Treatment Of Tardive Dyskinesia Research Articles

Valbenazine for the treatment of tardive dyskinesia

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

Treatment of tardive dyskinesia with tetrabenazine or valbenazine: a systematic review

Up to 30% of patients taking antipsychotics may develop tardive dyskinesia (TD). Recent evidence-based recommendations demonstrate an unmet need for effective TD management. This systematic review was designed to update the evidence for TD treatment, comparing two vesicular monoamine transporter 2 (VMAT2) inhibitors, tetrabenazine and valbenazine. Of 487 PubMed/Embase search results, 11 studies met the review criteria. Valbenazine efficacy was demonstrated in rigorously designed clinical trials that meet the guidelines for AAN Class I evidence. Due to differences in study designs and a lack of standardized and controlled trials with tetrabenazine, a formal meta-analysis comparing the agents was not possible. However, valbenazine appears to have fewer side effects and a more favorable once-daily dosing regimen for the treatment of TD.

Tardive dyskinesia: motor system impairments, cognition and everyday functioning.

The recent approval of treatments for tardive dyskinesia (TD) has rekindled interest in this chronic and previously recalcitrant condition. A large proportion of patients with chronic mental illness suffer from various degrees of TD. Even the newer antipsychotics constitute a liability for TD, and their liberal prescription might lead to emergence of new TD in patient populations previously less exposed to antipsychotics, such as those with depression, bipolar disorder, autism, or even attention deficit hyperactivity disorder. The association of TD with activity limitations remains poorly understood. We review potential new avenues of assessing the functional sequelae of TD, such as the performance of instrumental activities of daily living, residential status, and employment outcomes. We identify several mediating aspects, including physical performance measures and cognition, that may represent links between TD and everyday performance, as well as potential treatment targets.

New therapeutic agents marketed in 2017: Part 1

Abstract Objective To provide information on the most important properties of new therapeutic agents marketed in 2017. Data sources Product labeling supplemented selectively with published studies and drug information reference sources. Data synthesis Seven new therapeutic agents marketed in the United States in early 2017 are considered in this first part of a series: ocrelizumab, safinamide mesylate, edaravone, valbenazine tosylate, deutetrabenazine, crisaborole, and dupilumab. Indications, mechanisms of action, and information on dosage and administration for these new agents are reviewed, as are the most important pharmacokinetic properties, adverse events, and other risks and precautions. The new drugs are compared with older drugs marketed for the same indications, and advantages and disadvantages are identified. Summary Ocrelizumab is the first drug shown to be effective in the treatment of primary progressive multiple sclerosis and is more effective than interferon beta-1a in the treatment of relapsing multiple sclerosis. Safinamide is the third monoamine oxidase type B inhibitor for the treatment of patients with Parkinson disease, joining rasagiline and selegilene. Edaravone is only the second drug to be approved for the treatment of amyotrophic lateral sclerosis (ALS), joining riluzole, and has been reported to slow the worsening of ALS symptoms. Valbenazine is the first drug demonstrated to be effective for the treatment of tardive dyskinesia, a neurological disorder that is most often experienced by patients treated for long periods with antipsychotic medications. Deutetrabenazine is the deuterated form of tetrabenazine in which deuterium, the heavy isotope of regular hydrogen, is used instead of hydrogen in two of the substituent groups. Both agents are used to treat chorea associated with Huntington disease, but deutetrabenazine has a longer duration of action, may be administered less frequently, and may be better tolerated. Crisaborole joins the topical corticosteroids and topical calcineurin inhibitors as options for the topical treatment of mild to moderate atopic dermatitis. Dupilumab, which inhibits interleukins 4 and 13, is administered subcutaneously for the treatment of adults with moderate to severe atopic dermatitis whose disease is not adequately controlled with topical prescription therapies or when those therapies are not advisable.

