Tardive Syndromes are Rarely Reversible after Discontinuing Dopamine Receptor Blocking Agents: Experience from a University-based Movement Disorder Clinic

Outcome of Drug-Induced Parkinsonism in the Elderly: A Permanent Nonprogressive Parkinsonian Syndrome May Occur Following Discontinuation of Cinnarizine and Flunarizine

Parkinsonism induced by dopamine receptor antagonists, traditionally considered completely reversible following offending drug withdrawal, may unmask a degenerative parkinsonism in the patients with an underlying subclinical disease. In elderly patients, parkinsonism induced by the calcium channel blockers such as piperazine derivates cinnarizine and flunarizine may persist following drug discontinuation resulting in a permanent nonprogressive syndrome fulfilling the criteria for tardive parkinsonism. Whether this outcome occurs also following exposure to dopamine receptor antagonists such as neuroleptics and benzamide derivates or represents a class effect of the voltage-gated L-type calcium channel blockers, such as cinnarizine and flunarizine, due to their complex pharmacodynamic properties remains to be established.

Tardive Dyskinesia with Antipsychotic Medication in Children and Adolescents: A Systematic Literature Review

BACKGROUND

Tardive dyskinesia (TD) is a persisting, and potentially irreversible, movement disorder associated with treatment with dopamine receptor antagonists. Few data are available on the risk of TD in children and adolescents treated with antipsychotic medication.

OBJECTIVE

To review the literature on incidence, risk factors, and treatment options for antipsychotic-associated TD in children and adolescents (aged < 18 years).

METHODS

Relevant articles were identified through a systematic search of Embase and Medline performed in January 2024. Methodological quality was assessed using the Newcastle-Ottawa Scale and Joanna Briggs Institute Critical Appraisal tools.

RESULTS

Thirteen studies were identified. The reported TD point prevalence was 5-20%, with higher rates in studies involving typical antipsychotics. Lower estimates (around 1%) emerged from analyses of clinical database data suggesting underdiagnosis in clinical practice. Risk factors included treatment with typical antipsychotics, higher doses, longer duration of exposure, older age, female gender, higher baseline Abnormal Involuntary Movements Scale (AIMS) scores, intellectual impairment, and perinatal complications.

CONCLUSION

Although relatively few cases have been reported in children and adolescents, TD remains a risk in this population. Individuals receiving antipsychotics should be monitored carefully for the emergence of abnormal movements. Other than dose reduction, discontinuation, or switch to a lower-risk antipsychotic, few interventions have demonstrated efficacy. The strongest evidence for pharmacological treatment is for VMAT-2 inhibitors (valbenazine and deutetrabenazine), but these drugs are not licensed for use in children. To reduce risk, antipsychotics should be prescribed only if necessary, at the minimum effective dose and for the minimum necessary duration.

Symptomatic Treatment of Extrapyramidal Hyperkinetic Movement Disorders

Extrapyramidal hyperkinetic movement disorders comprise a broad range of phenotypic phenomena, including chorea, dystonia, and tics. Treatment is generally challenging and individualized, given the overlapping phenomenology, limited evidence regarding efficacy, and concerns regarding the tolerability and safety of most treatments. Over the past decade, the treatment has become even more intricate due to advancements in the field of deep brain stimulation as well as optimized dopamine- depleting agents. Here, we review the current evidence for treatment modalities of extrapyramidal hyperkinetic movement disorders and provide a comprehensive and practical overview to aid the choice of therapy. Mechanism of action and practical intricacies of each treatment modality are discussed, focusing on dosing and adverse effect management. Finally, future therapeutic developments are also discussed.

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.

[Tardive dyskinesia]

Tardive dyskinesia (TD) is a delayed, often irreversible iatrogenic movement disorder caused by long-term use of that dopamine receptors blocking drugs. Prevention of TD is paramount, and clinicians should follow best practice recommendations for prescribing antipsychotics, as well as reduction the using of dopamine receptor blocking drugs for non-psychiatric prescriptions. Replacement of antipsychotics with lower affinity for D2 receptors drugs, addition of VMAT2 (tetrabenazine), botulinum therapy, amantadine may be effective. In detection and incurable cases, the possibility of neuromodulation of brain structures should be considered. Most methods for testing TD currently have an insufficient level of evidence, although they include recommendations from professional communities. There is a great need for new clinical trials.

