Gastroparesis treatment options metoclopramide and prucalopride: analysis of the FDA Adverse Event Reporting System (FAERS) database.

BACKGROUND: We aimed to examine the common adverse drug reactions (ADRs) of metoclopramide, FDA-approved for treating many gastrointestinal conditions including gastroparesis, and prucalopride, FDA-approved for treating chronic idiopathic constipation but used off-label for other gastrointestinal conditions including gastroparesis. RESEARCH DESIGN AND METHODS: The FDA Adverse Event Reporting System (FAERS) was analyzed from January 2013 to December 2023. ADR reports regarding use of only metoclopramide or prucalopride were analyzed following exclusion of reports indicating use for treatment of non-gastrointestinal conditions. RESULTS: Analysis of 1,085 reports on metoclopramide revealed tardive dyskinesia (n = 393, 36.2%) and dystonia (n = 170, 15.7%) among the most reported ADRs in addition to QTc prolongation (n = 16, 1.5%) with progression to Torsade de pointes (n = 5, 0.5%) and triggering of pheochromocytoma crisis (n = 24, 2.2%). Analysis of 865 reports on prucalopride revealed headache (n = 120, 13.9%), diarrhea (n = 116, 13.4%), and abdominal pain (n = 100, 11.6%) as the most common ADRs with 22 reports (2.5%) of dystonia with the use of prucalopride. CONCLUSIONS: This FAERS database analysis shows post-marketing reports of ADRs from metoclopramide most frequently include tardive dyskinesia, dystonia, and tremor in addition to potentially fatal arrhythmias such as Torsade de pointes. Consumers of prucalopride may also be at risk of dystonia and other ADRs.

An Evidence-Based Update on Anticholinergic Use for Drug-Induced Movement Disorders.

Drug-induced movement disorders (DIMDs) are associated with use of dopamine receptor blocking agents (DRBAs), including antipsychotics. The most common forms are drug-induced parkinsonism (DIP), dystonia, akathisia, and tardive dyskinesia (TD). Although rare, neuroleptic malignant syndrome (NMS) is a potentially life-threatening consequence of DRBA exposure. Recommendations for anticholinergic use in patients with DIMDs were developed on the basis of a roundtable discussion with healthcare professionals with extensive expertise in DIMD management, along with a comprehensive literature review. The roundtable agreed that "extrapyramidal symptoms" is a non-specific term that encompasses a range of abnormal movements. As such, it contributes to a misconception that all DIMDs can be treated in the same way, potentially leading to the misuse and overprescribing of anticholinergics. DIMDs are neurobiologically and clinically distinct, with different treatment paradigms and varying levels of evidence for anticholinergic use. Whereas evidence indicates anticholinergics can be effective for DIP and dystonia, they are not recommended for TD, akathisia, or NMS; nor are they supported for preventing DIMDs except in individuals at high risk for acute dystonia. Anticholinergics may induce serious peripheral adverse effects (e.g., urinary retention) and central effects (e.g., impaired cognition), all of which can be highly concerning especially in older adults. Appropriate use of anticholinergics therefore requires careful consideration of the evidence for efficacy (e.g., supportive for DIP but not TD) and the risks for serious adverse events. If used, anticholinergic medications should be prescribed at the lowest effective dose and for limited periods of time. When discontinued, they should be tapered gradually.

Levodopa/Carbidopa to Augment the Treatment of Amblyopia: A Report by the American Academy of Ophthalmology.

PURPOSE: To review the published literature on the use of levodopa/carbidopa to augment the treatment of amblyopia. METHODS: Literature searches for English language studies were last conducted in October 2022 in the PubMed database with no date restrictions. The combined searches yielded 55 articles, of which 23 were reviewed in full text. Twelve of these were considered appropriate for inclusion in this assessment and were assigned a level of evidence rating by the panel methodologist. Nine studies were rated level I, and 3 studies were rated level II; there were no level III studies. RESULTS: The duration of treatment was limited to 3 to 16 weeks because of concern about long-term adverse effects such as tardive dyskinesia. This complication was not reported in any of the study participants. The dose of levodopa ranged from 1.5 to 8.3 mg/kg/day, generally divided into 3 daily doses. The carbidopa dose was approximately 25% of the levodopa dose in all treatments. Evidence from these studies indicates that augmenting traditional patch occlusion therapy with the oral administration of levodopa/carbidopa can improve the vision of amblyopic children, but the effect was small (0.17-0.3 logarithm of the minimum angle of resolution [logMAR] units) and only statistically significant when compared with patching alone in 2 of the 12 studies cited. Regression of vision was reported in the majority of studies (9 of 12 reported; range, 0-0.17 logMAR unit regression) after discontinuation of therapy. Short-term side effects of the medications were not consistently reported but were most frequently mild and included headache and nausea. CONCLUSIONS: The best available evidence is currently insufficient to show that augmenting amblyopia therapy using up to 16 weeks of levodopa/carbidopa will result in meaningful improvement in visual acuity. Given the potential for significant side effects such as tardive dyskinesia with long-term therapy, levodopa/carbidopa does not appear to be a viable option for amblyopia therapy FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Tardive dyskinesia in Chinese patients with schizophrenia: Prevalence, clinical correlates and relationship with cognitive impairment.

