Treating psychosis in movement disorder patients: a review

Evaluating pimavanserin tartrate as a treatment in Parkinson's disease

INTRODUCTION

Pimavanserin is an efficacious, atypical neuroleptic. It ameliorates the frequency and severity of hallucinations and delusions in patients with Parkinson's disease with psychosis. Most antipsychotic drugs directly block dopamine receptors and thus worsen motor behavior. In contrast, pimavanserin reduces the activity of excitatory serotonin receptor subtypes. They stimulate dopaminergic pathways in the mesolimbic system. As a result, onset of psychosis may occur particularly in patients on a chronic dopamine-substituting treatment regimen, like in Parkinson's disease.

AREAS COVERED

This narrative drug evaluation describes the properties and effects of pimavanserin. It is approved for the treatment of psychosis in Parkinson's disease. A literature search was performed using the terms dopamine, levodopa, psychosis, and Parkinson's disease without standardized selection of cited references.

EXPERT OPINION

An essential advantage of pimavanserin is the focus in the pivotal trials on the treatment of psychosis in patients with Parkinson's disease. Main competitors for the use in clinical practice are the atypical neuroleptic compounds quetiapine and clozapine. Both share considerable structural and pharmacological similarities, i.e. certain anticholinergic properties. They are recommended in guidelines. Once pimavanserin will become available as a generic drug, its use will probably increase worldwide.

Rethinking Clozapine: Lights and Shadows of a Revolutionary Drug

The current literature globally highlights the efficacy of Clozapine in several psychiatric disorders all over the world, with an FDA indication for reducing the risk of repeated suicidal behavior in patients with schizophrenia or schizoaffective disorder. A growing field of research is also stressing a possible broader beneficial effect of Clozapine in promoting neuroprotection and neurotrophism. However, this drug is linked to several life-threatening side effects, such as agranulocytosis, myocarditis and seizures, that limit its use in daily clinical practice. For this work, a search was performed on PubMed using the terms "Clozapine indications", "Clozapine adverse effects", "Clozapine regenerative effects", and "Clozapine neuroplasticity" with the aim of reviewing the scientific literature on Clozapine's treatment indications, adverse effects and potential regenerative role. The results confirmed the efficacy of clozapine in clinical practice, although limited by its adverse effects. It appears crucial to raise awareness among clinicians about the potential benefits of using Clozapine, as well educating medical personnel about its risks and the early identification of possible adverse effects and their management.

Clozapine Use in a Movement Disorder Clinic

BACKGROUND

Clozapine is an effective antipsychotic for Parkinson's disease (PD) that does not worsen motor function and can improve tremor. It is approved for PD psychosis in Europe and Australia.

OBJECTIVE

The aim of this study was to report on the use of clozapine in a movement disorder clinic.

METHODS

We report on patients monitored during the COVID-19 pandemic in clinic over a 7-month period.

RESULTS

Sixty-five patients were seen, of whom 50 had PD. Thirty-one were treated for psychosis, 18 for refractory tremor and 1 for levodopa dyskinesias. The remainder had psychotic symptoms with dementia with Lewy bodies (n = 2) or other movement disorders. Four had clozapine discontinued because of sedation and 1 for agranulocytosis. Three had clozapine temporarily halted because of granulocytopenia but were rechallenged successfully.

CONCLUSIONS

When comparing clozapine use in this clinic as compared with others, we deduce that clozapine is likely significantly underutilized in the United States.

Leukocytosis Associated with Clozapine Treatment: A Case Series and Systematic Review of the Literature

BACKGROUND AND OBJECTIVES

Clozapine is the only antipsychotic approved for treatment-resistant schizophrenia. Despite its superior efficacy profile as compared with other antipsychotics, clozapine remains underutilized. Clozapine monitoring systems clearly describe the proposed management of clozapine-induced neutropenia; however, no specific mention is made of how to interpret neutrophilic leukocytosis, despite that being a relatively frequent finding. Prescribers unfamiliar with this molecule may misjudge its clinical significance, potentially leading to untimely treatment interruption. Here, we systematically review the literature on the risk of neutrophilic leukocytosis during clozapine treatment, and describe eight additional cases among our patient cohort.