Pathophysiology, prognosis and treatment of tardive dyskinesia

Tardive dyskinesia (TD), a movement disorder associated with antipsychotics, most frequently affects the lower face and jaw muscles, but can also affect walking, breathing and use of the hands and limbs. Knowledge of TD among physicians may be limited, and the pathophysiology of TD is poorly understood. We conducted this review to summarise the current knowledge surrounding the pathophysiology of TD and present recommendations for prevention and treatment based on a literature search and roundtable discussion attended by psychiatrists in Japan. It has been suggested that dopamine hypersensitivity, damaged gamma-aminobutyric acidergic neurons and/or increased production of reactive oxygen species may contribute to development of TD. Symptoms can profoundly affect everyday life; patients who develop TD have poorer prognoses, worse health-related quality of life, greater social withdrawal and higher mortality than patients without TD. Traditional treatment options include dietary supplements, although evidence for their effectiveness is low. Among pharmaceutical interventions, there is moderate evidence that switching to the second-generation antipsychotic clozapine, which has a lower affinity for dopamine D2 receptors than other antipsychotics, may improve symptoms. Vesicular monoamine transporter 2 (VMAT-2) inhibitors, which oppose the increased dopaminergic activity associated with prolonged antipsychotic use by interfering with dopamine uptake and storage, have the strongest evidence for efficacy. VMAT-2 inhibitors are approved in the United States for the treatment of TD, and the first VMAT-2 inhibitor was approved in Japan for this indication in March 2022. Most guidelines recommend treating TD by first reducing the dose of antipsychotics or switching to clozapine or other second-generation antipsychotics, which have a lower association with TD than first-generation antipsychotics. We recommend focusing on prevention and monitoring for TD when prescribing antipsychotics, given that TD is often irreversible. Physicians should treat with antipsychotics only when necessary and at the lowest effective dose, and frequently monitor for TD symptoms.

Plain Language Summary

Plain Language Summary (In Japanese).

Visual Summary

Visual Summary (In Japanese).

Treatable Hyperkinetic Movement Disorders Not to Be Missed

Hyperkinetic movement disorders are characterized by the presence of abnormal involuntary movements, comprising most notably dystonia, chorea, myoclonus, and tremor. Possible causes are numerous, including autoimmune disorders, infections of the central nervous system, metabolic disturbances, genetic diseases, drug-related causes and functional disorders, making the diagnostic process difficult for clinicians. Some diagnoses may be delayed without serious consequences, but diagnosis delays may prove detrimental in treatable disorders, ranging from functional disabilities, as in dopa-responsive dystonia, to death, as in Whipple's disease. In this review, we focus on treatable disorders that may present with prominent hyperkinetic movement disorders.

A Method for Tapering Antipsychotic Treatment That May Minimize the Risk of Relapse

The process of stopping antipsychotics may be causally related to relapse, potentially linked to neuroadaptations that persist after cessation, including dopaminergic hypersensitivity. Therefore, the risk of relapse on cessation of antipsychotics may be minimized by more gradual tapering. There is converging evidence that suggests that adaptations to antipsychotic exposure can persist for months or years after stopping the medication-from animal studies, observation of tardive dyskinesia in patients, and the clustering of relapses in this time period after the cessation of antipsychotics. Furthermore, PET imaging demonstrates a hyperbolic relationship between doses of antipsychotic and D2 receptor blockade. We, therefore, suggest that when antipsychotics are reduced, it should be done gradually (over months or years) and in a hyperbolic manner (to reduce D2 blockade "evenly"): ie, reducing by one quarter (or one half) of the most recent dose of antipsychotic, equivalent approximately to a reduction of 5 (or 10) percentage points of its D2 blockade, sequentially (so that reductions become smaller and smaller in size as total dose decreases), at intervals of 3-6 months, titrated to individual tolerance. Some patients may prefer to taper at 10% or less of their most recent dose each month. This process might allow underlying adaptations time to resolve, possibly reducing the risk of relapse on discontinuation. Final doses before complete cessation may need to be as small as 1/40th a therapeutic dose to prevent a large decrease in D2 blockade when stopped. This proposal should be tested in randomized controlled trials.

A Comprehensive Review of Tic Disorders in Children

Tics are characterized by sudden, rapid, recurrent, nonrhythmic movement or vocalization, and are the most common movement disorders in children. Their onset is usually in childhood and tics often will diminish within one year. However, some of the tics can persist and cause various problems such as social embarrassment, physical discomfort, or emotional impairments, which could interfere with daily activities and school performance. Furthermore, tic disorders are frequently associated with comorbid neuropsychiatric symptoms, which can become more problematic than tic symptoms. Unfortunately, misunderstanding and misconceptions of tic disorders still exist among the general population. Understanding tic disorders and their comorbidities is important to deliver appropriate care to patients with tics. Several studies have been conducted to elucidate the clinical course, epidemiology, and pathophysiology of tics, but they are still not well understood. This article aims to provide an overview about tics and tic disorders, and recent findings on tic disorders including history, definition, diagnosis, epidemiology, etiology, diagnostic approach, comorbidities, treatment and management, and differential diagnosis.

Meta-analysis of probability estimates of worldwide variation of CYP2D6 and CYP2C19

Extensive migration has led to the necessity of knowledge regarding the treatment of migrants with different ethnical backgrounds. This is especially relevant for pharmacological treatment, because of the significant variation between migrant groups in their capacity to metabolize drugs. For psychiatric medications, CYP2D6 and CYP2C19 enzymes are clinically relevant. The aim of this meta-analysis was to analyze studies reporting clinically useful information regarding CYP2D6 and CYP2C19 genotype frequencies, across populations and ethnic groups worldwide. To that end, we conducted a comprehensive meta-analysis using Embase, PubMed, Web of Science, and PsycINFO (>336,000 subjects, 318 reports). A non-normal metabolizer (non-NM) probability estimate was introduced as the equivalent of the sum-prevalence of predicted poor, intermediate, and ultrarapid metabolizer CYP2D6 and CYP2C19 phenotypes. The probability of having a CYP2D6 non-NM predicted phenotype was highest in Algeria (61%) and lowest in Gambia (2.7%) while the probability for CYP2C19 was highest in India (80%) and lowest in countries in the Americas, particularly Mexico (32%). The mean total probability estimates of having a non-NM predicted phenotype worldwide were 36.4% and 61.9% for CYP2D6 and CYP2C19, respectively. We provide detailed tables and world maps summarizing clinically relevant data regarding the prevalence of CYP2D6 and CYP2C19 predicted phenotypes and demonstrating large inter-ethnic differences. Based on the documented probability estimates, pre-emptive pharmacogenetic testing is encouraged for every patient who will undergo therapy with a drug(s) that is metabolized by CYP2D6 and/or CYP2C19 pathways and should be considered in case of treatment resistance or serious side effects.