Valbenazine for the treatment of tardive dyskinesia

ABSTRACTIntroduction: Tardive dyskinesia (TD) is a hyperkinetic movement disorder that may result from treatment with antipsychotics or other dopamine receptor blocking agents. Underlying pathophysiology is incompletely understood but since the 1970s dopamine depleting agents have been used to reduce involuntary movements. The search for safe, effective treatments for TD is ongoing. Valbenazine, a novel VMAT2 inhibitor, has recently been FDA approved for treatment of TD.Areas covered: An overview of TD, unmet medical needs and current treatment guidelines are presented. The background, chemistry and clinical development of valbenazine to treat TD is detailed. A competitive market is developing as the treatment gap is identified and potential therapies are discussed in context of a broader market overview.Expert opinion: Antipsychotic use is growing among adults and children in the U.S. Consequently, prevalence of TD is expected to rise. Cessation of antipsychotics is often not possible as the psychiatric condition may deteriorate. Increasing doses of an antipsychotic to suppress involuntary movements is not sustainable long term as underlying TD worsens and movements typically recur. There were no FDA approved treatments for TD. The approval of valbenazine to treat TD is a critical step in addressing this gap in neurologic care.

Systematic review of interventions for treating or preventing antipsychotic-induced tardive dyskinesia.

Antipsychotic medication can cause tardive dyskinesia (TD) - late-onset, involuntary, repetitive movements, often involving the face and tongue. TD occurs in > 20% of adults taking antipsychotic medication (first-generation antipsychotics for > 3 months), with this proportion increasing by 5% per year among those who continue to use these drugs. The incidence of TD among those taking newer antipsychotics is not different from the rate in people who have used older-generation drugs in moderate doses. Studies of TD have previously been found to be limited, with no treatment approach shown to be effective. To summarise the clinical effectiveness and safety of treatments for TD by updating past Cochrane reviews with new evidence and improved methods; to undertake public consultation to gauge the importance of the topic for people living with TD/the risk of TD; and to make available all data from relevant trials. All relevant randomised controlled trials (RCTs) and observational studies. Cochrane review methods, network meta-analysis (NMA). Systematic reviews, patient and public involvement consultation and NMA. Any setting, inpatient or outpatient. For systematic reviews, adults with TD who have been taking a stable antipsychotic drug dose for > 3 months. Any, with emphasis on those relevant to UK NHS practice. Any measure of TD, global assessments and adverse effects/events. We included 112 studies (nine Cochrane reviews). Overall, risk of bias showed little sign of improvement over two decades. Taking the outcome of 'TD symptoms improved to a clinically important extent', we identified two trials investigating reduction of antipsychotic dose [n = 17, risk ratio (RR) 0.42, 95% confidence interval (CI) 0.17 to 1.04; very low quality]. Switching was investigated twice in trials that could not be combined (switching to risperidone vs. antipsychotic withdrawal: one RCT, n = 42, RR 0.45, 95% CI 0.23 to 0.89; low quality; switching to quetiapine vs. haloperidol: one RCT, n = 45, RR 0.80, 95% CI 0.52 to 1.22; low quality). In addition to RCTs, six observational studies compared antipsychotic discontinuation with decreased or increased dosage, and there was no clear evidence that any of these strategies had a beneficial effect on TD symptoms (very low-quality evidence). We evaluated the addition to standard antipsychotic care of several treatments, but not anticholinergic treatments, for which we identified no trials. We found no clear effect of the addition of either benzodiazepines (two RCTs, n = 32, RR 1.12, 95% CI 0.6 to 2.09; very low quality) or vitamin E (six RCTs, n = 264, RR 0.95, 95% CI 0.89 to 1.01; low quality). Buspirone as an adjunctive treatment did have some effect in one small study (n = 42, RR 0.53, 95% CI 0.33 to 0.84; low quality), as did hypnosis and relaxation (one RCT, n = 15, RR 0.45, 95% CI 0.21 to 0.94; very low quality). We identified no studies focusing on TD in people with dementia. The NMA model found indirect estimates to be imprecise and failed to produce useful summaries on relative effects of interventions or interpretable results for decision-making. Consultation with people with/at risk of TD highlighted that management of TD remains a concern, and found that people are deeply disappointed at the length of time it has taken researchers to address the issue. Most studies remain small and poorly reported. Clinicians, policy-makers and people with/at risk of TD are little better informed than they were decades ago. Underpowered trials of limited quality repeatedly fail to provide answers. TD reviews have data from current trials extracted, tabulated and traceable to source. The NMA highlights one context in which support for this technique is ill advised. All relevant trials, even if not primarily addressing the issue of TD, should report appropriate binary outcomes on groups of people with this problem. Randomised trials of treatments for people with established TD are indicated. These should be large (> 800 participants), necessitating accrual through accurate local/national registers, including an intervention with acceptable treatments and recording outcomes used in clinical practice. This study is registered as PROSPERO CRD4201502045. The National Institute for Health Research Health Technology Assessment programme.

