Tardive dyskinesia and other movement disorders secondary to aripiprazole

An update on the pharmacological management of Tourette syndrome and emerging treatment paradigms

INTRODUCTION

Tourette syndrome (TS) is a childhood-onset neurobehavioral disorder characterized by tics. Pharmacotherapy is advised for patients whose symptoms affect their quality of life.

AREAS COVERED

The authors review the tic phenomenology and TS diagnostic criteria. The bulk of this article focuses on pharmacotherapeutic options for treating tics. They also highlight pharmacotherapies in the research pipeline.

EXPERT OPINION

Tic treatment must be tailored to individual needs. Behavioral therapy is the first line of treatment. Most with bothersome tics need pharmacotherapy and rarely, for medication-refractory cases, surgical therapy is indicated. Alpha-2 agonists are considered in patients with mild tics, especially in those with attention deficit with or without hyperactivity. Second-generation antipsychotics like aripiprazole and tiapride may be considered for severe tics. However, prescribers should be mindful of potential side effects, especially drug-induced movement disorders. Botulinum toxin injections may be considered for focal motor tics. Topiramate can be considered when other treatments are ineffective, and its benefits outweigh the risks. The same holds true for vesicular monoamine transporter-2 inhibitors, as they are deemed to be safe and effective in real-world use and open-label trials despite not meeting primary endpoints in placebo-controlled trials. Cannabinoids may be considered in adults if the approaches above do not control tics.

Exploring molecular mechanisms, therapeutic strategies, and clinical manifestations of Huntington's disease

Huntington's disease (HD) is a paradigm of a genetic neurodegenerative disorder characterized by the expansion of CAG repeats in the HTT gene. This extensive review investigates the molecular complexities of HD by highlighting the pathogenic mechanisms initiated by the mutant huntingtin protein. Adverse outcomes of HD include mitochondrial dysfunction, compromised protein clearance, and disruption of intracellular signaling, consequently contributing to the gradual deterioration of neurons. Numerous therapeutic strategies, particularly precision medicine, are currently used for HD management. Antisense oligonucleotides, such as Tominersen, play a leading role in targeting and modulating the expression of mutant huntingtin. Despite the promise of these therapies, challenges persist, particularly in improving delivery systems and the necessity for long-term safety assessments. Considering the future landscape, the review delineates promising directions for HD research and treatment. Innovations such as Clustered regularly interspaced short palindromic repeats associated system therapies (CRISPR)-based genome editing and emerging neuroprotective approaches present unprecedented opportunities for intervention. Collaborative interdisciplinary endeavors and a more insightful understanding of HD pathogenesis are on the verge of reshaping the therapeutic landscape. As we navigate the intricate landscape of HD, this review serves as a guide for unraveling the intricacies of this disease and progressing toward transformative treatments.

Unique effect of clozapine on adenosine A2A-dopamine D2 receptor heteromerization

The striatal dopamine D₂ receptor (D₂R) is generally accepted to be involved in positive symptoms of schizophrenia and is a main target for clinically used antipsychotics. D₂R are highly expressed in the striatum, where they form heteromers with the adenosine A_2A receptor (A_2AR). Changes in the density of A_2AR-D₂R heteromers have been reported in postmortem tissue from patients with schizophrenia, but the degree to which A₂R are involved in schizophrenia and the effect of antipsychotic drugs is unknown. Here, we examine the effect of exposure to three prototypical antipsychotic drugs on A_2AR-D₂R heteromerization in mammalian cells using a NanoBiT assay. After 16 h of exposure, a significant increase in the density of A_2AR-D₂R heteromers was found with haloperidol and aripiprazole, but not with clozapine. On the other hand, clozapine, but not haloperidol or aripiprazole, was associated with a significant decrease in A_2AR-D₂R heteromerization after 2 h of treatment. Computational binding models of these compounds revealed distinctive molecular signatures that explain their different influence on heteromerization. The bulky tricyclic moiety of clozapine displaces TM 5 of D₂R, inducing a clash with A_2AR, while the extended binding mode of haloperidol and aripiprazole stabilizes a specific conformation of the second extracellular loop of D₂R that enhances the interaction with A_2AR. It is proposed that an increase in A_2AR-D₂R heteromerization is involved in the extrapyramidal side effects (EPS) of antipsychotics and that the specific clozapine-mediated destabilization of A_2AR-D₂R heteromerization can explain its low EPS liability.

A Case of Tardive Dystonia with Task Specificity Confined to the Lower Extremities only during Walking

Background

Task-specific dystonia (TSD) confined to the lower extremities (LE) is relatively rare. This report describes dystonia confined to the LE only during forward walking. This case required careful neurological and diagnostic assessment because the patient was taking several neuropsychiatric drugs that cause symptomatic dystonia, such as aripiprazole (ARP).

Case

A 53-year-old man visited our university hospital with a complaint of abnormalities in the LE that appeared only during walking. Neurological examinations other than walking were normal. Brain magnetic resonance imaging revealed meningioma in the right sphenoid ridge. The patient had been treated for depression with neuropsychiatric medications for a long time, and his abnormal gait appeared about 2 years after additional administration of ARP. After the meningioma was removed, his symptoms remained. Surface electromyography showed dystonia in both LE during forward walking, although his abnormal gait appeared to be accompanied by spasticity. The patient was tentatively diagnosed with tardive dystonia (TD). Although dystonia did not disappear clinically, it was alleviated after discontinuing ARP. Administration of trihexyphenidyl hydrochloride and concomitant rehabilitation improved his dystonia until return to work, but some residual gait abnormalities remained.

Discussion

We report an unusual case of TD with task specificity confined to the LE. The TD was induced by the administration of ARP in combination with multiple psychotropic medications. Careful consideration was required for clinical diagnosis, rehabilitation, and assessment of its relevance to TSD.

Individual and simultaneous treatment with antipsychotic aripiprazole and antidepressant trazodone inhibit sterol biosynthesis in the adult brain

Polypharmacy, or the simultaneous use of multiple drugs to treat a single patient, is a common practice in psychiatry. Unfortunately, data on the health effects of commonly used combinations of medications are very limited. In this study, we therefore investigated the effects and interactions between two commonly prescribed psychotropic medications with sterol inhibiting side effects, trazodone (TRZ), an antidepressant, and aripiprazole (ARI), an antipsychotic. In vitro cell culture experiments revealed that both medications alone disrupted neuronal and astroglial sterol biosynthesis in dose-dependent manners. Furthermore, when ARI and TRZ were combined, exposure resulted in an additive 7-dehydrocholesterol (7-DHC) increase, as well as desmosterol (DES) and cholesterol decreases in both cell types. In adult mice, at baseline, we found that the three investigated sterols showed significant differences in distribution across the eight assessed brain regions. Furthermore, experimental mice treated with ARI or TRZ, or a combination of both medications for 8 days, showed strong sterol disruption across all brain regions. We show ARI or TRZ alone elevated 7-DHC and decreased DES levels in all brain regions, but with regional differences. However, the combined utilization of these two medications for 8 days did not lead to additive changes in sterol disturbances. Based on the complex roles of 7-DHC derived oxysterols, we conclude that individual and potentially simultaneous use of medications with sterol biosynthesis-inhibiting properties might have undesired side effects on the adult brain, with as yet unknown long-term consequences on mental or physical health.