Tardive Dyskinesia: Spotlight on Current Approaches to Treatment

Tardive dyskinesia (TD) is a debilitating, iatrogenic, and potentially severe movement disorder characterized by involuntary, repetitive, purposeless movements that are present throughout the body. The authors present a review of studies of past, current, and possible future treatment approaches to the management of TD; consider the phenomenology, assessment, and putative pathophysiological mechanisms of TD, early pharmacological trials, a focus on the newer vesicular monoamine transporter 2 inhibitors, and other evidence-based approaches, such as clozapine; and present preliminary evidence for newer approaches, such as deep brain stimulation and repetitive transcranial magnetic stimulation. On the basis of the evidence presented here, the authors highlight the importance of early recognition and assessment of TD, as well as how to best approach management of these often incapacitating symptoms.

Recognition and Treatment of Tardive Dyskinesia in Individuals with Intellectual Disability

Individuals with intellectual disability (ID) commonly suffer from comorbid psychiatric and behavioral disorders that are frequently treated by antipsychotic medications. All individuals exposed to first- and second/third- generation antipsychotics are at risk for developing tardive dyskinesia (TD), characterized by abnormal, involuntary movements of the mouth/tongue/jaw, trunk, and extremities. TD can be highly disruptive for affected individuals and their caregivers, causing embarrassment, isolation, behavioral disturbances, and reduced functioning and quality of life. Information on TD incidence in individuals with ID is limited, but 2 small US studies reported TD prevalence rates of 42-45% in inpatients with ID. The safety and efficacy of vesicular monoamine transporter type 2 (VMAT2) inhibitors approved for treatment of TD in adults have been demonstrated in multiple clinical trials, but they excluded individuals with ID. Clinical characteristics and treatment outcomes of 5 adults (aged 28-63 years) with mild-to-severe ID and TD are presented, illustrating TD symptoms before/after treatment. All individuals had multiple comorbid psychiatric, behavioral, and other medical conditions, history of antipsychotic exposure, and abnormal movements affecting the tongue/mouth/jaw (n = 5), upper extremities (n = 5), lower extremities (n = 3), and trunk (n = 2), resulting in diminished ability to speak (n = 2), ambulate (n = 3), and perform activities of daily living (n = 3). Treatment with valbenazine resulted in meaningful improvements in TD symptoms and improved daily functioning, demeanor, and social/caregiver interactions. Given the high likelihood of antipsychotic exposure in the ID population, it is appropriate to screen for TD at every clinical visit through careful monitoring for abnormal movements and questioning the individual/caregiver regarding abnormal movements or TD-related functional impairments (i.e., speaking, swallowing, eating, ambulating, and social functioning). In this study, 5 individuals with ID and TD received once-daily valbenazine and experienced marked improvement in TD symptoms and daily functioning, resulting in increased quality of life for affected individuals and caregivers.

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.

Management of Tardive Syndrome: Medications and Surgical Treatments

Tardive syndrome (TS) is an iatrogenic, often persistent movement disorder caused by drugs that block dopamine receptors. It has a broad phenotype including movement (orobuccolingual stereotypy, dystonia, tics, and others) and nonmotor features (akathisia and pain). TS has garnered increased attention of late because of the Food and Drug Administration approval of the first therapeutic agents developed specifically for this purpose. This paper will begin with a discussion on pathogenesis, clinical features, and epidemiology. However, the main focus will be treatment options currently available for TS including a suggested algorithm based on current evidence. Recently, there have been significant advances in TS therapy, particularly with the development of 2 new vesicular monoamine transporter type 2 inhibitors for TS and with new data on the efficacy of deep brain stimulation. The discussion will start with switching antipsychotics and the use of clozapine monotherapy which, despite the lack of higher-level evidence, should be considered for the treatment of psychosis and TS. Anti-dyskinetic drugs are separated into 3 tiers: 1) vesicular monoamine transporter type 2 inhibitors, which have level A evidence, are approved for use in TS and are recommended first-choice agents; 2) drugs with lower level of evidence for efficacy including clonazepam, Ginkgo biloba, and amantadine; and 3) drugs that have the potential to be beneficial, but currently have insufficient evidence including levetiracetam, piracetam, vitamin B6, melatonin, baclofen, propranolol, zolpidem, and zonisamide. Finally, the roles of botulinum toxin and surgical therapy will be examined. Current therapies, though improved, are symptomatic. Next steps should focus on the prevention and reversal of the pathogenic process.