Phase 3 study finds once‐daily valbenazine improves symptoms of tardive dyskinesia

Once‐daily dosing of the vesicular monoamine transporter 2 (VMAT2) inhibitor valbenazine resulted in significant improvement over placebo in patients with tardive dyskinesia (TD) and an underlying psychotic or mood disorder, a Phase 3 trial has found. Soon after the study's publication online March 21 in the American Journal of Psychiatry, the Food and Drug Administration approved valbenazine as the first available treatment for TD (see From the FDA, page 8).

Valbenazine for Tardive Dyskinesia.

Tardive dyskinesia (TD) remains a clinical concern for any patient who receives an antipsychotic. While the overall risk of developing TD is lower with newer antipsychotics compared to older agents, a significant number of patients who require long-term treatment will develop TD. Recently, valbenazine (brand name Ingrezza) became the first drug to be approved by the FDA specifically for the treatment of TD. In this New Drug Review, we summarize the basic pharmacology and clinical trial results for valbenazine. Valbenazine is a modified metabolite of the vesicular monoamine transporter 2 (VMAT-2) inhibitor tetrabenazine, which is approved for the treatment of the hyperkinetic movement disorder, Huntington's disease. In short-term clinical trials, valbenazine at a dose of 80 mg/day improved TD, with an effect size that is clinically significant (d=0.90). The effect size for the 40-mg/day dose was lower (d=0.52). Compared to tetrabenazine, valbenazine has better clinical characteristics (i.e., once-a-day dosing, better short-term side effect profile). However, only long-term experience in routine clinical populations can delineate valbenazine's full benefits, optimal dosing, and risks not identified during short-term registration trials.

Spotlight on the May 23 issue

#### Notable in Neurology This issue features an article reporting clinical trial results on the efficacy and safety of deutetrabenazine as a treatment for tardive dyskinesia and another that demonstrates that small areas of the cortex may drive seizures and interictal disturbances. A featured review delves into the debate on the best treatment for asymptomatic carotid stenosis. ### Vagotomy and Parkinson disease: A Swedish register-based matched-cohort study![Graphic][1] This matched-cohort study provides preliminary evidence that Parkinson pathogenesis may start in the gut. Using linked Swedish registers, the authors found that truncal … [1]: /embed/inline-graphic-1.gif

Valbenazine for tardive dyskinesia: A systematic review of the efficacy and safety profile for this newly approved novel medication-What is the number needed to treat, number needed to harm and likelihood to be helped or harmed?

