RE-KINECT: A Prospective Study of the Presence and Healthcare Burden of Tardive Dyskinesia in Clinical Practice Settings

Guideline concordant screening and monitoring of extrapyramidal symptoms in patients prescribed antipsychotic medication: a protocol for a systematic literature review and narrative synthesis

INTRODUCTION

Given the increasing rates of antipsychotic use in multiple psychiatric conditions, greater attention to the assessment, monitoring and documentation of their side effects is warranted. While a significant degree of attention has been provided to metabolic side effect monitoring, comparatively little is known about how clinicians screen for, document and monitor the motor side effects of antipsychotics (ie, parkinsonism, akathisia, dystonia and dyskinesias, collectively 'extrapyramidal side effects', EPS). This review aims to systematically assess the literature for insights into current trends in EPS monitoring practices within various mental health settings globally.

METHODS AND ANALYSIS

An electronic search will be performed using the OVID Medline, PubMed, Embase, CINAHL and APA PsycINFO databases for studies published in the last quarter century (1998 to present day). Two independent reviewers will conduct the initial title and abstract screenings, using predetermined criteria for inclusion and exclusion. A third reviewer will resolve disagreements if consensus cannot be reached. If selected for inclusion, full-text data extraction will then be conducted using a pilot-tested data extraction form. Quality assessment will be conducted for all included studies using a modified version of the Quality Improvement Minimum Quality Criteria Set. A narrative synthesis and summary of the data will be provided. All stages of the review process will be reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

ETHICS AND DISSEMINATION

Ethical approval is not required. Findings will be peer reviewed, published and shared verbally, electronically and in print with interested clinicians and will also be presented as posters or talks at relevant medical conferences and meetings.

PROSPERO REGISTRATION NUMBER

CRD42023482372.

Analysis of schizophrenia-associated genetic markers in the HLA region as risk factors for tardive dyskinesia

OBJECTIVES

The pathology of Tardive Dyskinesia (TD) has yet to be fully understood, but there have been proposed hypotheses for the cause of this condition. Our team previously reported a possible association of TD with the Complement Component C4 gene in the HLA region. In this study, we explored the HLA region further by examining two previously identified schizophrenia-associated HLA-region single-nucleotide polymorphisms (SNPs), namely rs13194504 and rs210133.

METHODS

The SNPs rs13194504 and rs210133 were tested for association with the occurrence and severity of TD in a sample of 172 schizophrenia patients who were recruited for four studies from three different clinical sites in Canada and USA.

RESULTS

The rs13194504 AA genotype was associated with decreased severity for TD as measured by Abnormal Involuntary Movement Scale (AIMS) scores (p = 0.047) but not for TD occurrence. SNP rs210133 was not significantly associated with either TD occurrence or AIMS scores.

CONCLUSION

Our findings suggest that the rs13194504 AA genotype may play a role in TD severity, while SNP rs210133 may not have a major role in the risk or severity of TD.

Analysis of Antipsychotic Dosage in Patients With Tardive Dyskinesia: A Case-Control Study Using the Claims Database of the Corporate Health Insurance Association

PURPOSE

This study aimed to assess the association between antipsychotic doses and the risk of tardive dyskinesia (TD) in clinical practice using a Japanese claims database from 2010 to 2020.

METHODS

The study population included patients 15 years or older with a diagnosis record of schizophrenia, depression, or bipolar disorder who were prescribed antipsychotics. Using a case-control design, we categorized patients newly diagnosed with TD as cases, with corresponding 1:10 matching in the control group. The primary endpoint was the relative risk of TD in the >median dose and ≤median dose groups, as determined using conditional logistic regression analysis adjusted for age.