Hospital utilization rates following antipsychotic dose reduction in mood disorders: implications for treatment of tardive dyskinesia

BACKGROUND

The relative benefits and risks of long-term maintenance treatment with antipsychotics have not been well studied in patients with bipolar disorder and major depressive disorder. For example, while antipsychotic dose reduction has been recommended in the management of serious side effects associated with antipsychotics, there is limited evidence on the impact of lowering doses on the course of underlying mood disorders.

METHODS

This retrospective cohort study analyzed the impact of antipsychotic dose reduction in patients with bipolar disorder or major depressive disorder. Medical claims from six US states over a 6-year period were analyzed for patients with ≥10% or ≥ 30% reductions in antipsychotic dose (cases) and compared using survival analyses with matched controls receiving a stable dosage. Outcomes included hospitalizations for disease-specific mood disorders, other psychiatric disorders and all-cause emergency room visits, and claims for tardive dyskinesia.

RESULTS

A total of 23,992 patients with bipolar disorder and 17,766 with major depressive disorder had a ≥ 10% dose reduction, while 19,308 and 14,728, respectively, had a ≥ 30% dose reduction. In multivariate analyses, cases with a ≥ 10% dose reduction had a significantly increased risk of disease-specific admission (bipolar disorder: hazard ratio [95% confidence interval], 1.22 [1.15-1.31]; major depressive disorder: 1.22 [1.11-1.34]), other psychiatric admission (bipolar disorder: 1.19 [1.13-1.24]; major depressive disorder: 1.17 [1.11-1.23]), all-cause admission (bipolar disorder: 1.17 [1.12-1.23]; major depressive disorder: 1.11 [1.05-1.16]), and all-cause emergency room visits (bipolar disorder: 1.09 [1.05-1.13]; major depressive disorder: 1.07 [1.02-1.11]) (all P <  0.01). Similar results were observed following an ≥30% dose reduction. Dose reduction was not associated with decreased claims for tardive dyskinesia.

CONCLUSIONS

Patients with mood disorders who had antipsychotic dose reductions showed small but statistically significant increases in all-cause and mental health-related hospitalizations, which may lead to increased healthcare costs. These results highlight the need for additional long-term studies of the necessity and safety of maintenance antipsychotic treatment in mood disorders.

Long-term safety and efficacy of deutetrabenazine for the treatment of tardive dyskinesia

OBJECTIVE

To evaluate the long-term safety and efficacy of deutetrabenazine in patients with tardive dyskinesia (TD).

METHOD

Patients with TD who completed the 12 week, phase 3, placebo-controlled trials were eligible to enter this open-label, single-arm study. The open-label study consisted of a 6 week dose-escalation phase and a long-term maintenance phase (clinic visits at Weeks 4, 6 and 15, and every 13 weeks until Week 106). Patients began deutetrabenazine at 12 mg/day, titrating up to a dose that was tolerable and provided adequate dyskinesia control, based on investigator judgement, with a maximum allowed dose of 48 mg/day (36 mg/day for patients taking strong cytochrome P450 2D6 (CYP2D6) inhibitors). Safety measures included incidence of adverse events (AEs) and scales used to monitor parkinsonism, akathisia/restlessness, anxiety, depression, suicidality and somnolence/sedation. Efficacy endpoints included the change in Abnormal Involuntary Movement Scale (AIMS) score (items 1 to 7) from baseline and the proportion of patients rated as 'Much Improved' or 'Very Much Improved' on the Clinical Global Impression of Change.

RESULTS

A total of 343 patients enrolled in the extension study, and there were 331 patient-years of exposure in this analysis. The exposure-adjusted incidence rates of AEs with long-term treatment were comparable to or lower than those observed in the phase 3 trials. The mean (SE) change in AIMS score was -4.9 (0.4) at Week 54 (n = 146), - 6.3 (0.7) at Week 80 (n = 66) and -5.1 (2.0) at Week 106 (n = 8).

CONCLUSIONS

Overall, long-term treatment with deutetrabenazine was efficacious, safe, and well tolerated in patients with TD.

TRIAL REGISTRATION NUMBER

NCT02198794.

Effect of tardive dyskinesia on quality of life in patients with bipolar disorder, major depressive disorder, and schizophrenia

PURPOSE

Tardive dyskinesia (TD) is a common but serious hyperkinetic movement disorder and side effect of antipsychotic medications used to treat bipolar disorder (BD), major depressive disorder (MDD), and schizophrenia (SZ). The purpose of this study was to evaluate health-related quality of life (HRQoL) in a population with diagnoses for BD, MDD, or SZ by comparing patients with TD (n = 197) with those without TD (n = 219). HRQoL in each group was also compared with HRQoL of the general population.

METHODS

This study employed a cross-sectional web-based survey. HRQoL was assessed by four instruments: the SF-12 Health Survey, Version 2 (SF-12v2), the Quality of Life Enjoyment and Satisfaction Questionnaire, Short Form (Q-LES-Q-SF), the Social Withdrawal subscale of the Internalized Stigma of Mental Illness Scale (SW-ISMI); and two questions on movement disorders.

