Pimavanserin (Antipsychotic): Indications, Uses, and Side Effects

Psychotic symptoms appear not only in psychotic disorders such as schizophrenia or delusional disorder. They also appear frequently in some dementias, such as Parkinson's dementia and the Alzheimer's dementia.

Pimavanserin is a third-generation antipsychotic that was approved in 2016 for the treatment of psychoses in Parkinson's.. Other effects it may have to treat symptoms such as agitation and restlessness are still being investigated. depression in Alzheimer's, for example.

In this article we will learn about its characteristics, mechanism of action, uses and adverse effects, as well as the results of clinical trials carried out with this recently-appearing drug.

• Recommended article: "What is psychosis? Causes, symptoms and treatment"

Pimavanserin: what is it and what is it effective for?

Pimavanserin is a recent antipsychotic, specifically an atypical antipsychotic, and considered third generation.. It is marketed under the name of Nuplazid, and is synthesized by Acadia Pharmaceuticals laboratories.

This is a drug that has recently been discovered that can relieve psychotic symptoms in people with Alzheimer's disease without causing the usual side effects of other antipsychotics, such as risks of relapse, stroke or death.

However, for the moment, its use has only been approved to treat psychoses that appear in patients with Parkinson's dementia.

For its part, Parkinson's disease is a pathology that can end up developing dementia (and this is the case in many cases); We usually know this by its motor symptoms (tremors, rigidity...), but in many cases of Parkinson's patients, notable psychotic symptoms also appear, such as delusions and/or hallucinations.

Applied studies

This effect of Pimavanserin to treat psychotic symptoms in Alzheimer's patients has been demonstrated in a study. In addition, another study (a clinical trial) conducted with pimavanserin showed how this drug was also effective in relieving psychotic symptoms in people with dementia caused by the disease Parkinson.

FDA approval

This last finding allowed the FDA (United States government agency responsible for the regulation of medicines and other products) approved pimavanserin for such an indication, in April 2016.

It should be noted that the authorization of pimavanserin was based on the results of a single placebo-controlled trial, which lasted 6 weeks and in which 199 patients with Parkinson's disease participated, all of them with symptoms of hallucinations and/or delusions (symptoms psychotic).

Another relevant fact is that the patients who participated in the clinical trial with pimavanserin did not worsen their primary motor symptoms.

innovative therapy

Pimavanserin Named a Breakthrough Therapy by the FDA; thus, its approval as a treatment for psychoses in patients with Parkinson's dementia was logical.

The designation of "innovative therapy" granted by the FDA, is awarded to those drugs that, according to the preliminary clinical evidence, they can improve the symptoms of patients with serious diseases, and in a remarkable.

Mechanism of action

On the other hand, Pimavanserin has a different mechanism of action than usual in classic antipsychotics; what it does is block a specific serotonergic nerve receptor, the so-called THT2A or 5HT2A.

This receptor has been related to memory processes, cognitive functions and other organic functions; it is believed that it plays a mediating role in them.

Characteristics

As we have seen, pimavanserin is an atypical antipsychotic that is approved as an indication for treat psychotic symptoms associated with Parkinson's dementia (marketed under the name "Nuplazid").

Besides, a recent study has also found that pimavanserin can alleviate psychosis in patients with other types of dementia, Alzheimer's dementia, although research is still ongoing and no conclusive statements or definitive conclusions can yet be made. Specifically, what pimavanserin would do is reduce the frequency and intensity of psychotic symptoms in dementia (generally hallucinations and delusions).

Thus, pimavanserin is currently under development (under investigation) in relation to the possibility of treating possible cases of psychosis, schizophrenia, agitation and major depressive disorder in patients with dementia due to Alzheimer's.

format and take

Pimavanserin is taken orally, in "tablet" form. Generally, its administration schedule is once a day; It can be taken with or without food. It is recommended that it be taken at the same time each day, as is the case with other drugs.

Different from previous antipsychotics

As we already anticipated, the mechanism of action of pimavanserin is different from the usual mechanism in antipsychotics, which block D2 dopamine receptors in the brain (being antagonists dopaminergic).

In the case of pimavanserin, it is an inverse agonist and antagonist of 5-HT2A serotonin receptors; It has a high binding affinity with them (it fits almost perfectly).

Pimavanserin is a well-tolerated and fairly safe antipsychotic., as demonstrated by various clinical trials, carried out prior to its commercialization.

Adverse effects

Regarding the adverse effects (AEs) of pimavanserin, the aforementioned clinical trials showed how these were similar to those of the placebo condition. Specifically, they were: a confusional state and a peripheral edema. These adverse effects were found in at least 5% of the patients in the trials.

An important caveat regarding the use of pimavanserin, and one that you should know, is that, like all antipsychotic, may increase mortality in older (elderly) patients with psychotic symptoms related to his dementia. These are the side effects that appeared in clinical trials, but others are also associated, such as: nausea and swelling (in hands, feet or ankles). Regarding the serious adverse effects of pimavanserin, there is talk of: hallucinations, rashes, difficulty walking, confusion, hives, tightness in the throat, shortness of breath, and swelling of the language.

It is important to go to an emergency doctor in case of presenting any of the last mentioned adverse effects.

conclusions

Pimavanserin is a relatively recent drug, with antipsychotic actions and that has been shown to be effective in Parkinson's dementia, to treat associated psychosis. However, We must be cautious, because even though it is already on the market, pimavanserin is still under investigation.

On the other hand, although the symptoms that we are most aware of in patients with Parkinson's are motor (and cognitive in the case of Alzheimer), psychotic symptoms also appear in these pathologies, and also with relative frequency. In addition, they cause considerable discomfort in these patients and in the people around them.

These are symptoms that significantly interfere with the daily functioning of these patients. That is why pimavanserin can be a hopeful drug that helps improve the quality of life of these people, reducing their emotional deterioration and improving their psychological well-being.

Bibliographic references:

• Ballard, C., Banister, C., Khan, Z., Cummings, J., Demos, G., Coate, B., et al. (2018). Pimavanserin, a possible alternative to alleviate the psychosis of dementia. The Lancet Neurology, 17: 213-222.

• Kitten, A.K., Hallowell, S.A., Saklad, S.R., Evoy K.E. (2018). Pimavanserin: A Novel Drug Approved to Treat Parkinson's Disease Psychosis. Innov Clin Neurosci, 15(1-2): 16-22.

• MedLinePlus. (2019). Pimavanserin.