Atypical dyskinesias under treatment with antipsychotic drugs: Report from the AMSP multicenter drug safety project

OBJECTIVES

The aim of this study was to describe atypical dyskinesias (AtypDs) occurring during treatment with antipsychotic drugs (APDs). AtypDs are dyskinesias showing either an unusual temporal relationship between onset of treatment and start of the adverse drug reaction (ADR) or an unusual presentation of clinical symptoms.

METHODS

Data on the utilisation of APDs and reports of severe APD-induced AtypDs were collected using data from the observational pharmacovigilance programme - 'Arzneimittelsicherheit in der Psychiatrie (English: drug safety in psychiatry)' (AMSP) - from 1993 to 2016.

RESULTS

A total of 495,615 patients were monitored, of which 333,175 were treated with APDs. Sixty-seven cases (0.020%) of severe AtypDs under treatment with APDs were registered. The diagnoses of schizophrenic disorders as well as organic mental disorders were related to significantly higher rates of AtypDs. Second-generation antipsychotic drugs (SGAs) showed slightly higher rates of AtypDs (0.024%) than high-potency (0.011%) or low-potency first-generation antipsychotic drugs (FGAs; 0.006%). In 41 cases (61.2%), two or more drugs were found to cause AtypDs.

CONCLUSIONS

Our study indicates that AtypDs are rare ADRs. SGAs may have a higher risk for the occurrence of AtypDs than FGAs. Clinicians should be aware of this ADR and patients should be monitored and examined carefully.

Covert Dyskinesia With Aripiprazole: Tip of the Iceberg? A Case Report and Literature Review

BACKGROUND

Tardive dyskinesia (TD) is an involuntary movement disorder most commonly involving the tongue, lips, and face and less commonly the trunk and limbs. Although TD is historically associated with conventional antipsychotics, it still occurs with newer agents. Covert dyskinesia (CD), a form of TD, occurs after the discontinuation of antipsychotics, and it differs from other withdrawal emergent dyskinesia by its persistence for more than 8 to 12 weeks after discontinuation of dopamine receptor-blocking agents. Although initially reported in the 1960s with conventional antipsychotics, multiple recent reports describe several cases in association with aripiprazole (APZ).

METHODS

We used PubMed and the Google Scholar for CD reports during the past 20 years. We also report a recent case ofCD.

RESULTS

We identified 11 case reports of CD. Six were related to APZ, 3 to risperidone, 1 to amisulpride, and 1 to haloperidol. Our patient was an 81-year-old woman with a history of major depressive disorder who was admitted for worsening depression. Before hospitalization, she had been on APZ 5 mg/d for 2 years, but it was discontinued 4 months prior, and then she developed repetitive involuntary movements in her tongue, lips, and jaw 2 months after APZ discontinuation. The Abnormal Involuntary Movement Scale score was 5. Reinstating APZ a few months later led to disappearance of movements.

CONCLUSIONS

Literature to date suggests that APZ is the atypical antipsychotic most commonly reported with CD. A possible risk might be APZ's unique mechanism of action and its association with akathisia. Following up patients with serial Abnormal Involuntary Movement Scale after antipsychotic discontinuation is recommended.

Current Management of Tics and Tourette Syndrome: Behavioral, Pharmacologic, and Surgical Treatments

Tourette syndrome is a heterogeneous neurobehavioral disorder manifested by childhood-onset motor and phonic tics, often accompanied by a variety of behavioral comorbidities, including attention deficit and obsessive compulsive disorder. Treatment must be tailored to the needs and goals of the individual patients and their families. All patients should receive education on the condition and, if possible, engage behavioral therapy targeted towards tics and/or comorbidities. Pharmacological therapies, such as alpha agonists, topiramate, and vesicular monoamine transport type 2 inhibitors, are generally used as first-line therapies in patients with troublesome tics that are not controlled by behavioral therapy or when the latter is not available or accessible. Botulinum toxin injections can be used in patients with bothersome focal tics. Second-line therapy includes antipsychotics, such as fluphenazine, aripiprazole, risperidone, and ziprasidone. These medications are generally efficacious but carry the risk of metabolic syndrome, tardive dyskinesia, and other side effects. Much more research is needed before novel therapies such as cannabis-derived products or transcranial magnetic stimulation can be recommended. There is promise in ongoing clinical trials with D1 receptor antagonist ecopipam and other experimental therapeutics. Patients with tics that are refractory to conventional treatments may be candidates for deep brain stimulation, but further studies are needed to determine the optimal target selection.

Comparative Tolerability of Dopamine D2/3 Receptor Partial Agonists for Schizophrenia

Aripiprazole, brexpiprazole and cariprazine differ from all other second-generation antipsychotics due to partial agonism at the dopamine D2 and D3 receptors. In contrast to aripiprazole, brexpiprazole has lower intrinsic dopamine D2 activity and higher affinity for the serotonin 5-HT1A and 5-HT2A receptors, while cariprazine has the highest affinity for the dopamine D3 receptor, and the longest half-life. The main adverse effect of dopamine receptor partial agonists (DRPAs) is akathisia of low-to-moderate severity, which occurs in a small proportion of patients, usually in the first few weeks of treatment. While definitive conclusions concerning differences between the DRPAs require head-to-head comparison studies, on the available evidence, akathisia is probably least likely to occur with brexpiprazole and most likely with cariprazine; the risk of akathisia with aripiprazole lies in between. Weight-gain risk is low with aripiprazole and cariprazine, but moderate with brexpiprazole. Risk of sedation is low with DRPAs, as is risk of insomnia and nausea. Partial dopamine agonism leads to a low risk for hyperprolactinaemia (and probably a low risk of sexual dysfunction). Prolactin concentrations fall in some patients (particularly those with elevated levels prior to initiating the drugs). Rates of discontinuation due to adverse effects in pivotal studies were low, and on the whole, DRPAs are well tolerated. Aripiprazole has been implicated in pathological gambling and other impulse control behaviours, likely due to partial dopamine agonist activity (there have been no reports with brexpiprazole and cariprazine). The risks for diabetes and tardive dyskinesia with DRPAs are unknown, but are likely to be low. On the basis of tolerability, DRPAs should be considered as first-line treatment options, particularly in patients with early schizophrenia.