RESULTS

Patients with TD had significantly worse HRQoL and social withdrawal than those without. The differences were more pronounced for physical HRQoL domains than for mental health domains. Patients with more-severe TD, assessed through either self-rating or clinician rating, experienced significantly worse HRQoL than did those with less-severe TD. The impact of TD was substantially greater in patients with SZ than in those with BD or MDD. Compared with the general population, patients with BD, MDD, or SZ experienced significantly worse HRQoL regardless of TD status, although this deficit in HRQoL was greater among those with TD.

CONCLUSIONS

The presence of TD is associated with worse HRQoL and social withdrawal. The most severe impact of TD is on physical aspects of patients' HRQoL.

Lurasidone-Induced Tardive Syndrome

Introduction

Tardive syndrome (TS) is an often irreversible movement disorder caused by dopamine receptor-blocking agents (DRBAs). Although TS are well recognized to occur with typical antipsychotics, less well appreciated is that atypical antipsychotics also carry a risk of TS.

Methods

Case series.

Results

We describe 4 patients who developed tardive dystonia, tardive akathisia, and drug-induced parkinsonism with the use of the atypical antipsychotic, lurasidone, which was U.S. Food and Drug Administration approved in 2013 for use in bipolar disorder and schizophrenia.

Conclusion

Movement disorders are reported as a rare side effect of lurasidone, and, as such, prescribers may perceive a false sense of security regarding this potential complication. Our cases indicate that this relatively new atypical antipsychotic may cause irreversible disabling TS as well as parkinsonism. Caution must be taken when prescribing lurasidone.

Risk assessment and prediction of TD incidence in psychiatric patients taking concomitant antipsychotics: a retrospective data analysis

Background

Tardive dyskinesia (TD) is a serious, often irreversible movement disorder caused by prolonged exposure to antipsychotics; identifying patients at risk for TD is critical to preventing it. Predictive models for the occurrence of TD can improve patient monitoring and inform implementation of counteractive interventions. This study aims to identify risk factors associated with TD and to develop a model using a retrospective data analysis to predict the incidence of TD among patients taking antipsychotic medications.

Methods

Adult patients with schizophrenia, major depressive disorder, or bipolar disorder taking oral antipsychotics were identified in a Medicaid claims database (covering six US states from 1997 to 2016) and divided into cohorts based on whether they developed TD within 1 year after the first observed claim for antipsychotics. Patient characteristics between cohorts were compared, and univariate Cox analyses were used to identify potential TD risk factors. A cross-validated version of the least absolute shrinkage and selection operator regression method was used to develop a parsimonious multivariable Cox proportional hazards model to predict diagnosis of TD.

Results

A total of 189,415 eligible patients were identified. Potential TD risk factors were identified based on the cohort analysis within a sample of 151,280 patients with at least 1 year of continuous eligibility. The prediction model had a clinically meaningful concordance of 70% and was well calibrated (P = 0.32 for Hosmer–Lemeshow goodness-of-fit test). Age (hazard ratio [HR] = 1.04, P < 0.001), diagnosis of schizophrenia (HR = 1.99, P < 0.001), antipsychotic dosage (up to 100 mg/day chlorpromazine equivalent; HR = 1.65, P < 0.01), and comorbid bipolar and related disorders (HR = 1.39, P < 0.01) were significantly associated with an increased risk of TD. Other potential risk factors included history of extrapyramidal symptoms (HR = 1.35), other movement disorders (parkinsonism, HR = 1.43; bradykinesia, HR = 1.44; tremors, HR = 2.12, and myoclonus, HR = 2.33), and diabetes (HR = 1.13). A modest reduction in the risk of TD was associated with the use of second-generation antipsychotics (HR = 0.85) versus first-generation drugs.

Conclusions

This study identified factors associated with development of TD among patients taking antipsychotics. The prediction model described herein can enable physicians to better monitor patients at high risk for TD and recommend appropriate treatment plans to help maintain quality of life.

Electronic supplementary material

The online version of this article (10.1186/s12883-019-1385-4) contains supplementary material, which is available to authorized users.

Tardive dyskinesia among patients using antipsychotic medications in customary clinical care in the United States

Background

Tardive dyskinesia (TD) is a movement disorder resulting from treatment with typical and atypical antipsychotics. An estimated 16–50% of patients treated with antipsychotics have TD, but this number may be underestimated. The objectives of this study were to build an algorithm for use in electronic health records (EHRs) for the detection and characterization of TD patients, and to estimate the prevalence of TD in a population of patients exposed to antipsychotic medications.

Methods

This retrospective observational study included patients identified in the Optum EHR Database who received a new or refill prescription for an antipsychotic medication between January 2011 and December 2015 (follow-up through June 2016). TD mentions were identified in the natural language–processed clinical notes, and an algorithm was built to classify the likelihood that the mention represented documentation of a TD diagnosis as probable, possible, unlikely, or negative. The final TD population comprised a subgroup identified using this algorithm, with ≥1 probable TD mention (highly likely TD).

