Atypical antipsychotics for Parkinson's disease psychosis: a systematic review and meta-analysis

Retrospective analyses evaluating the mortality risk associated with pimavanserin or other atypical antipsychotics in patients with Parkinson disease psychosis

Introduction

Parkinson's disease (PD) is associated with increased mortality risk (MR), reflecting progression of motor and nonmotor symptoms. PD psychosis (PDP), a common nonmotor symptom, increases with prolonged disease and elevates the MR of PD even further. Pimavanserin is the only FDA-approved treatment for PDP. This review summarizes real-world evidence around the MR of patients with PDP treated with pimavanserin versus off-label atypical antipsychotics.

Methods

A PubMed search was conducted using the following search terms: pimavanserin AND antipsychotic AND mortality AND Parkinson's disease AND psychosis. Inclusion criteria specified the entry of retrospective, observational, and open-label studies comparing pimavanserin to atypical antipsychotics or untreated controls.

Results

A total of 10 of the 32 articles met inclusion criteria. Among five comparisons of pimavanserin with atypical antipsychotics, two were large (n = 21,719; n = 21,975), representative, Medicare-database studies, which demonstrated comparable or lower all-cause pimavanserin MR. Among three pimavanserin versus control studies, two reported lower or comparable pimavanserin MR and one, long-term care study reported higher MR for pimavanserin versus non-pimavanserin treated patients with unknown PDP status. Two open-label extensions reported pimavanserin mortality rates of 6.45 and 18.8 deaths per 100 patient-years, which are comparable to, or lower than, mortality rates for PD, PDP, and other atypical antipsychotics. Most studies (70 %; 7 of 10) demonstrated pimavanserin's MR was lower than or similar to other atypical antipsychotics or untreated controls.

Conclusions

Pimavanserin did not increase the MR in PDP. Pimavanserin's MR appears to be comparable to or lower than other atypical antipsychotics prescribed for PDP, including quetiapine.

Seizures due to pyridoxine deficiency in Parkinson's disease

Parkinson's disease (PD) is a complex neurodegenerative disorder characterized not only by its hallmark motor symptoms but also by a myriad of non-motor manifestations, including cognitive decline, autonomic manifestations, and gastrointestinal disturbances. Amidst these, a lesser-known but critical aspect is the increased risk of functional deficiency of pyridoxine (vitamin B6) in patients with PD, which is linked to an increased risk of seizures. This review investigates the intersection of PD, new-onset seizures, and pyridoxine deficiency, aiming to elucidate the significance of these associations and their contributions to the neurologic burden in PD. Case reports documenting the occurrence of seizures in patients with PD, particularly in the context of high-dose dopaminergic therapy and the subsequent revelation of pyridoxine deficiency were included. These cases, which often featured extensive workups revealing unremarkable findings aside from pyridoxine deficiency, underscore the multifaceted nature of PD and its treatment-related complications. The findings in these case reports suggest that dietary insufficiencies, gastrointestinal dysfunctions, and drug-nutrient interactions may eventually precipitate pyridoxine deficiency, which in turn may lead to seizures by disrupting GABAergic neurotransmission. This sheds the light on the need for increased clinical awareness and routine monitoring of pyridoxine levels in patients with PD, especially those undergoing significant therapeutic adjustments or exhibiting comorbidities that might interfere with their dietary intake such as gastrointestinal manifestations or depression. Such proactive measures could potentially mitigate the impact of this complication in patients with PD, ultimately enhancing patient care and quality of life.

Second-generation antipsychotics for Parkinson's disease psychosis: A systematic review and network meta-analysis

OBJECTIVE

This network meta-analysis assessed the efficacy, tolerability, and acceptability of second-generation antipsychotics (SGAs) for Parkinson's disease psychosis (PDP).

METHODS

We searched PubMed, Embase, Cochrane Library, and ClinicalTrials.gov for randomized controlled trials investigating SGAs for PDP up to October 26, 2023.

RESULTS

We included 16 trials (N = 1252) investigating clozapine, melperone, olanzapine, pimavanserin, quetiapine, ulotaront, and placebo. In comparisons between SGAs and placebo, the findings were: i) Standardized mean differences, 95% confidence intervals (SMDs, 95%CIs), for psychotic-symptom reduction revealed the first rank of clozapine (-1.31, -1.73 to -0.89), the second rank of pimavanserin, with significant inferiority of quetiapine (SMD = 0.47, 0.02 to 0.92); ii) Mean differences (MDs, 95%CIs) for abnormal movement, as assessed by the Unified Parkinson's Disease Rating Scale - Part III, indicated that clozapine had the least motor side effects (-0.92, -2.75 to 0.91); iii) Risk ratios (RRs, 95% CIs) for adverse-effect dropout rates were lowest for melperone (1.02, 0.20 to 5.24); and iv) RRs (95% CIs) for all-cause dropout rates were lowest for clozapine (0.73, 0.42 to 1.25).

CONCLUSIONS

For patients with PDP, clozapine may substantially reduce psychotic symptoms with minimal abnormal movement, high acceptability, and moderate overall tolerability. Pimavanserin, not quetiapine, could be an alternative.