Treatment of tics associated with Tourette syndrome

Motor and phonic tics associated with Tourette syndrome (TS) can range in severity from barely perceptible to disabling and most patients have a variety of behavioral co-morbidities, particularly, attention deficit disorder and obsessive compulsive disorder. Therefore, therapy must be tailored to the individual needs of the patients. In addition to behavioral therapy, oral medications such as alpha agonists, dopamine depletors, anti-psychotics, and topiramate are used to control the involuntary movements and noises. Botulinum toxin injections are particularly effective in patients with troublesome focal motor and phonic tics, including coprolalia. Deep brain stimulation may be considered for patients with "malignant" TS, that is, refractory to medical therapy. When appropriate therapy is selected and implemented, most patients with TS can achieve their full potential and lead essentially normal life.

Aripiprazole in Tardive Dyskinesia: Is it a Safe Choice?

Tardive dyskinesia (TD) is a potentially irreversible drug-induced movement disorder associated with prolonged administration of antipsychotics. Conventionally, first generation antipsychotics were the agents thought to have a higher risk of TD as compared to second and third generation antipsychotics. Aripiprazole is a third generation antipsychotic with a novel mechanism of action, and until recently, cases of drug-induced movement disorders were less well known with it. But off late, several cases of TD with aripiprazole have been reported. We present here a case of middle-aged women with preexisting tardive movements, which exacerbated with aripiprazole use and reduced in frequency and intensity on withdrawal of the drug.

Tardive Dyskinesia After Aripiprazole Treatment That Improved With Tetrabenazine, Clozapine, and Botulinum Toxin

We report on a patient with tardive dyskinesia (TDK) treated with aripiprazole, a third-generation antipsychotic with partial D2 agonist-antagonist activity at both the dopamine and serotonin receptors. The patient’s condition improved with administration of a combination of tetrabenazine, botulinum toxin, and clozapine, which has previously not been used. We suggest that this treatment combination may have potential benefits for patients with TDK. After aripiprazole discontinuation, the patient was treated with clozapine (150 mg/day) and biperiden (8 mg/day). Due to a lack of improvement, we administered 300 units (intramuscularly; IM) of botulinum toxin into the paravertebral muscles every 3 months and 1,000 units IM every 4 months in addition to tetrabenazine (75 mg/day) and biperiden (8 mg/day). The patient stopped this treatment, at which point TDK reappeared. After starting a treatment regimen of clozapine (100 mg/day), tetrabenazine (75 mg/day), and botulinum toxin (300 units IM), the patient’s symptoms remitted.

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.

Pharmacoepidemiology of Tourette and Chronic Tic Disorders in Sweden 2005-2013

BACKGROUND

Monitoring "real world" dispensation patterns over time is important to build the evidence base for safe and efficient use of psychotropic drugs. In this study, we aimed to comprehensively examine the patterns of psychotropic drug dispensations in patients with Tourette and chronic tic disorders (TD/CTD) in Sweden between 2005 and 2013.

METHODS

A cohort of 6979 TD/CTD patients was identified through the Swedish National Patient Register. Their drug dispensation patterns, collected in the Swedish Prescribed Drug Register, were examined between July 1, 2005 and December 31, 2013. Frequencies of drug dispensations were further stratified by gender and comorbidities. Additionally, differences in the patterns of dispensation in children and adolescents versus adults in the last year of the follow-up were examined, as well as the time trends of the dispensations over the 8-year study period.

RESULTS

A total of 5299 (75.9%) TD/CTD patients were dispensed at least one drug during the study period. The most frequently dispensed medications were attention-deficit/hyperactivity disorder (ADHD) drugs (53.8%), antidepressants (50.7%), hypnotics/sedatives (41.7%), and antipsychotics (41.5%). Most of the medicated patients (72.1%) were dispensed more than one drug during the study period. Patterns of dispensation varied according to patient's gender, associated comorbidities, and age group. Dispensation of quetiapine and aripiprazole, antiadrenergics, ADHD drugs, antiepileptics, and hypnotics/sedatives and anxiolytics (particularly the nonbenzodiazepine types) significantly increased over time, whereas dispensation of antidepressants, typical antipsychotics, and benzodiazepine-based anxiolytics significantly decreased over the study period.

CONCLUSIONS

Long-term monitoring of these drug dispensation patterns and the study of both their beneficial and adverse effects is warranted.

Decreased Gray Matter Volume of Cuneus and Lingual Gyrus in Schizophrenia Patients with Tardive Dyskinesia is Associated with Abnormal Involuntary Movement

Tardive dyskinesia (TD) is a devastating motor disorder associated with the etiological process of schizophrenia or antipsychotic medication treatments. To examine whether cerebral morphological changes may manifest in TD, we used voxel-based morphometry to analyze high-resolution T1-weighted brain structural magnetic resonance images from 32 schizophrenics with TD (TD group), 31 schizophrenics without TD (non-TD group), and 32 healthy controls (HC group). We also assessed psychopathological symptoms with the Positive and Negative Syndrome Scale (PANSS), and TD severity with the Abnormal Involuntary Movement Scale (AIMS). We compared gray matter volumes (GMVs) among groups, and tested for correlations between GMV changes and psychopathological symptoms or TD severity. The results showed significant differences in GMV in the frontal and temporal cortices, insula and cerebellum among the three groups. Brainstem and inferior frontal and precentral gyri GMVs were significantly larger, whereas cuneus and lingual gyrus GMVs were significantly smaller in the TD group as compared to non-TD group. Further, the cuneus and lingual gyrus GMVs were positively correlated with AIMS scores in the TD group. The current results suggest that TD may be associated with the alterations in GMV that are different from that of schizophrenics without TD. Further studies are needed to confirm and to examine the functional significance of these structural findings.

