Epidemiology of tardive dyskinesia: Is risk declining with modern antipsychotics?

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.

Tardive dyskinesia: therapeutic options for an increasingly common disorder

Tardive dyskinesia (TD) is a serious, often disabling, movement disorder that is caused by medications that block dopamine receptors (i.e., neuroleptics, anti-emetics). There is currently no standard treatment approach for physicians confronted with such patients. This may be the result of notions that TD is disappearing because of the switch to second-generation antipsychotic agents and that it is largely reversible. In this article we demonstrate that second-generation antipsychotics do, indeed, cause TD and, in fact, the frequency is likely higher than expected because of growing off-label uses and a tripling of prescriptions written in the last 10 years. In addition, studies demonstrate that TD actually remits in only a minority of patients when these drugs are withdrawn. Furthermore, neuroleptic agents are often utilized to treat TD, despite prolonged exposure being a risk factor for irreversibility. The outcome of these trends is a growing population afflicted with TD. We review non-neuroleptic agents that have shown positive results in small, early-phase, blinded trials, including tetrabenazine, amantadine, levetiracetam, piracetam, clonazepam, propranolol, vitamin B6, and Ginkgo biloba. Other options, such as botulinum toxin and deep brain stimulation, will also be discussed, and a suggested treatment algorithm is provided. While these agents are reasonable treatment options at this time there is a need, with a concerted effort between neurology and psychiatry, for full-scale drug development, including multicenter, randomized, blinded trials to confirm the effectiveness of the agents that were positive in phase 2 trials and the development of newer ones.

Association study of the vesicular monoamine transporter gene SLC18A2 with tardive dyskinesia

Tardive dyskinesia (TD) is an involuntary movement disorder that can occur in up to 25% of patients receiving long-term first-generation antipsychotic treatment. Its etiology is unclear, but family studies suggest that genetic factors play an important role in contributing to risk for TD. The vesicular monoamine transporter 2 (VMAT2) is an interesting candidate for genetic studies of TD because it regulates the release of neurotransmitters implicated in TD, including dopamine, serotonin, and GABA. VMAT2 is also a target of tetrabenazine, a drug used in the treatment of hyperkinetic movement disorders, including TD. We examined nine single-nucleotide polymorphisms (SNPs) in the SLC18A2 gene that encodes VMAT2 for association with TD in our sample of chronic schizophrenia patients (n = 217). We found a number of SNPs to be nominally associated with TD occurrence and the Abnormal Involuntary Movement Scale (AIMS), including the rs2015586 marker which was previously found associated with TD in the CATIE sample (Tsai et al., 2010), as well as the rs363224 marker, with the low-expression AA genotype appearing to be protective against TD (p = 0.005). We further found the rs363224 marker to interact with the putative functional D2 receptor rs6277 (C957T) polymorphism (p = 0.001), supporting the dopamine hypothesis of TD. Pending further replication, VMAT2 may be considered a therapeutic target for the treatment and/or prevention of TD.

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.

Withdrawal symptoms and rebound syndromes associated with switching and discontinuing atypical antipsychotics: theoretical background and practical recommendations

With the widespread use of atypical or second-generation antipsychotics, switching treatment has become current practice and more complicated, as the pharmacological profiles of these agents differ substantially despite their similarity in being 'atypical'. All share the ability to block dopamine D₂ receptors, and most of them also block serotonin 5-HT2A receptors. Apart from these common features, some atypical antipsychotics are also able to block or stimulate other dopamine or serotonin receptors, as well as histaminergic, muscarinergic or adrenergic receptors. As a result of the varying receptor affinities, in switching or discontinuing compounds several possible pitfalls have to be considered, including the occurrence of withdrawal and rebound syndromes. This article reviews the pharmacological background of functional blockade or stimulation of receptors of interest in regard to atypical antipsychotics and the implicated potential withdrawal and rebound phenomena. A MEDLINE search was carried out to identify information on withdrawal or rebound syndromes occurring after discontinuation of atypical antipsychotics. Using the resulting literature, we first discuss the theoretical background to the functional consequences of atypical antipsychotic-induced blockade or stimulation of neurotransmitter receptors and, secondly, we highlight the clinical consequences of this. We then review the available clinical literature on switching between atypical antipsychotics, with respect to the occurrence of withdrawal or rebound symptoms. Finally, we offer practical recommendations based on the reviewed findings. The systematic evaluation of withdrawal or rebound phenomena using randomized controlled trials is still understudied. Knowledge of pharmacological receptor-binding profiles may help clinicians in choosing adequate switching or discontinuation strategies for each agent. Results from large switching trials indicate that switching atypical antipsychotics can be performed in a safe manner. Treatment-emergent adverse events during or after switching are not always considered to be, at least in part, associated with the pre-switch antipsychotic. Further studies are needed to substantiate the evidence gained so far on different switching strategies. The use of concomitant medication, e.g., benzodiazepines or anticholinergic drugs, may help to minimize symptoms arising from the discontinuation or switching of antipsychotic treatment.

There is no evidence for an association between the serotonin receptor 3A gene C178T polymorphism and tardive dyskinesia in Korean schizophrenia patients

BACKGROUND

Tardive dyskinesia (TD) is a potential adverse effect of long-term treatment with antipsychotics. Previous studies have suggested a link between brain serotonergic systems and TD vulnerability. A recent report described that a serotonin 3 receptor (5-HTR3) agonist induced rhythmic movements in mice with complete paraplegia. Furthermore, it has been reported that the 5-HTR3 antagonist ondansetron is efficacious in the treatment of Gilles de la Tourette syndrome (GTS).