Risk of long-term care admissions among Medicare beneficiaries treated with pimavanserin or quetiapine for Parkinson's disease psychosis in USA: a retrospective administrative claims database analysis

Aim: Risk of long-term care (LTC) admission (LTCA) associated with atypical antipsychotic (AAP) use among patients with Parkinson's disease psychosis (PDP) is a major concern. However, no comparative studies have examined the differences in risk of LTC admissions between pimavanserin (PIM), the only FDA-approved AAP for PDP, and other off-label AAPs including quetiapine (QUE). Objective: To examine all-cause LTCA rates and risk among PDP patients treated with AAPs such as QUE or PIM. Methods: Analysis of Parts A, B and D claims (100% Medicare sample; 2013-2019) of Medicare beneficiaries with PDP that initiate ≥12-month continuous PIM or QUE monotherapy from 1 January 2014 to 31 December 2018 (i.e., index date) without any AAP use in the 12-month pre-index period was conducted. Outcome assessments among 1:1 propensity score-matched (31 variables - age, sex, race, region and 27 Elixhauser comorbidities) beneficiaries on PIM versus QUE included risk of all-cause skilled nursing facility stays (SNF-stays), LTC-stays, and overall LTCA (i.e., SNF-stays or LTC-stays). All-cause LTCA rates and LTCA risk were compared using logistic regression and cox proportional hazards models, respectively, controlling for demographics, comorbidities and co-existing-dementia or insomnia. Results: Of the matched sample (n = 842 for each group) from total sample (n = 9652), overall all-cause LTCA and SNF-stay rates were 23.2 and 20.2% for PIM versus 33.8 and 31.4% for QUE, respectively (p < 0.05, for each). Hazard ratio (95% CI) for risk of SNF-stay and overall LTCA was 0.78 (0.61, 0.98) and 0.80 (0.66, 0.97), respectively, for PIM versus QUE beneficiaries (p < 0.05, for each). Conclusion: The 20% lower risk of LTCA (i.e., greater delay) with PIM versus QUE in this analysis may suggest that PIM should be started early for the treatment of PDP.

Safety Profile of Pimavanserin Therapy in Elderly Patients with Neurodegenerative Disease-Related Neuropsychiatric Symptoms: A Phase 3B Study

Background

Pimavanserin, a 5-HT2A receptor inverse agonist/antagonist, is the only medication approved by the FDA for the treatment of hallucinations and delusions associated with Parkinson's disease psychosis (PDP). Further expanding knowledge of the safety profile of pimavanserin in PDP and neurodegenerative diseases (NDD) such as Alzheimer's disease is of great interest for informing its use in patients with PDP (with or without dementia), given this population is highly sensitive to adverse effects following antipsychotic use.

Objective

This trial evaluated the effects of pimavanserin compared to placebo in frail older adults and elderly patients with neuropsychiatric symptoms related to NDD, such as hallucinations and delusions, to better understand the safety of pimavanserin in this population.

Methods

This was a phase 3b, 8-week treatment (study duration of up to 16 weeks), multicenter, randomized, double-blind, placebo-controlled, two-arm parallel-group trial (NCT03575052). The primary endpoint was safety and tolerability, measured by treatment-emergent adverse events (TEAEs). Secondary safety endpoints were change from baseline in motor and cognitive function; exploratory endpoints included suicidality, sleep quality, and neuropsychiatric symptoms.

Results

Incidences of TEAEs were similar between treatment groups; 29.8% reported ≥1 TEAE (pimavanserin: 30.4%; placebo: 29.3%), and 1.8% reported serious TEAEs (pimavanserin: 2.0%; placebo: 1.5%). Pimavanserin did not impact motor- or cognitive-related function.

Conclusions

Pimavanserin was well tolerated and not associated with motor or cognitive impairment. Together, these findings highlight the manageable and generally favorable safety profile of pimavanserin in patients with NDD, contributing to our knowledge on the safety of pimavanserin as it generalizes to patients with PDP.

Advances in the Diagnosis and Management of Psychotic Symptoms in Neurodegenerative Diseases: A Narrative Review

Background: Approximately 15% of older adults may experience psychotic phenomena. Primary psychiatric disorders that manifest with psychosis (delusions, hallucinations, and disorganized thought or behavior) account for less than half. Up to 60% of late-life psychotic symptoms are due to systemic medical or neurological conditions, particularly neurodegenerative diseases. A thorough medical workup including laboratory tests, additional procedures if indicated, and neuroimaging studies is recommended. This narrative review summarizes current evidence regarding the epidemiology and phenomenology of psychotic symptoms encountered as part of the neurodegenerative disease continuum (including prodromal and manifest stages). Results: Prodromes are constellations of symptoms that precede the onset of overt neurodegenerative syndromes. Prodromal psychotic features, particularly delusions, have been associated with an increased likelihood of receiving a neurodegenerative disease diagnosis within several years. Prompt prodrome recognition is crucial for early intervention. The management of psychosis associated with neurodegenerative diseases includes behavioral and somatic strategies, although evidence is scarce and mostly limited to case reports, case series, or expert consensus guidelines, with few randomized controlled trials. Conclusion: The complexity of psychotic manifestations warrants management by interprofessional teams that provide coordinated, integrated care.

Comparative Efficacy, Safety, and Acceptability of Pimavanserin and Other Atypical Antipsychotics for Parkinson's Disease Psychosis: Systematic Review and Network Meta-Analysis

BACKGROUND

The current comparative efficacy, safety, and acceptability of atypical antipsychotics (AAPs) in treating Parkinson's Disease Psychosis (PDP) are not entirely understood.