MATERIALS AND METHODS

We performed a systematic review of the literature on PubMed and Embase using the PRISMA 2020 guidelines, and selected all original reports describing either (1) the prevalence of neutrophilic leukocytosis during clozapine treatment, or (2) the clinical significance of neutrophilic leukocytosis. We described eight additional cases of neutrophilic leukocytosis during clozapine treatment while attending an outpatient psychiatric clinic.

RESULTS

Our research ultimately yielded the selection of 13 articles included in this systematic review. The case series highlighted the presence of stable and clinically unremarkable neutrophilia during a follow-up ranging from one to ten years.

CONCLUSIONS

Existing evidence indicates that leukocytosis associated with clozapine treatment can be considered as an asymptomatic and benign condition, suggesting that no change in clozapine treatment is needed upon its detection.

Setting up a clozapine service for Parkinson's psychosis

Parkinson's psychosis can be very challenging to manage, with limited treatment options available. There is a good evidence base to support the use of clozapine, but practical obstacles often prevent its use. There is a drive nationally to set up services so that people with Parkinson's psychosis can access treatment with clozapine in a timely manner and, where possible, with initiation in the community. The authors describe their experiences in setting up clozapine services specifically for this patient group in England and offer a practical approach to the assessment of Parkinson's psychosis. They also outline the evidence base in relation to treatment options and share their experiences of prescribing clozapine for Parkinson's psychosis.

[Huntington's disease with childhood and adolescent onset: course of disease, clinical presentation and diagnostic challenges]

Huntington's disease (HD) is an autosomal-dominant neurodegenerative disorder caused by a gene mutation in chromosome 4 that leads to an expansion of CAG - triplet repeats. It occurs mainly between the age of 30 and 50. Only less than 10 % of HD patients are younger than 20 years. In contrast to adult patients young HD patients show more often psychiatric and cognitive symptoms at disease onset than chorea. One third of the children with HD develops an epilepsy.We present 6 children diagnosed with HD in different stages of childhood. We describe first symptoms as well as genetic characteristics and other distinctive features.Both, the clinical presentation and the course of HD in childhood differ from HD in adults. In adolescents the clinical symptoms at onset are often psychiatric (like depression or attention deficit disorder). Choreatic movements typical for adult HD patients are missing.Due to the low prevalence of HD in childhood and the variability of clinical symptoms the process of diagnosing HD in children is difficult. Very often the diagnosis is made years after the first symptoms. Early diagnosis, however, is often important for managing social problems and problems in school.

Psychiatric pharmacist's role in overcoming barriers to clozapine use and improving management

Clozapine is an antipsychotic that exhibits superior efficacy and effectiveness for those with schizophrenia and other serious mental illness. However, its side-effect profile and administrative burdens present challenges to its use. In the United States, the medication is grossly underused even though it may improve outcomes and reduce costs. Current barriers to use include lack of prescriber knowledge and confidence, negative prescriber attitudes, special monitoring requirements, administrative factors, lack of clozapine on formularies, lack of support and infrastructure to use the medication within many health systems, and inadequate understanding or acknowledgement of clozapine prescribing and risks by policy makers and payers. Approaches using interprofessional models of care, which include pharmacists specializing in psychiatric care, can help meet the needs of patients receiving clozapine. This article lays out the big picture of barriers to clozapine and how psychiatric pharmacists could play a role in improving access.

[Modern approaches to treatment of psychosis in Parkinson's disease]

Psychotic disorders in Parkinson's disease (PDPD) are common and significantly influence the quality of life and disability level. The pathogenesis of PDPD is complex and not yet fully understood. Taking into consideration the features of the Parkinson's disease (usually older patients with a risk of cognitive decline), and the pharmacodynamics of the antiparkinsonian and traditional antipsychotic drugs, the management of PDPD is a challenging issue of clinical neurology and psychiatry. In this systematic review, scientific publications for the period 2014-2016 were analyzed within two bibliographic databases: MEDLINE/PubMed and eLIBRARY.RU. Additionally, the guidelines of the International Parkinson and Movement Disorders Society, American Academy of Neurology and European Academy of Neurology were included in the analysis. Clozapine is recommended to use in the treatment of PDPD, quetiapine is possible to use, pimavanserin will probably become a remedy of choice. Nonpharmacological approaches have positive effects on the general condition of the patients with PDPD, however the efficacy of such approaches to treat psychosis is unclear.