RESULTS

The analysis population included 58,452 patients, and the median daily antipsychotic dose was 75 mg/d of chlorpromazine equivalent (CPZE). Of these, 80 were identified as TD cases, and doses >75 mg/d were associated with a significantly increased risk of TD at the last prescription and the maximum dose, respectively, before the date of the first diagnosis of TD. Post-hoc analysis further showed a significant association between doses ≥300 mg/d and the risk of TD compared to doses ≤75 mg/d and doses >75 to <300 mg/d. Comparing ≥300 mg/d versus >75 to <300 mg/d, the odd ratios at the last prescription and maximum dose before the first diagnosis of TD were 3.40 and 3.50, respectively.

CONCLUSIONS

In the Japanese medical claims database of patients receiving relatively low doses of antipsychotics, doses >75 mg/d were associated with an increased risk of TD in a dose-dependent manner.

Tardive dyskinesia in Asia- current clinical practice and the role of neurologists in the care pathway

Tardive dyskinesia (TD) is a movement disorder that can arise as a side effect of treatment with dopamine receptor-blocking agents (DRBAs), including antipsychotic drugs (APDs) used to manage psychotic illnesses. Second-generation APDs (SGAs) are often preferred to first-generation drugs due to their lower propensity to cause TD, however many SGAs-treated patients still develop the condition. Although TD is a global health concern, evidence regarding the occurrence of TD and how it is managed in Asian countries is currently limited. This article reports the results of a systematic review of the published literature on TD focusing on its prevalence, types of patients, knowledge of the condition, causative factors, and usual treatment pathways in clinical practice in Asian countries. Epidemiological data suggest that the prevalence of TD is increasing globally due to an overall rise in APD use, contributing factors being polypharmacy with multiple APDs, the use of higher than necessary doses, and off-label use for non-psychotic indications. Although exact prevalence figures for TD in Asian countries are difficult to define, there is a similar pattern of rising APD use which will result in increasing numbers of TD patients in this region. These issues need to be addressed and strategies developed to minimize TD risk and manage this disabling condition which impacts patients' quality of life and daily functioning. To date, both research into TD has been predominantly psychiatry focused and the perspectives from neurologists regarding the clinical management of this challenging condition are scarce. However, neurologists have an essential role in managing the movement disorders manifestations that characterize TD. Optimum management of TD, therefore, should ideally involve collaboration between psychiatrists and neurologists in joint care pathways, wherever practical. Collaborative pathways are proposed in this article, and the challenges that will need to be addressed in Asian countries to improve the care of people with TD are highlighted, with a focus on the neurologist's viewpoint and the implications for the management of TD globally.

Impact of tardive dyskinesia on patients and caregivers: a survey of caregivers in the United States

BACKGROUND

Tardive dyskinesia (TD) has a multidimensional impact on patients with TD and, as importantly, their caregivers. An online survey was developed and administered to assess patient and caregiver burden of TD. Survey participants were unpaid caregivers for patients with diagnoses of TD and schizophrenia, bipolar disorder, and/or major depressive disorder. Overall, 162 caregivers rated the 7-day impact of TD on the physical, psychological, and social functioning of patients and the impact of TD on these domains in their own lives and in their professional lives.

RESULTS

Across physical, psychological, and social domains, most caregivers (82.7%) reported that TD had severe impact on the cared-for patients, and 23.5% reported severe impact of TD in their own lives. Caregivers experienced 46.4% activity impairment, and caregivers who were employed (n = 136) experienced 49.5% overall work impairment because of TD-related caregiving.

CONCLUSIONS

These results suggest that TD imposes substantial burden for both caregivers and patients.

Exploring real-world symptom impact and improvement in well-being domains for tardive dyskinesia in VMAT2 inhibitor-treated patients via clinician survey and chart review

Introduction

Two vesicular monoamine transporter 2 (VMAT2) inhibitors are approved in the United States (US) for the treatment of tardive dyskinesia (TD). There is a paucity of information on the impact of VMAT2 inhibitor treatment on patient social and physical well-being. The study objective was to elucidate clinician-reported improvement in symptoms and any noticeable changes in social or physical well-being in patients receiving VMAT2 inhibitors.