OBJECTIVE

To evaluate comparative efficacy, safety, and acceptability of AAPs in patients with PDP.

METHODS

We conducted a systematic review and a network meta-analysis to compare the efficacy, safety, and acceptability of pimavanserin, quetiapine, olanzapine, clozapine, ziprasidone, and risperidone. We estimated relative standardized mean differences (SMDs) for continuous outcomes and odds ratios (OR) for binary outcomes, with their respective 95% confidence intervals (CIs).

RESULTS

We included 19 unique studies evaluating AAPs in a total of 1,242 persons with PDP. Based on Clinical Global Impression Scale for Severity, pimavanserin (SMD, -4.81; 95% CI, -5.39, -4.24) and clozapine (SMD, -4.25; 95% CI, -5.24, -3.26) significantly improved symptoms compared with placebo. Also, compared to placebo, pimavanserin (OR, 1.16; 95% CI, 1.07, 1.24) significantly improved psychotic symptoms based on Scale for Assessment of Positive Symptoms for Parkinson's Disease Psychosis/Hallucinations and Delusions scores. In comparison to placebo, clozapine (SMD, -0.69; 95% CI, -1.35, -0.02), pimavanserin (SMD, -0.01; 95% CI, -0.56, 0.53), and quetiapine (SMD, 0.00; 95% CI, -0.68, 0.69) did not impair motor function per Unified Parkinson's Disease Rating scale. Based on Mini-Mental State Examination scale, quetiapine (SMD, 0.60; 95% CI, 0.07, 1.14) significantly impaired cognition compared to placebo.

CONCLUSIONS

In patients with PDP, pimavanserin and clozapine demonstrated significant improvement in psychosis without affecting motor function. With quetiapine being associated with a significant decline in cognition and despite not impairing motor function, our findings suggest that it should be avoided in patients with PDP and reduced cognitive abilities.

The complex molecular pharmacology of the dopamine D2 receptor: Implications for pramipexole, ropinirole, and rotigotine

With L-DOPA, dopamine agonists such as pramipexole, ropinirole and rotigotine constitute key therapeutic options for the management of motor symptoms of Parkinson's disease. These compounds exert their beneficial effect on motor behaviours by activating dopamine D₂-class receptors and thereby compensating for the declining dopaminergic transmission in the dorsal striatum. Despite a strong similarity in their mechanism of action, these three dopamine agonists present distinct clinical profiles, putatively underpinned by differences in their pharmacological properties. In this context, this review aims at contributing to close the gap between clinical observations and data from molecular neuropharmacology by exploring the properties of pramipexole, ropinirole and rotigotine from both the clinical and molecular perspectives. Indeed, this review first summarizes and compares the clinical features of these three dopamine agonists, and then explores their binding profiles at the different dopamine receptor subtypes. Moreover, the signalling profiles of pramipexole, ropinirole and rotigotine at the D₂ receptor are recapitulated, with a focus on biased signalling and the potential therapeutic implications. Overall, this review aims at providing a unifying framework of interpretation for both clinicians and fundamental pharmacologists interested in a deep understanding of the pharmacological properties of pramipexole, ropinirole and rotigotine.

Costs and Utilization of New-to-Market Neurologic Medications

BACKGROUND AND OBJECTIVES

The objective of this study was to compare the utilization and costs (total and out-of-pocket) of new-to-market neurologic medications with existing guideline-supported neurologic medications over time.

METHODS

We used a healthcare pharmaceutical claims database (from 2001 to 2019) to identify patients with both a diagnosis of 1 of 11 separate neurologic conditions and either a new-to-market medication or an existing guideline-supported medication for that condition. Neurologic conditions included orthostatic hypotension, spinal muscular atrophy, Duchenne disease, Parkinson disease, multiple sclerosis, amyotrophic lateral sclerosis, myasthenia gravis, Huntington disease, tardive dyskinesia, transthyretin amyloidosis, and migraine. New-to-market medications were defined as all neurologic medications approved by the US Food and Drug Administration (FDA) between 2014 and 2018. In each year, we determined the median out-of-pocket and standardized total costs for a 30-day supply of each medication. We also measured the proportion of patients receiving new-to-market medications compared with all medications specific for the relevant condition.

RESULTS

We found that the utilization of most new-to-market medications was small (<20% in all but 1 condition), compared with existing, guideline-supported medications. The out-of-pocket and standardized total costs were substantially larger for new-to-market medications. The median (25th percentile, 75th percentile) out-of-pocket costs for a 30-day supply in 2019 were largest for edaravone ($712.8 [$59.8-$802.0]) and eculizumab ($91.1 [$3.0-$3,216.4]). For new-to-market medications, the distribution of out-of-pocket costs was highly variable and the trends over time were unpredictable compared with existing guideline-supported medications.

DISCUSSION

Despite the increasing number of FDA-approved neurologic medications, utilization of newly approved medications in the privately insured population remains small. Given the high costs and similar efficacy for most of the new medications, limited utilization may be appropriate. However, for new medications with greater efficacy, future studies are needed to determine whether high costs are a barrier to utilization.