Typical features of Parkinson disease and diagnostic challenges with microdeletion 22q11.2

OBJECTIVE

To delineate the natural history, diagnosis, and treatment response of Parkinson disease (PD) in individuals with 22q11.2 deletion syndrome (22q11.2DS), and to determine if these patients differ from those with idiopathic PD.

METHODS

In this international observational study, we characterized the clinical and neuroimaging features of 45 individuals with 22q11.2DS and PD (mean follow-up 7.5 ± 4.1 years).

RESULTS

22q11.2DS PD had a typical male excess (32 male, 71.1%), presentation and progression of hallmark motor symptoms, reduced striatal dopamine transporter binding with molecular imaging, and initial positive response to levodopa (93.3%). Mean age at motor symptom onset was relatively young (39.5 ± 8.5 years); 71.4% of cases had early-onset PD (<45 years). Despite having a similar age at onset, the diagnosis of PD was delayed in patients with a history of antipsychotic treatment compared with antipsychotic-naive patients (median 5 vs 1 year, p = 0.001). Preexisting psychotic disorders (24.5%) and mood or anxiety disorders (31.1%) were common, as were early dystonia (19.4%) and a history of seizures (33.3%).

CONCLUSIONS

Major clinical characteristics and response to standard treatments appear comparable in 22q11.2DS-associated PD to those in idiopathic PD, although the average age at onset is earlier. Importantly, treatment of preexisting psychotic illness may delay diagnosis of PD in 22q11.DS patients. An index of suspicion and vigilance for complex comorbidity may assist in identifying patients to prioritize for genetic testing.

Pharmacological interventions for psychosis in Parkinson's disease patients

INTRODUCTION

Psychosis is a common problem for people treated for Parkinson's disease. The syndrome is quite stereotypic, with hallucinations being the most common, followed by delusions. While the hallucinations are usually not very bothersome, the delusions are typically paranoid in nature. Treatment is often, but not always, required.

AREAS COVERED

This article reviews the therapeutic approaches of this syndrome focusing on drug treatments used once contributory factors have been removed. This includes a review of the evidence supporting the use of clozapine and, most recently, pimavanserin, the first drug with antipsychotic efficacy that has no effect on dopamine. Treatment with second generation antipsychotic drugs and cholinesterase inhibitors are also reviewed.

EXPERT OPINION

Clozapine and pimavanserin have proven efficacy for Parkinson's disease psychosis (PDP), without impairing motor function. In clozapine's favor are its antipsychotic benefits seen within 1 week and its effectiveness in improving tremor in PD. However, this is counterbalanced by the need for blood monitoring, despite the extremely low doses used, and sedation. Pimanvanserin is well tolerated, without sedation or other significant side effects. Its onset of benefit, however takes 4-6 weeks. While quetiapine is also frequently used, its efficacy is not supported by double blinded, randomized trials.

Investigation of metabolic profile of pimavanserin in rats by ultrahigh-performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry

RATIONALE

Pimavanserin, a selective serotonin 2A receptor inverse agonist, is a promising candidate for treating Parkinson's disease psychosis. Our previous study revealed that there might be the presence of extensive metabolites of pimavanserin in rats. However, the metabolic fate of pimavanserin in vivo remains unknown. Thus, it is essential to develop an efficient method to investigate the metabolic profile of pimavanserin in rats. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) to date has the highest mass measurement accuracy and resolution of any mass spectrometry platform.

METHODS

After a single intragastric administration of pimavanserin at a dose of 50 mg kg^-1 , plasma, bile, urine and feces were collected from rats. A novel and efficient strategy was developed to analyze the metabolic profile of pimavanserin in vivo based on ultrahigh-performance liquid chromatography (UHPLC) coupled with FT-ICR-MS.