Methods

A web-based survey was offered to physicians, nurse practitioners, and physician assistants based in the US who prescribed valbenazine for TD within the past 24 months. Clinicians reported data from the charts of patients who met the inclusion criteria and were allowed to recall missing information.

Results

Respondents included 163 clinicians who reviewed charts of 601 VMAT2-treated patients with TD: 47% had TD symptoms in ≥2 body regions, with the most common being in the head or face and upper extremities. Prior to treatment, 93% of patients showed impairment in ≥1 social domain, and 88% were impaired in ≥1 physical domain. Following treatment, among those with improvement in TD symptoms (n = 540), 80% to 95% showed improvement in social domains, 90% to 95% showed improvement in physical domains, and 73% showed improvement in their primary psychiatric condition.

Discussion

In VMAT2-treated patients with TD symptom improvement, clinicians reported concomitant improvement in psychiatric disorder symptoms and in social and physical well-being. Regular assessment of TD impact on these types of domains should occur simultaneously with movement disorder ratings when evaluating the value of VMAT2 inhibitor therapy.

The Outcome of Antipsychotics-induced Tardive Syndromes: A Ten-year Follow-up Study

Objective

Tardive syndrome (TS) is an umbrella term used to describe a group of abnormal movement disorders caused by chronic exposure to dopamine receptor blocking agents. Few follow-up studies have been performed on the outcome of TS in patients using antipsychotics. The purpose of our study was to investigate the prevalence, incidence, remission rate, and factors associated with remission in patients using antipsychotics.

Methods

This retrospective cohort study consisted of 123 patients who received continuous treatment of antipsychotics in a medical center in Taiwan, from April 1, 2011 to May 31, 2021. We assessed the demographic and clinical characteristics, prevalence, incidence, remission rate, and factors associated with remission in patients using antipsychotics. TS remission was defined as a Visual Analogue Scale score ≤ 3.

Results

Of the 92 patients who completed the 10-year follow-up, 39 (42.4%) were found to have at least one episode of TS, with tardive dyskinesia (TD) being the most prevalent subtype (51.3%). With regard to concurrent physical illness, a history of extrapyramidal symptoms were significant risk factors for TS. During the 10-year follow-up period, the remission rate of TS was 74.3%. The use of antioxidants including vitamin B6 and piracetam was related to the remission of TS. Patients with tardive dystonia had a higher remission rate (87.5%) compared to TD (70%).

Conclusion

Our study suggests that TS may be a treatable condition, and the key to a better outcome is early detection and prompt intervention, including closely monitoring antipsychotics-related TS symptoms and using antioxidants.

A new era in the diagnosis and treatment of tardive dyskinesia

Tardive dyskinesia (TD) is a heterogeneous, hyperkinetic movement disorder induced by dopamine-receptor blocking agents that presents a unique challenge in the treatment of psychosis. Although acceptance of TD as a serious consequence of antipsychotic treatment was resisted initially, subsequent research by many investigators in psychopharmacology contributed to a rich store of knowledge on many aspects of the disorder. While basic neuroscience investigations continue to deepen our understanding of underlying motor circuitry, past trials of potential treatments of TD focusing on a range of theoretical targets were often inconclusive. Development of newer antipsychotics promised to reduce the risk of TD compared to older drugs, but their improved tolerability unexpectedly enabled an expanding market that paradoxically both increased the absolute number of patients at risk and diminished attention to TD which was relegated to legacy status. Fortunately, development and approval of novel vesicular monoamine transporter inhibitors offered evidence-based symptomatic treatment of TD for the first time and rekindled interest in the disorder. Despite recent progress, many questions remain for future research including the mechanisms underlying TD, genetic predisposition, phenomenological diversity, whether new cases are reversible, how to implement best practices to prevent and treat TD, and whether the development of novel antipsychotics free of the risk of TD is attainable. We owe our patients the aspirational goal of striving for zero prevalence of persistent symptoms of TD in anyone treated for psychosis.