Recent advances in dopamine D2 receptor ligands in the treatment of neuropsychiatric disorders

Dopamine is a biologically active amine synthesized in the central and peripheral nervous system. This biogenic monoamine acts by activating five types of dopamine receptors (D_1-5 Rs), which belong to the G protein-coupled receptor family. Antagonists and partial agonists of D₂ Rs are used to treat schizophrenia, Parkinson's disease, depression, and anxiety. The typical pharmacophore with high D₂ R affinity comprises four main areas, namely aromatic moiety, cyclic amine, central linker and aromatic/heteroaromatic lipophilic fragment. From the literature reviewed herein, we can conclude that 4-(2,3-dichlorophenyl), 4-(2-methoxyphenyl)-, 4-(benzo[b]thiophen-4-yl)-1-substituted piperazine, and 4-(6-fluorobenzo[d]isoxazol-3-yl)piperidine moieties are critical for high D₂ R affinity. Four to six atoms chains are optimal for D₂ R affinity with 4-butoxyl as the most pronounced one. The bicyclic aromatic/heteroaromatic systems are most frequently occurring as lipophilic appendages to retain high D₂ R affinity. In this review, we provide a thorough overview of the therapeutic potential of D₂ R modulators in the treatment of the aforementioned disorders. In addition, this review summarizes current knowledge about these diseases, with a focus on the dopaminergic pathway underlying these pathologies. Major attention is paid to the structure, function, and pharmacology of novel D₂ R ligands, which have been developed in the last decade (2010-2021), and belong to the 1,4-disubstituted aromatic cyclic amine group. Due to the abundance of data, allosteric D₂ R ligands and D₂ R modulators from patents are not discussed in this review.

Emerging role of psychosis in Parkinson's disease: From clinical relevance to molecular mechanisms

Parkinson’s disease (PD) is the second most common neurodegenerative disease. Psychosis is one of the common psychiatric presentations in the natural course of PD. PD psychosis is an important non-motor symptom, which is strongly correlated with a poor prognosis. Increasing attention is being given to PD psychosis. In this opinion review, we summarized and analyzed the identification, screening, epidemiology, mechanisms, risk factors, and therapeutic approaches of PD psychosis based on the current clinical evidence. PD psychosis tends to have a negative effect on patients' quality of life and increases the burden of family caregiving. Screening and identification in the early stage of disease is crucial for establishing tailored therapeutic strategies and predicting the long-term outcome. Development of PD psychosis is believed to involve a combination of exogenous and endogenous mechanisms including imbalance of neurotransmitters, structural and network changes, genetic profiles, cognitive impairment, and antiparkinsonian medications. The therapeutic strategy for PD psychosis includes reducing or ceasing the use of dopaminergic drug, antipsychotics, cholinesterase inhibitors, and non-pharmacological interventions. Ongoing clinical trials are expected to provide new insights for tailoring therapy for PD psychosis. Future research based on novel biomarkers and genetic factors may help inform individualized therapeutic strategies.

Management of Parkinson's Disease Psychosis

Objectives To discuss therapeutic management of Parkinson's disease psychosis (PDP) and the burdens associated with it. Parkinson's disease (PD) is an incurable, progressive, and devastating neurodegenerative disease. The prolonged use of dopamine agonists to improve the motor symptoms of PD may result in nonmotor complications such as psychosis. These complications are as devastating as the motor symptoms that accompany PD. PDP is associated with financial burden for patients and health care organizations. Data Sources PubMed search using the phrases Parkinson's disease, Parkinson's disease psychosis, clozapine, quetiapine, and "pimavanserin." Conclusion Pimavanserin is the only US Food and Drug Administration approved drug for the management of hallucinations and delusions associated with PD psychosis. The off-label use of clozapine and quetiapine has demonstrated clinical utility; however, there is still a need for the development of novel therapeutic molecules to avoid side effects associated with current therapeutic options and reduce the burdens of patients, caregivers, and health care institutions.

Caring for patients with cognitive dysfunction, fluctuations and dementia caused by Parkinson's disease

Cognitive dysfunction is one of the most prevalent non-motor symptoms in patients with Parkinson's disease (PD). While it tends to worsen in the later stages of disease, it can occur at any time, with 15-20% of patients exhibiting cognitive deficits at diagnosis (Aarsland et al., 2010; Goldman and Sieg, 2020). The characteristic features of cognitive dysfunction include impairment in executive function, visuospatial abilities, and attention, which vary in severity from subtle impairment to overt dementia (Martinez-Horta and Kulisevsky, 2019). To complicate matters, cognitive dysfunction is prone to fluctuate in PD patients, impacting diagnosis and the ability to assess progression and decision-making capacity. The diagnosis of cognitive impairment or dementia has a huge impact on patient independence, quality of life, life expectancy and caregiver burden (Corallo et al., 2017; Lawson et al., 2016; Leroi et al., 2012). It is therefore essential that physicians caring for patients with PD provide education, screening and treatment for this aspect of the disease. In this chapter, we provide a practical guide for the assessment and management of various degrees of cognitive dysfunction in patients with PD by approaching the disease at different stages. We address risk factors for cognitive dysfunction, prevention strategies prior to making the diagnosis, available tools for screening. Lastly, we review aspects of care, management and considerations, including decision-making capacity, that occur after the patient has been diagnosed with cognitive dysfunction or dementia.

