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Tardive dyskinesia and dystonia are intractable extrapyramidal symptoms caused by the blockade of dopamine receptors by antipsychotic drugs. In addition to the reduction or discontinuation of the causative drug, valbenazine for tardive dyskinesia and botulinum toxin for tardive dystonia have been reported to be effective. However, their efficacy has not been fully demonstrated. In this study, we report the case of a female patient with bipolar disorder, valbenazine-resistant tardive dystonia, and tardive dyskinesia who achieved improvement in extrapyramidal symptoms with electroconvulsive therapy. Additionally, we conducted a narrative literature review on the safety and efficacy of electroconvulsive therapy for tardive dyskinesia and dystonia. [ABSTRACT FROM AUTHOR]

Valbenazine is a highly potent and selective inhibitor of synaptic vesicular monoamine transporter 2. The current therapeutic doses of valbenazine for tardive dyskinesia (TD) are 40, 60, or 80 mg capsules, given orally, once daily (QD). While 40 and 80 mg were investigated in phase 3 KINECT® 3 trial and initially approved, the approval of valbenazine 60 mg was based on the analysis utilizing the Model‐informed drug development (MIDD) approach, facilitated through the US Food and Drug Administration's MIDD Pilot Program. This study aimed to demonstrate the efficacy of 60 mg QD dose through model simulations using an established exposure‐response (E‐R) relationship between valbenazine active metabolite [+]‐α‐dihydrotetrabenazine exposure and the change from baseline in Abnormal Involuntary Movement Scale total score (AIMS‐CFB). A longitudinal E–R model was constructed based on the 40 and 80 mg data from the KINECT 3 trial. The final Emax model adequately predicted dose‐dependent improvement in the primary endpoint and was used to interpolate AIMS‐CFB for 60 mg at week 6. The efficacy of the unstudied 60 mg dose regimen is expected to be within the range of doses studied clinically with predicted mean AIMS‐CFB (95% confidence interval) of −2.69 (−3.30, −2.13) between observed mean AIMS‐CFB for 40 mg of −1.92 and 80 mg of −3.39. Results from this analysis provided the key evidence to establish efficacy of 60 mg QD without the need for an additional clinical trial. The availability of valbenazine 60 mg dose fills an existing medical need for patients with TD who could benefit from this third effective dose. [ABSTRACT FROM AUTHOR]

Valbenazine is commonly used to treat tardive dyskinesia, and we conducted a pharmacovigilance analysis using the Food and Drug Administration Adverse Event Reporting System (FAERS) to evaluate neurological safety signals associated with valbenazine. Data was collected in FAERS from the second quarter of 2017 to the fourth quarter of 2023 for data cleaning. Neurological adverse event (AE) signals of valbenazine were mined by calculating reporting odds ratios (ROR), information component (IC) and empirical Bayesian geometric mean (EBGM). The serious and non-serious cases and signals were prioritized using a rating scale. The number of neurological AE reports where the primary suspect (PS) drug was 8981 for valbenazine. Significant AE signals were identified by the preferred term (PT) analysis for valbenazine, including somnolence (ROR 19.69), tremor (ROR 15.17), and tardive dyskinesia (ROR 236.91), among which 18 AEs were identified as new signals. Patient age (p < 0.009) and sex (p = 0.197) might be associated with an increased risk of neurological AE severity. Notably, the association between valbenazine and neurological disorders remained when stratified by sex, age, and reporter type. AE timing analysis was performed for the drug and four moderate clinical priority signals [i.e., somnolence, balance disorder, parkinsonism, and akathisia (priorities 7)], showing the same early failure type profiles. The increase in neurological safety signals is identified in the post-marketing research of valbenazine. Clinicians need to pay attention to not only common AEs but also be alert to new neurological AE signals when using valbenazine. • This study provides the latest valbenazine-related neurological safety profiles, and eighteen AEs were identified as new signals. • Neurological AEs most commonly identified for valbenazine were somnolence, tremor, dizziness, drooling, dyskinesia, and balance disorder. • Our findings could potentially prompt improved awareness of valbenazine-related toxicities and help healthcare professionals mitigate the risk of neurological events. [ABSTRACT FROM AUTHOR]

The crystal structure of valbenazine has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. Valbenazine crystallizes in space group P212121 (#19) with a = 5.260267(17), b = 17.77028(7), c = 26.16427(9) Å, V = 2445.742(11) Å3, and Z = 4 at 295 K. The crystal structure consists of discrete molecules and the mean plane of the molecules is approximately (8,−2,15). There are no obvious strong intermolecular interactions. There is only one weak classical hydrogen bond in the structure, from the amino group to the ether oxygen atom. Two intramolecular and one intermolecular C–H⋯O hydrogen bonds also contribute to the lattice energy. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®) [ABSTRACT FROM AUTHOR]

Background: Valbenazine is used for tardive movement disorders in adults. Current studies on its safety are mostly from clinical trials and small case reports, limiting information on rare adverse reactions. This study investigated valbenazine-related adverse event (AE) risk signals using the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS) database. Methods: Valbenazine AEs data were collected from the FAERS database from 2017 Q2 to 2023 Q1, employing methods like reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian confidence propagation neural network, and empirical Bayesian geometric mean. Results: After data cleaning and drug screening, there were 20,837 AEs primarily suspecting valbenazine, involving 26 system organ classes and 125 AEs related to valbenazine at the preferred terms level. AEs related to valbenazine were mainly concentrated in nervous system disorders, general disorders and administration site conditions, and psychiatric disorders. Eye disorders and gastrointestinal disorders are new AEs not labeled in the valbenazine instructions. In addition, some new potential AE signals were found, such as Tardive dyskinesia and eyelid function disorder. Conclusion: The common AEs of valbenazine in the real world are consistent with the instructions, but there are some newly discovered suspicious AEs. [ABSTRACT FROM AUTHOR]

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.