OBJECTIVE: Tardive dyskinesia (TD) has a high prevalence and is one of the distressing side effects of antipsychotic medications. Few studies have explored the relationship between TD, clinical correlates, and cognition. The aim of this study was to assess the prevalence, clinical correlates and cognitive impairment of co-occurring TD in Chinese patients with schizophrenia. METHODS: We recruited 655 patients with chronic schizophrenia who met the DSM-IV diagnostic criteria for schizophrenia and collected clinical and demographic data. All patients were assessed using the Abnormal Involuntary Movement Scale (AIMS) for the severity of TD, Positive and Negative Syndrome Scale (PANSS) for psychopathological symptoms, and Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) for cognition. RESULTS: The overall TD prevalence was 41.1%, 42.9% (246/574) in men and 28.4% (23/81) in women (χ2 = 6.1 df = 1, p < 0.05). There were significant differences in age, sex, duration of illness, number of hospitalizations, drug type, smoking and PANSS negative symptom subscore between TD and non-TD groups (all p < 0.05). Moreover, patients with TD scored lower for immediate memory, attention, delayed memory, and RBANS total scores (all p < 0.05). Logistic regression showed a significant correlation between TD and age, sex, drug type and attention subscore. CONCLUSION: Our results suggest that multiple demographic and clinical variables may be associated with the development of TD. Moreover, TD patients may exhibit more cognitive impairment than non-TD patients.

Prevalence, clinical correlates and risk factors associated with Tardive Dyskinesia in Chinese patients with schizophrenia.

Tardive Dyskinesia (TD) is a serious, nonrhythmic and iatrogenic movement disorder, and is a common comorbidity in patients with schizophrenia (SZ). The main goal of this study was to investigate the prevalence, clinical correlates, and risk factors of TD in Chinese patients with chronic SZ, which has not been fully studied. This study adopted a cross-sectional design. A total of 901 Chinese inpatients with SZ were recruited between 2008 and 2011. We used the Abnormal Involuntary Movement Scale (AIMS) to measure the severity of TD, and the Positive and Negative Syndrome Scale (PANSS) was used to measure the psychopathological symptoms of SZ. Blood samples were also collected for routine blood tests, including the levels of triglyceride (TG), cholesterol (CHO), HDL-cholesterol (HDL-CHO), LDL-cholesterol (LDL-CHO), Apolipoprotein A1 (ApoA1), and Apolipoprotein B (ApoB). Overall, 36% of patients with SZ had TD. Compared with the non-TD patients, the TD patients were more likely to be men, had older age, lower education level, higher smoking rate, higher hospitalization frequency, and longer duration of illness (DOI). Further, compared with the non-TD patients, the TD patients had higher PANSS total, PANSS negative subscale, and cognitive subscale scores, but had lower depressive subscale scores and lower mean levels of metabolic biomarkers, including TG, CHO, HDL-CHO, LDL-CHO, ApoA1 and ApoB. Moreover, binary regression analysis showed that antipsychotic type, BMI, gender, age, HDL-CHO, and ApoB were associated with TD. Our findings indicate that TD is a common movement disorder in patients with chronic SZ, with certain demographic and clinical variables being risk factors for the development of TD.

Clinical Spectrum of Drug-Induced Movement Disorders: A Study of 97 Patients.