Identifying the common genetic networks of ADR (adverse drug reaction) clusters and developing an ADR classification model

Adverse drug reactions (ADRs) are one of the major concerns threatening public health and have resulted in failures in drug development. Thus, predicting ADRs and discovering the mechanisms underlying ADRs have become important tasks in pharmacovigilance. Identification of potential ADRs by computational approaches in the early stages would be advantageous in drug development. Here we propose a computational method that elucidates the action mechanisms of ADRs and predicts potential ADRs by utilizing ADR genes, drug features, and protein-protein interaction (PPI) networks. If some ADRs share similar features, there is a high possibility that they may appear together in a drug and share analogous mechanisms. Proceeding from this assumption, we clustered ADRs according to interactions of ADR genes in the PPI networks and the frequency of co-occurrence of ADRs in drugs. ADR clusters were verified based on a side effect database and literature data regarding whether ADRs have relevance to other ADRs in the same cluster. Gene networks shared by ADRs in each cluster were constructed by cumulating the shortest paths between drug target genes and ADR genes in the PPI network. We developed a classification model to predict potential ADRs using these gene networks shared by ADRs and calculated cross-validation AUC (area under the curve) values for each ADR cluster. In addition, in order to demonstrate correlations between gene networks shared by ADRs and ADRs in a cluster, we applied the Wilcoxon rank sum statistical test to the literature data and results of a Google query search. We attained statistically meaningful p-values (<0.05) for every ADR cluster. The results suggest that our approach provides insights into discovering the action mechanisms of ADRs and is a novel attempt to predict ADRs in a biological aspect.

Treatment options for chorea

INTRODUCTION

Chorea is defined as jerk-like movements that move randomly from one body part to another. It is due to a variety of disorders and although current symptomatic therapy is quite effective there are few etiology- or pathogenesis-targeted therapies. The aim of this review is to summarize our own experience and published evidence in the treatment of chorea. Areas covered: After evaluating current guidelines and clinical practices for chorea of all etiologies, PubMed was searched for the most recent clinical trials and reviews using the term 'chorea' cross referenced with specific drug names. Expert commentary: Inhibitors of presynaptic vesicular monoamine transporter type 2 (VMAT2) that cause striatal dopamine depletion, such as tetrabenazine, deutetrabenazine, and valbenazine, are considered the treatment of choice in patients with chorea. Some clinicians also use dopamine receptor blockers (e.g. antipsychotics) and other drugs, including anti-epileptics and anti-glutamatargics. 'Dopamine stabilizers' such as pridopidine and other experimental drugs are currently being investigated in the treatment of chorea. Deep brain stimulation is usually reserved for patients with disabling chorea despite optimal medical therapy.

Effect of psychotropic drug treatment on sterol metabolism

Cholesterol metabolism is vital for brain function. Previous work in cultured cells has shown that a number of psychotropic drugs inhibit the activity of 7-dehydrocholesterol reductase (DHCR7), an enzyme that catalyzes the final steps in cholesterol biosynthesis. This leads to the accumulation of 7-dehydrocholesterol (7DHC), a molecule that gives rise to oxysterols, vitamin D, and atypical neurosteroids. We examined levels of cholesterol and the cholesterol precursors desmosterol, lanosterol, 7DHC and its isomer 8-dehydrocholesterol (8DHC), in blood samples of 123 psychiatric patients on various antipsychotic and antidepressant drugs, and 85 healthy controls, to see if the observations in cell lines hold true for patients as well. Three drugs, aripiprazole, haloperidol and trazodone increased circulating 7DHC and 8DHC levels, while five other drugs, clozapine, escitalopram/citalopram, lamotrigine, olanzapine, and risperidone, did not. Studies in rat brain verified that haloperidol dose-dependently increased 7DHC and 8DHC levels, while clozapine had no effect. We conclude that further studies should investigate the role of 7DHC and 8DHC metabolites, such as oxysterols, vitamin D, and atypical neurosteroids, in the deleterious and therapeutic effects of psychotropic drugs. Finally, we recommend that drugs that increase 7DHC levels should not be prescribed during pregnancy, as children born with DHCR7 deficiency have multiple congenital malformations.

Aripiprazole-induced Tardive Dyskinesia in 13 Years Old Girl Successfully Treated with Biperiden: A Case Report

In the last years second-generation antipsychotics are increasingly prescribed in the pediatric population for the treatment of several psychiatric disorders. Among the long term adverse effects, extrapyramidal symptoms (EPS) are less reported compared to first-generation antipsychotics. Tardive dyskinesia (TD) is a iatrogenic rare syndrome characterized by persistent slow writhing and sudden involuntary movements mainly involving the oral-buccal-lingual area with masticatory movements. We report a young girl with mood disorders accompanied by mild intellectual disability and behavioral problems who had TD after treatment with Aripiprazole, which responded to Biperiden therapy.

Antipsychotic-induced Tardive dyskinesia: from biological basis to clinical management

INTRODUCTION

Tardive dyskinesia (TD) is a chronic and disabling movement disorder with a complex pathophysiological basis. A significant percentage of patients does not receive correct diagnosis, resulting in delayed or inaccurate treatment and poor outcome. Therefore, there is a critical need for prompt recognition, implementation of efficacious treatment regimens and long-term follow up of patients with TD. Areas covered: The current paper provides an overview of emerging data concerning proposed pathophysiology theories, epidemiology, risk factors, and therapeutic strategies for TD. Expert commentary: Despite considerable research efforts, TD remains a challenge in the treatment of psychosis as the available strategies remain sub-optimal. The best scenario will always be the prophylaxis or prevention of TD, which entails limiting the use of antipsychotics.

[Tardive movement disorders with antipsychotics – a case of aripirazole-induced tardive dystonia and review of the literature]

Extrapyramidal adverse events (EPS) occur less frequently with second-generation antipsychotics (SGAs) than with first-generation antipsychotics (FGAs). Tardive dyskinesia (TD), but not tardive dystonia (TDt), also seems to occur less often in adults. TD was found to occur less frequently in children and adolescents treated with FGAs than in adults. No data are available on TDt, and the data pertaining to SGAs are limited and conflicting. SGAs differ in their profile of adverse events. Aripiprazole is less frequently associated with adverse metabolic or cardiac events, but more often with EPS, at least in children and adolescents. To date, there are several case reports of TD or TDt with aripiprazole in adults. Symptomatology, differential diagnosis, pathophysiology, prevalence, and therapy of TDt are presented here based on a case report of TDt during aripiprazole therapy in a 13-year-old girl. During medication with SGAs, the occurrence of EPS, including tardive movement disorders, should be considered and regularly monitored.

Drug-Induced Dyskinesia, Part 2: Treatment of Tardive Dyskinesia

Dyskinesias encompass a variety of different hyperkinetic phenomenologies, particularly chorea, dystonia, stereotypies, and akathisia. The main types of drug-induced dyskinesias include levodopa-induced dyskinesia (LID) in patients with Parkinson's disease and tardive syndrome (TS), typically present in patients with psychiatric or gastrointenstinal disorders treated with dopamine receptor blocking drugs, also referred to as neuroleptics. Besides preventive measures (i.e., avoiding the use of the offending drugs), general treatment strategies include slow taper of the offending agent and use of dopamine-depleting agents like tetrabenazine. Botulinum toxin may be helpful for wearing off focal dystonia and some forms of tardive dystonia. Deep brain stimulation is usually reserved for patients with disabling motor fluctuations, LID, and for severe TS that cannot be managed medically.