Huntington's Disease (HD) is a severely debilitating neurodegenerative disorder in which sufferers exhibit different combinations of movement disorders, dementia, and behavioral or psychiatric abnormalities. The disorder is a result of a trinucleotide repeat expansion mutation that is inherited in an autosomal dominant manner. While there is currently no treatment to alter the course of HD, there are medications that lessen abnormal movement and psychiatric symptoms. ClinicalTrials.gov was searched to identify drugs that are currently in or have completed phase III drug trials for the treatment of HD. The described phase III trials were further limited to interventional studies that were recruiting, active not recruiting, or completed. In addition, all studies must have posted an update within the past year. PubMed was used to gather further information on these interventional studies. Of the nine clinical trials that met these criteria, eight involved the following drugs: metformin, dextromethorphan/quinidine, deutetrabenazine, valbenazine, Cellavita HD, pridopidine, SAGE-718, and RO7234292 (RG6042). Of these drug treatments, four are already FDA approved. This systematic review provides a resource that summarizes the present therapies for treating this devastating condition that are currently in phase III clinical trials in the United States. [ABSTRACT FROM AUTHOR]

Objectives: We aimed to review our "real-world" experience with the vesicular monoamine transporter 2 (VMAT2) inhibitors tetrabenazine, deutetrabenazine, and valbenazine for treatment of Tourette syndrome, focusing on therapeutic benefits, side effect profile, and accessibility for the off-label use of these drugs. Methods: We performed a retrospective chart review, supplemented with a telephone survey, of all our patients treated for their tics with VMAT2 inhibitors over a period of 4 years from January 2017 until January 2021. Results: We identified 164 patients treated with the various VMAT2 inhibitors (tetrabenazine, n = 135; deutetrabenazine, n = 71; valbenazine, n = 20). Data on the mean treatment duration and daily dosages were collected. The response to VMAT2 inhibitors was assessed by a Likert scale by comparing the symptom severity before initiation and while on treatment. Side effects were mild and mostly consisted of depression as the major side effect but there was no suicidality reported. Conclusion: VMAT2 inhibitors are effective and safe in the treatment of tics associated with Tourette syndrome but are not readily accessible by patients in the United States, partly because of lack of approval by the Food and Drug Administration. [ABSTRACT FROM AUTHOR]

A simple, specific, rapid, sensitive reversed‐phase high‐performance liquid chromatography method was developed and validated for the determination of Valbenazine, impurities, and its degradation products. The proposed high‐performance liquid chromatography method showed optimum separation in 60 min using potassium dihydrogen phosphate buffer and ACN in the ratio of 90:10 (V/V) as mobile phase‐A whereas ACN and methanol in the ratio of 60:40 (V/V) as mobile phase‐B. YMC‐Pack ODS‐AQ (150 × 4.6 mm, 3.0 μm), column used along with security guard cartridge C18, (4.0 × 3.0 mm) at 1.1 ml/min flow. The injection volume was 10 μl and detection was carried out at 285 nm. The drug was degraded under different stress conditions and the method was validated as per International Conference on Harmonization guidelines on the basis of accuracy, precision, linearity, and robustness. A degradation study indicates that Valbenazine is prone to oxidative degradation. The method was linear over the concentration range of limit of quantitation to 200% for impurities and drug substances. The method was found robust and was studied by the design of experiments. The proposed method is applicable for the determination of the stability of Valibenazine and was successfully used in the quality control of bulk drug manufacturing and pharmaceuticals. [ABSTRACT FROM AUTHOR]

Valbenazine and deutetrabenazine are vesicular monoamine transporter 2 (VMAT2) inhibitors approved for tardive dyskinesia. The clinical activity of valbenazine is primarily attributed to its only dihydrotetrabenazine (HTBZ) metabolite, [+]‐α‐HTBZ. Deutetrabenazine is a deuterated form of tetrabenazine and is metabolized to four deuterated HTBZ metabolites: [+]‐α‐deuHTBZ, [+]‐β‐deuHTBZ, [−]‐α‐deuHTBZ, and [−]‐β‐deuHTBZ. An open‐label, crossover study characterized the pharmacokinetic profiles of the individual deuHBTZ metabolites, which have not been previously reported. VMAT2 inhibition and off‐target interactions of the deuHTBZ metabolites were evaluated using radioligand binding. The only valbenazine HTBZ metabolite, [+]‐α‐HTBZ, was a potent VMAT2 inhibitor, with negligible affinity for off‐target dopamine, serotonin, and adrenergic receptors. Following deutetrabenazine administration, [−]‐α‐deuHTBZ represented 66% of circulating deuHTBZ metabolites and was a relatively weak VMAT2 inhibitor with appreciable affinity for dopamine (D2S, D3) and serotonin (5‐HT1A, 5‐HT2B, 5‐HT7) receptors. [+]‐β‐deuHTBZ was the most abundant deuHTBZ metabolite that potently inhibited VMAT2, but it represented only 29% of total circulating deuHTBZ metabolites. The mean half‐life of [+]‐α‐HTBZ (22.2 hours) was ∼3× longer than that of [+]‐β‐deuHTBZ (7.7 hours). These findings are similar to studies with tetrabenazine, in that deutetrabenazine is metabolized to four deuHTBZ stereoisomers, the most abundant of which has negligible interaction with VMAT2 in vitro and appreciable affinity for several off‐target receptors. In contrast, valbenazine's single HTBZ metabolite is a potent VMAT2 inhibitor in vitro with no discernible off‐target activity. Determination of the effects of intrinsic/extrinsic variables on deutetrabenazine's safety/efficacy profile should incorporate assessment of the effects on all deuHTBZ metabolites. [ABSTRACT FROM AUTHOR]

Huntington’s Disease (HD) is a severely debilitating neurodegenerative disorder in which sufferers exhibit different combinations of movement disorders, dementia, and behavioral or psychiatric abnormalities. The disorder is a result of a trinucleotide repeat expansion mutation that is inherited in an autosomal dominant manner. While there is currently no treatment to alter the course of HD, there are medications that lessen abnormal movement and psychiatric symptoms. ClinicalTrials.gov was searched to identify drugs that are currently in or have completed phase III drug trials for the treatment of HD. The described phase III trials were further limited to interventional studies that were recruiting, active not recruiting, or completed. In addition, all studies must have posted an update within the past year. PubMed was used to gather further information on these interventional studies. Of the nine clinical trials that met these criteria, eight involved the following drugs: metformin, dextromethorphan/quinidine, deutetrabenazine, valbenazine, Cellavita HD, pridopidine, SAGE-718, and RO7234292 (RG6042). Of these drug treatments, four are already FDA approved. This systematic review provides a resource that summarizes the present therapies for treating this devastating condition that are currently in phase III clinical trials in the United States.