Historical developments, hotspots, and trends in tardive dyskinesia research: a scientometric analysis of 54 years of publications

Background

Since being recognized as an important drug-induced clinical entity during the 1960s, tardive dyskinesia (TD) has generated an extensive body of research seeking to understand its clinical characteristics, epidemiology, pathophysiology and management. Modern scientometric approaches allow interactive visualization of large bodies of literature to identify trends and hotspots within knowledge domains. This study thus aimed to provide a comprehensive scientometric review of the TD literature.

Methods

Web of Science was searched for articles, reviews, editorials and letters with the term "tardive dyskinesia" in the title, abstract, or keywords through 12/31/2021. A total of 5,228 publications and 182,052 citations were included. Annual research output, prominent research areas, authors, affiliations and countries were summarized. VOSViewer and CiteSpace were used for bibliometric mapping and co-citation analysis. Structural and temporal metrics were used to identify key publications in the network.

Results

TD-related publications peaked in the 1990s, gradually declined after 2004, and showed a further small increase after 2015. The most prolific authors were Kane JM, Lieberman JA, and Jeste DV overall (1968-2021), and Zhang XY, Correll CU and Remington G in the last decade (2012-2021). The most prolific journal was the Journal of Clinical Psychiatry overall, and the Journal of Psychopharmacology in the last decade. Knowledge clusters in the 1960-1970s dealt with clinical and pharmacological characterization of TD. In the 1980s, epidemiology, clinical TD assessment, cognitive dysfunction and animal models predominated. During the 1990s, research diverged into pathophysiological studies, especially oxidative stress, and clinical trials on atypical antipsychotics, with a focus on clozapine and bipolar disorder. In the 1990-2000s, pharmacogenetics emerged. More recent clusters include serotonergic receptors, dopamine-supersensitivity psychosis, primary motor abnormalities of schizophrenia, epidemiology/meta-analyses, and advances in TD treatment, particularly vesicular monoamine transporter-2 inhibitors since 2017.

Conclusion

This scientometric review visualized the evolution of scientific knowledge on TD over more than five decades. These findings will be useful for researchers to find relevant literature when writing scientific articles, choosing appropriate journals, finding collaborators or mentors for research, and to understand the historical developments and emerging trends in TD research.

Impact of possible tardive dyskinesia on physical wellness and social functioning: results from the real-world RE-KINECT study

BACKGROUND

Tardive dyskinesia (TD) is a persistent and potentially disabling movement disorder associated with antipsychotic use. Data from RE-KINECT, a real-world study of antipsychotic-treated outpatients, were analyzed to assess the effects of possible TD on patient health and social functioning.

METHODS

Analyses were conducted in Cohort 1 (patients with no abnormal involuntary movements) and Cohort 2 (patients with possible TD per clinician judgment). Assessments included: EuroQoL's EQ-5D-5L utility (health); Sheehan Disability Scale (SDS) total score (social functioning); patient- and clinician-rated severity of possible TD ("none", "some", "a lot"); and patient-rated impact of possible TD ("none", "some", "a lot"). Regression models were used to analyze the following: associations between higher (worse) severity/impact scores and lower (worse) EQ-5D-5L utility (indicated by negative regression coefficients); and associations between higher (worse) severity/impact scores and higher (worse) SDS total score (indicated by positive regression coefficients).

RESULTS

In Cohort 2 patients who were aware of their abnormal movements, patient-rated TD impact was highly and significantly associated with EQ-5D-5L utility (regression coefficient: - 0.023, P < 0.001) and SDS total score (1.027, P < 0.001). Patient-rated severity was also significantly associated with EQ-5D-5L utility (- 0.028, P < 0.05). Clinician-rated severity was moderately associated with both EQ-5D-5L and SDS, but these associations were not statistically significant.

CONCLUSIONS

Patients were consistent in evaluating the impacts of possible TD on their lives, whether based on subjective ratings ("none", "some", "a lot") or standardized instruments (EQ-5D-5L, SDS). Clinician-rated severity of TD may not always correlate with patient perceptions of the significance of TD.