The objective of this systematic review was to describe the efficacy, tolerability, and safety of valbenazine for the treatment of tardive dyskinesia (TD). The pivotal registration trials were accessed by querying http://www.ncbi.nlm.nih.gov/pubmed/ and http://www.clinicaltrials.gov, for the search terms 'valbenazine' OR 'NBI-98854', and by also querying the EMBASE (Elsevier) commercial database for clinical poster abstracts, and by asking the manufacturer for copies of posters presented at congresses. Product labeling provided additional information. All available clinical reports of studies were identified. Descriptions of the principal results and calculation of number needed to treat (NNT) and number needed to harm (NNH) for relevant dichotomous outcomes were extracted from the available study reports and other sources of information. Valbenazine, a reversible inhibitor of Vesicular Monoamine Transporter Type 2 (VMAT2), received approval for the treatment of TD in adults based on a clinical trial development programme that included three 6-week parallel group, randomised, placebo-controlled studies, including one Phase III trial described in product labeling. The recommended dose for valbenazine is 80mg/d. The percentage of responders in the Phase III acute study, as defined by ≥50% reduction from baseline in the Abnormal Involuntary Movement Scale dyskinesia score was 40.0% for valbenazine 80mg/d vs 8.7% for placebo, yielding a NNT of 4 (95% CI 3-6). As pooled from available data, discontinuation rates because of an adverse event were 2.9% for valbenazine-treated patients vs 1.6% for placebo-treated patients, resulting in a NNH of 76 (ns). The only adverse event that met the threshold of incidence ≥5% for valbenazine and a rate of ≥2 times than that observed with placebo was somnolence (somnolence, fatigue, sedation), with rates of 10.9% for valbenazine (all doses) vs 4.2% for placebo, resulting in a NNH of 15 (95% CI 9-52). An additional warning and precaution is that valbenazine can prolong the ECG QT interval, however, the valbenazine product label does not contain any bolded boxed warnings or contraindications. Valbenazine is presently the only US Food and Drug Administration-approved agent specifically indicated for the treatment of TD. Valbenazine is about 15 times more likely to result in a response than in a discontinuation because of an adverse event. Head-to-head comparisons with other VMAT2 inhibitors among patients with TD in the 'real world' are needed.

Angiotensin II type 1/adenosine A2A receptor oligomers: a novel target for tardive dyskinesia

Tardive dyskinesia (TD) is a serious motor side effect that may appear after long-term treatment with neuroleptics and mostly mediated by dopamine D2 receptors (D2Rs). Striatal D2R functioning may be finely regulated by either adenosine A2A receptor (A2AR) or angiotensin receptor type 1 (AT1R) through putative receptor heteromers. Here, we examined whether A2AR and AT1R may oligomerize in the striatum to synergistically modulate dopaminergic transmission. First, by using bioluminescence resonance energy transfer, we demonstrated a physical AT1R-A2AR interaction in cultured cells. Interestingly, by protein-protein docking and molecular dynamics simulations, we described that a stable heterotetrameric interaction may exist between AT1R and A2AR bound to antagonists (i.e. losartan and istradefylline, respectively). Accordingly, we subsequently ascertained the existence of AT1R/A2AR heteromers in the striatum by proximity ligation in situ assay. Finally, we took advantage of a TD animal model, namely the reserpine-induced vacuous chewing movement (VCM), to evaluate a novel multimodal pharmacological TD treatment approach based on targeting the AT1R/A2AR complex. Thus, reserpinized mice were co-treated with sub-effective losartan and istradefylline doses, which prompted a synergistic reduction in VCM. Overall, our results demonstrated the existence of striatal AT1R/A2AR oligomers with potential usefulness for the therapeutic management of TD.

Valbenazine approved for treatment of tardive dyskinesia.

FDA and Neurocrine Biosciences Inc. on April 11 announced the approval of valbenazine oral capsules for the treatment of tardive dyskinesia in adults. The product, a vesicular monoamine transporter 2 inhibitor, is marketed as Ingrezza. Tardive dyskinesia is a movement disorder associated with the

ICER to review treatments for tardive dyskinesia

ICER to review treatments for tardive dyskinesia

Pharmacologic Characterization of Valbenazine (NBI-98854) and Its Metabolites.