Aim: Valbenazine is approved in the US for treatment of tardive dyskinesia (TD); however, efficacy/safety data in Asian populations are lacking. We assessed the efficacy/safety of valbenazine in Japanese patients. Methods: This phase II/III, multicenter, randomized, double‐blind, placebo‐controlled study (NCT03176771) included adult psychiatric patients with TD, who were randomly allocated to receive placebo or valbenazine (once‐daily 40‐ or 80‐mg) for a 6‐week, double‐blind period, after which the placebo group was switched to valbenazine for a 42‐week extension. The primary endpoint was change from baseline in Abnormal Involuntary Movement Scale (AIMS) total score at Week 6; clinical global impression of improvement of TD (CGI‐TD) was also assessed. Results: Of 256 patients, 86, 85, and 85 were allocated to the 40‐mg valbenazine, 80‐mg valbenazine, and placebo groups, respectively. Least‐squares mean (95% confidence interval) change from baseline in AIMS score at Week 6 was −2.3 (−3.0 to −1.7) in the valbenazine 40‐mg group, −3.7 (−4.4 to −3.0) in the 80‐mg group, and −0.1 (−0.8 to 0.5) in the placebo group; both treatment groups showed statistically significant improvements vs. placebo. Patients switched to valbenazine at Week 6 showed similar improvements in AIMS scores, which were maintained to Week 48. Improvements in CGI‐TD scores were observed for both treatment groups vs. placebo. Incidence of adverse events was highest in the 80‐mg group; common events included nasopharyngitis, somnolence, schizophrenia worsening, hypersalivation, insomnia, and tremor. Conclusion: The efficacy/safety profile of valbenazine was similar to that of previous clinical trials, supporting its use for TD treatment in Japanese patients. [ABSTRACT FROM AUTHOR]

Tardive dyskinesia and dystonia are intractable extrapyramidal symptoms caused by the blockade of dopamine receptors by antipsychotic drugs. In addition to the reduction or discontinuation of the causative drug, valbenazine for tardive dyskinesia and botulinum toxin for tardive dystonia have been reported to be effective. However, their efficacy has not been fully demonstrated. In this study, we report the case of a female patient with bipolar disorder, valbenazine-resistant tardive dystonia, and tardive dyskinesia who achieved improvement in extrapyramidal symptoms with electroconvulsive therapy. Additionally, we conducted a narrative literature review on the safety and efficacy of electroconvulsive therapy for tardive dyskinesia and dystonia.

Tardive dyskinesia (TD) is a movement disorder associated with dopamine receptor blocking medications. Recommended treatments for TD include discontinuing the causative agent, adding vesicular monoamine transporter 2 (VMAT2) inhibitors, or adding vitamin B6. We present a 66-year-old Caucasian male with bipolar I disorder who developed TD while on lithium and quetiapine having been euthymic on this regimen for three years. He was initially treated with 1200 mg B6 daily. This failed to improve his TD and was associated with a depressive episode. He switched to valbenazine 40 mg daily which improved his TD and concurrently his mood, but months later the TD symptoms worsened again. Our case adds to the literature by demonstrating that some patients with TD will not respond to vitamin B6. To our knowledge, ours is the first case suggesting association of high dose vitamin B6 with depression. This case also demonstrates that response to valbenazine may not last and further studies are needed.

Tardive dyskinesia (TD) is a potentially irreversible movement disorder characterized by involuntary, repetitive movements, most commonly affecting the face, tongue, and extremities. It is primarily associated with the long-term use of first-generation (typical) antipsychotics but can also occur with second-generation (atypical) antipsychotics such as aripiprazole. Despite its lower risk profile, aripiprazole can induce TD, as illustrated by a 45-year-old woman with schizophrenia who developed severe involuntary movements after five years of stable treatment with this medication. Her symptoms, including facial grimacing and choreiform movements, were assessed using the Abnormal Involuntary Movement Scale (AIMS), scoring 18, indicative of moderate to severe TD. Following a switch to clozapine and the addition of valbenazine, a VMAT2 inhibitor, the patient experienced significant symptom reduction and improved quality of life. This case emphasizes the need for ongoing monitoring of TD in patients on long-term antipsychotic therapy, even with atypical agents. Effective management strategies, including medication adjustment and the use of VMAT2 inhibitors, are crucial for optimizing patient outcomes and quality of life. Continued research is needed to better understand and address TD in clinical practice., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Mulla et al.)

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. [ABSTRACT FROM AUTHOR]

Stanley N Caroff Corporal Michael J Crescenz VA Medical Center, and the Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA Abstract: 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. Keywords: tardive dyskinesia, valbenazine, deutetrabenazine, tetrabenazine vesicular monoamine transporter inhibitors, antipsychotics, schizophrenia, bipolar disorder, major depressive disorder, drug-induced movement disorders

Hyperkinetic movement disorders are a common group of movement abnormalities in children, characterized with repetitive unintended involuntary movements. Major hyperkinetic movements include tremor, tic, dystonia, myoclonus, and chorea. Although a number of drugs have been proven to be beneficial for these abnormalities, some patients may become resistant to conventional treatments. Vesicular monoamine transporter2 (VMAT2) inhibitors (Tetrabenazine, Deutetrabenazine, and Valbenazine) are new agents introduced in the last decade for treating some of movement disorders, in particular tardive dyskinesia, Huntington chorea, and Tourette syndrome. In this brief review, we discussed the role of these drugs in managing hyperkinetic movement disorders. [ABSTRACT FROM AUTHOR]

Introduction: Significant need exists for effective, well-tolerated pharmacologic treatments for Tourette syndrome (TS). Medications that inhibit vesicular monoamine transporters (i.e. VMAT2 inhibitors) downregulate presynaptic packaging and release of dopamine into the neuronal synapse and are effective in treating hyperkinetic movement disorders such as Huntington's chorea and tardive dyskinesia (TD); thus, they may be useful in treating TS. Areas covered: This review describes the clinical program evaluating the safety and efficacy of valbenazine in the treatment of involuntary tics associated with TS in adult and pediatric subjects. While there was a trend in the 6 completed trials toward greater improvement in valbenazine-treated versus placebo subjects on the primary efficacy endpoint (Yale Global Tic Severity Scale Total Tic Score), this difference did not reach statistical significance. Valbenazine was generally well-tolerated in the studies, and treatment-emergent adverse events were consistent with valbenazine studies in TD. Expert opinion: Due to the failure to meet the primary endpoint in these trials, further investigation of valbenazine for TS is unlikely. Given the need for safe and effective TS therapies and the key role of VMAT2 in modulating dopaminergic activity, it is reasonable for future studies to investigate other VMAT2 inhibitors as potential treatments for TS. [ABSTRACT FROM AUTHOR]