AIM

The aim of the present study was to determine whether the 5-HTR3A gene C178T polymorphism is associated with antipsychotic-induced TD in Korean schizophrenia patients.

METHODS

We investigated 280 Korean schizophrenia patients. Subjects with TD (n = 105) and without TD (n = 175) were matched for antipsychotic drug exposure and other relevant variables.

RESULTS

The distributions of genotypic (chi-squared = 3.55, p = 0.169) and allelic (chi-squared = 0.40, p = 0.528) frequencies did not differ between patients with and without TD. The total score on the Abnormal Involuntary Movement Scale also did not differ between the two genotype groups (F = 0.94, p = 0.391).

CONCLUSIONS

The findings of the present study do not support the involvement of the 5-HTR3A gene C178T polymorphism in TD in Korean schizophrenia subjects.

Association of the dopamine β-hydroxylase 19 bp insertion/deletion polymorphism with positive symptoms but not tardive dyskinesia in schizophrenia

OBJECTIVE

Overactivity of dopaminergic neurotransmission is a putative mechanism of tardive dyskinesia (TD). Dopamine beta-hydroxylase (DBH) is a key enzyme in the conversion of dopamine to norepinephrine, and plasma DBH activity is altered in TD patients. This study examined whether the functional DBH 5'-Ins/Del polymorphism was associated with TD severity in Chinese patients with schizophrenia.

METHODS

We compared the rate of this polymorphism in patients with (n = 312) and without TD (n = 435), and healthy controls (n = 625). The severity of TD was assessed using the Abnormal Involuntary Movement Scale (AIMS) and psychopathology using the Positive and Negative Syndrome Scale (PANSS).

RESULTS

There were no significant differences in the distribution of the allele and genotype frequencies between the patients and controls, or between the patients with and without TD. Also, there was no significant difference in the AIMS total score between the three genotype groups. However, the PANSS positive symptom subscore was significantly higher in patients with Del/Del genotype (13.2 ± 5.2) than those with Ins/Del (11.2 ± 4.9) and Ins/Ins (11.1 ± 3.1) genotypes (both p < 0.05).

CONCLUSION

These results suggest that although the DBH 5'-Ins/Del polymorphism was not associated with susceptibility to TD in patients with schizophrenia, it might be related to positive symptoms of schizophrenia.

Haloperidol-induced striatal Nur77 expression in a non-human primate model of tardive dyskinesia

Tardive dyskinesia (TD) is a delayed and potentially irreversible motor complication arising in patients chronically exposed to antipsychotic drugs. As several modern (so-called atypical) antipsychotic drugs are common offenders, combined with the widening clinical indications for prescription as well as exposure of vulnerable individuals, TD will remain a significant drug-induced unwanted side effect. In addition, the pathophysiology of TD remains elusive and therapeutics are difficult. Based on rodent experiments, we have previously shown that the transcriptional factor Nur77 (also known as nerve growth factor inducible gene B or Nr4a1) is induced in the striatum following antipsychotic drug exposure as part of a long-term neuroadaptive process. To confirm this, we exposed adult capuchin (Cebus apella) monkeys to prolonged treatments with haloperidol (median 18.5 months, N = 11) or clozapine (median 6 months, N = 6). Six untreated animals were used as controls. Five haloperidol-treated animals developed mild TD movements similar to those found in humans. No TD was observed in the clozapine group. Postmortem analysis of Nur77 expression measured by in situ hybridization revealed a stark contrast between the two drugs, as Nur77 mRNA levels in the caudate-putamen were strongly upregulated in animals exposed to haloperidol but were spared following clozapine treatment. Interestingly, within the haloperidol-treated group, TD-free animals showed higher Nur77 expression in putamen subterritories compared with dyskinetic animals. This suggests that Nur77 expression might be associated with a reduced risk of TD in this experimental model and could provide a novel target for drug intervention.

[Tardive dyskinesia induced by classical antipsychotic drugs: a Tunisian sample of schizophrenics]

INTRODUCTION

The term tardive dyskinesia (TD) is used to describe abnormal movement, primarily associated with typical antipsychotic drugs, which are used to treat psychotic states such as schizophrenia. TD is characterised by repetitive involuntary purposeless muscle contractions that force parts of the body into abnormal, and sometimes painful, movements or postures. These movements are involuntary and are difficult or impossible to control. TD usually begins with the face, mouth, lips and tongue, and includes grimacing, lip-smacking, tongue movements and rapid blinking. It may also involve the rest of the body and produce involuntary gestures, tics and writhing movements. TD is severe physically and socially disabling. Schizophrenia is thought to be the psychiatric diagnosis the most frequently associated with TD.

MATERIALS AND METHODS

The purpose of this article is to study the characteristics of TD in a Tunisian sample of 157 schizophrenics. A variety of demographic and clinical information was obtained by a questionnaire. Diagnoses of schizophrenia and TD were determined by using DSM-VI-R criteria. TD was assessed using the Abnormal Involuntary Movements Scale (AIMS).