Dopamine depleters in the treatment of hyperkinetic movement disorders

INTRODUCTION

Abnormal involuntary movements often improve in response to anti-dopaminergic drugs. In contrast to classic neuroleptics that block dopamine receptors, drugs that deplete presynaptic dopamine by blocking vesicular monoamine transporter type 2 (VMAT2) seem to be safer and have little or no risk of tardive dyskinesia. This is one reason why there has been a recent emergence of novel VMAT2 inhibitors. Areas covered: Since the approval of tetrabenazine, the classic VMAT2 inhibitor, in the treatment of chorea associated with Huntington disease (HD), other VMAT2 inhibitors (e.g. deutetrabenazine and valbenazine) have been studied in the treatment of HD-related chorea, tardive dyskinesia and tics associated with Tourette syndrome. This review, based largely on a detailed search of PubMed, will summarize the pharmacology and clinical experience with the various VMAT2 inhibitors. Expert commentary: Because of differences in pharmacology and pharmacokinetics these new VMAT2 inhibitors promise to be at least as effective as tetrabenazine but with a lower risk of adverse effects, such as sedation, insomnia, depression, parkinsonism, and akathisia.

Current Pharmacological Approaches to Reduce Chorea in Huntington's Disease

There are currently no effective pharmacological agents available to stop or prevent the progression of Huntington's disease (HD), a rare hereditary neurodegenerative disorder. In addition to psychiatric symptoms and cognitive impairments, HD causes progressive motor disturbances, in particular choreiform movements, which are characterized by unwanted contractions of the facial muscles, trunk and extremities. Management of choreiform movements is usually advised if chorea interferes with daily functioning, causes social isolation, gait instability, falls, or physical injury. Although drugs to reduce chorea are available, only few randomized controlled studies have assessed the efficacy of these drugs, resulting in a high variety of prescribed drugs in clinical practice. The current pharmacological treatment options to reduce chorea in HD are outlined in this review, including the latest results on deutetrabenazine, a newly developed pharmacological agent similar to tetrabenazine, but with suggested less peak dose side effects. A review of the existing literature was conducted using the PubMed, Cochrane and Medline databases. In conclusion, mainly tetrabenazine, tiapride (in European countries), olanzapine, and risperidone are the preferred first choice drugs to reduce chorea among HD experts. In the existing literature, these drugs also show a beneficial effect on motor symptom severity and improvement of psychiatric symptoms. Generally, it is recommended to start with a low dose and increase the dose with close monitoring of any adverse effects. New interesting agents, such as deutetrabenazine and pridopidine, are currently under development and more randomized controlled trials are warranted to assess the efficacy on chorea severity in HD.

A Case of Aripiprazole-Induced Tardive Dyskinesia with Dramatic Evolution

Aripiprazole is reported to be a good clinical safety profile antipsychotic. However, recent data suggest that the risk of tardive dyskinesia could be higher than initially thought. We report the case of aripiprazole-induced tardive dyskinesia with dramatic evolution in a patient with several risk factors, including older age and exposure to antipsychotic over a period longer than six months. This case and its dramatic evolution, associated with other cases recently published, suggest reconsidering the real risk of tardive dyskinesia associated with aripiprazole, particularly in the elderly.

Deutetrabenazine in Tics Associated with Tourette Syndrome

Background

Deutetrabenazine, an inhibitor of vesicular monoamine transporter type 2 (VMAT2) depletes presynaptic dopamine and is useful in the treatment of hyperkinetic movement disorders. This study explored the safety, tolerability, and preliminary efficacy of deutetrabenazine in adolescents with moderate-to-severe tics associated with Tourette syndrome (TS).

Methods

In this open-label study of 12–18-year-old patients with TS-related tics, deutetrabenazine was titrated up to 36 mg/day over 6 weeks to adequately suppress tics without bothersome adverse effects (AEs), followed by maintenance at optimal dose for 2 weeks. An independent blinded rater assessed tic severity using the Yale Global Tic Severity Scale (YGTSS), which was the primary outcome measure. Secondary outcome measures included the TS Clinical Global Impression (TS-CGI) and TS Patient Global Impression of Change (TS-PGIC).

Results

Twenty-three enrolled patients received deutetrabenazine and had at least 1 post-baseline YGTSS assessment. The mean (SD [standard deviation]) baseline YGTSS Total Tic Severity Score (TTS) was 31.6 (7.9) and had decreased by 11.6 (8.2) points at week 8, a 37.6% reduction in tic severity (p<0.0001). The TS-CGI score improved by 1.2 (0.81) points (p<0.0001) and the TS-PGIC results at week 8 indicated that 76% of patients were much improved or very much improved compared with baseline. The mean (SD) daily deutetrabenazine dose at week 8 was 32.1 (6.6) mg (range 18–36 mg). One week after withdrawal of deutetrabenazine, the TTS scores increased by 5.6 (8.4) points, providing confirmation of the drug effect. No serious or severe adverse events were reported.

Discussion

The results of this open-label 8-week study suggest that deutetrabenazine is safe and associated with improvement in tic severity in adolescents with TS and troublesome tics.

Risk of Extrapyramidal Adverse Events With Aripiprazole

Aripiprazole is a unique atypical antipsychotic with partial agonist activity on the dopamine-2 (D2) receptor. This unique pharmacological profile of aripiprazole was thought to lead to a lower incidence of extrapyramidal symptoms (EPSs). However, recent case reports have alluded to an increase in the risk of EPS in aripiprazole users compared with nonusers of the drug. No epidemiologic studies to date have quantified this risk. We conducted a pharmacoepidemiologic study composed of a nested case-control study using a large health claims database (IMS Health) in the United States. In the nested case-control analysis, there were 5242 cases of EPS with 50,532 corresponding controls in the entire cohort. The odds ratio (OR) for EPS among those with any prescription of aripiprazole was 5.38 (95% confidence interval [CI], 3.03-9.57). The OR was lower among those taking 2 to 3 prescriptions (OR, 2.9; 95% CI, 1.07-7.85) but increased in those receiving greater than 4 prescriptions (OR, 8.64; 95% CI, 2.63-28.38). All risk periods were compared with those of subjects who had not used aripiprazole or other antipsychotics. For the secondary outcome of dyskinesia, the risk for aripiprazole was 8.50 (95% CI, 8.53-2.27-31.97) compared with that of nonusers. In conclusion, we found an increase in the risk of EPS and dyskinesias among users of aripiprazole.