Background: Drug-induced movement disorders (DIMDs) are commonly encountered, but an often-under-reported subgroup of movement disorders. Objectives: We aimed to highlight the spectrum of DIMDs in patients taking different groups of drugs at our movement disorder center. Methods: It is a cross-sectional descriptive study including 97 consecutive DIMDs patients diagnosed over the past two years (2017-2019). Results: The mean ± standard deviation (SD) age of our study population was 35.89 ± 17.8 years (Range-2-80 years). There were 51 males and 46 females. Different DIMDs observed included tardive dystonia (n = 41; 42.2%), postural tremor (n = 38; 39.2%), parkinsonism (n = 32; 33%), tardive dyskinesia (n = 21; 21.6%), acute dystonia (n = 10; 10.3%), neuroleptic malignant syndrome (NMS) (n = 2; 2.1%), and others [(n = 10; 10.30%) including chorea and stereotypy each in 3; acute dyskinesia in 2; and myoclonic jerks and acute akathisia each in 1 patient]. Of these 97 patients, 49 had more than one type of DIMDs while 48 had a single type of DIMDs. In our study 37 (38%) patients had received non-dopamine receptor blocking agents (non-DRBA), 30 (31%) patients had received dopamine receptor blocking agents (DRBA), and 30 (31%) patients had received both DRBA and non-DRBA. Conclusions: Tardive dystonia was the most common DIMDs observed in our study. Our DIMDs patients were younger than other reported studies. We observed a significant number of non-DRBA drugs causing DIMD in our study as compared to previous studies. Drug-induced parkinsonism (DIP) was the most common DIMDs in the DRBA group. Tardive dystonia was the most common DIMDs seen in DRBA + non-DRBA group and the second most common in the DRBA and non-DRBA group. The postural tremor was the most common DIMDs in the non-DRBA group.

Assesment of Risk Factors for Tardive Dyskinesia.

Objective: Aim of the study is to evaluate sociodemographic and clinical features that may be associated with the development of Tardive dyskinesia (TD). Methods: 80 patients attending an outpatient psychiatry clinic in Istanbul, Turkey were divided into TD (n = 50) and control groups (CG) (n = 30). Sociodemographic and clinical data was collected through face-to-face interviews and a retrospective search of medical records. Results: There was a significant difference between TD and control group (CG) in terms of mean; onset of psychiatric disease at or after 35 years of age; first use of APD at or after 35 years of age; use of long-acting injectable APD; history of extrapyramidal side-effects; history of akathisia and family history of psychiatric disease. There was no significant difference between the two groups in terms of DSM- IV-based psychiatric diagnosis distributions, the existence of complete recovery periods during the course of the disease; total duration of APD use for at least 10 years; APD holidays; regular APD use; history of ECT and smoking or alcohol and substance abuse/addiction. Conclusion: Advancing age seemed to be the most significant risk factor in the development of TD. Clinicians need to be cautious about TD when prescribing APD for elderly patients.

A Modified Delphi Consensus Study of the Screening, Diagnosis, and Treatment of Tardive Dyskinesia.

OBJECTIVE: A nominal group process followed by a modified Delphi method was used to survey expert opinions on best practices for tardive dyskinesia (TD) screening, diagnosis, and treatment and to identify areas lacking in clinical evidence. PARTICIPANTS: A steering committee of 11 TD experts met in nominal group format to prioritize questions to be addressed and identify core bibliographic materials and criteria for survey panelists. Of 60 invited experts, 29 (23 psychiatrists and 6 neurologists) agreed to participate. EVIDENCE: A targeted literature search of PubMed (search term: tardive dyskinesia) and recommendations of the steering committee were used to generate core bibliographic material. Inclusion criteria were as follows: (1) review articles, meta-analyses, guidelines, or clinical trials; (2) publication in English between 2007 and 2017; (3) > 3 pages in length; and (4) publication in key clinical journals with impact factors ≥ 2.0. Of 29 references that met these criteria, 18 achieved a score ≥ 5 (calculated as the number of steering committee votes multiplied by journal impact factor and number of citations divided by years since publication) and were included. CONSENSUS PROCESS: Two survey rounds were conducted anonymously through electronic media from November 2017 to January 2018; responses were collected, collated, and analyzed. Respondent agreement was defined a priori as unanimous (100%), consensus (75%-99%), or majority (50%-74%). For questions using a 5-point Likert scale, agreement was based on percentage of respondents choosing ≥ 4 ("agree completely" or "agree"). Round 1 survey included questions on TD screening, diagnosis, and treatment. Round 2 questions were refined per panelist feedback and excluded Round 1 questions with < 25% agreement and > 75% agreement (unless feedback suggested further investigation). CONCLUSIONS: Consensus was reached that (1) a brief, clinical assessment for TD should be performed at every clinical encounter in patients taking antipsychotics; (2) even mild movements in 1 body area may represent possible TD; (3) management requires an overall evaluation of treatment, including reassessment of antipsychotics and anticholinergics as well as consideration of vesicular monoamine transporter 2 (VMAT2) inhibitors; and (4) informed discussions with patients/caregivers are essential.