Pimavanserin in the Treatment of Parkinson's Disease Psychosis: Meta-analysis and Meta-regression of Randomized Clinical Trials

BACKGROUND

Up to 60 percent of patients with Parkinson's disease (PD) develop Parkinson's disease psychosis (PDP). PDP is associated with a significant economic burden. The management of PDP has been divided into two approaches-one focuses on decreasing the doses of anti-Parkinsonian medications and the other involves prescribing atypical antipsychotics. Of these atypical antipsychotics, pimavanserin is United States (US) Food and Drug Administration (FDA)-approved specifically for the treatment of PDP.

OBJECTIVE

The goal was to evaluate the safety and efficacy of pimavanserin in the treatment of PDP based on data from randomized clinical trials.

METHODS

All the articles, which assessed pimavanserin's effect on the treatment of PDP, were retrieved from Google Scholar, PubMed, and abstracts from annual scientific sessions. The data on dose, therapy duration, patient numbers, and study duration were collected. These data were analyzed with random effect modeling using the inverse variance method and the Mantel-Haenszel method.

RESULTS

Four studies comparing pimavanserin to a placebo provided data on 680 patients (263 placebo, 417 pimavanserin). Treatment with pimavanserin was associated with a significant reduction in scores using the Scale of Assessment of Positive Symptoms, Hallucinations, and Delusion (SAPS-H+D) (mean difference [MD]: -1.55 [-2.71, -0.379], p=0.009). The groups had similar composite scores for Unified Parkinson's Disease Rating Scale II and III (UPDRS II and III) (MD: 0.093 [-1.28, 1.46], p=0.89). Interestingly, pimavanserin was protective against orthostatic hypotension (risk ratio: 0.33 [0.30, 0.37], p<0.001). All other adverse events were similarly distributed across both groups.

CONCLUSION

There was a significant improvement in psychosis symptoms in patients with PD who took pimavanserin. Pimavanserin was also shown to be protective against orthostatic hypotension.

Falls and Fractures in Patients with Parkinson's Disease-Related Psychosis Treated with Pimavanserin vs Atypical Antipsychotics: A Cohort Study

Background

Parkinson’s disease-related psychosis increases patients’ risk of falls. Pimavanserin is an atypical antipsychotic approved in the USA in 2016 for the treatment of hallucinations and delusions associated with Parkinson’s disease-related psychosis.

Objective

We aimed to compare the risk of falls/fractures among patients with Parkinson’s disease-related psychosis treated with pimavanserin vs other atypical antipsychotics.

Patients and Methods

We identified a cohort of patients with Parkinson’s disease-related psychosis aged ≥ 40 years initiating either pimavanserin or a comparator antipsychotic (clozapine, quetiapine, risperidone, olanzapine, aripiprazole, brexpiprazole) in US commercial insurance and supplementary Medicare claims (2015–2019). Comparators were propensity score matched 2:1 with pimavanserin initiators; incidence rates of falls/fractures were compared using incidence rate ratios (IRRs) and 95% confidence intervals (CIs).

Results

We identified 112 eligible pimavanserin initiators and 982 comparators. Pimavanserin initiators were younger and had fewer severe comorbidities, indicators of impairment, and healthcare encounters, though they had higher Parkinson’s disease medication use. The crude incidence rates [cases/100 person-years] (95% CI) for composite falls/fractures were 17.8 (7.7–35.0) for pimavanserin and 40.8 (35.0–47.4) for comparators. Matching retained 108 pimavanserin initiators and 216 comparators—all characteristics were well balanced after matching—with a matched IRR (pimavanserin vs comparator) of 0.71 (95% CI 0.27–1.67). Sensitivity analysis IRR estimates were consistently below 1.00, with a sensitivity analysis not requiring a diagnosis of psychosis resulting in an IRR estimate of 0.55 (95% CI 0.34–0.86).

Conclusions

The results of this study do not suggest an increase in the risk of falls or fractures associated with pimavanserin compared with other antipsychotics in patients with Parkinson’s disease-related psychosis. Sensitivity analyses suggest a decreased risk.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40801-021-00284-1.

Management of Visual Dysfunction in Patients with Parkinson's Disease

Parkinson’s disease (PD) is a movement disorder with many symptoms responsive to treatment with dopamine agonists, anti-cholinergics and the dopamine precursor, levodopa. The cardinal features of PD include tremor, rigidity, bradykinesia, and postural instability. There also are non-motor features that include sleep disorders, cognitive and affective dysfunction, hyposmia, pain and dysautonomia (constipation, bloating, orthostasis, urinary symptoms, sexual dysfunction, dysphagia). Among these non-motor features are signs and symptoms of visual system impairment that range from subtle examination findings to those causing severe disability. In this review we describe common PD-related abnormalities in the visual system, how they present, and potential treatments.