Therapeutic effectiveness and tolerability of aripiprazole as initial choice of treatment in first episode psychosis in an early intervention service: A one-year outcome study

INTRODUCTION

Aripiprazole has been associated with a low prevalence of metabolic side effects as compared to other second generation antipsychotic (SGA) medications mostly in patients with long standing illness. The purpose of the present study was to assess specifically the effectiveness and safety of aripiprazole as a first choice for antipsychotic therapy for young patients presenting with a previously untreated first episode of a psychotic disorder (FEP).

METHODS

Seventy-three patients presenting with a FEP and with minimal prior exposure to antipsychotic medications were recruited to be part of an open label naturalistic outcome study using aripiprazole as the first choice of antipsychotic medication. Data on positive, negative and total symptom severity including general psychopathological symptoms, level of functioning and metabolic indices were collected prospectively over a one-year period.

RESULTS

As compared to baseline, patients treated with aripiprazole (mean dose 9.6mg) improved significantly on measures of positive (p<0.001), negative (p<0.001) and total severity-general psychopathology symptoms (p<0.001) and level of functioning (p<0.001). Seventy two percent of the participants achieved positive symptom remission and 50% achieved total remission (positive and negative) at one year of follow up. Unlike reports on patients with longer standing illness, significant weight gain (p<0.001) was observed, with 44% of participants experiencing >7% increase in body weight.

CONCLUSION

FEP patients starting treatment with aripiprazole improved on symptoms and social and occupational functioning. Aripiprazole was well tolerated except for a significant weight gain.

Determining Whether a Definitive Causal Relationship Exists Between Aripiprazole and Tardive Dyskinesia and/or Dystonia in Patients With Major Depressive Disorder, Part 4: Case Report Data

This series of columns has 3 main goals: (1) to explain class warnings as used by the United States Food and Drug Administration, (2) to increase awareness of movement disorders that may occur in patients treated with antipsychotic medications, and (3) to understand why clinicians should refrain from immediately assuming a diagnosis of tardive dyskinesia/dystonia (TD) in patients who develop abnormal movements during treatment with antipsychotics. The first column in the series presented a patient who developed abnormal movements while being treated with aripiprazole as an augmentation strategy for major depressive disorder and reviewed data concerning the historical background, incidence, prevalence, and risk factors for tardive and spontaneous dyskinesias, the clinical presentations of which closely resemble each other. The second column in the series reviewed the unique mechanism of action of aripiprazole and reviewed preclinical studies and an early-phase human translational study that suggest a low, if not absent, risk of TD with aripiprazole. The third column in this series reviewed the registration trial data for aripiprazole across all of its indications and found a raw incidence of TD ranging from 0.004 (4 out of 987) in long-term studies of the drug as an augmentation strategy for major depressive disorder to 0.0016 (19 out of 11,897) based on all short-term (ie, weeks to <6 mo) and long-term (6 mo to 1 y) studies combined. This fourth column in the series reviews the "real-world" data on aripiprazole and assesses whether these data also support the conclusion that aripiprazole has a low to absent risk of causing TD. The "real-world" data consist of case reports from the medical literature and the United States Food and Drug Administration Adverse Event Reporting System (FAERS). We found 37 cases in the medical literature reporting what was termed TD in association with aripiprazole treatment as well as 27 case reports suggesting improvement in preexisting TD with aripiprazole treatment. On the basis of the case reports from the medical literature, the potential or raw incidence of TD during "real-world" treatment with aripiprazole was 0.0000062 (37 out of the 6 million individuals who had been treated with aripiprazole in the United States as of 2013 according to a report from Otsuka). A query of the FAERS yielded 312 cases of TD in which aripiprazole was the primary suspect. On the basis of the FAERS data and again assuming 6 million individuals exposed to aripiprazole, this yields a raw incidence of 0.000052 (312 out of 6 million) for TD in patients treated with aripiprazole. However, these estimates have limitations because they are based on anecdotal reports and pharmacovigilance data and, thus, the events themselves were not confirmed or verified in a systematic way. Further, the figure of 6 million people exposed to aripiprazole was based on data reported to the authors by the drug's manufacturer and only applies to exposure in the United States. The final column in this 5-part series will discuss the types of prohibitively expensive and logistically difficult studies that would be needed to determine whether a definitive causal relationship between aripiprazole and TD exists.

Recent Advances in Understanding and Managing Tourette Syndrome

Tourette syndrome (TS) is a neurologic and behavioral disorder consisting of motor and phonic tics with onset in childhood or adolescence. The severity of tics can range from barely perceptible to severely impairing due to social embarrassment, discomfort, self-injury, and interference with daily functioning and school or work performance. In addition to tics, most patients with TS have a variety of behavioral comorbidities, including attention deficit hyperactivity disorder and obsessive-compulsive disorder. Studies evaluating the pathophysiology of tics have pointed towards dysfunction of the cortico-striato-thalamo-cortical circuit, but the mechanism of this hyperkinetic movement disorder is not well understood. Treatment of TS is multidisciplinary, typically involving behavioral therapy, oral medications, and botulinum toxin injections. Deep brain stimulation may be considered for “malignant” TS that is refractory to conventional therapy. In this review, we will highlight recent developments in the understanding and management strategies of TS.

À propos d’un cas de dyskinésie tardive d’évolution fatale induite par l’aripiprazole

L’aripiprazole peut être considéré comme un antipsychotique de 3e génération et présente théoriquement un faible risque d’induire des symptômes extrapyramidaux. Cependant, des cas de dyskinésies tardives et de dystonies induites par l’aripiprazole sont désormais rapportés assez fréquemment dans la littérature. Nous décrivons ici le cas d’un patient ayant présenté une dyskinésie d’évolution dramatique. À l’automne 2011, alors âgé de 74 ans, M X., qui n’a pas d’antécédent psychiatrique connu, présente un syndrome dépressif majeur pris en charge initialement par une association aripiprazole/escitalopram. En 2012, l’apparition progressive de dyskinésies bucco-linguo-faciales et de mouvements choréiques des membres inférieurs conduisent à l’arrêt de l’aripiprazole. Une IRM ne révèle aucune lésion des noyaux gris ou du tronc cérébral, notamment. Courant 2013 les symptômes sont amandés par l’utilisation de la tétrabénazine. Au cours de l’année suivante, on note successivement l’apparition d’une dyspnée d’effort bruyante sur spasmes diaphragmatiques, puis d’un stridor permanent sur spasme laryngé. La tétrabénazine est arrêtée en novembre 2014 dans un contexte d’aggravation de la symptomatologie dépressive. Le spasme laryngé est amélioré début 2015 par l’injection de toxine botulique, mais l’effet bénéfique s’estompe rapidement. Une nouvelle IRM réalisée en décembre 2014 ne révèle pas d’élément pour une étiologie alternative à l’hypothèse d’une dyskinésie iatrogène. En mars, la tétrabénazine est finalement réintroduite face aux dyskinésies qui persistent et deviennent de plus en plus sévères dans leur intensité. Mr X décède début juillet 2015 suite à un arrêt cardiaque dans un contexte d’insuffisance respiratoire terminale. Ce cas rappelle la prudence indispensable qu’il convient d’adopter dans l’utilisation de l’aripiprazole perçu comme un traitement antipsychotique avec un bon profil de sécurité clinique. Notre patient présentait plusieurs facteurs de risque de dyskinésie tardive incluant un âge avancé, la présence d’un trouble de l’humeur et une exposition à l’antipsychotique sur une durée supérieure à 6 mois.