RESULTS

The average age in this sample was 37 ± 6 years. The intermediate duration of evolution of the disease was 8 ± 3 years with a medium full number of hospitalizations of 4 ± 3. We found 58% of the paranoid sub-type. The intermediate duration of exposure to classical neuroleptics was 7 ± 3 years. The average of daily neuroleptic amount was 572.9 ± 145.3 equivalent milligrams of chlorpromazine. Extended release antipsychotics were used in 64.3% of cases, with fluphenazine deaconate in 90% and haloperidol deaconate in 10%. Anticholinergics were used by 74.5% of patients, with use of biperidene in 96% of cases. Therapeutic observance was good in 89.2% of patients. The prevalence of TD was an estimated 35%. The average of AIMS score was 17 ± 9, with a minimal score of 3 and a maximal one of 34. The distribution of patients according to severity found a prevalence of 52.7% of subjects with moderate TD, 38.2% with light TD and 9.1% with severe TD. The distribution of patients according to type, according to DSM-IV criteria, found 78.4% of cases with choreiform TD, 17.5% of cases with athetosic TD and 4.1% of cases with rhythmic TD. The intermediate duration of evolution of TD was estimated at 18 ± 6 months with a minimal duration of 3 months and a maximum of 72 months. The distribution of subjects according to duration of evolution of TD found that approximately three quarter of patients presented with TD that had evolved since one duration, lower or equal to one year. The average age of patients at the moment of installation of TD was estimated at 36 ± 6 years with 22 years as a minimal and 46 years as a maximal age. Among them, 81.8% of patients were aged over 30 at the time of the installation of TD.

CONCLUSION

The majority of patients with schizophrenia in Tunisia are still treated with typical antipsychotic drugs, and that's why the prevalence of TD remains relatively high.

Diagnostic Challenges Revealed from a Neuropsychiatry Movement Disorders Clinic

Background:

Abnormal movements are frequently associated with psychiatric disorders. Optimized management and diagnosis of these movements depends on correct labeling. However, there is evidence of reduced accuracy in the labeling of these movements, which could result in sub-optimal care.

Objective:

To determine the consensus inter-rater reliability between a movement disorders neurologist and physicians referring from the community for phenomenology and diagnoses of individuals with co-existing psychiatric conditions and movement disorders.

Method:

Charts of all consecutive patients seen in a combined Movement Disorders and Neuropsychiatry Clinic between 2001-2009 were reviewed retrospectively. Consensus estimates and kappa values for inter-rater reliability were determined for phenomenology and diagnostic terms for the respective referring source and movement disorders neurologist for each patient.

Results:

A total of 106 charts were reviewed (62 men and 44 women). Agreement for phenomenology terms ranged from 0% (psychogenic) to 73% (tremor). Only 3 terms had kappa values that met or exceeded criteria for moderate inter-rater reliability. Agreement for diagnosis terms was highest for tardive dyskinesia (83%), drug induced tremor (33%), and drug induced parkinsonism (20%). In 18 of the 22 charts (82%), a diagnosis was made of drug induced movement disorder (DIMD) by the referring physician. In contrast, a diagnosis of DIMD was made in only 54 of 106 charts (51%) after the patients were assessed in the clinic.

Conclusions:

A movement disorders specialist frequently disagreed with referring physicians' identification of patient phenomenology and diagnosis. This suggests that clinicians would benefit from educational resources to assist in characterizing abnormal movements.

Second-generation antipsychotics: reviewing the cost-effectiveness component of the CATIE trial

The cost-effectiveness component of the 18-month CATIE trial of schizophrenia pharmacotherapy (n = 1460) showed that the first-generation antipsychotic perphenazine was US$300-600 per month less expensive than each of four second-generation antipsychotics, and no less effective across multiple measures. We consider whether or not each of eight potential methodological limitations could weaken this conclusion: follow-up rates, study duration, sample characteristics, the choice of outcome measures, exclusion of patients with tardive dyskinesia from assignment to perphenazine, choice of study drugs and doses, reliance on intention-to-treat analysis, and differences in prestudy treatment. We conclude that results of CATIE are robust to these limitations. Perphenazine seems to have been a more representative choice for first-generation antipsychotic comparison treatment than haloperidol.

Are atypical antipsychotics safer than typical antipsychotics for treating behavioral and psychological symptoms of dementia?

Atypical antipsychotics seem to be preferable than conventional agents in treating psychological symptoms of dementia (BPSD), because they have substantially lower risks of extrapyramidal neurological effects with lower reported rates of parkinsonism and tardive dyskinesia. However, in the course of time, with the increase in their use, more and more side effects have been reported. The benefits and risks of antipsychotic treatment should be carefully evaluated according to the co-morbidity and the severity of the psychological and behavioral symptoms and their impact on the individual elderly patient. It is recommended to keep those medications in the lower range of therapeutic doses. Due to the complexity of the individual patient, no guidelines have been yet established. Therefore, clinical judgment should be used in applying the dose and the type of those drugs.