Purpose of review This a comprehensive review of the literature regarding the use of Valbenazine in treating tardive dyskinesia. A primarily oral movement disorder induced by chronic exposure to certain classes of medications, tardive dyskinesia is often resistant to many therapeutic approaches. This review presents the background, evidence, and indications for the use of Valbenazine as a treatment option for this condition. Recent Findings Tardive dyskinesia is a disorder arising from long-term exposure to medications that blocked dopamine receptors, primarily antipsychotics. It is characterized by abnormal movements of the oral-buccal-lingual structures as well as associated pain and hypertrophy. Simply stopping the use of the dopamine blocking agents effectively alleviates the symptoms but is not always reliable hence the need for another therapeutic approach. Valbenazine is thought to function as a highly selective inhibitor of the VMAT2 vesicular monoamine transporter resulting in decreased availability of dopamine in the presynaptic cleft. This leads to decreased dopaminergic activation of the striatal motor pathway. The FDA approved Valbenazine in 2017 to treat tardive dyskinesia in adults and needs to be evaluated with existing therapeutic approaches. Summary The chronic use of dopamine receptor blocking agents, most commonly antipsychotics, can lead to a movement disorder called tardive dyskinesia. Once symptom onset has occurred, these movement abnormalities can persist for years to permanently, depending on the speed and effectiveness of treatment. Valbenazine is a relatively newer option for the treatment of tardive dyskinesia in adults. Compared to other pharmaceutical agents, it is more selective and has limited toxicities making it an effective treatment regimen. However, further research, including additional direct comparison studies, should be conducted to fully evaluate this drug's usefulness. [ABSTRACT FROM AUTHOR]

Marco Solmi,1 Giorgio Pigato,2 John M Kane,3,4 Christoph U Correll3–5 1Neuroscience Department, Psychiatry Unit, University of Padua, Padua, Italy; 2Psychiatry Unit, Padua Hospital, Padua, Italy; 3Department of Psychiatry, Northwell Health, The Zucker Hillside Hospital, Glen Oaks, NY, USA; 4Department of Psychiatry and Molecular Medicine, Hofstra Northwell School of Medicine, Hempstead, NY, USA; 5Department of Child and Adolescent Psychiatry, Charité Universitätsmedizin, Berlin, Germany Aim: The aim of this study was to summarize the characteristics, efficacy, and safety of vesicular monoamine transporter-2 (VMAT-2) inhibitors for treating tardive dyskinesia (TD).Materials and methods: We conducted a literature search in PubMed, Cochrane Database, and ClinicalTrials.gov, screening for systematic reviews, meta-analyses or double-blind, randomized, placebo-controlled trials (DBRPCTs) reporting efficacy or safety data of VMAT-2 inhibitors (tetrabenazine, deutetrabenazine, and valbenazine) in patients with TD. A random effects meta-analysis of efficacy and safety data from DBRPCTs was performed.Results: Two acute, 12-week DBRPCTs with deutetrabenazine 12–48 mg/day (n=413) and 4 acute, 4–6-week double-blind trials with valbenazine 12.5–100 mg/day (n=488) were meta-analyzable, without meta-analyzable, high-quality data for tetrabenazine. Regarding reduction in total Abnormal Involuntary Movement Scale (AIMS) scores (primary outcome), both deutetrabenazine (k=2, n=413, standardized mean difference [SMD] =-0.40, 95% confidence interval [CI] =-0.19, -0.62, p

Objective: Vesicular monoamine transporter-2 (VMAT2) inhibitors have been proven to be effective for the treatment of tardive dyskinesia and their use is likely to increase. The evidence base of published clinical reports was reviewed to evaluate the possible risk of neuroleptic malignant syndrome (NMS) with these drugs. Methods: Pubmed, Embase, Web of Science and PsycINFO databases were queried for all years using terms for "neuroleptic malignant syndrome", "hyperthermia" AND "vesicular monoamine transporter inhibitors", "reserpine", "tetrabenazine", "valbenazine" or "deutetrabenazine" Results: Thirteen clinical cases, ten of which involved tetrabenazine, were identified in which VMAT2 inhibitors were prescribed in patients with current or past NMS episodes. In most cases, the association was confounded by limited reporting of clinical data, variable temporal correlation with VMAT2 inhibitors, polypharmacy with antipsychotics, and uncertain differential diagnoses. Conclusion: While rare cases of NMS meeting consensus criteria have been reported primarily with tetrabenazine, the risk with recently developed VMAT2 inhibitors may be even less. Evidence of causality of NMS with VMAT2 inhibitors is confounded by concomitant treatment with antipsychotics and diagnostic uncertainties in patients susceptible to basal ganglia dysfunction. Nevertheless, clinicians should remain vigilant for early signs of NMS in all patients treated with any drugs that affect brain dopamine activity. [ABSTRACT FROM AUTHOR]

Purpose The purpose of this review is to summarize the current evidence for valbenazine and deutetrabenazine use for the treatment of tardive dyskinesia (TD). Summary A literature search was conducted to gather relevant data regarding the use of valbenazine and deutetrabenazine for TD management. PubMed, MEDLINE, and ClinicalTrials.gov were searched using the following keywords and MeSH terms: valbenazine, deutetrabenazine, tardive dyskinesia, VMAT2 inhibitors, and vesicular monoamine transporter 2 inhibitors. Randomized, double-blind, placebo-controlled trials and meta-analyses published in English from April 2015 to August 2019 were included. Valbenazine 40–80 mg and deutetrabenazine 12–36 mg per day have been evaluated for the treatment of TD. Abnormal Involuntary Movement Scale (AIMS) scores decline similarly (by 2–5 points) with use of either agent. AIMS response rates, defined by a 50% decline in symptoms, range from 33% to 50%. Both agents are well tolerated, with somnolence and akathisia reported most frequently (at low rates). Agent selection may be guided by manufacturer labeling recommendations for special populations and cost considerations. Conclusions Valbenazine and deutetrabenazine were demonstrated to be effective in decreasing AIMS scores and were well tolerated in randomized controlled trials. These treatments may be considered as a next-line option when traditional strategies are not feasible or are ineffective. Head-to-head studies are warranted to decipher if either agent is preferable in terms of efficacy or tolerability. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effects of once-daily valbenazine (40 or 80 mg/d) in older and younger adults with tardive dyskinesia (TD).Methods: Data were pooled from three 6-week, randomized, double-blind, placebo-controlled (DBPC) studies (KINECT [NCT01688037], KINECT 2 [NCT01733121], and KINECT 3 [NCT02274558]) and two long-term studies (KINECT 3 extension and KINECT 4 [NCT02405091]). Outcomes analyzed in older and younger participants (55 years or older and younger than 55 years, respectively) included Abnormal Involuntary Movement Scale (AIMS) response (threshold of greater than or equal to 50% improvement from baseline in total score [items 1 to 7]) and Clinical Global Impression of Change-Tardive Dyskinesia (CGI-TD) response (score 2 or less ["very much improved" or "much improved"]). Safety assessments included treatment-emergent adverse events (TEAEs).Results: At week 6 (end of DBPC treatment), the percentage of participants who met the AIMS response threshold was higher with valbenazine versus placebo in both subgroups: 55 years or older (80 mg/d, 39.7% [P < .001]; 40 mg/d, 28.6% [P < .01]; placebo, 9.7%); younger than 55 years (80 mg/d, 39.5% [P < .001]; 40 mg/d, 20.0% [P > .05]; placebo, 10.8%). The percentage of participants with CGI-TD response was also higher with valbenazine versus placebo: 55 years or older (80 mg/d, 41.3% [P < .01]; 40 mg/d, 30.2% [P > .05]; placebo, 19.4%); younger than 55 years (80 mg/d, 39.5% [P < .05]; 40 mg/d, 35.3% [P < .05]; placebo, 18.5%). Responses at week 48 (end of long-term treatment, combined doses) were as follows: 55 years or older (AIMS, 70.7%; CGI-TD, 82.8%); younger than 55 years (AIMS, 58.7%; CGI-TD, 72.3%). No significant differences between older and younger subgroups were found for AIMS or CGI-TD response. No new safety signals or TEAEs of clinical concern were found in older participants who received long-term treatment.Conclusions: Valbenazine improved TD and was generally well tolerated in older and younger adults. [ABSTRACT FROM AUTHOR]