Characteristics of Patients Experiencing Extrapyramidal Symptoms or Other Movement Disorders Related to Dopamine Receptor Blocking Agent Therapy.

PURPOSE/BACKGROUND: Dopamine receptor blocking agents (DRBAs), also known as antipsychotics, are medications widely used to treat a growing number of mental health diagnoses. However, their utility is limited by the potential to cause serious adverse movement reactions. Akathisia, dystonia, parkinsonism, and tardive dyskinesia (collectively known as extrapyramidal symptoms or EPSs) are associated with reduced social and occupational functioning, negative patient attitudes toward treatment, and nonadherence to pharmacotherapy. Neuroleptic malignant syndrome is a life-threatening reaction that can result from DRBA use and cause musculoskeletal dysfunction. The aim of this study is to profile patients who have developed DRBA-related movement adverse effects and identify risk factors significantly associated with each subtype of EPSs or other movement disorders (OMDs) such as neuroleptic malignant syndrome. METHODS/PROCEDURES: A report of all potential DRBA-related EPSs or OMDs occurrences within a large community hospital network was generated using International Classification of Diseases, Ninth Revision (ICD-9) and 10th Revision (ICD-10) billing codes. Each patient encounter was manually reviewed to confirm that a documented case of DRBA-related EPSs or OMDs had indeed occurred and subsequently determine the likely causative agent(s). FINDINGS/RESULTS: The resultant cohort of 148 patients experiencing unique DRBA-related EPS or OMD events was analyzed. The average patient was female, middle-aged, and overweight. The most common DRBAs precipitating EPSs or OMDs were haloperidol and quetiapine. In the population studied, age was significantly associated with the subtype of EPSs experienced such that those patients with akathisia and dystonia tended to be younger, whereas those with tardive dyskinesia tended to be older. Body mass index (BMI) category was also negatively correlated with the incidence of dystonia. In addition, it was observed that exposure to specific DRBAs, classes, and routes of administration significantly affected the risk of developing different subtypes of EPSs or OMDs in the study population. IMPLICATIONS/CONCLUSIONS: To our knowledge, this is the first study to describe an association between age and BMI with the risk of akathisia and dystonia, respectively, in patients taking DRBAs. Other trends observed with age and BMI in patients developing DRBA-related EPSs support previously reported findings. Expanding the knowledge base of individual characteristics associated with the risk of developing different subtypes of EPSs or OMDs can help providers and patients anticipate and attempt to mitigate these reactions, and may ultimately improve adherence to DRBA therapy.

Giant Tongue in a Patient With Chiari Malformation and Neuroleptic-Induced Tardive Dyskinesia.

A 68-year-old woman, presented with a squamous cell carcinoma of the malar region, and underwent wide local excision. During her clinical examination, repetitive protrusion and intrusion of the tongue as well as stereotypic, abnormal movements of the mouth and lips were observed, in a pattern that resembled chewing, sucking or lip pursing; dyskinesias ceased when she was speaking or bringing food to the mouth. She was unaware of the movements and the tongue was observed to move similar to choreiform movements, while revealing a giant "snake-like" macroglossia. She had history of mental retardation and alcohol abuse, and was under classic antipsychotic medications for several years. During a previous neurological investigation, type I Chiari malformation was diagnosed. In this case, concomitant Chiari malformation and neuroleptic-induced tardive dyskinesia, may together have been responsible for giant macroglossia, and to our best knowledege no similar observation has been reported in the literature.

No evidence so far of a major role of AKT1 and GSK3B in the pathogenesis of antipsychotic-induced tardive dyskinesia.

OBJECTIVE: AKT1 and GSK3B take part in one of the intracellular cascades activated by the D2 dopamine receptor (DRD2). This receptor is antagonized by antipsychotics and plays a role in the pathogenesis of antipsychotic-induced tardive dyskinesia (TD). The present study investigated association of several polymorphisms in the two candidate genes, AKT1 and GSK3B, with TD in antipsychotic-treated patients with schizophrenia. METHODS: DNA samples from 449 patients from several Siberian regions (Russia) were genotyped, and the results were analyzed using chi-squared tests and analyses of variance. RESULTS: Antipsychotic-induced TD was not associated with either of the tested functional polymorphisms (rs334558, rs1130214, and rs3730358). CONCLUSIONS: Despite regulation of AKT1 and GSK3B by DRD2, we found no evidence that these two kinases play a major role in the pathogenesis of antipsychotic-induced TD. These results agree with previously published data and necessitate further exploration of other pathogenic mechanisms, such as neurotoxicity due to excessive dopamine metabolism.