Pharmacogenetics of response to antipsychotics in patients with schizophrenia

This review presents the findings of pharmacogenetic studies exploring the influence of gene variants on antipsychotic treatment response, in terms of both symptom improvement and adverse effects, in patients with schizophrenia. Despite numerous studies in the field, replicating findings across different cohorts that include subjects of different ethnic groups has been challenging. It is clear that non-genetic factors have an important contribution to antipsychotic treatment response. Differing clinical, demographic and environmental characteristics of the cohorts studied have added substantial complexity to the interpretation of the positive and negative findings of many studies. Pharmacogenomic genome-wide investigations are beginning to yield interesting data although they have failed to replicate the most robust findings of candidate gene studies, and are limited by the sample size, especially given the need for studying homogeneous cohorts. Most of the studies conducted on cohorts treated with single antipsychotics have investigated clozapine, olanzapine or risperidone response. These studies have provided some of the most replicated associations with treatment efficacy. Serotonergic system gene variants are significantly associated with the efficacy of clozapine and risperidone, but may have less influence on the efficacy of olanzapine. Dopamine D3 receptor polymorphisms have been more strongly associated with the efficacy of clozapine and olanzapine, and D2 genetic variants with the efficacy of risperidone. Serotonin influences the control of feeding behaviour and has been hypothesized to have a role in the development of antipsychotic-induced weight gain. Numerous studies have linked the serotonin receptor 2C (5-HT2C) -759-C/T polymorphism with weight gain. The leptin gene variant, -2548-G/A, has also been associated with weight gain in several studies. Pharmacogenetic studies support the role of cytochrome P450 enzymes and dopamine receptor variants in the development of antipsychotic-induced movement disorders, with a contribution of serotonergic receptors and other gene variants implicated in the mechanism of action of antipsychotics. Clozapine-induced agranulocytosis has been associated with polymorphisms in the major histocompatibility complex gene (HLA).

Motor symptoms of schizophrenia: is tardive dyskinesia a symptom or side effect? A modern treatment

Abnormal involuntary dyskinetic movements in schizophrenia patients have been documented for more than 140 years. Clinicians should distinguish between two kinds of disturbances-spontaneous dyskinetic movements and movements induced by psychotropic medications-which may look familiar clinically. As a modern term, tardive dyskinesia (TD) is a potentially permanent neurological hyperkinetic movement disorder that occurs after months or years of taking psychotropic drugs. Several distinct forms of TD exist, specifically tardive akathisia, tardive blepharospasm, tardive dystonia, tardive gait, tardive myoclonus, tardive tremor, and tardive tics, and they have different pathophysiologies and treatment. The pathogenesis of TD remains unclear, and the pathophysiology is complex and multifactorial. Moreover, there is solid evidence of a genetic predisposition to TD. This article summarizes recent relevant publications concerning TD and the most recent studies regarding treatment of this disorder with antioxidative agents.

Mechanisms of action of antipsychotic drugs of different classes, refractoriness to therapeutic effects of classical neuroleptics, and individual variation in sensitivity to their actions: Part II

Rapid-onset psychotic rebound is uncommon on discontinuation of most antipsychotic drugs, as might be expected for antipsychotic drugs with (hypothetically) indirect actions at their final target receptors. Rapid-onset psychosis is more common on withdrawal of clozapine, which might be expected if its action is direct. Drugs other than clozapine (notably thioridazine) may have hitherto unrecognised similarities to clozapine (but without danger of agranulocytosis), and may be useful in treatment of refractory psychosis. Quetiapine fulfils only some criteria for a clozapine-like drug. Clinical response to neuroleptics varies widely at any given plasma level. Haase's "neuroleptic threshold" concept suggests that the dose producing the slightest motor side effects produces most or all of the therapeutic benefit, but analyses presented here suggest that antipsychotic actions are not subject to a sharp "all-or-none" threshold but increase over a small dose range. This concept could provide a method for quantitative determination of individualized optimal doses.

Ethical and Policy Considerations in the Application of Pharmacogenomic Testing for Tardive Dyskinesia: Case Study of the Dopamine D3 Receptor

Tardive dyskinesia (TD) is a serious adverse effect often associated with the first generation antipsychotic medications used in the management of mental health disorders such as schizophrenia. Pharmacogenomics is the study of human genomic variation in relation to individual and population variability in medication response and side effects. Neuropsychiatry is one of the clinical domains in which pharmacogenomic approaches have been extensively studied. In the late 1990s, the Glycine9 (Gly9) allele of the Serine-9-Glycine (Ser9Gly) polymorphism in dopamine D3 receptor gene (DRD3) was found to be associated with both a liability to, and worsened severity of, TD in schizophrenic patients treated with typical antipsychotics. This initial discovery has been subsequently replicated and testing for the Ser9Gly polymorphism has now become commercially available. The question that currently presents itself is whether its use should be encouraged for patients who may be prescribed a typical or atypical antipsychotic medication. However, the translation of this new technology to clinical practice presents multiple social, ethical and policy challenges. Though pharmacogenomic testing holds much promise in this scenario, many important questions remain to be answered before its widespread use can be medically and ethically justified. This article highlights the key advances in our understanding of the role of human genetic variation in the D3 receptor in relation to TD. Then, issues of uncertainty, consent, confidentiality, and access are considered with respect to the use of DRD3 polymorphism testing in risk stratification for susceptibility to tardive dyskinesia. We propose three recommendations that may help bring this technology into the clinic: 1) prospective pharmacogenomic studies of DRD3 polymorphism and TD risk should be conducted; 2) the design of such studies should be influenced by scientists, ethicists and policy makers to protect potentially vulnerable patients; and 3) appropriate knowledge transfer to front-line health care workers must take place.

