Evidence for the use of pimavanserin in the treatment of Parkinson's disease psychosis

Advances in the treatment and management of frontotemporal dementia

INTRODUCTION

Frontotemporal dementia (FTD) is a complex neurodegenerative disorder, characterized by a wide range of pathological conditions associated with the buildup of proteins such as tau and TDP-43. With a strong hereditary component, FTD often results from genetic variants in three genes - MAPT, GRN, and C9orf72.

AREAS COVERED

In this review, the authors explore abnormal protein accumulation in FTD and forthcoming treatments, providing a detailed analysis of new diagnostic advancements, including innovative markers. They analyze how these discoveries have influenced therapeutic strategies, particularly disease-modifying treatments, which could potentially transform FTD management. This comprehensive exploration of FTD from its molecular underpinnings to its therapeutic prospects offers a compelling overview of the current state of FTD research.

EXPERT OPINION

Notable challenges in FTD management involve identifying reliable biomarkers for early diagnosis and response monitoring. Genetic forms of FTD, particularly those linked to C9orf72 and GRN, show promise, with targeted therapies resulting in substantial progress in disease-modifying strategies. The potential of neuromodulation techniques, like tDCS and rTMS, is being explored, requiring further study. Ongoing trials and multi-disciplinary care highlight the continued push toward effective FTD treatments. With increasing understanding of FTD's molecular and clinical intricacies, the hope for developing effective interventions grows.

Atypical antipsychotics in the treatment of psychotic symptoms in Alzheimer's disease: a systematic review

With the advancement of Alzheimer's disease as well as other types of dementia, in addition to the cognitive decline, psychiatric symptoms have been outlined, including psychotic symptoms. The aim of the study is to review the available results on the antipsychotic treatment of Alzheimer's disease associated psychotic symptoms. The main objective of the study is to evaluate the efficacy of the treatment. The second objective is to assess the tolerability of this treatment. Double-blind, randomized, placebo-controlled trials, which took place over the course of at least 4 weeks, have been searched. Studies that compared one atypical antipsychotic to placebo, as well as more atypical antipsychotics, compared one to another, have been taken into account. In total 17 studies have been selected. The efficacy of the atypical antipsychotics has proven to be significant in most studies. Moreover, antipsychotic medication, such as risperidone, aripiprazole, olanzapine, quetiapine and pimavanserin, has been well tolerated. Atypical antipsychotics are the treatment of choice for psychotic symptoms in dementia. Despite the consistent results present in the literature up to this point, various antipsychotics remain insufficiently studied and would need more generous sample sizes for their outcomes to be substantiated.

Treatment Patterns With Antipsychotics in Long-Term Care Patients With Parkinson's Disease Psychosis

This study assessed treatment change patterns in Parkinson's disease psychosis (PDP) residents receiving antipsychotic (AP) therapies in U.S. long-term care (LTC) facilities. Residents with PDP in LTC between 01/01/13 and 06/30/16 were identified with ≥1 claim of psychosis, hallucinations, or delusions after PD diagnosis. Treatment patterns were evaluated during the 12 months post index. We identified 864 PDP residents: 408 (47.2%) on AP therapy and 456 (52.8%) on no AP therapy. A total of 335 residents (82.1%) continued, 13 (3.2%) discontinued, 11 (2.7%) switched, and 49 (12.0%) augmented (used ≥2 APs) their index AP therapy. Based on the multivariate regression analysis, younger age, male gender, anemia, anxiolytic use or anxiety, sedatives/hypnotic use, bladder disorders including urinary tract infections, coronary conditions, diabetes, hypertension, and dementia were associated with a higher likelihood of treatment change. Understanding the factors associated with treatment change may inform ways to improve management of PDP in the U.S. LTC setting.