Valbenazine is the first drug approved by the US Food and Drug Administration for the treatment of adults with tardive dyskinesia (TD) on April 11, 2017. It acts as a reversible inhibitor of vesicular monoamine transporter 2. It is available orally with a starting dose of 40 mg once daily which can be increased after 1 week to the recommended dose of 80 mg. Clinical trials showed positive outcomes in Abnormal Involuntary Movement Scale and Clinical Global Impression - Global Improvement of TD score with respect to placebo. Valbenazine has an acceptable safety and tolerability profile, the most common side effect observed is somnolence. However, long-term study is lacking, and more data are required to establish its full benefits and concomitant risks which can be missed in the recent trials.

Background: Tardive Dyskinesia (TD) is a neurological disorder characterized by involuntary movements, often caused by dopamine receptor antagonists. Vesicular Monoamine Transporter 2 (VMAT2) inhibitors, such as valbenazine and deutetrabenazine, have emerged as promising therapies for TD and several clinical trials have shown their efficacy. This study aims to compare the efficacy and safety profile of VMAT2 inhibitors, focusing on a recent trial conducted in the Asian population., Methods: We reviewed the PubMed, Cochrane Library, Embase database, and clinicaltrials.gov between January 2017 and October 2023, using the keywords "tardive dyskinesia" AND ("valbenazine" [all fields] OR " deutetrabenazine " [all fields]) AND "clinical trial". The reviewed articles were studied for efficacy and side effects., Results: An initial search yielded 230 articles, of which 104 were duplicates. Following the title and abstract screening, 25 additional articles were excluded. A full-text review resulted in the exclusion of 96 more articles. Ultimately, four double-blind clinical trials met the inclusion criteria. The deutetrabenazine studies demonstrated significant improvements in Abnormal Involuntary Movement Scale (AIMS) scores compared to placebo, with no difference in adverse events. The valbenazine studies showed favorable results in reducing TD symptoms and were well-tolerated., Discussion: The studies reviewed in this analysis underscore the potential of deutetrabenazine and valbenazine as valuable treatment options for TD in diverse populations. Both medications demonstrated significant improvements in AIMS scores, suggesting their effectiveness in managing TD symptoms. Additionally, they exhibited favorable safety profiles, with low rates of serious adverse events and no significant increase in QT prolongation, parkinsonism, suicidal ideation, or mortality., Conclusion: The studies reviewed highlight the promising efficacy and tolerability of deutetrabenazine and valbenazine as treatments for Tardive Dyskinesia, providing new hope for individuals affected by this challenging condition., Competing Interests: Dr. Khashayar Dashtipour’s conflict of interest: Amneal, Teva, Neurocrine, Abbvie, Supernus, Ipsen, Acadia, Acorda, Sunovion. The authors have no competing interests to declare., (Copyright: © 2024 The Author(s).)

Background: A minimal clinically important difference has not been established for the Abnormal Involuntary Movement Scale in patients with tardive dyskinesia. Valbenazine is a vesicular monoamine transporter 2 inhibitor approved for the treatment of tardive dyskinesia in adults. Efficacy in randomized, double-blind, placebo-controlled trials was defined as the change from baseline in Abnormal Involuntary Movement Scale total score (sum of items 1-7).Objectives: To estimate an minimal clinically important difference for the Abnormal Involuntary Movement Scale using valbenazine trial data and an anchor-based method.Methods: Data were pooled from three 6-week double-blind, placebo-controlled trials: KINECT (NCT01688037), KINECT 2 (NCT01733121), and KINECT 3 (NCT02274558). Valbenazine doses were pooled for analyses as follows: "low dose," which includes 40 or 50 mg/day; and "high dose," which includes 75 or 80 mg/day. Mean changes from baseline in Abnormal Involuntary Movement Scale total score were analyzed in all participants (valbenazine- and placebo-treated) with a Clinical Global Impression of Change-Tardive Dyskinesia or Patient Global Impression of Change score of 1 (very much improved) to 3 (minimally improved).Results: The least squares mean improvement from baseline to week 6 in Abnormal Involuntary Movement Scale total score was significantly greater with valbenazine (low dose: -2.4; high dose: -3.2; both, P < 0.001) versus placebo (-0.7). An minimal clinically important difference of 2 points was estimated based on least squares mean changes in Abnormal Involuntary Movement Scale total score in participants with a Clinical Global Impression of Change-Tardive Dyskinesia score ≤3 at week 6 (mean change: -2.2; median change: -2) or Patient Global Impression of Change score ≤3 at week 6 (mean change: -2.0; median change: -2).Conclusions: Results from an anchor-based method indicate that a 2-point decrease in Abnormal Involuntary Movement Scale total score may be considered clinically important. © 2019 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Tardive dyskinesia is a potentially irreversible, debilitating, hyperkinetic movement disorder that can result from dopamine receptor antagonists. Prompt recognition and resolution of symptoms are instrumental in preventing disease irreversibility, though current treatment options have fallen short of robust, effective, and long-term symptom control. In April 2017, the Food and Drug Administration (FDA) approved 2 new vesicular monoamine transporter 2 (VMAT2) inhibitors, deutetrabenazine and valbenazine, for chorea related to Huntington's disease and tardive dyskinesia, respectively. These agents were pharmacologically modified from tetrabenazine, a VMAT2 inhibitor used off-label in the treatment of tardive dyskinesia. Despite FDA-labeled indications of deutetrabenazine and valbenazine, each agent was explored as a treatment option for those with tardive dyskinesia. In this study, the pharmacologic modifications of the 2 new VMAT2 inhibitors are described, with detailed explanation as to how these may impact clinical practice. The associated case series, observational studies, and clinical trials exploring their use in the treatment of tardive dyskinesia are reported with expert opinion on practice implication. [ABSTRACT FROM AUTHOR]