A probable case of movement disorder (Tardive dyskinesia) due to duloxetine treatment.

Tardive dyskinesia and tardive dystonia are caused by dopamine receptor blocking agents, mostly antipsychotics and sometimes antidepressants or calcium channel blockers. Duloxetine is a serotonin-noradrenaline reuptake inhibitor used in the treatment of diabetic neuropathic pain and fibromyalgia, as well as major depression. In this case, we aimed to discuss the tardive dyskinesia-like appearance of a patient using duloxetine due to fibromyalgia.

Movement side effects of antipsychotic drugs in adults with and without intellectual disability: UK population-based cohort study.

OBJECTIVES: To measure the incidence of movement side effects of antipsychotic drugs in adults with intellectual disability and compare rates with adults without intellectual disability. DESIGN: Cohort study using data from The Health Improvement Network. SETTING: UK primary care. PARTICIPANTS: Adults with intellectual disability prescribed antipsychotic drugs matched to a control group of adults without intellectual disability prescribed antipsychotic drugs. OUTCOME MEASURES: New records of movement side effect including acute dystonias, akathisia, parkinsonism, tardive dyskinaesia and neuroleptic malignant syndrome. RESULTS: 9013 adults with intellectual disability and a control cohort of 34 242 adults without intellectual disability together contributed 148 709 person-years data. The overall incidence of recorded movement side effects was 275 per 10 000 person-years (95% CI 256 to 296) in the intellectual disability group and 248 per 10 000 person-years (95% CI 237 to 260) in the control group. The incidence of any recorded movement side effect was significantly greater in people with intellectual disability compared with those without (incidence rate ratio 1.30, 95% CI 1.18 to 1.42, p<0.001, after adjustment for potential confounders), with parkinsonism and akathisia showing the greatest difference between the groups. Neuroleptic malignant syndrome, although occurring infrequently, was three times more common in people with intellectual disability-prescribed antipsychotic drugs (incidence rate ratio 3.03, 95% CI 1.26 to 7.30, p=0.013). Differences in rates of movement side effects between the groups were not due to differences in the proportions prescribed first and second-generation antipsychotic drugs. CONCLUSIONS: This study provides evidence to substantiate the long-held assumption that people with intellectual disability are more susceptible to movement side effects of antipsychotic drugs. Assessment for movement side effects should be integral to antipsychotic drug monitoring in people with intellectual disability. Regular medication review is essential to ensure optimal prescribing in this group.

Psychotic and Bipolar Disorders: Antipsychotic Drugs.

Antipsychotic drugs block dopamine receptors and are used to manage psychosis as well as other mental illnesses that may or may not have psychotic features, such as bipolar disorders and major depressive disorder. First-generation antipsychotic drugs are more likely to cause adverse effects such as extrapyramidal symptoms and tardive dyskinesia. Adverse effects of second-generation antipsychotic drugs typically are related to metabolic abnormalities such as weight gain, abnormal blood glucose levels, and elevated lipid levels. Neuroleptic malignant syndrome is a rare but serious adverse effect of antipsychotic drugs that causes mental status changes, hyperthermia, and generalized rigidity. Timely diagnosis is essential due to a high risk of related morbidities if the syndrome remains untreated. Some adverse effects of antipsychotics can be identified and managed so that patients can continue beneficial therapy while minimizing the physiologic consequences. Patients taking antipsychotic drugs should be monitored regularly for adverse effects. Antipsychotics are also associated with potential drug interactions, the most lethal being prolongation of the QT interval, which can lead to fatal arrhythmias. Antipsychotic drugs can be used in special populations, such as pregnant women, children, and elderly patients, per recommendation from a mental health subspecialist.

Antioxidant effects of rice bran oil mitigate repeated haloperidol-induced tardive dyskinesia in male rats.