Defining utility values for patients with tardive dyskinesia

OBJECTIVE

To measure health state preferences and estimate utility values for tardive dyskinesia (TD) from the perspective of the US general population, accounting for factors affecting quality of life (QOL).

METHODS

Participants from the general population were recruited and asked to watch and assess videos of professional actors simulating nine health states, including psychiatric disorders with/without TD and moderate-to-severe TD without any underlying disease. Time tradeoff (TTO) methods were used to elicit utility values, which ranged from -1 (worse than death) to +1 (perfect health) and represented individual preferences for avoiding specific health states associated with TD. Lower TTO utility values indicated individuals' willingness to give up more years of life to avoid living in each health state.

RESULTS

Based on TTO responses (n = 157), mean ± standard deviation utility for TD alone was 0.59 ± 0.38. Mean utilities for schizophrenia with negative symptoms (without TD: 0.43; with TD: 0.29) and positive symptoms (without TD: 0.44; with TD: 0.30) were generally lower than those for bipolar disorder (without TD: 0.59; with TD: 0.46) and major depressive disorder (without TD: 0.60; with TD: 0.44). According to utility decrements associated with TD (0.13-0.16), respondents were willing to give up 1.3 to 1.6 years during a 10-year lifespan to avoid living with TD.

CONCLUSIONS

Utility decrements for TD in this study were slightly larger than previously reported values, potentially due to incorporation of QOL and social consequences in TD health state descriptions. An important limitation of this analysis is that participants' willingness to trade future years of healthy life may not indicate actual willingness to accept the life decrement. These findings can be leveraged to improve cost-effectiveness analyses used to assess the value of treatments for TD.

VMAT2 Inhibitors for the Treatment of Tardive Dyskinesia

Psychiatric nurses are at the forefront of optimizing psychiatric care, including educating patients and caregivers on the risks of antipsychotic-induced movement disorders such as tardive dyskinesia (TD). Nurses should be aware that all patients taking antipsychotics should be regularly monitored for the development of TD. Given the current pandemic and increase in telehealth, assessing for TD is challenging; however, evaluation can be successfully completed by implementing the best practices described in this paper. Once TD is diagnosed, nurses can reassure patients that safe and effective FDA-approved treatments for TD (e.g., valbenazine) are now available.

Current perspectives on the epidemiology and burden of tardive dyskinesia: a focused review of the clinical situation in Japan

Tardive dyskinesia (TD) is a movement disorder that can develop with the use of dopamine receptor-blocking agents and is most commonly caused by antipsychotics. The use of antipsychotics is expanding, which may lead to an increased number of patients experiencing TD. To summarise the current knowledge of the epidemiology and risk factors for TD in Japan, we reviewed articles related to the current state of knowledge around TD identified through a PubMed search, and held a roundtable discussion of experts in Japan on 9 September 2021 to form the basis of the opinion presented within this review. The true prevalence of TD among patients treated with antipsychotics is not well characterised; it is reported to be between 15% and 50% globally and between 6.5% and 7.7% in Japan. Potential barriers to timely treatment of TD include the stigma surrounding mental health issues and the lack of data regarding TD in Asian patients. This review summarises the current knowledge of the epidemiology, challenges to TD diagnosis and risk factors for TD in Japan. Recent strategies for symptom monitoring and early diagnosis, as well as consensus recommendations are included. Achieving a high level of awareness of TD among physicians who treat patients with psychiatric disorders is of great importance and physicians should ensure that patients with psychiatric disorders receiving antipsychotics are proactively monitored for signs of TD.

PLAIN LANGUAGE SUMMARY

Plain Language Summary (In Japanese).

VISUAL SUMMARY

Visual Summary (In Japanese).

The Clinical and Economic Burden of Tardive Dyskinesia in Israel: Real-World Data Analysis

PURPOSE/BACKGROUND

Tardive dyskinesia (TD) is a hyperkinetic movement disorder caused by exposure to dopamine-receptor blockers. Data on TD burden in Israel are scarce. This analysis assesses the clinical and economic burden of TD in Israeli patients.