Treatment of psychosis in Parkinson's disease and dementia with Lewy Bodies: A review

There is a considerable overlap between Parkinson's Disease Dementia (PDD) and Dementia with Lewy Bodies (DLB). They present a challenge therapeutically, with regard to morbidity and mortality risk. In particular, symptoms of psychosis in these conditions augur a considerably increased burden. To date, there has been a myriad of prospective, retrospective and case studies examining the use of neuroleptics in the treatment of psychotic symptoms in PDD/DLB. Clozapine has the most robust evidence base however its use is limited by agranulocytosis risk and the associated need for frequent blood count monitoring. Quetiapine is more readily used, however, it has a more equivocal evidence base, in terms of efficacy. Other neuroleptics have thus far demonstrated mixed results with increased risk of extrapyramidal worsening. In addition to the atypical agents, the introduction of pimavanserin has provided another treatment option for Parkinson's Disease Psychosis (PDP), decreasing concern for deterioration in motor function. We await further research to confidently demonstrate its efficacy and safety in DLB psychosis. Cholinesterase inhibitors likely have a limited role in treating milder psychosis symptomatology in DLB and perhaps PDD. After review of the current literature for antipsychotic therapy in both PDD and DLB, we provide a logical framework for addressing psychotic symptoms in each condition.

Quantification of Pimavanserin in Bulk and Tablet Dosage Form Using A Stability Indicating High Performance Liquid Chromatographic Method

Background: Pimavanserin, an antipsychotic agent, is used to treat patients suffering with Parkinson's disease. Till now no stability indicating reverse phase HPLC method was reported for the quantification of pimavanserin in bulk and tablet dosage form. Hence in the present study, a new sensitive, precise and accurate stability indicating reverse phase HPLC method with photodiode array detector has been developed for the quantification of pimavanserin in bulk and tablet dosage form. Methods: Separation and analysis of pimavanserin was achieved on Kromasil C18 (5 µm, 250 mm × 4.6 mm) column using 0.1M NaH2PO4, methanol and acetonitrile in ratio of 55:30:15 (v/v/v) as mobile phase at 25°C. The flow rate was 1.0 ml/min. The effluents were monitored with detector set at 239 nm. The method validation was done with regard to the guidelines by the International Conference on Harmonization. Pimavanserin was subjected to acid, alkali and neutral hydrolysis, hydrogen peroxide oxidation, thermal degradation, and photo (sunlight) degradation. Results: Linear relationship was obtained between the concentration of drug and peak area response in the range of 4.25-34.0 µg/ml. The limits of detection and quantitation were found to be 0.027 µg/ml and 0.089 µg/ml, respectively. All the validation characteristics were within the acceptance criteria. The peaks of degradation products were well resolved from the pimavanserin peak. Conclusion: The developed and validated method is able to quantify the pimavanserin in the presence of degradation products.

Molecular targets of atypical antipsychotics: From mechanism of action to clinical differences

The introduction of atypical antipsychotics (AAPs) since the discovery of its prototypical drug clozapine has been a revolutionary pharmacological step for treating psychotic patients as these allow a significant recovery not only in terms of hospitalization and reduction in symptoms severity, but also in terms of safety, socialization and better rehabilitation in the society. Regarding the mechanism of action, AAPs are weak D₂ receptor antagonists and they act beyond D₂ antagonism, involving other receptor targets which regulate dopamine and other neurotransmitters. Consequently, AAPs present a significant reduction of deleterious side effects like parkinsonism, hyperprolactinemia, apathy and anhedonia, which are all linked to the strong blockade of D₂ receptors. This review revisits previous and current findings within the class of AAPs and highlights the differences in terms of receptor properties and clinical activities among them. Furthermore, we propose a continuum spectrum of "atypia" that begins with risperidone (the least atypical) to clozapine (the most atypical), while all the other AAPs fall within the extremes of this spectrum. Clozapine is still considered the gold standard in refractory schizophrenia and in psychoses present in Parkinson's disease, though it has been associated with adverse effects like agranulocytosis (0.7%) and weight gain, pushing the scientific community to find new drugs as effective as clozapine, but devoid of its side effects. To achieve this, it is therefore imperative to characterize and compare in depth the very complex molecular profile of AAPs. We also introduce relatively new concepts like biased agonism, receptor dimerization and neurogenesis to identify better the old and new hallmarks of "atypia". Finally, a detailed confrontation of clinical differences among the AAPs is presented, especially in relation to their molecular targets, and new means like therapeutic drug monitoring are also proposed to improve the effectiveness of AAPs in clinical practice.

