MDS 2016 Rajesh Pahwa Interview
Rajesh Pahwa reviews the current unmet needs in Parkinson’s Disease Psychosis and available treatment options.
FILMED AT THE INTERNATIONAL CONGRESS OF PARKINSON’S DISEASE AND MOVEMENT DISORDERS (IPMDS), JUNE 2016
HOW PREVALENT IS PSYCHOSIS IN PARKINSON’S DISEASE?
00:10 – Parkinson’s disease psychosis is a major unmet need as far as the treatment is concerned. If you are to look at the prevalence of psychosis in general in Parkinson’s disease, it is about 50%. In other words, 50% of the Parkinson’s patients will develop psychosis sometime during their disease duration. If you are to look at a cross section of patients with Parkinson’s disease, then the number might be closer to 30% to 40%. But depending upon how you look at it, it’s between 30% and 50%.
WHAT TREATMENT OPTIONS ARE AVAILABLE FOR PARKINSON’S DISEASE PSYCHOSIS?
00:45 – Currently there’s only one FDA-approved medication for Parkinson’s disease psychosis, that is basically Nuplazid or pimavanserin. This drug was approved in the United States approximately one month ago and it’s the only approved medication we have for PD psychosis.
WHAT TREATMENTS SHOULD BE AVOIDED FOR PARKINSON’S DISEASE PSYCHOSIS?
01:08 – Right now, when a patient with Parkinson’s disease has psychosis, we use Nuplazid. The problem is that before that, we did not have any medications that we had to treat PD psychosis. We used to use medications that are used for schizophrenia in patients with PD psychosis. The major problem with those medications are that it interacts in the dopamine system. So it actually has a risk of worsening Parkinson’s symptoms. So other than clozapine and maybe quetiapine for PD psychosis, which will be off-label use, all other anti-psychotic medication should be avoided in Parkinson’s disease because it can actually worsen Parkinson’s symptoms.
WHAT ARE THE REMAINING UNMET NEEDS IN THIS AREA?
01:56 – We have a number of unmet needs in Parkinson’s disease. One of the major ones is still Parkinson’s disease dementia. Once a patient with Parkinson’s starts having dementia, everything gets worse for them. The other one is balance difficulty and falls, because there’s nothing to prevent falls, that becomes a major risk factor on why some of the patients end up in a wheelchair because they cannot walk safely. Another one is freezing of patients trying to walk, suddenly their feet get stuck, they cannot move. Again, that’s something that we really don’t have medication for. Parkinson’s disease dyskinesia has no approved medications for dyskinesia as related to Parkinson’s disease. Today, our best option is reducing the Parkinson’s medication, which results in the worsening of the Parkinson’s symptoms, or considering aggressive therapies such as deep brain stimulation. The other unmet need I would say is patients who have a lot of off time. Again, when patients have off time, we can increase their medications which could result in having more dyskinesia, maybe having psychosis, but that’s another one where if the off time is a major problem, we end up using surgical therapies such as deep brain stimulation. So basically Parkinson’s dementia, falls, freezing, dyskinesia, off periods, these are all still unmet needs when we talk of Parkinson’s disease. Our biggest unmet need, actually, is curing the disease, or short of that, actually slowing the disease. And again, we don’t have anything for either of those conditions.