METHODS/PROCEDURES

This retrospective analysis used a national health plan database (Maccabi Healthcare Services), representing 25% of the Israeli population. The study included adults alive at index date with an International Classification of Diseases, Ninth Revision, Clinical Modification TD diagnosis before 2018 and more than or equal to 1-year enrollment before diagnosis. Tardive dyskinesia patients were matched to non-TD patients (1:3) by underlying psychiatric condition, birth year, and sex. Treatment patterns and 2018 annual health care resource utilization and costs were assessed.

FINDINGS/RESULTS

Of 454 TD patients alive between 2013 and 2018, 333 alive on January 1, 2018, were matched to 999 non-TD patients. At baseline, TD patients had lower socioeconomic status and higher proportion of chronic kidney disease and antipsychotic medication use; all analyses were adjusted accordingly. Tardive dyskinesia patients had significantly more visits to general physicians, neurologists, psychiatrists, physiotherapists, and emergency departments versus non-TD patients (all P < 0.05). Tardive dyskinesia patients also had significantly longer hospital stays than non-TD patients ( P = 0.003). Total healthcare and medication costs per patient were significantly higher in the TD versus non-TD population (US $11,079 vs US $7145, P = 0.018).

IMPLICATIONS/CONCLUSIONS

Israeli TD patients have higher clinical and economic burden than non-TD patients. Understanding real-world health care resource utilization and costs allows clinicians and decision makers to quantify TD burden and prioritize resources for TD patients' treatment.

Assessment of the Impact of Tardive Dyskinesia in Clinical Practice: Consensus Panel Recommendations

PURPOSE

Tardive dyskinesia (TD) is a hyperkinetic movement disorder in which patients experience abnormal involuntary movements that can have profound negative impacts on physical, cognitive, and psychosocial functioning. Use of measures to assess the functional impact of TD in routine clinical practice is lacking. To address this gap, an advisory panel of experts in psychiatry and movement disorder neurology was convened to develop consensus recommendations on assessment of the impact of TD on patients' functioning that can be used in clinical practice.

METHODS

An advisory panel provided recommendations using an iterative process, beginning with a narrative literature review regarding current practices for assessing the impact of TD in clinical settings. A detailed summary was generated, and the advisory panel provided comments about the content and answered questions about assessing TD impact in clinical practice. The panelists' responses were discussed during a virtual meeting held on August 28, 2020. A second meeting on September 25, 2020, focused on developing and refining recommendations for assessment of the impact of TD in clinical practice. At the conclusion of the second meeting, general consensus was reached on all recommendation statements.

RESULTS

As part of routine clinical practice, it is imperative to assess the impact of TD on the patient's life to help guide treatment decisions. Key domains for assessing the overall impact of TD include social, physical, vocational, and psychological functioning and the impact of TD on the underlying psychiatric disorder. Assessment of TD impact should be performed at every patient visit. Impact assessments should include consultation with patients, caregivers, and family members. Shared decision-making to initiate TD treatment should consider impact.

CONCLUSION

The impact of TD should be assessed routinely, including the key domains of social, physical, vocational, and psychological functioning and the impact of TD on the underlying psychiatric disorder.

Patient perspective of tardive dyskinesia: results from a social media listening study

BACKGROUND

Tardive dyskinesia (TD) is a persistent and potentially disabling movement disorder associated with prolonged exposure to dopamine receptor blocking agents such as antipsychotics. With the expanding use of antipsychotics, research is needed to better understand patient perspectives of TD, which clinical assessments may fail to capture. Social media listening (SML), which is recognized by the US FDA as a method that can advance ongoing efforts for more patient-focused drug development, has been used to understand patient experiences in other disease states. This is the first study to use SML analysis of unsolicited patient and caregiver insights to help clinicians understand how patients describe their symptoms, the emotional distress associated with TD, and the impact on caregivers.