A case of aripiprazole induced tardive dyskinesia in a neuroleptic-naïve patient with two years of follow up

Tardive dyskinesia (TD) is arguably the most serious and potential irreversible side effect of antipsychotic medication. Traditionally first generation antipsychotics are the neuroleptics considered to have higher risk of TD as compared to second and third generation antipsychotics. Aripiprazole is a third-generation antipsychotic with a novel mechanism of action. Risk of developing TD with use of aripiprazole has been unknown. Recently many cases of aripiprazole associated TD have been reported. A case of 52 year old Caucasian woman is discussed who presented to us with first manic episode. Patient had never been treated with any antipsychotic medication in her life before. During current episode, she was treated with aripiprazole 30 mg/day. During follow up, patient was found to have developed dyskinetic oro-facial movements within 2 months of starting aripiprazole. She was not taking any other antipsychotic/anti-dopaminergic medication at that time. Patient's abnormal oro-facial movements could not be reversed in spite of immediate discontinuation of aripiprazole. Multiple medications are tried over the next 2 years but her movement disorder never remitted. Above case (along with other recent reports) suggest that risk of movement disorder with aripiprazole use could be higher than previously thought. Further studies are required to find out incidence of movement disorder with aripiprazole. Aripiprazole use should be preferably restricted to FDA approved indications. Clinician needs to be very vigilant about emergence of any movement disorder while using aripiprazole, especially in patients with risk factors for TD.

Treatment of Tourette syndrome

Tourette's syndrome (TS) consists of chronic motor and phonic tics and characteristically begins in childhood. The tics can be disabling and commonly associated behavioral comorbities such as attention deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD), can also cause problems in daily functioning. The underlying etiology and neurobiology of TS remain unknown although genetic factors appear to be important, cortical control of basal ganglia motor function appears to be disturbed and neurochemical abnormalities, particularly involving dopamine neurotransmission, are likely present. The treatment of TS involves appropriate education and support. Tics can be treated with habit reversal cognitive behavioral therapy, medications (most commonly alpha agonists and antipsychotics), local intramuscular injections of botulinum toxin and some severe, refractory cases have responded to deep brain stimulation surgery (DBS). It is important to appropriately diagnose and treat comorbid behavioral disorders that are disrupting function. OCD can be treated with cognitive behavioral therapy, selective serotonin reuptake inhibitors, and atypical antipsychotics. DBS has become a treatment option for patients with disabling OCD despite other therapies. ADHD is treated with appropriate classroom accommodations, behavioral therapy, alpha agonists, atomoxetine or methylphenidate-containing stimulant drugs.

Long-term efficacy and safety of fluphenazine in patients with Tourette syndrome

OBJECTIVES

Haloperidol and pimozide are the only drugs currently approved by the U.S. Food and Drug Administration for treatment of Tourette syndrome (TS), but their potential side effects, which include tardive dyskinesia (TD), limit their use.

METHODS

We performed a retrospective chart review of patients with TS treated with fluphenazine over a 26-year period.

RESULTS

Among 268 patients with TS, fluphenazine was initiated at a mean age of 15.8 ± 10.7 years (range, 4.1-70.2) and titrated to an optimal dose of 3.24 ± 2.3 mg/day (range, 0.5-12.0), which was continued for an average of 2.6 ± 3.2 years (range, 0.01-16.8). Marked to moderate improvement was noted in 211 (80.5%). The most common side effects included drowsiness, fatigue, or both, observed in 70 (26.1%) patients. There were no cases of TD.

CONCLUSIONS

Fluphenazine appears to be safe and effective in the treatment of TS, and there were no cases of TD in this cohort treated up to 16.8 years.

Dopamine D3 and 5-HT1B receptor dysregulation as a result of psychostimulant intake and forced abstinence: Implications for medications development

Addiction to psychostimulants, including cocaine and amphetamine, is associated with dysregulation of dopamine and serotonin (5-HT) neurotransmitter systems. Neuroadaptations in these systems vary depending on the stage of the drug taking-abstinence-relapse cycle. Consequently, the effects of potential treatments that target these systems may vary depending on whether they are given during abstinence or relapse. In this review, we discuss evidence that dopamine D3 receptors (D3Rs) and 5-HT1B receptors (5-HT1BRs) are dysregulated in response to both chronic psychostimulant use and subsequent abstinence. We then review findings from preclinical self-administration models which support targeting D3Rs and 5-HT1BRs as potential medications for psychostimulant dependence. Potential side effects of the treatments are discussed and attention is given to studies reporting positive treatment outcomes that depend on: 1) whether testing occurs during self-administration versus abstinence, 2) whether escalation of drug self-administration has occurred, 3) whether the treatments are given repeatedly, and 4) whether social factors influence treatment outcomes. We conclude that D3/D2 agonists may decrease psychostimulant intake; however, side effects of D3/D2R full agonists may limit their therapeutic potential, whereas D3/D2R partial agonists have fewer undesirable side effects. D3-selective antagonists may not reduce psychostimulant intake during relapse, but nonetheless, may decrease motivation for seeking psychostimulants with relatively few side-effects. 5-HT1BR agonists provide a striking example of treatment outcomes that are dependent on the stage of the addiction cycle. Specifically, these agonists initially increase cocaine's reinforcing effects during maintenance of self-administration, but after a period of abstinence they reduce psychostimulant seeking and the resumption of self-administration. In conclusion, we suggest that factors contributing to dysregulation of monoamine systems, including drug history, abstinence, and social context, should be considered when evaluating potential treatments to better model treatment effects in humans. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.

Gray matter abnormalities in schizophrenia patients with tardive dyskinesia: a magnetic resonance imaging voxel-based morphometry study

OBJECTIVE

The pathophysiological mechanism of TD remains unknown. All previous studies, using the region-of-interest method, focused on basal ganglion areas, were with inconsistent results. This whole-brain voxel-based morphometry (VBM) study investigate the grey matter abnormality of TD and its correlates with clinical ratings.