Results

164,417 patients were identified for the antipsychotic population, with1,314 comprising the final TD population. Conservatively, the estimated average annual prevalence of TD in patients receiving antipsychotics was 0.8% of the antipsychotic user population. The average annual prevalence may be as high as 1.9% per antipsychotic user per year, allowing for a more-inclusive algorithm using both probable and possible TD. Most TD patients were prescribed atypical antipsychotics (1049/1314, 79.8%). Schizophrenia (601/1314, 45.7%), and paranoid and schizophrenia‐like disorders (277/1314, 21.1%) were more prevalent in the TD population compared with the entire antipsychotic drug cohort (13,308/164,417; 8.1% and 19,359/164,417; 11.8%, respectively).

Conclusions

Despite a lower TD prevalence than previously estimated and the predominant use of atypical antipsychotics, identified TD patients appear to have a substantial comorbidity burden that requires special treatment and management consideration.

Treatment Recommendations for Tardive Dyskinesia

BACKGROUND

Tardive dyskinesia is a movement disorder characterised by irregular, stereotyped, and choreiform movements associated with the use of antipsychotic medication. We aim to provide recommendations on the treatment of tardive dyskinesia.

METHODS

We performed a systematic review of studies of the treatment of tardive dyskinesia. Studies were rated for methodological quality using the American Academy of Neurology Risk of Bias Classification system. Overall level of evidence classifications and grades of recommendation were made using the Scottish Intercollegiate Guidelines Network framework.

RESULTS

Preventing tardive dyskinesia is of primary importance, and clinicians should follow best practice for prescribing antipsychotic medication, including limiting the prescription for specific indications, using the minimum effective dose, and minimising the duration of therapy. The first-line management of tardive dyskinesia is the withdrawal of antipsychotic medication if clinically feasible. Yet, for many patients with serious mental illness, the discontinuation of antipsychotics is not possible due to disease relapse. Switching from a first-generation to a second-generation antipsychotic with a lower D2 affinity, such as clozapine or quetiapine, may be effective in reducing tardive dyskinesia symptoms. The strongest evidence for a suitable co-intervention to treat tardive dyskinesia comes from tests with the new VMAT inhibitors, deutetrabenazine and valbenazine. These medications have not been approved for use in Canada.

CONCLUSION

Data on tardive dyskinesia treatment are limited, and the best management strategy remains prevention. More long-term safety and efficacy data are needed for deutetrabenazine and valbenazine, and their routine availability to patients outside of the USA remains in question.

Overcoming barriers to effective management of tardive dyskinesia

Tardive dyskinesia (TD) is a heterogeneous syndrome of involuntary hyperkinetic movements that is often persistent and occurs belatedly during treatment with antipsychotics. Recent approval of two dopamine-depleting analogs of tetrabenazine based on randomized controlled trials offers an evidence-based therapeutic approach to TD for the first time. These agents are optimally used within the context of a comprehensive approach to patient management that includes a practical screening and monitoring program, sensitive and specific criteria for the diagnosis of TD, awareness of the severity and impact of the disorder, informed discussions with patients and caregivers, and a rational basis for prescribing decisions about continued antipsychotic and adjunctive agents. Areas of limited or inconclusive data, bias and misunderstandings about key aspects, and neglect of training about TD in recent years contribute to barriers in providing effective care and promoting patient safety.

Treatment of Tardive Dyskinesia: A General Overview with Focus on the Vesicular Monoamine Transporter 2 Inhibitors

Tardive dyskinesia (TD) encompasses the spectrum of iatrogenic hyperkinetic movement disorders following exposure to dopamine receptor-blocking agents (DRBAs). Despite the advent of atypical or second- and third-generation antipsychotics with a presumably lower risk of complications, TD remains a persistent and challenging problem. Prevention is the first step in mitigating the risk of TD, but early recognition, gradual withdrawal of offending medications, and appropriate treatment are also critical. As TD is often a persistent and troublesome disorder, specific antidyskinetic therapies are often needed for symptomatic relief. The vesicular monoamine transporter 2 (VMAT2) inhibitors, which include tetrabenazine, deutetrabenazine, and valbenazine, are considered the treatment of choice for most patients with TD. Deutetrabenazine-a deuterated version of tetrabenazine-and valbenazine, the purified parent product of one of the main tetrabenazine metabolites, are novel VMAT2 inhibitors and the only drugs to receive approval from the US FDA for the treatment of TD. VMAT2 inhibitors deplete presynaptic dopamine and reduce involuntary movements in many hyperkinetic movement disorders, particularly TD, Huntington disease, and Tourette syndrome. The active metabolites of the VMAT2 inhibitors have high affinity for VMAT2 and minimal off-target binding. Compared with tetrabenazine, deutetrabenazine and valbenazine have pharmacokinetic advantages that translate into less frequent dosing and better tolerability. However, no head-to-head studies have compared the various VMAT2 inhibitors. One of the major advantages of VMAT2 inhibitors over DRBAs, which are still being used by some clinicians in the treatment of some hyperkinetic disorders, including TD, is that they are not associated with the development of TD. We also briefly discuss other treatment options for TD, including amantadine, clonazepam, Gingko biloba, zolpidem, botulinum toxin, and deep brain stimulation. Treatment of TD and other drug-induced movement disorders must be individualized and based on the severity, phenomenology, potential side effects, and other factors discussed in this review.