Tardive dyskinesia: treatment with aripiprazole

Tardive dyskinesia is characterized by choreiform movements, or rhythmic abnormal involuntary movements of the face, mouth, tongue, trunk, and limbs. It is frequently associated with the use of neuroleptic medications. The choreiform movements are irreversible in some patients, even after the drug is withdrawn. Although no reliable treatment for tardive dyskinesia exists, atypical antipsychotics are associated with a significantly lower incidence of tardive dyskinesia than typical antipsychotics. Moreover, recent reports suggest that atypical antipsychotics may have a beneficial effect on tardive dyskinesia remission. Until recently, evidence for the effectiveness of aripiprazole on tardive dyskinesia has been mixed. Aripiprazole has a unique mechanism of action and has various effects in tardive dyskinesia. The drug acts as a partial D₂ receptor agonist that can stabilize D₂ up-regulation, and as a partial 5-HT_1A receptor agonist and a 5-HT_2A receptor antagonist, and can increase the release of dopamine in the striatum.

Treatment outcomes of patients with tardive dyskinesia and chronic schizophrenia

OBJECTIVE

We compared the response to antipsychotic treatment between patients with and without tardive dyskinesia (TD) and examined the course of TD.

METHOD

This analysis compared 200 patients with DSM-IV-defined schizophrenia and TD and 997 patients without TD, all of whom were randomly assigned to receive one of 4 second-generation antipsychotics. The primary clinical outcome measure was time to all-cause treatment discontinuation, and the primary measure for evaluating the course of TD was change from baseline in Abnormal Involuntary Movement Scale (AIMS) score. Kaplan-Meier survival analysis and Cox proportional hazards regression models were used to compare treatment discontinuation between groups. Changes in Positive and Negative Syndrome Scale (PANSS) and neurocognitive scores were compared using mixed models and analysis of variance. Treatment differences between drugs in AIMS scores and all-cause discontinuation were examined for those with TD at baseline. Percentages of patients meeting criteria for TD postbaseline or showing changes in AIMS scores were evaluated with χ(2) tests. Data were collected from January 2001 to December 2004.

RESULTS

Time to treatment discontinuation for any cause was not significantly different between the TD and non-TD groups (χ(2)(1) = 0.11, P = .743). Changes in PANSS scores were not significantly different (F(1,974) = 0.82, P = .366), but patients with TD showed less improvement in neurocognitive scores (F(1,359) = 6.53, P = .011). Among patients with TD, there were no significant differences between drugs in the decline in AIMS scores (F(3,151) = 0.32, P = .811); 55% met criteria for TD at 2 consecutive visits postbaseline, 76% met criteria for TD at some or all postbaseline visits, 24% did not meet criteria for TD at any subsequent visit, 32% showed a ≥ 50% decrease in AIMS score, and 7% showed a ≥ 50% increase in AIMS score.

CONCLUSIONS

Schizophrenia patients with and without TD were similar in time to discontinuation of treatment for any cause and improvement in psychopathology, but differed in neurocognitive response. There were no significant differences between treatments in the course of TD, with most patients showing either persistence of or fluctuation in observable symptoms.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00014001.

No Evidence for an Association between Dopamine D2 Receptor Polymorphisms and Tardive Dyskinesia in Korean Schizophrenia Patients

OBJECTIVE

Tardive dyskinesia (TD) is a long-term adverse effect of antipsychotic. Dopaminergic activity in the nigrostriatal system have been proposed to be involved in development of TD and dopamine D2 receptors (DRD2) has been regarded as a candidate gene for TD because the antipsychotics have potent antagonism DRD2. This study was aimed to find the relationship between DRD2 gene and antipsychotic-induced TD.

METHODS

We evaluated whether 5 DRD2 single nucleotide polymorphisms (-141Cins>del/TaqID/NcoI/Ser311Cys/TaqIA) are associated with antipsychotic-induced TD in 263 Korean schizophrenia patients with (n=100) and without TD (n=163) who were matched for antipsychotic drug exposure and other relevant variables. Haplotype analyses were also performed.

RESULTS

None of 5 polymorphisms were found to be significantly associated with TD and with TD severity as measured by Abnormal Involuntary Movement Scale. Overall haplotype (-141Cins>del/TaqID/NcoI/Ser311Cys/TaqIA) frequency was also not significantly different between TD and non-TD groups, although one rare haplotype (I-D1-T-G-A1) showed significantly different frequency between TD and non-TD groups (2.7% vs. 8.5%, respectively, p=0.031).

CONCLUSION

The present study does not support that DRD2 gene may be involved in TD in the Korean population, although further studies are warranted.

Molecular properties affecting fast dissociation from the D2 receptor

Dopamine D(2) receptor antagonism is the foundation of antipsychotic treatment. Antipsychotic agents vary in how fast they dissociate from the D(2) receptors. It has been proposed that the liability to exhibit side effects such as extra pyramidal symptoms may be the result of a slow rate of dissociation. Compounds with a faster rate of dissociation, while still blocking efficiently the D(2) receptors, will subsequently respond better to physiological surges in dopamine transmission. Therefore, work in our laboratories has focussed on identifying fast dissociating and selective D(2) antagonists. Biological screening was performed to measure the affinity and extent of dissociation for a large dataset of over 1800 D(2) antagonists. Subsequent univariate and multivariate statistical analysis revealed the molecular properties which differentiate fast and slow dissociating compounds. It is shown that faster dissociating antagonists are less lipophilic and have lower molecular weight. There was a clear and expected inverse relationship with extent of dissociation and binding affinity with more potent compounds tending to be slower dissociating. However, within a range of comparable affinity both fast and slow dissociating compounds were identified. After de-correlating affinity and dissociation the analysis revealed the important descriptors.