Efficacy and safety of clozapine in psychotic disorders-a systematic quantitative meta-review

A recent increase in the literature regarding the evidence base for clozapine has made it increasingly difficult for clinicians to judge "best evidence" for clozapine use. As such, we aimed at elucidating the state-of-the-art for clozapine with regard to efficacy, effectiveness, tolerability, and management of clozapine and clozapine-related adverse events in neuropsychiatric disorders. We conducted a systematic PRISMA-conforming quantitative meta-review of available meta-analytic evidence regarding clozapine use. Primary outcome effect sizes were extracted and transformed into relative risk ratios (RR) and standardized mean differences (SMD). The methodological quality of meta-analyses was assessed using the AMSTAR-2 checklist. Of the 112 meta-analyses included in our review, 61 (54.5%) had an overall high methodological quality according to AMSTAR-2. Clozapine appears to have superior effects on positive, negative, and overall symptoms and relapse rates in schizophrenia (treatment-resistant and non-treatment-resistant subpopulations) compared to first-generation antipsychotics (FGAs) and to pooled FGAs/second-generation antipsychotics (SGAs) in treatment-resistant schizophrenia (TRS). Despite an unfavorable metabolic and hematological adverse-event profile compared to other antipsychotics, hospitalization, mortality and all-cause discontinuation (ACD) rates of clozapine surprisingly show a pattern of superiority. Our meta-review outlines the superior overall efficacy of clozapine compared to FGAs and most other SGAs in schizophrenia and suggests beneficial efficacy outcomes in bipolar disorder and Parkinson's disease psychosis (PDP). More clinical studies and subsequent meta-analyses are needed beyond the application of clozapine in schizophrenia-spectrum disorders and future studies should be directed into multidimensional clozapine side-effect management to foster evidence and to inform future guidelines.

Potentially inappropriate prescriptions of antipsychotic and anticholinergic drugs in patients with Parkinson's disease

Aim: The objective was to determine the prevalence of the potentially inappropriate antipsychotics and anticholinergics used in patients with Parkinson's disease. Materials & methods: A cross-sectional study identified the prescription of antipsychotics, anticholinergics and drugs for the treatment of Parkinson's disease. The anticholinergic burden was evaluated, and quetiapine and clozapine were considered to be adequate antipsychotics. Results: 2965 patients with Parkinson's disease were identified. The presence of psychiatric disorders and other neurological pathologies was associated with a greater probability of receiving potentially inappropriate antipsychotic prescriptions. The presence of greater number of comorbidities was associated with a greater probability of receiving anticholinergics. Conclusion: Older age and associated comorbidities, especially psychiatric and neurological comorbidities, increase the likelihood of patients with Parkinson's disease being prescribed antipsychotics and anticholinergics.

Clozapine: Why Is It So Uniquely Effective in the Treatment of a Range of Neuropsychiatric Disorders?

Clozapine is superior to other antipsychotics as a therapy for treatment-resistant schizophrenia and schizoaffective disorder with increased risk of suicidal behavior. This drug has also been used in the off-label treatment of bipolar disorder, major depressive disorder (MDD), and Parkinson's disease (PD). Although usually reserved for severe and treatment-refractory cases, it is interesting that electroconvulsive therapy (ECT) has also been used in the treatment of these psychiatric disorders, suggesting some common or related mechanisms. A literature review on the applications of clozapine and electroconvulsive therapy (ECT) to the disorders mentioned above was undertaken, and this narrative review was prepared. Although both treatments have multiple actions, evidence to date suggests that the ability to elicit epileptiform activity and alter EEG activity, to increase neuroplasticity and elevate brain levels of neurotrophic factors, to affect imbalances in the relationship between glutamate and γ-aminobutyric acid (GABA), and to reduce inflammation through effects on neuron-glia interactions are common underlying mechanisms of these two treatments. This evidence may explain why clozapine is effective in a range of neuropsychiatric disorders. Future increased investigations into epigenetic and connectomic changes produced by clozapine and ECT should provide valuable information about these two treatments and the disorders they are used to treat.

Cardiovascular Events Associated with Antipsychotics in Newly Diagnosed Parkinson's Disease Patients: A Propensity Score Matched Cohort Study

Purpose

Observational studies have examined the association between antipsychotics and ischemic heart disease (IHD) in general populations, but results did not take into account other comorbid diseases, such as Parkinson's disease (PD). This study investigates the one-year risk of IHD, all cardiovascular events, and all-cause mortality among newly diagnosed PD patients who used antipsychotics compared to non-users.

Materials and Methods

This study included individuals aged 40 years or older with a first definitive PD diagnosis Read Code in the Secure Anonymised Information Linkage (SAIL) databank who had been initiated on any PD medication between 2000 and 2016. Antipsychotic users were matched 1:1 with non-users by a propensity score model to control the confounding effects of patients' demographics, social deprivation status, comorbidities, and medication history. Cox regression was performed to calculate the hazard ratios (HR) and 95% CIs for the association between antipsychotics and study outcomes.

Results

A total of 1837 participants were included in the analysis. Users of first-generation antipsychotics (FGA) were significantly more likely to develop IHD compared to non-users, with an HR of 2.60 (95% CI 1.103-6.167). Among the FGAs, haloperidol had the highest likelihood of IHD developing, with an HR of 3.01 (95% CI 1.038-8.729). Any use of antipsychotics, regardless of whether they were FGA or second-generation antipsychotics (SGA), was linked to all-cause mortality, with an HR of 4.201 (95% CI 3.272-5.394). When subdividing antipsychotics into FGAs and SGAs, mortality was more likely in FGA users, with an HR of 7.557 (95% CI 5.633-10.139). Mortality also occurred in SGA users, but with a lower HR of 3.278 (95% CI 2.509-4.282).