METHODS

In this pilot study, a comprehensive search was performed for publicly available, English-language, online content posted between March 2017 and November 2019 on social media platforms, blogs, and forums. An analytics platform (NetBase™) identified posts containing patient or caregiver experiences of assumed TD using predefined search terms. All posts were manually curated and reviewed to ensure quality and validity of the post and to further classify key symptoms, sentiments, and themes.

RESULTS

A total of 261 posts from patients/caregivers ("patient insights") were identified using predefined search terms; 107 posts were used for these analyses. Posts were primarily from forums (47%) and Twitter (33%). Analysis of the most common sentiment-related terms (e.g. "feel" [n = 31], "worse" [n = 17], "symptom" [n = 14], "better" [n = 12]) indicated that 64% were negative, 33% were neutral, and 3% were positive. Theme analysis revealed that patients often felt angry about having TD from a medication used to treat a different condition. In addition, patients felt insecure, including feeling unaccepted by society and fear of being judged by others.

CONCLUSION

Although this study was limited by inherent methodological constraints (e.g., small sample size, reliance on patient self-report), the perspectives generated from analyzing social media may help convey the unmet needs of patients with TD. This analysis indicated that movement-related symptoms are the most common patient concern, resulting in strong feelings of anger and insecurity.

Tardive Dyskinesia in Older Persons Taking Antipsychotics

Tardive dyskinesia (TD) is a hyperkinetic movement disorder caused by the use of dopamine receptor-blocking agents (DRBAs), a category of medications that includes first- and second-generation antipsychotics (APs) and agents such as metoclopramide that are used for the treatment of nausea and gastrointestinal dysmotility. While TD can affect people of all ages, older age is associated with increased risk of TD and also with the emergence of TD occurring after shorter treatment durations and lower dosages of DRBAs. TD is characterized by involuntary movements that include the face, limbs, and trunk, and is associated with increased comorbidities, social stigmatization, and impaired physical and mental health. Once present, TD tends to persist despite AP dose adjustment or discontinuation. Even with the use of US Food and Drug Administration (FDA)-approved medications for TD, symptoms may persist. Because the leading hypothesis for the pathophysiology of TD has been dysregulation of dopamine transmission due to treatment with DRBAs, APs that avoid postsynaptic dopamine receptor blockade may provide an alternative therapeutic approach for patients who require an AP. In this review, we discuss the risks, burdens, prevention, and management of TD, with a focus on older people.

Cost-effectiveness of valbenazine compared with deutetrabenazine for the treatment of tardive dyskinesia

AIMS

To evaluate clinical and economic outcomes associated with valbenazine compared with deutetrabenazine in patients with tardive dyskinesia (TD) using a model that accounts for multiple dimensions of patient health status.

MATERIALS AND METHODS

A discretely integrated condition event model was developed to evaluate the cost-effectiveness of treatment with valbenazine and deutetrabenazine in a synthetic cohort of 1,000 patients with TD who were receiving antipsychotic medication to treat an underlying psychiatric disorder. Clinical inputs were derived from relevant clinical trials or from publicly available sources. Patients were assessed over 1 year using ≥50% improvement from baseline in Abnormal Involuntary Movement Scale (AIMS) total score as the primary definition of response. Response at 1 year using Clinical Global Impression of Change (CGIC) score ≤2 was also assessed. Health outcomes included quality-adjusted life years (QALYs), life years, proportion responding to treatment at 1 year, and number of psychiatric relapses.

RESULTS

Regardless of the definition used for response, patients treated with valbenazine were more likely to have responded to treatment at 1 year, lived longer, and accrued more QALYs than patients who received deutetrabenazine. Using the AIMS response criterion, the incremental cost-effectiveness ratio was $9,951/QALY for valbenazine compared with deutetrabenazine. By comparison, using the CGIC response criterion valbenazine dominated deutetrabenazine with valbenazine-treated patients accumulating more QALYs (3.4 vs 3.3 years) and incurring lower lifetime costs ($252,311 vs $283,208) than deutetrabenazine-treated patients.

