’s disease.
Parkinson’s disease affects about 1 million Americans, about 40 to 50 percent of whom experience hallucinations or delusions at some point during their illness, usually in the later stages. The thoughts and emotions that come from these symptoms can be disturbing and debilitating. In addition to the characteristic tremor or shaking, these symptoms can also worsen the depression, sleep disturbances and other symptoms of the progressive disease.
This new medication improved psychotic symptoms without making the shaking and movement symptoms worse or causing tardive dyskinesia. Almost 200 patients were studied over six weeks to establish whether the drug was safe and effective in a placebo-controlled study. Common side effects included swelling of the legs and feet, nausea and confusion.
The drug underwent priority review as a breakthrough therapy, a classification reserved for drugs that show clear advantages over available therapy in the treatment of serious conditions. While the FDA states, “Designation of a drug as ‘Priority’ does not alter the scientific/medical standard for approval or the quality of evidence necessary.”
Aaron Kesselheim, M.D., J.D., M.P.H., of Harvard’s T.H. Chan School of Public Health, expressed concern that too many drugs are going through the expedited process and that the scientific rigor behind them suffers as a result.
Before the approval of pimavanserin, Parkinson’s patients experiencing psychotic symptoms were treated with general antipsychotic drugs. Coincidentally, a recently published study revealed an increased risk of death for Parkinson’s patients taking antipsychotics.
Most people think of Parkinson’s disease as having to do with dopamine, but serotonin has also been implicated. Pimavanserin is an atypical antipsychotic that its manufacturer refers to as a “selective serotonin inverse agonist” or SSIA. The drug binds to the same receptors associated with hallucinogenic drugs like LSD and PCP.
Drugs that stimulate receptors by binding to them are called agonists. Drugs that prevent stimulation by binding to receptors and prevent symptoms are called inverse agonists, like pimavanserin. By preventing stimulation of the receptors associated with hallucinations, symptoms are prevented.
Like other atypical antipsychotics, the new drug carries a boxed warning that alerts prescribers to the increased risk of using antipsychotics in the elderly, even though this drug is the first SSIA to receive FDA approval. Peter N. Schmidt, Ph.D., the senior vice president and chief mission officer of the National Parkinson Foundation, expressed concern over the dangers of dopamine-blocking antipsychotics in Parkinson’s patients and hopes that most patients will have access to this new medication designed just for Parkinson’s patients.
Schmidt further stated: “We hope this approval will lead to better outcomes for people with Parkinson’s today and that this success of the drug approval process will inspire others to pursue the next breakthrough.” Only time will tell.
Psychosis in older adults can be very frightening for the person experiencing symptoms as well as for his or her loved ones. The Sovereign Health Group is a leader in the treatment of people with mental and behavioral disorders and dual diagnosis. We have many specialized programs, including those for older adults with psychosis, with or without co-occurring Parkinson’s disease. Comprehensive treatment includes novel, conventional and holistic therapies tailored for each individual client. Our ongoing continuing care program provides the support patients need to remain free from addiction and recover from all of its consequences. To find out more about specialized programs at Sovereign Health, please call us at our 24/7 helpline.
About the author
Dana Connolly, Ph.D., is a senior staff writer for the Sovereign Health Group, where she translates current research into practical information. She earned her Ph.D. in research and theory development from New York University and has decades of experience in clinical care, medical research and health education. The Sovereign Health Group is a health information resource and Dr. Connolly helps to ensure excellence in our model. For more information and other inquiries about this article, contact the author at firstname.lastname@example.org.