Background: Few studies have assessed the treatment of tardive dyskinesia (TD) in patients with primary mood disorders who are managed with antipsychotics. The effects of once-daily valbenazine on TD were evaluated in adults with a bipolar or depressive disorder.Methods: Data were pooled from two 6-week double-blind placebo-controlled trials (KINECT 2 and KINECT 3; 114 mood participants) and a long-term blinded extension study (KINECT 3 extension; 77 mood participants) of valbenazine in adults with TD. Efficacy assessments included Abnormal Involuntary Movement Scale (AIMS) total score (sum of items 1-7), Clinical Global Impression of Change-Tardive Dyskinesia (CGI-TD), and Patient Global Impression of Change (PGIC). Safety assessments included treatment-emergent adverse events (TEAEs), Young Mania Rating Scale, and Montgomery-Åsberg Depression Rating Scale.Results: At Week 6, mean improvements in AIMS total score were significantly greater with valbenazine versus placebo (40 mg/day, -3.1 [P < 0.01]; 80 mg/day, -3.5 [P < 0.001]; placebo, -0.9). Significant differences between valbenazine (80 mg/day) and placebo were also found for Week 6 AIMS response (≥50% total score improvement) and CGI-TD response ("much improved" or "very much improved"), but not PGIC response. Sustained improvements in AIMS, CGI-TD, and PGIC were found through 48 weeks. Valbenazine was generally well tolerated, with no unexpected TEAEs, worsening in psychiatric symptoms, or emergence of suicidality.Limitations: Pooled analyses were conducted post hoc, and neither study was designed to focus solely on mood disorder patients.Conclusions: In participants with primary mood disorders, once-daily treatment with valbenazine was generally well tolerated and resulted in 6-week and sustained TD improvements. [ABSTRACT FROM AUTHOR]

Tardive dyskinesia (TD) is a common, iatrogenic movement disorder affecting many individuals treated with dopamine-receptor blocking agents (DRBAs). Studying treatment of TD can be complex, as the symptoms can be affected by changes in either dosage or type of DRBA, as well as by the variable natural course of the disease. Historically many pharmacological therapies have been studied in TD, finding varying degrees of treatment success. Most recently, the VMAT2 inhibitors valbenazine and deutetrabenazine were rigorously studied in TD in large, phase III clinical trials, and were shown to be beneficial in this population. In this article, we will review various treatments of TD, including manipulation of the offending agent, VMAT2 inhibitors, other non-VMAT2-inhibiting medications, and non-pharmacological approaches. [ABSTRACT FROM AUTHOR]

The term 'pharmacogenetics (PGx)' was first coined in 1959 with the aim of identifying clinically meaningful genetic predictors of responses to drug treatments and their adverse effects. PGx addresses the [...]

Tardive dyskinesia (TD) has long been thought to be a generally irreversible consequence of the use of dopamine receptor blocking agents. There is now an opportunity to successfully manage this condition with agents approved by the US Food and Drug Administration. This is important because TD has not been eliminated with the use of second-generation antipsychotics, and the expansion of antipsychotics to treat conditions other than schizophrenia has resulted in millions of additional individuals at risk for developing TD. Recognition of TD requires careful observation; a structured approach using the Abnormal Involuntary Movement Scale is encouraged. Harm reduction can be achieved by using antipsychotics judiciously when possible and by paying attention to other modifiable risk factors such as drug-induced parkinsonian symptoms and the use of anticholinergic medication. Once TD has emerged and is associated with dysfunction or distress, treatment with a VMAT2 inhibitor such as deutetrabenazine or valbenazine is well supported by several controlled clinical trials. [ABSTRACT FROM AUTHOR]

Tardive dyskinesia (TD) is an often disabling hyperkinetic movement disorder caused by exposure to dopamine receptor blocking agents. Although initially thought to most commonly occur with typical antipsychotics, the incidence is likely similar with atypical antipsychotics and antiemetics such as metoclopramide. Increased prescribing of these agents as well as low rates of remission have contributed to a rising prevalence of TD. Although this condition was described nearly 60 years ago, it is only within the past year that two novel therapeutic agents were FDA approved. Characterization of the VMAT2 inhibitor tetrabenazine, which was identified as a therapeutic agent for TD in older clinical trials, has yielded two distinct pharmacologic strategies to optimize response. The first strategy, used to create deutetrabenazine, employed deuterization of tetrabenazine to stabilize the pharmacokinetics and eliminate high peak plasma levels. The second strategy was the creation of a prodrug, valbenazine, for the two most active isoforms of tetrabenazine that also resulted in more stable pharmacokinetics and eliminated peak plasma levels. Both agents have been demonstrated to be effective and safe for the treatment of TD in multicenter, controlled trials and their development has led to a resurgence of interest in the characterization and treatment of this movement disorder. [ABSTRACT FROM AUTHOR]

Tardive dyskinesia (TD) is a medication-induced permanent movement disorder with no United States Food and Drug Administration (FDA)-approved treatments prior to 2017. Although TD is medication-induced, patients who have responded well to antipsychotics might not be candidates for dose reduction or discontinuation due to a risk of psychiatric decompensation. Valbenazine and deutetrabenazine were recently approved by the FDA for the treatment of TD. They offer a unique mechanism of action by inhibiting vesicular monoamine transporter type 2. The objective of this review is to discuss the efficacy, tolerability, dosing, drug interactions, and precautions for valbenazine and deutetrabenazine. [ABSTRACT FROM AUTHOR]

Introduction: Tardive dyskinesia (TD) is an iatrogenic movement disorder caused by exposure to dopamine receptor blocking agents. Two vesicular monoamine transporter type 2 (VMAT2) inhibitors for the treatment of TD were approved by the US Food and Drug Administration in 2017: valbenazine and deutetrabenazine. Areas covered: A brief review of TD and its identification, as well as a review of older treatment interventions is provided, followed by a detailed synthesis regarding the clinical utility of valbenazine and deutetrabenazine. Expert commentary: As evidenced from well-designed clinical trials, both valbenazine and deutetrabenazine are efficacious and tolerable. They differ in terms of labeled instructions for frequency of administration (twice daily for deutetrabenazine vs. once daily for valbenazine), titration requirements (dose to efficacy/tolerability for deutetrabenazine vs. titrate to target dose of 80 mg/day for valbenazine), need for food (administer deutetrabenazine with food), drug-drug interactions (consider CYP2D6 modulators for deutetrabenazine vs. both CYP2D6 and CYP3A4 for valbenazine), contraindications (hepatic impairment for deutetrabenazine), and minor differences in adverse event profile. [ABSTRACT FROM AUTHOR]