Tardive dyskinesia risk with first- and second-generation antipsychotics in comparative randomized controlled trials: a meta-analysis

Tardive dyskinesia (TD) risk with D2/serotonin receptor antagonists or D2 receptor partial agonists (second-generation antipsychotics, SGAs) is considered significantly lower than with D2 antagonists (first-generation antipsychotics, FGAs). As some reports questioned this notion, we meta-analyzed randomized controlled studies (RCTs) to estimate the risk ratio (RR) and annualized rate ratio (RaR) of TD comparing SGAs vs. FGAs and SGAs vs. SGAs. Additionally, we calculated raw and annualized pooled TD rates for each antipsychotic. Data from 57 head-to-head RCTs, including 32 FGA and 86 SGA arms, were meta-analyzed, yielding 32 FGA-SGA pairs and 35 SGA-SGA pairs. The annualized TD incidence across FGA arms was 6.5% (95% CI: 5.3-7.8%) vs. 2.6% (95% CI: 2.0-3.1%) across SGA arms. TD risk and annualized rates were lower with SGAs vs. FGAs (RR=0.47, 95% CI: 0.39-0.57, p<0.0001, k=28; RaR=0.35, 95% CI: 0.28-0.45, p<0.0001, number-needed-to-treat, NNT=20). Meta-regression showed no FGA dose effect on FGA-SGA comparisons (Z=-1.03, p=0.30). FGA-SGA TD RaRs differed by SGA comparator (Q=21.8, df=7, p=0.003), with a significant advantage of olanzapine and aripiprazole over other non-clozapine SGAs in exploratory pairwise comparisons. SGA-SGA comparisons confirmed the olanzapine advantage vs. non-clozapine SGAs (RaR=0.66, 95% CI: 0.49-0.88, p=0.006, k=17, NNT=100). This meta-analysis confirms a clinically meaningfully lower TD risk with SGAs vs. FGAs, which is not driven by high dose FGA comparators, and documents significant differences with respect to this risk between individual SGAs.

Cardiovascular Profile of Valbenazine: Analysis of Pooled Data from Three Randomized, Double-Blind, Placebo-Controlled Trials

Introduction

Valbenazine is a novel vesicular monoamine transporter 2 inhibitor approved for the treatment of tardive dyskinesia in adults.

Objective

Using data from double-blind, placebo-controlled trials, analyses were conducted to evaluate the cardiovascular effects of once-daily valbenazine in patients with a psychiatric disorder who developed tardive dyskinesia after exposure to a dopamine-blocking medication.

Methods

Data were pooled from three 6-week, double-blind, placebo-controlled trials: KINECT (NCT01688037), KINECT 2 (NCT01733121), and KINECT 3 (NCT02274558). Data from the 42-week valbenazine extension period of KINECT 3 were also analyzed. Outcomes of interest included cardiovascular-related treatment-emergent adverse events, vital sign measurements, and electrocardiogram parameters.

Results

The pooled safety population included 400 participants (placebo, n = 178; valbenazine 40 mg/day, n = 110; valbenazine 80 mg/day, n = 112). A history of cardiac disorders was present in 11.8% of participants, and 74.3% were taking a concomitant medication with known potential for QT prolongation. Mean changes from baseline to week 6 in supine vital signs and QTcF (Fridericia correction) were as follows for placebo, valbenazine 40 mg/day, and valbenazine 80 mg/day, respectively: systolic blood pressure (0.2, − 2.1, − 1.8 mmHg), diastolic blood pressure (− 0.1, − 1.6, − 1.2 mmHg), heart rate (− 1.7, − 2.2, − 1.7 bpm), QTcF interval (1.2, 1.1, 2.1 ms); all p > 0.05 for valbenazine vs. placebo. No statistically significant differences were observed between placebo and valbenazine in cardiovascular-related, treatment-emergent adverse events. No notable additional effects on cardiovascular outcomes were found with up to 48 weeks of valbenazine treatment.

Conclusions

Results from double-blind, placebo-controlled trials showed no apparent difference between valbenazine and placebo on cardiovascular outcomes. No additional cardiovascular risk was detected during a longer extension study with valbenazine.

Hospital utilization rates following antipsychotic dose reductions: implications for tardive dyskinesia

BACKGROUND

Data are limited on the benefits and risks of dose reduction in managing side effects associated with antipsychotic treatment. As an example, antipsychotic dose reduction has been recommended in the management of tardive dyskinesia (TD), yet the benefits of lowering doses are not well studied. However, stable maintenance treatment is essential to prevent deterioration and relapse in schizophrenia.

METHODS

A retrospective cohort study was conducted to analyze the healthcare burden of antipsychotic dose reduction in patients with schizophrenia. Medical claims from six US states spanning a six-year period were analyzed for ≥10% or ≥ 30% antipsychotic dose reductions compared with those from patients receiving a stable dose. Outcomes measured were inpatient admissions and emergency room (ER) visits for schizophrenia, all psychiatric disorders, and all causes, and TD claims.