RESULTS

A total of 23 metabolites were detected and tentatively identified through comparing their mass spectrometry profiles with those of pimavanserin. These metabolites were found in feces (22), bile (21), rat urine (16) and plasma (15). Results demonstrated that metabolic pathways of pimavanserin in rats included dehydrogenation, demethylation, deethylation, depropylation, debutylation, hydroxylation, dihydroxylation and trihydroxylation.

CONCLUSIONS

A total of 22 phase I metabolites of pimavanserin were detected and tentatively identified. This report presents the first study of screening and identification of the metabolites of pimavanserin. The UHPLC/FT-ICR-MS method is a powerful tool for exploring and identifying metabolites in complex biological samples.

A Clinical Approach to the Diagnosis of Traumatic Encephalopathy Syndrome: A Review

IMPORTANCE

Chronic traumatic encephalopathy (CTE) refers to pathologic changes that have been found in some individuals with a history of repetitive traumatic impact to the head (hereinafter referred to as head trauma). These changes cannot be assessed during the clinical evaluation of a living patient.

OBSERVATIONS

The neuropathologic features, taxonomy, history, role of biomarkers in diagnosis, and existing criteria of CTE are reviewed. Previous criteria have been proposed to approach the living patient; however, a unified, specific approach is needed for the practicing clinician. We propose a new diagnostic construct for the clinical syndrome associated with repetitive exposure to head trauma: traumatic encephalopathy syndrome. This clinical paradigm will provide the framework for a diagnosis of probable, possible, and unlikely traumatic encephalopathy syndrome, with included discussion regarding the minimum exposure, nature of the clinical course, and additional clinical features needed for diagnosis.

CONCLUSIONS AND RELEVANCE

While prospective longitudinal studies are ongoing to further elucidate the association of exposure to head trauma, clinical features, and the development of pathologic changes, a corresponding clinical construct for diagnosis is necessary.

Modulatory effect of the 5-HT1A agonist buspirone and the mixed non-hallucinogenic 5-HT1A/2A agonist ergotamine on psilocybin-induced psychedelic experience

The mixed serotonin (5-HT) 1A/2A/2B/2C/6/7 receptor agonist psilocybin dose-dependently induces an altered state of consciousness (ASC) that is characterized by changes in sensory perception, mood, thought, and the sense of self. The psychological effects of psilocybin are primarily mediated by 5-HT2A receptor activation. However, accumulating evidence suggests that 5-HT1A or an interaction between 5-HT1A and 5-HT2A receptors may contribute to the overall effects of psilocybin. Therefore, we used a double-blind, counterbalanced, within-subject design to investigate the modulatory effects of the partial 5-HT1A agonist buspirone (20mg p.o.) and the non-hallucinogenic 5-HT2A/1A agonist ergotamine (3mg p.o.) on psilocybin-induced (170 µg/kg p.o.) psychological effects in two groups (n=19, n=17) of healthy human subjects. Psychological effects were assessed using the Altered State of Consciousness (5D-ASC) rating scale. Buspirone significantly reduced the 5D-ASC main scale score for Visionary Restructuralization (VR) (p<0.001), which was mostly driven by a reduction of the VR item cluster scores for elementary and complex visual hallucinations. Further, buspirone also reduced the main scale score for Oceanic Boundlessness (OB) including derealisation and depersonalisation phenomena at a trend level (p=0.062), whereas ergotamine did not show any effects on the psilocybin-induced 5D-ASC main scale scores. The present finding demonstrates that buspirone exerts inhibitory effects on psilocybin-induced effects, presumably via 5-HT1A receptor activation, an interaction between 5-HT1A and 5-HT2A receptors, or both. The data suggest that the modulation of 5-HT1A receptor activity may be a useful target in the treatment of visual hallucinations in different psychiatric and neurological diseases.

The Spectrum of Psychiatric Pathology in a Patient with Genetically Verified Huntington's Disease

Psychiatric and behavioral disturbances are common in Huntington's disease (HD) and contribute significantly to its morbidity and mortality. We herein present the case of a 43-year-old woman with genetically verified HD, whose deteriorating psychiatric condition necessitated multiple inpatient psychiatric hospitalizations and featured a clinical spectrum of neuropsychiatric disturbances classically associated with HD. This paper reviews the literature concerning Huntington's psychopathology and provides an illustrative case example of its clinical nature.