METHOD

High resolution T1-weighted brain volumetric MRI from 25 schizophrenia patients with TD (TD group), 25 age-, gender-, and handedness-matched schizophrenia patients without TD (non-TD group), and 25 matched healthy subjects (NC group) were analyzed using a VBM approach. Clinical ratings included the Positive and Negative Symptom Scale (PANSS), Abnormal Involuntary Movement Scale (AIMS), and the Simpson-Angus Scale (SAS).

RESULTS

The TD group had significantly smaller total gray matter volumes than the NC group (p = 0.05). Compared to the non-TD group, the TD group had significantly higher PANSS negative (p<0.001), SAS (p<0.001), and AIMS (p<0.001) scores; and smaller bilateral inferior frontal gyrus, which correlated negatively with the PANSS negative scores (r = -0.366, p<0.05); and smaller right superior frontal gyrus, which correlated negatively with AIMS scores (r = -0.399, p<0.001), and PANSS general score (r = -0.338, p<0.05).

LIMITATIONS

The cross-section design can't separate the gray matter change to TD from the context of the illness of schizophrenia, although TD with more severe clinical psychopathology could be a phenotype.

CONCLUSIONS

The schizophrenia patients with TD had significantly reduced gray matter, mostly at the bilateral inferior frontal gyrus and the right superior frontal gyrus, which correlated with severity of clinical symptoms and involuntary movement, respectively.

An update on tardive dyskinesia: from phenomenology to treatment

Tardive dyskinesia (TD), characterized by oro-buccal-lingual stereotypy, can manifest in the form of akathisia, dystonia, tics, tremor, chorea, or as a combination of different types of abnormal movements. In addition to movement disorders (including involuntary vocalizations), patients with TD may have a variety of sensory symptoms, such as urge to move (as in akathisia), paresthesias, and pain. TD is a form of tardive syndrome-a group of iatrogenic hyperkinetic and hypokinetic movement disorders caused by dopamine receptor-blocking agents. The pathophysiology of TD remains poorly understood, and treatment of this condition is often challenging. In this update, we provide the most current information on the history, nomenclature, etiology, pathophysiology, epidemiology, phenomenology, differential diagnosis, and treatment of TD.

Treatment of neurolept-induced tardive dyskinesia

Tardive dyskinesia (TDK) includes orobuccolingual movements and "piano-playing" movements of the limbs. It is a movement disorder of delayed onset that can occur in the setting of neuroleptic treatment as well as in other diseases and following treatment with other drugs. The specific pathophysiology resulting in TDK is still not completely understood but possible mechanisms include postsynaptic dopamine receptor hypersensitivity, abnormalities of striatal gamma-aminobutyric acid (GABA) neurons, and degeneration of striatal cholinergic interneurons. More recently, the theory of synaptic plasticity has been proposed. Considering these proposed mechanisms of disease, therapeutic interventions have attempted to manipulate dopamine, GABA, acetylcholine, norepinephrine and serotonin pathways and receptors. The data for the effectiveness of each class of drugs and the side effects were considered in turn.

Tetrabenazine for the treatment of chorea and other hyperkinetic movement disorders

Tetrabenazine (TBZ; Xenazine) is a potent, selective, reversible depletor of monoamines from nerve terminals. TBZ inhibits the vesicular monoamine transporter type 2 which, in humans, is expressed nearly exclusively in the brain. TBZ is rapidly metabolized in the liver by carbonyl reductase to stereoisomers of hydrotetrabenazine, some of which are potent inhibitors of vesicular monoamine transporter type 2. Initially developed in the 1950s for schizophrenia, since the 1970s several publications have reported on the efficacy of TBZ in the treatment of various hyperkinetic movement disorders. Although quite effective in controlling the involuntary movements, there were considerable inter-individual differences in the optimal dose, defined as the dose judged by the investigator to provide the greatest efficacy with minimal or tolerable adverse events. This variability is in part owing to differences in severity and mechanism of the target symptoms and to variable activity of the enzyme carbonyl reductase that metabolizes TBZ to its active metabolites. Dose-limiting adverse events, consisting mainly of sedation, parkinsonism, akathisia and depression, are usually rapidly reversible upon dosage reduction. In addition to its established antichorea efficacy in Huntington's disease, the drug has been reported to also be effective in a variety of other hyperkinetic movement disorders, including tardive dyskinesia and tics associated with Tourette's syndrome.

Aripiprazole: a review of its use in the management of mania in adults with bipolar I disorder

Aripiprazole (Abilify®) is an atypical antipsychotic indicated for the treatment of mania associated with bipolar I disorder. It is unique in its class, as it is a partial agonist of dopamine D(2) and D(3), and serotonin 5-HT(1A) receptors and a modest antagonist of 5-HT(2A) receptors. This article reviews the pharmacological properties, clinical efficacy and tolerability of oral aripiprazole in the management of mania associated with bipolar I disorder in adults. In well designed clinical trials in patients with recent manic or mixed episodes associated with bipolar I disorder, oral aripiprazole monotherapy or adjunctive therapy to lithium or valproate improved symptoms of mania following short-term (≤12 weeks) or maintenance (≤100 weeks) treatment. In addition, maintenance treatment with aripiprazole (as monotherapy or adjunctive therapy) prevented the recurrence of any mood episodes or manic episodes (but not depressive episodes) in patients who had previously been stabilized and maintained on aripiprazole. Aripiprazole was generally well tolerated in these studies and was associated with a low risk of prolactin elevation, corrected QT interval prolongation and metabolic disturbances. Extrapyramidal symptoms occurred in up to 28% of aripiprazole recipients, but after longer-term treatment (≤100 weeks), symptom severity did not differ significantly from that in placebo recipients. Aripiprazole treatment generally did not increase bodyweight to a clinically relevant extent; however, more patients receiving aripiprazole monotherapy than placebo had clinically significant bodyweight gain during 100 weeks' treatment. Additionally, in a comparative trial, aripiprazole monotherapy was at least as effective as haloperidol monotherapy in terms of improving symptoms of mania, but had the advantage of a lower incidence of some adverse events, such as extrapyramidal symptom-related adverse events. Further trials comparing aripiprazole with other agents, including atypical antipsychotics, would help to definitively position aripiprazole relative to these agents. Current guidelines recommend aripiprazole as a first-line option (as monotherapy or adjunctive therapy) for the short-term treatment of mania associated with bipolar I disorder, and as a first-line (as monotherapy) or second-line (as adjunctive therapy) option for preventing the recurrence of mood episodes during longer-term therapy.