LIMITATIONS

There are no head-to-head trials of valbenazine and deutetrabenazine, so probabilities of response used in the model were calculated based on an indirect treatment comparison of results from individual trials with one drug or the other, using only those metrics reported across trials.

CONCLUSIONS

In patients with TD, treatment with valbenazine is highly cost-effective compared with deutetrabenazine.

Recent Advances in the Pharmacology of Tardive Dyskinesia

Tardive dyskinesia (TD) is a syndrome of abnormal involuntary movements that follows treatment with dopamine D2-receptor antagonists. Recent approval of vesicular monoamine transporter-2 (VMAT2) inhibitors offers hope for reducing the impact of TD. Although these drugs represent a significant advance in patient care and a practical step forward in providing relief for patients with TD, understanding of the pharmacology of TD that could inform future research to prevent and reverse TD remains incomplete. This review surveys evidence for the effectiveness of VMAT2 inhibitors and other agents in the context of theories of pathogenesis of TD. In patients for whom VMAT2 inhibitors are ineffective or intolerable, as well as for extending therapeutic options and insights regarding underlying mechanisms, a review of clinical trial results examined as experimental tests of etiologic hypotheses is worthwhile. There are still compelling reasons for further investigations of the pharmacology of TD, which could generate alternative preventive and potentially curative treatments. Finally, benefits from novel drugs are best realized within an overall treatment strategy addressing the condition and needs of individual patients.

Deutetrabenazine for treatment of involuntary movements in patients with tardive dyskinesia

Introduction: Tardive dyskinesia (TD) is a hyperkinetic movement disorder that arises as a complication of exposure to dopamine receptor blocking agents. Vesicular monoamine transporter type 2 (VMAT2) inhibitors reduce dyskinesia by decreasing transport of monoamines, including dopamine, into presynaptic vesicles, leaving unpackaged dopamine to be metabolized by monoamine oxidase. Deutetrabenazine was adapted from an earlier VMAT2 inhibitor, tetrabenazine, by substituting three deuterium isotopes in place of three hydrogen isotopes at the site of metabolic degradation to improve upon the pharmacokinetics of the parent compound. Areas covered: The authors reviewed the pivotal trials examining the safety and efficacy of deutetrabenazine, as well as long-term data from an open-label extension. Also reviewed were posters and oral presentations, as well as information from the product label and the United States Food and Drug Administration. Expert opinion: Deutetrabenazine is effective at decreasing dyskinesia in TD, but drug selection and cost-effectiveness between existing VMAT2 inhibitors are evolving areas of study. Other areas of investigation include novel anti-dyskinetic agents and use of deep brain stimulation.

A Focused Update on Tardive Dyskinesia

Tardive dyskinesia (TD) is a delayed and potentially irreversible motor complication following chronic exposure to centrally acting dopamine receptor antagonists, mainly of the class of antipsychotics drugs. New generations of antipsychotic drugs reduced its mean prevalence to 20%, but it continues to mar the drug experience and social integration in a significant fraction of patients. The underlying molecular cascade remains elusive, explaining in part why TD management is so often difficult. Protocol variations between experimental laboratories and inter-species differences in the biological response to antipsychotic drugs have added layers of complexity. The traditional dopamine D2 receptor supersensitivity hypothesis was revisited in an experimental nonhuman primate model. Findings in the striatum revealed a strong upregulation of D3, not D2, receptors specific to dyskinetic animals, and indirect evidence suggestive of a link between overactivation of glycogen synthase kinase-3β signaling and TD. New effective vesicular monoamine transporter type 2 inhibitors alleviating TD have been approved in the USA. They were integrated to an emerging stepwise treatment algorithm for troublesome TD, which also includes consideration for changes in the current antipsychotic drug regimen and recognition of potentially aggravating factors such as anticholinergic co-medications. These advances may benefit TD.