Introduction: Valbenazine is a selective VMAT2 inhibitor that the FDA approved in April 2017 for the specific treatment of tardive dyskinesia (TD), a movement disorder commonly caused by dopamine blocking agents. Valbenazine acts to decrease dopamine release, reducing excessive movement found in TD. Areas covered: This drug profile reviews the development of valbenazine and the clinical trials that led to its approval as the first treatment specific to TD. The literature search was performed with the PubMed online database. Expert commentary: Two clinical trials assessing the efficacy of valbenazine have shown the reduction of antipsychotic-induced involuntary movement. No life threatening adverse effects were found. Data from a 42-week extension study demonstrated sustained response. [ABSTRACT FROM PUBLISHER]

Tardive dyskinesia (TD) has long been thought to be a generally irreversible consequence of the use of dopamine receptor blocking agents. There is now an opportunity to successfully manage this condition with agents approved by the US Food and Drug Administration. This is important because TD has not been eliminated with the use of second-generation antipsychotics, and the expansion of antipsychotics to treat conditions other than schizophrenia has resulted in millions of additional individuals at risk for developing TD. Recognition of TD requires careful observation; a structured approach using the Abnormal Involuntary Movement Scale is encouraged. Harm reduction can be achieved by using antipsychotics judiciously when possible and by paying attention to other modifiable risk factors such as drug-induced parkinsonian symptoms and the use of anticholinergic medication. Once TD has emerged and is associated with dysfunction or distress, treatment with a VMAT2 inhibitor such as deutetrabenazine or valbenazine is well supported by several controlled clinical trials. [ABSTRACT FROM AUTHOR]

Introduction:Chronic intake of typical neuroleptics or centrally acting dopamine receptor blocking antiemetics may cause onset of tardive syndromes. Various types exist. One of them is tardive dyskinesia, characterised by often stigmatising, purposeless, rapid, repetitive, stereotypic, involuntary movements of face, limbs or trunk. Effective symptomatic drug treatment options beyond application of tetrabenazine are rare. Tetrabenazine is usually administered three times daily due to the short half life of this agent. Areas covered:This narrative review discusses the value of valbenazine for the treatment of tardive dyskinesia as a therapeutic alternative to tetrabenazine. Expert commentary:Valbenazine is a selective inhibitor of vesicular monoamine transporter 2, which is metabolized to (+)-alpha-dihydrotetrabenazine. Valbenazine and particularly its metabolite inhibit vesicular monoamine transporter 2 function. Once daily intake of valbenazine ameliorated the severity of tardive dyskinesia. The chiral purity of valbenazine circumvents generation of the (-)alpha and (+) and (-)beta dihydrotetrabenazine metabolites of tetrabenazine or deutetrabenazine. Valbenazine and its metabolite do not antagonize postsynaptic monoamine receptors in contrast to the tetrabenazine formulations. Therefore one may hypothesize that fewer and less severe motor and psychopathological side effects will occur during valbenazine long term application compared with tetrabenazine or deutretrabenazine. [ABSTRACT FROM PUBLISHER]

Objective: Tardive dyskinesia is a persistent movement disorder induced by dopamine receptor blockers, including antipsychotics. Valbenazine (NBI-98854) is a novel, highly selective vesicular monoamine transporter 2 inhibitor that demonstrated favorable efficacy and tolerability in the treatment of tardive dyskinesia in phase 2 studies. This phase 3 study further evaluated the efficacy, safety, and tolerability of valbenazine as a treatment for tardive dyskinesia.Method: This 6-week, randomized, double-blind, placebo-controlled trial included patients with schizophrenia, schizoaffective disorder, or a mood disorder who had moderate or severe tardive dyskinesia. Participants were randomly assigned in a 1:1:1 ratio to once-daily placebo, valbenazine at 40 mg/day, or valbenazine at 80 mg/day. The primary efficacy endpoint was change from baseline to week 6 in the 80 mg/day group compared with the placebo group on the Abnormal Involuntary Movement Scale (AIMS) dyskinesia score (items 1-7), as assessed by blinded central AIMS video raters. Safety assessments included adverse event monitoring, laboratory tests, ECG, and psychiatric measures.Results: The intent-to-treat population included 225 participants, of whom 205 completed the study. Approximately 65% of participants had schizophrenia or schizoaffective disorder, and 85.5% were receiving concomitant antipsychotics. Least squares mean change from baseline to week 6 in AIMS dyskinesia score was -3.2 for the 80 mg/day group, compared with -0.1 for the placebo group, a significant difference. AIMS dyskinesia score was also reduced in the 40 mg/day group (-1.9 compared with -0.1). The incidence of adverse events was consistent with previous studies.Conclusions: Once-daily valbenazine significantly improved tardive dyskinesia in participants with underlying schizophrenia, schizoaffective disorder, or mood disorder. Valbenazine was generally well tolerated, and psychiatric status remained stable. Longer trials are necessary to understand the long-term effects of valbenazine in patients with tardive dyskinesia. [ABSTRACT FROM AUTHOR]

The approvals of the first two medications, valbenazine and deutetrabenazine, to treat tardive dyskinesia have ushered in a new era in neuropsychiatric care. Tardive syndromes are defined as delayed onset, persistent movement disorders or sensory phenomena that occur in association with exposure to dopamine receptor blocking agents (DRBAs). Their underlying pathophysiology remains to be fully elucidated, but clinicians can conceptualize tardive syndromes as persistent dopamine supersensitivity states. Tardive syndromes can potentially cause distress, disfigurement, embarrassment, and dysfunction, and are often permanent. Therefore, practitioners who prescribe DRBAs should be aware of this potential, carefully assess the risk/benefit ratio when considering the use of these medications, and be sure that patients are appropriately informed. Patients on DRBAs should be monitored for the development of tardive syndromes, including through the use of regularly scheduled Abnormal Involuntary Movement Scale (AIMS) (or similar) examinations. Clinicians prescribing DRBAs should be familiar with the diagnosis and management of tardive syndromes, and be able to institute treatment or refer patients when treatment is appropriate. Future research may focus on the potential benefit of earlier introduction of VMAT2 inhibitors to delay onset or progression of tardive syndromes. More effective treatments are still needed, as are effective, well-tolerated antipsychotics that do not cause tardive syndromes. [ABSTRACT FROM AUTHOR]

Aim: To separate and evaluate 9-cyclopropylmethoxy-dihydrotetrabenazine (13a) and its stereoisomers for their high affinity for vesicular monoamine transporter-2 (VMAT2). Method: Stereoisomers of 13a were separated and configurations were ascertained by chiral chromatography and crystal diffraction combined with 1 H- 1 H NOESY assay. Possible binding modes of eight stereoisomers and VMAT2 were explored by molecular docking assays. The VMAT2 affinity of the stereoisomers, inhibition in vivo  and pharmacokinetics in rats were evaluated. Results: Three stereoisomers were obtained: P1, P2 and P3, and all had similar VMAT2 binding modes. P2 [(2 R , 3 R , 11b R )-13a] showed the highest potential VMAT2 binding activity ( K i  = 0.75 nM), decreased locomotor activity in rats and had an oral absolute bioavailability of 92.0%. Conclusion: P2 has good efficacy and pharmacokinetic properties and warrants further development to treat tardive dyskinesia.