Conclusion

FGAs were associated with an increased risk of IHD and all-cause mortality in newly diagnosed PD patients with psychosis. This finding emphasizes the need to use antipsychotics with caution in PD patients with psychosis.

Spotlight on Pimavanserin Tartrate and Its Therapeutic Potential in the Treatment of Major Depressive Disorder: The Evidence to Date

Major depressive disorder (MDD) is widely prevalent and one of the leading causes of disability. Treatment outcomes remain suboptimal with 1 in 3 patients with MDD responding inadequately to commonly used antidepressants. Pimavanserin, an atypical antipsychotic that modulates serotonergic neurotransmission by selectively binding to serotonin receptor (2A and 2C) subtypes and without dopaminergic activity, may have the potential as an adjunctive treatment for MDD. In a phase 2 trial (n=203), addition of pimavanserin, as compared to placebo, to stable treatment with antidepressants was associated with greater reduction in 17-item Hamilton Depression Rating Scale score [HAMD, least square means (95% confidence interval) of -1.7 (-0.03, -3.37), p=0.039]. Furthermore, treatment with pimavanserin was associated with significantly greater improvement in specific symptoms associated with depression such as impaired sexual function, anxiety, sleepiness, and irritability. However, the availability of pimavanserin for clinical care of patients with MDD remains uncertain. Top-line results of phase 3 studies (n=298) that were announced by the sponsor found similar reductions in HAMD (mean baseline-to-week-5 reduction of 9.0 and 8.1, p=0.296) and rates of adverse events (58.1% and 54.7%) with addition of pimavanserin and placebo respectively to stable treatment with antidepressants. Given the potential benefit for specific symptoms such as impaired sexual function, anxiety and sleep/wakefulness disturbances, future studies that enrich for these symptoms may be needed to clarify the utility of adjunctive pimavanserin in treatment of patients with MDD.

Treating hallucinations in Parkinson's disease

Introduction: Hallucinations in Parkinson's disease are common, can complicate medication management and significantly impact upon the quality of life of patients and their carers.Areas covered: This review aims to examine current evidence for the management of hallucinations in Parkinson's disease.Expert opinion: Treatment of hallucinations in Parkinson's disease should be both individualized and multifaceted. Screening, education, medication review and the avoidance of common triggers are important. For well-formed visual hallucinations, acetylcholinesterase inhibitors are recommended first-line. Refractory or severe symptoms may require the cautious use of atypical antipsychotics. Antidepressants may be beneficial in the appropriate setting. Unfortunately, current therapies for hallucinations offer only limited benefits and future research efforts are desperately required to improve the management of these challenging symptoms.

Pharmacological management of dementia with Lewy bodies with a focus on zonisamide for treating parkinsonism

INTRODUCTION

Dementia with Lewy bodies (DLB) has no approved symptomatic or disease-modifying treatments in the US and Europe, despite being the second most common cause of neurodegenerative dementia.

AREAS COVERED

Herein, the authors briefly review the DLB drug development pipeline, providing a summary of the current pharmacological intervention studies. They then focus on the anticonvulsant zonisamide, a benzisoxazole derivative with a sulfonamide group and look at its value for treating parkinsonism in DLB.

EXPERT OPINION

Several new compounds are being tested in DLB, the most innovative being those aimed at decreasing brain accumulation of α-synuclein. Unfortunately, new drug testing is challenging in terms of consistent diagnostic criteria and lack of reliable biomarkers. Few randomized controlled trials (RCTs) are well-designed, with enough power to detect significant drug effects. Levodopa monotherapy can treat the parkinsonism in DLB, but it can cause agitation or visual hallucination worsening. Two Phase II/III RCTs of DLB patients recently reported a statistically significant improvement in motor function in those receiving zonisamide as an adjunctive treatment to levodopa. New biomarker strategies and validated outcome measures for DLB or prodromal DLB may enhance clinical trial design for the development of specific disease-modifying treatments.

Effect of chemogenetic actuator drugs on prefrontal cortex-dependent working memory in nonhuman primates

The most common chemogenetic neuromodulatory system, designer receptors exclusively activated by designer drugs (DREADDs), uses a non-endogenous actuator ligand to activate a modified muscarinic acetylcholine receptor that is insensitive to acetylcholine. It is crucial in studies using these systems to test the potential effects of DREADD actuators prior to any DREADD transduction, so that effects of DREADDs can be attributed to the chemogenetic system rather than the actuator drug, particularly in experiments using nonhuman primates. We investigated working memory performance after injections of three DREADD actuators, clozapine, olanzapine, and deschloroclozapine, in four male rhesus monkeys tested in a spatial delayed response task before any DREADD transduction took place. Performance at 0.1 mg/kg clozapine and 0.1 mg/kg deschloroclozapine did not differ from vehicle in any of the four subjects. 0.2 mg/kg clozapine impaired working memory function in three of the four monkeys. Two monkeys were impaired after 0.1 mg/kg olanzapine and two were impaired after 0.3 mg/kg deschloroclozapine. We speculate that the unique neuropharmacology of prefrontal cortex function makes the primate prefrontal cortex especially vulnerable to off-target effects of DREADD actuator drugs with affinity for endogenous monoaminergic receptor systems. These findings underscore the importance of within-subject controls for DREADD actuator drugs in the specific tasks under study to confirm that effects following DREADD receptor transduction are not owing to the actuator drug itself. They also suggest that off-target effects of DREADD actuators may limit translational applications of chemogenetic neuromodulation.