The vesicular monoamine transporter 2 (VMAT2) is an integral presynaptic protein that regulates the packaging and subsequent release of dopamine and other monoamines from neuronal vesicles into the synapse. Valbenazine (NBI-98854), a novel compound that selectively inhibits VMAT2, is approved for the treatment of tardive dyskinesia. Valbenazine is converted to two significant circulating metabolites in vivo, namely, (+)-α-dihydrotetrabenazine (R,R,R-HTBZ) and a mono-oxy metabolite, NBI-136110. Radioligand-binding studies were conducted to assess and compare valbenazine, tetrabenazine, and their respective metabolites in their abilities to selectively and potently inhibit [3H]-HTBZ binding to VMAT2 in rat striatal, rat forebrain, and human platelet homogenates. A broad panel screen was conducted to evaluate possible off-target interactions of valbenazine, R,R,R-HTBZ, and NBI-136110 at >80 receptor, transporter, and ion channel sites. Radioligand binding showed R,R,R-HTBZ to be a potent VMAT2 inhibitor in homogenates of rat striatum (Ki = 1.0-2.8 nM), rat forebrain (Ki = 4.2 nM), and human platelets (Ki = 2.6-3.3 nM). Valbenazine (Ki = 110-190 nM) and NBI-136110 (Ki = 160-220 nM) also exhibited inhibitory effects on VMAT2, but with lower potency than R,R,R-HTBZ. Neither valbenazine, R,R,R-HTBZ, nor NBI-136110 had significant off-target interactions at serotonin (5-HT1A, 5-HT2A, 5-HT2B) or dopamine (D1 or D2) receptor sites. In vivo studies measuring ptosis and prolactin secretion in the rat confirmed the specific and dose-dependent interactions of tetrabenazine and R,R,R-HTBZ with VMAT2. Evaluations of potency and selectivity of tetrabenazine and its pharmacologically active metabolites were also performed. Overall, the pharmacologic characteristics of valbenazine appear consistent with the favorable efficacy and tolerability findings of recent clinical studies [KINECT 2 (NCT01733121), KINECT 3 (NCT02274558)].

Behavioral and neurochemical effects of alpha lipoic acid associated with omega-3 in tardive dyskinesia induced by chronic haloperidol in rats

Tardive dyskinesia (TD) is characterized by involuntary movements of the lower portion of the face being related to typical antipsychotic therapy. TD is associated with the oxidative imbalance in the basal ganglia. Lipoic acid (LA) and omega-3 (ω-3) are antioxidants acting as enzyme cofactors, regenerating antioxidant enzymes. This study aimed to investigate behavioral and neurochemical effects of supplementation with LA (100 mg/kg) and ω-3 (1 g/kg) in the treatment of TD induced by chronic use of haloperidol (HAL) (1 mg/kg) in rats. Wistar male rats were used, weighing between 180-200 g. The animals were treated chronically (31 days) with LA alone or associated with HAL or ω-3. Motor behavior was assessed by open-field test, the catalepsy test, and evaluation of orofacial dyskinesia. Oxidative stress was accessed by determination of lipid peroxidation and concentration of nitrite. LA and ω-3 alone or associated caused an improvement in motor performance by increasing locomotor activity in the open-field test and decreased the permanence time on the bar in the catalepsy test and decreased the orofacial dyskinesia. LA and ω-3 showed antioxidant effects, decreasing lipid peroxidation and nitrite levels. Thus, the use of LA associated with ω-3 reduced the extrapyramidal effects produced by chronic use of HAL.

SA17. Response to Treatment With Valbenazine (NBI-98854) in Subjects With Tardive Dyskinesia