RESULTS

A total of 19,556 patients were identified with ≥10% dose reduction and 15,239 patients with ≥30% dose reduction. Following a ≥ 10% dose reduction, the risk of an all-cause inpatient admission increased (hazard ratio [HR] 1.17; 95% confidence interval [CI] 1.11, 1.23; P < 0.001), and the risk of an all-cause ER visit increased (HR 1.09; 95% CI 1.05, 1.14; P < 0.001) compared with controls. Patients with a ≥ 10% dose reduction had an increased risk of admission or ER visit for schizophrenia (HR 1.27; 95% CI 1.19, 1.36; P < 0.001) and for all psychiatric disorders (HR 1.16; 95% CI 1.10, 1.23; P < 0.001) compared with controls. A dose reduction of ≥30% also led to an increased risk of admission for all causes (HR 1.23; 95% CI 1.17, 1.31; P < 0.001), and for admission or ER visit for schizophrenia (HR 1.31; 95% CI 1.21, 1.41; P < 0.001) or for all psychiatric disorders (HR 1.21; 95% CI 1.14, 1.29; P < 0.001) compared with controls. Dose reductions had no significant effect on claims for TD.

CONCLUSION

Patients with antipsychotic dose reductions showed significant increases in both all-cause and mental health-related hospitalizations, suggesting that antipsychotic dose reductions may lead to increased overall healthcare burden in some schizophrenia patients. This highlights the need for alternative strategies for the management of side effects, including TD, in schizophrenia patients that allow for maintaining effective antipsychotic treatment.

No Effect of Dose Adjustment to the CYP2D6 Genotype in Patients With Severe Mental Illness

Background: The CYP2D6 enzyme is involved in the metabolism of numerous psychopharmacological drugs. Guidelines recommend how to adjust the dose of medication based on the CYP2D6 genotype. Aims: To evaluate the effect of dose adjustment to the CYP2D6 genotype and phenotype, in patients with severe mental illness (SMI) already receiving psychopharmacological treatment. Methods: A total of 269 psychiatric patients (on the island Curaçao) receiving antipsychotic treatment were genotyped for CYP2D6. Of these, 45 patients were included for dose adjustment according to the clinical guideline of the Royal Dutch Association for the Advancement of Pharmacy, i.e., 17 CYP2D6 poor metabolizers, 26 intermediate metabolizers, and 2 ultrarapid metabolizers. These 45 patients were matched for age, gender, and type of medication with a control group of 41 patients who were CYP2D6 extensive metabolizers (i.e., with a normal CYP2D6 function). At baseline and at 4 months after dose adjustment, subjective experience, psychopathology, extrapyramidal side-effects, quality of life, and global functioning were assessed in these two groups. Results: At baseline, there were no differences between the groups regarding the prescribed dosage of antipsychotics, the number of side-effects, psychiatric symptoms, global functioning, or quality of life. After dose adjustment, no significant improvement in these parameters was reported. Conclusion: In psychiatric patients with SMI already receiving antipsychotic treatment, dose adjustment to the CYP2D6 genotype or phenotype according to the guidelines showed no beneficial effect. This suggests that dose adjustment guidelines are currently not applicable for patients already using antipsychotics. ClinicalTrials.gov: Cost-effectiveness of CYP2D6 and CYP2C19 Genotyping in Psychiatric Patients in Curacao; Identifier: NCT02713672; https://clinicaltrials.gov/ct2/show/NCT02713672?term=CYP2D6&rank=5.

Randomized controlled trial of deutetrabenazine for tardive dyskinesia: The ARM-TD study

Objective:

To determine the efficacy and safety of deutetrabenazine as a treatment for tardive dyskinesia (TD).

Methods:

One hundred seventeen patients with moderate to severe TD received deutetrabenazine or placebo in this randomized, double-blind, multicenter trial. Eligibility criteria included an Abnormal Involuntary Movement Scale (AIMS) score of ≥6 assessed by blinded central video rating, stable psychiatric illness, and stable psychoactive medication treatment. Primary endpoint was the change in AIMS score from baseline to week 12. Secondary endpoints included treatment success at week 12 on the Clinical Global Impression of Change (CGIC) and Patient Global Impression of Change.

Results:

For the primary endpoint, deutetrabenazine significantly reduced AIMS scores from baseline to week 12 vs placebo (least-squares mean [standard error] −3.0 [0.45] vs −1.6 [0.46], p = 0.019). Treatment success on CGIC (48.2% vs 40.4%) favored deutetrabenazine but was not significant. Deutetrabenazine and placebo groups showed low rates of psychiatric adverse events: anxiety (3.4% vs 6.8%), depressed mood/depression (1.7% vs 1.7%), and suicidal ideation (0% vs 1.7%, respectively). In addition, no worsening in parkinsonism, as measured by the Unified Parkinson's Disease Rating Scale motor subscale, was noted from baseline to week 12 in either group.

Conclusions:

In patients with TD, deutetrabenazine was well tolerated and significantly reduced abnormal movements.

Classification of evidence:

This study provides Class I evidence that in patients with TD, deutetrabenazine reduces AIMS scores.

Reversibility of tardive dyskinesia syndrome

In Response to:

Zutshi D, Cloud LJ, Factor SA. Tardive syndromes are rarely reversible after discontinuing dopamine receptor blocking agents: Experience from a university-based movement disorder clinic. Tremor Other Hyperkinet Mov. 2014; 4. doi: 10.7916/D8MS3R8C