Parkinson's disease psychosis: presentation, diagnosis and management

Parkinson's disease is a neurodegenerative disorder characterized by motor and nonmotor symptoms. Psychosis is a common feature of Parkinson's disease. Parkinson's disease psychosis (PDP) encompasses minor phenomena (illusions, passage hallucinations and presence hallucinations), visual and nonvisual hallucinations and delusions. PDP is associated with reduced function and quality of life. The initial management approach should focus on identification and treatment of any contributory medical factors, reduction or discontinuation of medications with potential to induce or worsen psychosis, nonpharmacological strategies and consideration of acetylcholinesterase inhibitor treatment in the setting of dementia. Pimavanserin, quetiapine and clozapine may all be considered for use in PDP. In this review, we discuss the presentation, diagnosis and management of PDP.

Ventral striatal dopaminergic defect is associated with hallucinations in Parkinson's disease

BACKGROUND AND PURPOSE

Visual hallucinations (VHs) are a common complication of Parkinson's disease (PD). The pathogenesis of VHs in PD is still largely unclear. The aim of this study was to investigate the dopaminergic mechanisms of VHs and specifically whether the degree of striatal dopamine transporter (DAT) function or extrastriatal serotonin transporter (SERT) function can predict the appearance of VHs in patients with PD.

METHODS

Twenty-two PD patients scanned with [¹²³ I]FP-CIT single photon emission computed tomography at an early stage of their disease who later developed VHs were identified and compared with 48 non-hallucinating PD patients. The groups were matched for age, medication, disease duration and motor symptom severity. Clinical follow-up after the scan was a median (range) of 6.9 (3.8-9.6) years. Imaging analyses were performed with both regions-of-interest-based and voxel-based (Statistical Parametric Mapping) methods for the striatal and extrastriatal regions.

RESULTS

The median interval between the scan and the emergence of VHs was 4.8 years. Patients who developed VHs had 18.4% lower DAT binding in the right ventral striatum (P = 0.009), 16.7% lower binding in the left ventral striatum (P = 0.02) and 18.8% lower binding in the right putamen (P = 0.03) compared to patients who did not develop VHs.

CONCLUSIONS

Low striatal DAT function may predispose PD patients to VHs, and the regional distribution of the findings suggests a particular role of the ventral striatum. This is in line with non-PD research that has implicated ventral striatal dysfunction in psychosis.

The Emerging Role of Pimavanserin in the Management of Parkinson's Disease Psychosis

A panel of experts drawn from neurology, psychiatry, geropsychiatry, geriatrics, and pharmacy representatives of 3 health plans convened in New York City on July 30, 2016, with the objective of sharing opinions, ideas, and information regarding the optimal management of Parkinson's disease psychosis (PDP). Three key points emerged from the discussion: (1) Because of the nature of Parkinson's disease and PDP, finding appropriate treatment can prove challenging; (2) emerging therapies may present an opportunity for effective disease management; and (3) moving forward, provider and patient education regarding PDP and available treatment options is essential for well-managed symptoms and better quality of life. The panel reviewed current practices and formulated recommendations on moving forward in the treatment of PDP.

DISCLOSURES

This project and manuscript was funded by ACADIA Pharmaceuticals and developed by Magellan Rx Management. Lopes and Farnum are employees of Magellan Rx Management. Kremens has received consulting/speaker fees from Teva Pharmaceuticals, UCB, Sunovion, Impax, Lundbeck, ACADIA, USWorldMeds, Merz, Acorda, Kyowa, Neurocrine, and GE Healthcare. Pagan reports consulting/speaker fees from Teva Nanoscience, AbbVie, Impax, ACADIA, Medtronic, USWorldMeds, Merz, and Cynapsus and research and educational grants from USWorldMeds, Teva, and Medtronic. Patel has received consultant/speaker fees from ACADIA, Allergen, and Avanir. Alva reports research support from Accera, Allergan, Axovant, Eisai, Neurotrope, Genentech, Intra Cellular, Janssen, Lundbeck, Neurim, Novartis, Otsuka, Roche, Suven, and Trans Tech and consultant/speaker fees from ACADIA, Alkermes, Allergan, Avanir, Janssen, Lundbeck, Merck, Nestle, Otsuka, Sunovion, Takeda, and Vanda. The other authors report no potential conflicts of interest, financial or otherwise.