Abstract Background: Tardive dyskinesia (TD) is a persistent and potentially disabling movement disorder resulting from exposure to dopamine receptor-blocking agents (DRBAs), such as antipsychotics. Valbenazine is a novel and highly selective vesicular monoamine transporter 2 (VMAT2) inhibitor that is being evaluated for the treatment of TD and other movement disorders. Clinical studies include a Phase 3 trial of valbenazine in adults who had TD and underlying schizophrenia/schizoaffective disorder or mood disorder (KINECT 3; NCT02274558). The primary end point of this trial was met as demonstrated by a significant difference between valbenazine 80 mg/day and placebo for the Abnormal Involuntary Movement Scale (AIMS) dyskinesia total score (Items 1–7) change from baseline. Additional analyses of AIMS data from this trial were conducted to assess treatment response in subjects with TD. Methods: In this 6-week, double-blind, placebo-controlled trial, subjects were randomized 1:1:1 to once-daily treatment with valbenazine 80 mg, valbenazine 40 mg, or placebo. Treatment response was defined as ≥50% reduction in the AIMS total score. AIMS responders were analyzed by study visit (Weeks 2, 4, and 6) in the intent-to-treat (ITT) population and in subgroups categorized by underlying psychiatric diagnosis (schizophrenia/schizoaffective disorder or mood disorder). Numbers needed to treat (NNTs) were calculated for AIMS responders (valbenazine vs placebo) at Week 6. Significance testing was not conducted in the subgroups. Results: At Week 6 in the ITT population (N = 225), AIMS responder rates were significantly higher with valbenazine than with placebo: 80 mg, 40.0% (P < .0001; NNT = 4); 40 mg, 23.8% (P = .0200; NNT=7); placebo, 8.7%. Treatment with valbenazine 80 mg versus placebo also resulted in significantly higher responder rates at Week 2 (23.4% vs 5.3%, P = .0016) and Week 4 (28.8% vs 9.7%, P = 0.0039). Subjects treated with valbenazine 40 mg also had higher response rates at Week 2 (14.3% vs 5.3%) and Week 4 (15.6% vs 9.7%) relative to placebo-treated subjects, but the differences were not statistically significant. In subjects with schizophrenia/schizoaffective disorder (n = 148) or mood disorder (n = 77), AIMS responder rates were higher with valbenazine than placebo at all study visits. The highest responder rates were found at Week 6 and similar in the schizophrenia subgroup (80 mg, 40.9%, NNT = 4; 40 mg, 26.2%, NNT = 6; placebo, 9.3%) and mood subgroup (80 mg, 38.5%, NNT = 4; 40 mg, 19.0%, NNT=9; placebo, 7.7%). Conclusion: These study results, based on a rigorous definition of treatment response, indicate that substantial TD improvements occurred more frequently with valbenazine than placebo in adults diagnosed with schizophrenia/schizoaffective disorder or mood disorder. A significant difference between the 80-mg dose and placebo for the AIMS response was observed as early as 2 weeks of treatment.

Forgotten but not gone: new developments in the understanding and treatment of tardive dyskinesia

The broad use of atypical antipsychotics was expected to dramatically reduce the prevalence and incidence of tardive dyskinesia (TD), but data show that TD remains an important challenge due the persistent nature of its symptoms and resistance to numerous treatment modalities, including antipsychotic discontinuation. Recent insights on genetic risk factors and new concepts surrounding pathophysiology have spurred interest in the possibility of targeted treatment for TD. As will be reviewed in this article, the number of evidence-based strategies for TD treatment is small: only clonazepam, amantadine, ginkgo biloba extract, and the vesicular monoamine transporter 2 (VMAT2) inhibitor tetrabenazine have compelling data. Using new insights into the metabolism of tetrabenazine and the properties of its active metabolites, 2 modifications of tetrabenazine have been synthesized to improve the kinetic profile, and are currently involved in double-blind placebo controlled studies aimed at U.S. Food and Drug Administration (FDA) regulatory approval. The possible availability of these new agents, deuterated tetrabenazine and valbenazine, significantly widens the range of treatment choices for patients with TD. For clinicians with patients at risk for TD due to dopamine antagonist exposure, experience has shown that the problem of TD will be an ongoing issue in modern psychiatry, and that an appreciation of new developments in the pathophysiology of, risk factors for, and treatment of TD is crucial to managing this condition.

Emerging pharmacological therapies in schizophrenia: what's new, what's different, what's next?