Keywords: Valbenazine; Parkinsonism; Tardive dyskinesia; Drug-induced parkinsonism; Valbenazine-induced parkinsonism; VMAT inhibitors Treatment with antipsychotic drugs (APD) can lead to concurrent tardive dyskinesia (TD) and parkinsonism [[1]]. Valbenazine, Parkinsonism, Tardive dyskinesia, Drug-induced parkinsonism, Valbenazine-induced parkinsonism, VMAT inhibitors. [Extracted from the article]

Background: Individuals with tardive dyskinesia (TD) who completed a long-term study (KINECT 3 or KINECT 4) of valbenazine (40 or 80 mg/day, once-daily for up to 48 weeks followed by 4-week washout) were enrolled in a subsequent study (NCT02736955) that was primarily designed to further evaluate the long-term safety of valbenazine., Methods: Participants were initiated at 40 mg/day (following prior valbenazine washout). At week 4, dosing was escalated to 80 mg/day based on tolerability and clinical assessment of TD; reduction to 40 mg/day was allowed for tolerability. The study was planned for 72 weeks or until termination due to commercial availability of valbenazine. Assessments included the Clinical Global Impression of Severity-TD (CGIS-TD), Patient Satisfaction Questionnaire (PSQ), and treatment-emergent adverse events (TEAEs)., Results: At study termination, 85.7% (138/161) of participants were still active. Four participants had reached week 60, and none reached week 72. The percentage of participants with a CGIS-TD score ≤2 (normal/not ill or borderline ill) increased from study baseline (14.5% [23/159]) to week 48 (64.3% [36/56]). At baseline, 98.8% (158/160) of participants rated their prior valbenazine experience with a PSQ score ≤2 (very satisfied or somewhat satisfied). At week 48, 98.2% (55/56) remained satisfied. Before week 4 (dose escalation), 9.4% of participants had ≥1 TEAE. After week 4, the TEAE incidence was 49.0%. No TEAE occurred in ≥5% of participants during treatment (before or after week 4)., Conclusions: Valbenazine was well-tolerated and persistent improvements in TD were found in adults who received once-daily treatment for >1 year.

Hyperkinetic movement disorders comprise a variety of conditions characterized by involuntary movements, which include but are not limited to tardive dyskinesia, chorea associated with Huntington's Disease, and tic disorders. The class of medications that have been used to treat these conditions includes Vesicular Monoamine Transporter-2 (VMAT2) inhibitors. In 2008, the FDA approved tetrabenazine as a treatment for chorea associated with Huntington's Disease. Optimization of the pharmacology of tetrabenazine has since led to the approval of two new VMAT2 inhibitors, deutetrabenazine and valbenazine. The objective of this review is to provide background on the role of VMAT in monoamine neurotransmission, the mechanism of VMAT2 inhibition on the treatment of hyperkinetic disorders (specifically tardive dyskinesia and chorea associated with Huntington's Disease), the pharmacology and pharmacokinetics of the commercially available VMAT2 inhibitors, and a summary of the clinical data to support application of these medications. [ABSTRACT FROM AUTHOR]

This letter to the editor acknowledges the contribution of Akbar et al. to the field of tardive dyskinesia (TD) and provides important regulatory information about the potential for parkinson-like symptoms in patients with TD who are treated with valbenazine. [ABSTRACT FROM AUTHOR]

Hyperkinetic movement disorders are a common group of movement abnormalities in children, characterized with repetitive unintended involuntary movements. Major hyperkinetic movements include tremor, tic, dystonia, myoclonus, and chorea. Although a number of drugs have been proven to be beneficial for these abnormalities, some patients may become resistant to conventional treatments. Vesicular monoamine transporter 2 (VMAT 2 ) inhibitors (Tetrabenazine, Deutetrabenazine, and Valbenazine) are new agents introduced in the last decade for treating some of movement disorders, in particular tardive dyskinesia, Huntington chorea, and Tourette syndrome. In this brief review, we discussed the role of these drugs in managing hyperkinetic movement disorders., Competing Interests: The author declares that there is no conflict of interest.

Tardive dyskinesia (TD) is an iatrogenic condition that encompasses a wide phenomenological spectrum of movement disorders caused by exposure to dopamine receptor blocking agents (DRBAs). TD may cause troublesome or disabling symptoms that impair quality of life. Due to frequent, often inappropriate, use of DRBAs, TD prevalence rates among patients exposed to DRBAs continue to be high. The judicious use of DRBAs is key to the prevention of TD, reduction of disease burden, and achieving lasting remission. Dopamine-depleting vesicular monoamine transporter type 2 inhibitors are considered the treatment of choice of TD., Competing Interests: Disclosure Dr H.H. Bashir has nothing to disclose. Dr J. Jankovic has received research/training funding from Allergan; CHDI Foundation; Dystonia Coalition; F. Hoffmann-La Roche Ltd; Huntington Study Group; Medtronic Neuromodulation; Merz Pharmaceuticals; Michael J Fox Foundation for Parkinson Research; National Institutes of Health; Neurocrine Biosciences; Parkinson's Foundation; Parkinson Study Group; Revance Therapeutics, Inc; and Teva Pharmaceutical Industries. He has served as a consultant/advisory board member for Abide; Aeon BioPharma; Nuvelution; Retrophin; and Teva Pharmaceutical Industries Ltd. He has served on editorial boards of Expert Review of Neurotherapeutics; Journal of Parkinson’s Disease; Medlink; Neurology in Clinical Practice; The Botulinum Journal; PeerJ; Therapeutic Advances in Neurologic Disorders; Neurotherapeutics; Tremor and Other Hyperkinetic Movements; Toxins; and UpToDate. He has received royalties from Cambridge; Elsevier; Future Science Group; Hodder Arnold; Medlink: Neurology; Lippincott Williams and Wilkins; and Wiley-Blackwell., (Copyright © 2020 Elsevier Inc. All rights reserved.)