Effect of biological treatments on psychotic symptoms in lewy body disease: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

Parkinson disease and dementia with Lewy bodies (collectively termed Lewy body disease) are common neurodegenerative conditions of later life and are frequently associated with distressing psychotic symptoms. The best approach to manage these symptoms is yet to be established and current treatments carry the risk of serious adverse effects.

METHODS

We performed a systematic review and meta-analysis of 19 randomized controlled trials investigating the efficacy of biological treatments for psychotic symptoms in Lewy body disease.

RESULTS

The summary effect estimate did not show a statistically significant benefit of biological treatments for psychotic symptoms in Lewy body disease (SMD -0.48, 95%CI -1.01 to 0.04). This was irrespective of the choice of intervention (SMD -0.53, 95%CI -1.20 to 0.14 for antipsychotic trials) or disease status (SMD -0.59, 95%CI -1.24 to 0.05 for trials of Parkinson disease). There was a significant effect for biological treatments compared with placebo in trials that lasted at least 6 weeks (SMD -0.25, 95%CI -0.43 to -0.08) and those with sample sizes greater than 100 participants (SMD of -0.28 95%CI -0.45 to -0.11).

CONCLUSIONS

In this systematic review and meta-analysis, treatment of psychotic symptoms by biological means did not improve symptoms compared with placebo. Small sample sizes, modest treatment durations, and other methodological differences across the trials do make it difficult to draw firm conclusions. Longer, adequately powered trials utilizing established and novel treatments are needed to provide more definitive evidence to guide clinicians in the best choice of agent to treat these distressing and often persistent symptoms.

Efficacy and safety of atypical antipsychotics for psychosis in Parkinson's disease: A systematic review and Bayesian network meta-analysis

INTRODUCTION

We performed a systematic review and Bayesian network meta-analysis to clarify the relative efficacy and safety of pimavanserin compared to atypical antipsychotics for psychosis in Parkinson's disease (PD).

METHODS

PubMed, Embase, Cochrane Central Register of Controlled Trials, and Japana Centra Revuo Medicina Web were searched for relevant articles until October 31, 2019. Eligible randomized controlled trials were synthesized for efficacy (Brief Psychiatry Rating Scale [BPRS] and Clinical Global Impression Scale [CGI-S]) and safety (Unified Parkinson's Disease Rating Scale part III [UPDRS-III] and dropouts due to adverse events). The mean differences (BPRS, CGI-S, and UPDRS-III) or odds ratios (dropouts due to adverse events) between each active drug and placebo were estimated and summarized as means and 95% credible intervals, respectively.

RESULTS

We identified 17 relevant trials. Clozapine showed significant efficacy (BPRS, -5.6 [-8.4 to -2.7] and CGI-S, -1.2 [-1.7 to -0.7]), with low impact on motor functions (UPDRS-III, -1.1 [-3.8 to 1.5]), but an increase in dropouts due to adverse events (2.9 [0.9 to 9.6]) as compared to placebo. Pimavanserin also showed significant efficacy (CGI-S, -0.5 [-0.9 to -0.2]) and similar impact on motor functions (UPDRS-III, 0.2 [-1.4 to 1.9]), but a tendency of increase in dropouts due to adverse events (2.2 [0.5 to 12.4]) as compared to placebo.

CONCLUSIONS

Clozapine showed an efficacy with low impact on motor functions that was consistent with previous reports. Although the efficacy of pimavanserin may be inferior to that of clozapine, it had a favorable profile for the treatment of psychosis in PD.

Up-to-date expert opinion on the safety of recently developed antipsychotics

Introduction There are several new and emerging antipsychotic medication strategies recently marketed or under clinical development for the treatment of several mental disorders. There is the need to provide an up-to-date overview on the safety of this new generation of antipsychotic medications, which includes also the third-generation antipsychotics (TGA). Areas covered The authors aimed at providing a synthesis of the most current evidence about the safety profile of the recently developed and/or marketed antipsychotics. Qualitative synthesis followed an electronic search made inquiring of the following databases: MEDLINE, Embase, PsycINFO, and the Cochrane Library from inception until March 2020, combining free terms and MESH headings for the topics of TGA and recently developed and/or marketed antipsychotics as following: ((safety OR adverse events OR side effects) AND ((brexpiprazole OR cariprazine OR inhaled loxapine OR lumateperone (ITI-007) OR lurasidone OR pimavanserin OR roluperidone (MIN-101) OR transdermal patch asenapine)). Expert opinion Overall, newer antipsychotics display a good safety profile, with a well-demonstrated lower metabolic liability compared to second-generation antipsychotics. Furthermore, TGA appear to specifically target negative symptomatology and improving cognitive domains. Abbreviations Aps=Antipsychotic Drugs; AEs = Adverse Effects; EPS = Extrapyramidal Symptoms; NMS = Neuroleptic malignant syndrome; D = Dopamine; K_i = Inhibitory Constant; 5-HT = Serotonin; ECG = Electrocardiogram; H = Histamine; M = Muscarinic; BMI = Body Mass Index.