Tardive dyskinesia (TD) is associated with the use of antipsychotic drugs such as D2 antagonist haloperidol (HP). The chronic use of HP is involved in the causation of free radicals and/or oxidative stress. In view of the nootropic, anti-anxiety, anti-inflammatory-like effects of rice bran oil (RBO) in a variety of investigations, we assessed the protective properties of RBO on HP-induced TD and neurochemical alteration. Rats treated with HP orally at a dose of 0.2 mg/kg/day for a period of 5 weeks developed VCMs which increased progressively as the treatment continued for 5 weeks. Co-administration of RBO by oral tubes at a dose of 0.4 ml/day prevented the induction of HP-induced VCMs. Repeated administration of HP increases the turnover of dopamine metabolism in the striatum. Conversely animals treated with HP + RBO decrease the metabolism of DA than water + HP treated animals. Striatal, malondieldehyde (MDA), hydrogen peroxide (H2O2) and antioxidant enzyme superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were also determined. It is suggested that beneficial role of RBO in attenuation of HP-induced TD. The results therefore recommended that supplementation of RBO may be useful in the HP-induced TD. The findings have also potential implication in the treatment of schizophrenia and motor disorders.

Rat brain CYP2D enzymatic metabolism alters acute and chronic haloperidol side-effects by different mechanisms.

Risk for side-effects after acute (e.g. parkinsonism) or chronic (e.g. tardive dyskinesia) treatment with antipsychotics, including haloperidol, varies substantially among people. CYP2D can metabolize many antipsychotics and variable brain CYP2D metabolism can influence local drug and metabolite levels sufficiently to alter behavioral responses. Here we investigated a role for brain CYP2D in acutely and chronically administered haloperidol levels and side-effects in a rat model. Rat brain, but not liver, CYP2D activity was irreversibly inhibited with intracerebral propranolol and/or induced by seven days of subcutaneous nicotine pre-treatment. The role of variable brain CYP2D was investigated in rat models of acute (catalepsy) and chronic (vacuous chewing movements, VCMs) haloperidol side-effects. Selective inhibition and induction of brain, but not liver, CYP2D decreased and increased catalepsy after acute haloperidol, respectively. Catalepsy correlated with brain, but not hepatic, CYP2D enzyme activity. Inhibition of brain CYP2D increased VCMs after chronic haloperidol; VCMs correlated with brain, but not hepatic, CYP2D activity, haloperidol levels and lipid peroxidation. Baseline measures, hepatic CYP2D activity and plasma haloperidol levels were unchanged by brain CYP2D manipulations. Variable rat brain CYP2D alters side-effects from acute and chronic haloperidol in opposite directions; catalepsy appears to be enhanced by a brain CYP2D-derived metabolite while the parent haloperidol likely causes VCMs. These data provide novel mechanistic evidence for brain CYP2D altering side-effects of haloperidol and other antipsychotics metabolized by CYP2D, suggesting that variation in human brain CYP2D may be a risk factor for antipsychotic side-effects.

Striatal cholinergic interneurons and D2 receptor-expressing GABAergic medium spiny neurons regulate tardive dyskinesia.

Tardive dyskinesia (TD) is a drug-induced movement disorder that arises with antipsychotics. These drugs are the mainstay of treatment for schizophrenia and bipolar disorder, and are also prescribed for major depression, autism, attention deficit hyperactivity, obsessive compulsive and post-traumatic stress disorder. There is thus a need for therapies to reduce TD. The present studies and our previous work show that nicotine administration decreases haloperidol-induced vacuous chewing movements (VCMs) in rodent TD models, suggesting a role for the nicotinic cholinergic system. Extensive studies also show that D2 dopamine receptors are critical to TD. However, the precise involvement of striatal cholinergic interneurons and D2 medium spiny neurons (MSNs) in TD is uncertain. To elucidate their role, we used optogenetics with a focus on the striatum because of its close links to TD. Optical stimulation of striatal cholinergic interneurons using cholineacetyltransferase (ChAT)-Cre mice expressing channelrhodopsin2-eYFP decreased haloperidol-induced VCMs (~50%), with no effect in control-eYFP mice. Activation of striatal D2 MSNs using Adora2a-Cre mice expressing channelrhodopsin2-eYFP also diminished antipsychotic-induced VCMs, with no change in control-eYFP mice. In both ChAT-Cre and Adora2a-Cre mice, stimulation or mecamylamine alone similarly decreased VCMs with no further decline with combined treatment, suggesting nAChRs are involved. Striatal D2 MSN activation in haloperidol-treated Adora2a-Cre mice increased c-Fos+ D2 MSNs and decreased c-Fos+ non-D2 MSNs, suggesting a role for c-Fos. These studies provide the first evidence that optogenetic stimulation of striatal cholinergic interneurons and GABAergic MSNs modulates VCMs, and thus possibly TD. Moreover, they suggest nicotinic receptor drugs may reduce antipsychotic-induced TD.