Association study of cannabinoid receptor 1 (CNR1) gene in tardive dyskinesia

Tardive dyskinesia (TD) is a severe, debilitating movement disorder observed in 25-30% of the patients treated with typical antipsychotics. Cannabinoid receptor 1 (CNR1) activators tend to inhibit movement, an effect prevented by rimonabant and other selective CNR1 antagonists. Furthermore, CNR1 receptor is downregulated in Huntington's disease and upregulated in Parkinson's disease. Twenty tagSNPs spanning the CNR1 gene were analyzed in schizophrenia patients of European ancestry (n=191; 74 with TD). Significant genotypic (P=0.012) and allelic (P=0.012) association was observed with rs806374 (T>C). Carriers of the CC genotype were more likely to be TD positive (CC vs TT+TC, odds ratio=3.4 (1.5-7.8), P=0.003) and had more severe TD (CC vs TT+TC; 9.52±9.2 vs 5.62±6.9, P=0.046). These results indicate a possible role of CNR1 in the development of TD in our patient population. However, these observations are marginal after correcting for multiple testing and need to be replicated in a larger patient population.

Efficacy of aripiprazole in sulpiride-induced tardive oromandibular dystonia

Tardive dystonia is a side effect of dopamine receptor-blocking agents, which are mainly used as antipsychotic drugs. The treatment of tardive dystonia is difficult and often unsuccessful. An 82-year-old woman experienced mandibular deviation to the left due to spasm of the masticatory muscles with involuntary chewing movement and Parkinsonism. She had been treated with sulpiride for motility disorder for 5 years. Parkinsonism almost disappeared after the withdrawal of sulpiride, but tardive oromandibular dystonia showed no improvement. Aripiprazole treatment at 3 mg/day improved tardive oromandibular dystonia without worsening Parkinsonism. Low-dosage aripiprazole may be effective for tardive oromandibular dystonia in patients with no other psychiatric disorder.

Epidemiology of tardive dyskinesia before and during the era of modern antipsychotic drugs

Late or tardive dyskinesias/dystonias (TD), contrary to expectation, have not disappeared with the use of expensive, modern antipsychotic drugs (APDs). Risk appears to be substantially lower than with older neuroleptics, and there is sparing of most acute movement disorders traditionally associated with APD treatment. However, risks of TD with modern APDs have been reduced much less than expected, by perhaps two- to threefold or even less, with substantial risks in the elderly. Major challenges in assessing prevalence or, preferably, incidence of TD arise from prolonged and erratic past exposure to various APDs, relatively recent use of modern APDs, and the occurrence of spontaneous movement disorders (about 5% and more in the elderly). TD risks associated with modern APDs may be similar to some older neuroleptics, especially those of low-moderate potency. Risperidone (and its active metabolite paliperidone), at high doses, may carry unusually high TD risk, whereas TD risk is low with clozapine, and perhaps quetiapine and aripiprazole. Optimistic expectations for the efficacy and neurological safety of modern APDs have encouraged their wide use in many conditions, sometimes off-label or in combinations, with little research support, increasing the chance of a higher prevalence of TD, especially at older ages. Measures to limit TD risk include: (1) critical, objective indications for APD use; (2) long-term use only for compelling or research-supported indications, primarily chronic psychotic illness that worsens when APD is slowly discontinued; (3) avoiding off-label indications; (4) using alternative treatments when APD treatment is elective, or early dyskinesia is identified; (5) using low but effective doses of single APDs, especially in the elderly; and (6) regular and specific examination for early TD.

[Aripiprazole - a medical treatment alternative for Tourette Syndrome in childhood and adolescence]

OBJECTIVE

We report a case-series of seven patients with a medical history of at least two years of tic disorder treated with the partial dopamine agonist aripiprazole to illustrate its efficacy as a treatment alternative for motor and vocal tics in children and adolescents.

METHOD

A case series of five patients with Tourette Syndrome (TS) and two with chronic motor tic disorder (age range 8; 7-18; 1 year), the majority of whom had been refractory to treatment with other neuroleptics or had ceased treatment due to intolerable side effects, were treated for eight weeks with aripiprazole. Before and after treatment, parents rated the severity of motor and vocal tic symptoms on the Yale Tourette Syndrome Checklist.

RESULTS

Within eight weeks mean motor tic symptoms decreased by 66% and mean vocal tic symptoms decreased by 26%. Mean effective dosage was 14.3 mg/day (min. 5 mg, max. 30 mg). Symptoms of comorbid ADHD or Obsessive Compulsive Disorder were not significantly influenced. During medication only mild side effects were observed, e.g., abdominal pain, fatigue and increased emotional sensitivity. No patient dropped out of treatment due to side effects.

CONCLUSIONS

Aripiprazole may be an effective pharmacologic treatment alternative for individuals with chronic motor tic disorder and TS. It induces quick, significant and sustained effects with few generally mild and transient side effects, if anything. Its effectiveness, especially relative to comorbidities, should be verified in double-blind, placebo-controlled studies.