There are several new and emerging medication interventions for both the acute and maintenance treatment phases of schizophrenia. Recently approved are 2 new dopamine receptor partial agonists, brexpiprazole and cariprazine, as well as 2 new long-acting injectable antipsychotic formulations, aripiprazole lauroxil and 3-month paliperidone palmitate. Although differences in efficacy compared to other available choices are not expected, the new oral options offer different tolerability profiles that may be attractive for individual patients who have had difficulties with older medications. The new long-acting injectable options provide additional flexibility in terms of increasing the time interval between injections. In Phase III of clinical development is a novel antipsychotic, lumateperone (ITI-007), that appears to have little in the way of significant adverse effects. Deutetrabenazine and valbenazine are agents in Phase III for the treatment of tardive dyskinesia, a condition that can be found among persons receiving chronic antipsychotic therapy. On the horizon are additional injectable formulations of familiar antipsychotics, aripiprazole and risperidone, that may be more convenient than what is presently available.

Crocin prevents haloperidol-induced orofacial dyskinesia: possible an antioxidant mechanism.

Long-term treatment with antipsychotics causes serious side effects such as tardive dyskinesia that characterized by abnormal movements in the orofacial region. Oxidative stress in the brain specific area is implicated in the pathophysiology of tardive dyskinesia. In this study the protective effect of crocin on haloperidol-induced orofacial dyskinesia was evaluated. Haloperidol (1 mg/kg, IP) and crocin (10, 20 and 40 mg/kg, IP) were administrated to rats for 21 days. Behavioral assessments such as orofacial dyskinesia movements, open field test and elevated plus maze (EPM) were evaluated every week. Malondealdehyde (MDA) and glutathione (GSH) levels in the hippocampus, cortex and striatum were also measured. Haloperidol increased vacuous chewing movements (VCMs) and tongue protrusions (TPs) in rats and co-administration of crocin (20 and 40 mg/kg) significantly reduced them. Furthermore, haloperidol decreased the locomotor and exploratory activities (rearing) in the open field test and decreased the percentage of entries into open arms and the percentage of the time spent on open arms in the EPM. Pretreatment with crocin (10 mg/kg) modified haloperidol effects on these behavioral parameters. Haloperidol induced lipid peroxidation in three brain regions, whereas crocin co-administration reduced the MDA and restored the decreased GSH levels. Our finding suggests that oxidative stress has an important role in the development of tardive dyskinesia. Crocin showed protective effect against haloperidol induced tardive dyskinesia and as a potent naturally antioxidant could be a new and useful drug and a possible therapeutic option for the treatment of tardive dyskinesia.

Uzun süreli ve yatırılarak izlenen şizofreni hastalarında tardiv diskinezi

Objective: Tardive dyskinesia (TD) is a group of delayed-onset iatrogenic movement disorders caused by dopamine receptor-blocking agents. TD prevalence is estimated as 20-50% of all patients treated with neuroleptics. This study aimed to investigate the prevalence rate of TD in long-term hospitalized patients with schizophrenia. Method: We recorded age, gender, duration and type (first/second generation or mixed) of medication both at the time of interview and over preceding years. Dyskinesia was assessed by using the Abnormal Involuntary Movements Scale (AIMS). We also used the Simpson–Angus Scale for tardive parkinsonism. Akathisia was measured using the Barnes Akathisia Rating Scale (BARS). Results: Mean duration of the longest used antipsychotic was 206.63 months. Probable TD was found in 18 (22.5%) of patients. None of the patients had tardive akathisia. Relation between type of the longest used treatment and prevalence of TD was not statistically significant. Relationship between type of ongoing treatment and prevalence of TD was not determined statistically significant either. There was a statistically significant relationship between the mean age and TD. Discussion: Despite very long duration of antipsychotic use, 22.5% rate of prevalence is still lower than expected. This can be explained that these patients are under direct and close follow-up of healthcare providers and in hospital conditions, so that risky conditions can be intervened rapidly. Another noteworthy finding of our study is that there is no statistically significant difference betwen first and second generation antipsychotic use and TD prevalence.