Tardive dyskinesia and other movement disorders secondary to aripiprazole

The objective of this report is to draw attention to tardive dyskinesia (TD) caused by aripiprazole, a third generation antipsychotic. TD has been traditionally attributed to typical (first-generation) antipsychotics, but other dopamine receptor blocking drugs and atypical (second- and third-generation) neuroleptics are emerging as an important cause of TD. We reviewed the medical records of patients with TD seen at the Baylor College of Medicine Movement Disorders Clinic between 2002 and 2010 to identify patients with TD associated with aripiprazole. Among 236 patients with TD seen over the specified period, 8 (3.4%) were found to have aripiprazole-associated TD. In 5 patients, TD occurred after exclusive exposure to aripiprazole. The mean age at onset was 55.8 ± 14.8 years with a female predominance. The average duration of treatment with aripiprazole was 18.4 ± 26.4 months. Oro-bucco-lingual stereotypy was seen in all patients. In most patients, TD did not spontaneously improve after stopping aripiprazole. Of the 5 patients treated with tetrabenazine, 4 improved during follow-up. Although aripiprazole, a third generation antipsychotic, has been promoted to have a low risk of TD, the drug accounts for about 3.5% of patients with TD evaluated in a movement disorders clinic. This largest reported series draws attention to the growing incidence of TD and other drug-induced movement disorders associated with "atypical antipsychotics."

The catechol-O-methyl-transferase gene in tardive dyskinesia

Tardive dyskinesia (TD) is a severe and potentially irreversible motor side effect linked to long-term antipsychotic exposure. Changes in dopamine neurotransmission have been implicated in the etiology of TD, and catechol-O-methyl-transferase (COMT) is an enzyme that metabolizes dopamine.

OBJECTIVES

We investigated five single-nucleotide polymorphisms in addition to the functional Val158Met variant spanning the COMT gene for association with TD.

METHODS

We analyzed the six COMT single-nucleotide polymorphisms in a sample of schizophrenia/schizoaffective disorder patients (n=226; 196 Caucasians and 30 African Americans).

RESULTS

We found a significant association between the marker rs165599 in the 3' untranslated region of COMT and TD (AA versus G-carrier: OR(AA)=2.22, 95% CI:1.23-4.03; P=0.007). The association appeared to be originating from males. We did not find a significant association of the other five tested polymorphisms with TD in our samples. We performed a sex-stratified meta-analysis across all of the published studies (n=6 plus our own data) of COMT and TD, and found an association between ValVal genotype and TD in females (OR(ValVal)=1.63, 95% CI: 1.09-2.45; P=0.019) but not in males.

CONCLUSIONS

Overall, our results suggest that the COMT gene may have a minor but consistent role in TD, although sex-stratified studies with additional markers in larger clinical samples should be performed.

Can atypical antipsychotics improve tardive dyskinesia associated with other atypical antipsychotics? Case report and brief review of the literature

Tardive dyskinesia (TD) is a devastating adverse effect of long-term antipsychotic drug treatment. Atypical antipsychotics produce less TD, and it has been shown that they may have a therapeutic effect on pre-existing TD. Here, we report a case of olanzapine-induced TD which did not improve after switching to risperidone but improved after the addition of quetiapine to risperidone regimen. We also provide a brief review of the reported cases on TD induced by atypical antipsychotics which improved after switching to another atypical agent. It is unclear whether some atypical antipsychotics are more effective than others in the treatment of TD. Differences in this property and the underlying mechanism require further study.

Incidence of tardive dyskinesia with atypical versus conventional antipsychotic medications: a prospective cohort study

OBJECTIVE

Most previous studies of the incidence of tardive dyskinesia with atypical antipsychotics compared with conventional antipsychotics have not had tardive dyskinesia as their primary focus. The current study aimed to compare the incidence of tardive dyskinesia with atypical vs conventional antipsychotics using methods similar to those from a previous prospective cohort study at our site in the 1980s.

METHOD

Three hundred fifty-two initially tardive dyskinesia-free psychiatric outpatients (diagnosed at baseline using the Structured Clinical Interview for DSM-IV) were examined for a new diagnosis of tardive dyskinesia (using the Abnormal Involuntary Movement Scale and Glazer-Morgenstern criteria) every 6 months for up to 4 years at a community mental health center. At baseline, subjects were receiving conventional antipsychotics only (23%), atypicals only (64%), or both (14%). Only 26 subjects had never received conventional antipsychotics. Baseline evaluations were conducted from November 2000 through May 2003. Follow-ups were conducted through February 2005.

RESULTS

Compared with subjects treated with conventional antipsychotics alone since the previous visit, the adjusted tardive dyskinesia incidence rate-ratio for subjects treated with atypical antipsychotics alone was 0.68 (95% CI, 0.29-1.64). The incidence and prevalence of tardive dyskinesia was similar to previous findings at this site in the 1980s.

CONCLUSIONS

The incidence of tardive dyskinesia with recent exposure to atypical antipsychotics alone was more similar to that for conventional antipsychotics than in most previous studies. Despite high penetration of atypical antipsychotics into clinical practice, the incidence and prevalence of tardive dyskinesia appeared relatively unchanged since the 1980s. Clinicians should continue to monitor for tardive dyskinesia, and researchers should continue to pursue efforts to treat or prevent it.

Association of the HSPG2 gene with neuroleptic-induced tardive dyskinesia

Tardive dyskinesia (TD) is characterized by repetitive, involuntary, and purposeless movements that develop in patients treated with long-term dopaminergic antagonists, usually antipsychotics. By a genome-wide association screening of TD in 50 Japanese schizophrenia patients with treatment-resistant TD and 50 Japanese schizophrenia patients without TD (non-TD group) and subsequent confirmation in independent samples of 36 treatment-resistant TD and 136 non-TD subjects, we identified association of a single nucleotide polymorphism, rs2445142, (allelic p=2 x 10(-5)) in the HSPG2 (heparan sulfate proteoglycan 2, perlecan) gene with TD. The risk allele was significantly associated with higher expression of HSPG2 in postmortem human prefrontal brain (p<0.01). Administration of daily injection of haloperidol (HDL) for 50 weeks significantly reduced Hspg2 expression in mouse brains (p<0.001). Vacuous chewing movements (VCMs) induced by 7-week injection of haloperidol-reserpine were significantly infrequent in adult Hspg2 hetero-knockout mice compared with wild-type littermates (p<0.001). Treatment by the acetylcholinesterase inhibitor, physostigmine, was significantly effective for reduction of VCMs in wild-type mice but not in Hspg2 hetero-knockout mice. These findings suggest that the HSPG2 gene is involved in neuroleptic-induced TD and higher expression of HSPG2, probably even after antipsychotic treatment, and may be associated with TD susceptibility.

Use of aripiprazole in tardive dyskinesia: an open label study of six cases

Aripiprazole, a partial dopamine agonist has been reported to help reduce symptoms of tardive dyskinesia (TD). In a prospective, open label study of a series of cases, we examined the effectiveness of aripiprazole in reducing TD symptoms. Six clinically stable patients with schizophrenia or Schizoaffective disorder and a moderate to severe TD participated in this study. They were systematically cross-titrated from their current medication to aripiprazole and maintained for 16 weeks. The mean extra pyramidal symptom score measured by Abnormal Involuntary Movement Scale (AIMS) improved from a baseline score of 15.8 to final score of 5 (paired t-test; P=0.0009). The severity of psychiatric symptoms remained unchanged. This study supports our hypothesis that clinically stable patients with moderate tardive dyskinesia who are under treatment with other first- or second-generation antipsychotics may benefit from switching to aripiprazole with a reduction of TD symptoms but with out any significant benefit in psychiatric symptoms. The results need to be viewed with caution and not considered as indicative of a viable treatment option for TD as this is an open label study, and a small sample size.

New atypical antipsychotics for schizophrenia: iloperidone

The optimal treatment of schizophrenia poses a challenge to develop more effective treatments and safer drugs, to overcome poor compliance, discontinuation and frequent switching with available antipsychotics. Iloperidone is a new dopamine type 2/serotonin type 2A (D(2)/5-HT(2A)) antagonist structurally related to risperidone, expected to give better efficacy with less extrapyramidal symptoms than D(2) receptor antagonist antipsychotics. In double-blind phase III trials iloperidone reduced the symptoms of schizophrenia at oral doses from 12 to 24 mg. It was more effective than placebo in reducing positive and negative syndrome total score and Brief Psychiatric Rating scale scores; it was as effective as haloperidol and risperidone in post-hoc analysis. Its long-term efficacy was equivalent to that of haloperidol. The most common adverse events were dizziness, dry mouth, dyspepsia and somnolence, with few extrapyramidal symptoms and metabolic changes in short- and long-term studies in adults. Akathisia was rare, but prolongation of the corrected QT (QTc) interval was comparable to haloperidol and ziprasidone, which is of particular concern. Further comparative studies are needed to clarify the benefit/risk profile of iloperidone and its role in the treatment of schizophrenia.

Genetic study of BDNF, DRD3, and their interaction in tardive dyskinesia

Tardive dyskinesia (TD) is a neuroleptic-induced movement disorder. Its pathophysiology is unclear. The most consistent genetic findings have shown an association with the Ser9Gly polymorphism of the DRD3 gene. However, only few polymorphisms within DRD3 has been tested, and a comprehensive examination of DRD3 in TD is still lacking. Further, brain-derived neurotrophic factor (BDNF), a neuronal growth and survival peptide, regulates DRD3 expression and may be involved in the neuronal degeneration observed in TD. In the present study, we investigated 15 tag DRD3 polymorphisms and four tag BDNF polymorphisms for association with TD in our sample of Caucasian schizophrenia patients (N=171). While BDNF markers showed no association, a haplotype containing rs3732782, rs905568, and rs7620754 in the 5' region of DRD3 was associated with TD diagnosis (p[10,000 permutations]=0.007). We also found evidence of interaction between BDNF and DRD3 polymorphisms. Further studies are needed to confirm these findings.

Genetic underpinnings of tardive dyskinesia: passing the baton to pharmacogenetics

Manifestation of tardive dyskinesia (TD) among schizophrenia subjects on long-term antipsychotic treatment with typical drugs has been a clinical concern. Despite its association with extrapyramidal symptoms, typical drugs are still routinely prescribed globally though marginally superior atypical drugs have long been available. The genetic component in the etiology of TD is well documented. Search for these determinants has led to a few consensus associations of CYP2D6 *10, CYP1A2*1F, DRD2 Taq1A (rs1800497), DRD3 Ser9Gly (rs6280) and MnSOD Ala9Val (rs4880) variants with TD. However, translation of these observations into the clinic has not been achieved so far. This review discusses the salient features of TD etiopathology, current status of TD genetics, interactions between genetic and nongenetic factors, some major drawbacks, challenges and expected focus in TD research over the next decade, with emphasis on pharmacogenetics.