Movement disorders related to antidiabetic medications: a real-world pharmacovigilance study

BACKGROUND

Diabetic Mellitus (DM) has progressively emerged as a worldwide health problem, leading to the widespread deployment of antidiabetic drugs as the primary therapy in the global population. The incidence of diabetes medications-related movement disorders (drMD) is noteworthy but underestimated by clinical practitioners.

RESEARCH DESIGN AND METHODS

In order to address the incidence of drMD in DM patients and realize the serious outcomes associated with drMD, we conducted a real-world pharmacovigilance study of 612,043 DM patients using the FDA Adverse Event Reporting System (FAERS) database from January 2004 to September 2023. Reporting Odd Ratio (ROR) was calculated to reflect the risk of drMD. A multivariable logistic regression analysis was employed to adjust crude ROR with the mixed factors including age, sex and various antidiabetic treatments. Afterward, a Mendelian Randomization (MR) study was performed to elucidate the underlying genetic correlation between the genetically proxied targets of antidiabetic drugs and motor disorders.

RESULTS

Among 11,729 cases of motor adverse events in DM patients, six categories of drMD were significantly associated with DM medications. Noticeably, metformin was revealed to drastically increase the incidence of parkinsonism (adjusted ROR:3.97; 95 %CI (3.03, 5.19), p = 5.68e-24), bradykinesia (adjusted ROR:1.69; 95 %CI (1.07,2.59), p = 0.02) and irregular hyperkinesia, including chorea, choreoathetosis and athetosis. Insulin/insulin analogues and GLP-1 analogues presented notably higher odds of tremor: the adjusted ROR (aROR) of insulin and GLP-1 analogue is respectively 1.24 (95 %CI (1.15,1.34), p = 2.51e-08) and 1.78 (95 %CI (1.65,1.91), p = 5.64e-54). The combined therapeutic effects of multiple genetic variants of metformin, especially AMP-activated protein kinase (AMPK) were markedly linked to a greater likelihood of developing secondary parkinsonism (OR:10.816, p = 0.049) according to MR analyses.

CONCLUSION

The use of antidiabetic medications was significantly related to an increased incidence of movement disorders in DM patients. Moreover, MR analyses provided further genetic evidence for the pharmacovigilance study. This comprehensive investigation might help physicians recognize neurological adverse events associated with antidiabetic treatments and administer effective interventions.

Psychotropic drug-induced adverse drug reactions in 462,661 psychiatric inpatients in relation to age: results from a German drug surveillance program from 1993-2016

BACKGROUND

Clinical practice suggests that older adults (i.e., ≥ 65 years of age) experience adverse drug reactions (ADRs) more often than younger patients (i.e., < 65 years of age). ADRs such as falls, extrapyramidal symptoms (EPS), metabolic disorders, sedation, and delirium are particularly worrisome and often associated with psychotropic drugs.

METHODS

This observational study investigated the risk for psychotropic drug-related ADRs in older (n = 99,099) and younger adults (n = 363,562) in psychiatric inpatients using data from the German pharmacovigilance program "Arzneimittelsicherheit in der Psychiatrie" (AMSP) from 1993-2016. The aim was to assess whether age influenced the risk of specific ADR types and if certain psychotropic drugs posed particular concerns.

RESULTS

The risk for ADRs did not differ between older and younger patients (relative risk 0.98, 95% confidence interval 0.92-1.05). However, older patients had a higher risk for delirium (2.35, 1.85-2.99), hyponatremia (3.74, 2.85-4.90), and orthostatic syncope (2.37, 1.72-3.26), as well as certain types of EPS, e.g., parkinsonism (1.89, 1.45-2.48) and Pisa-/metronome syndrome (3.61, 2.51-5.18). The risk for other ADRs, such as acute dystonia (0.20, 0.10-0.37), akathisia (0.47, 0.29-0.76), liver dysfunction (0.63, 0.48-0.82), weight gain (0.07, 0.04-0.14), sexual dysfunction (0.03, CI 0.00-0.25), and hyperprolactinemia/galactorrhea (0.05, 0.02-0.17) was significantly lower for older patients. Older patients treated with any type of antidepressant drug (1.33, 1.26-1.40)-especially selective serotonin reuptake inhibitors (1.57, 1.26-1.40) and selective serotonin-norepinephrine reuptake inhibitors (2.03, 1.80-2.29)-and lithium (1.74, 1.52-2.00) had a higher ADR risk than younger patients. Second-generation antipsychotic drugs had a lower (0.74, 0.71-0.77) and low-potency first-generation antipsychotic drugs a higher (1.19, 1.07-1.33) ADR risk in older patients. The risk for ADRs involving multiple drugs was higher in older patients (1.28, 1.22-1.34). ADRs in older patients were 6.4 times more likely to result in death.

CONCLUSIONS

Clinicians and pharmacists should be aware of the types of ADRs and high-risk drugs across age groups and provide appropriate monitoring. Pharmacovigilance is crucial in psychiatric patients of all ages and should not be neglected, even for drugs generally considered "safe".

White Matter Microstructure Alteration in Patients with Drug-Induced Parkinsonism: A Diffusion Tensor Imaging Study with Tract-Based Spatial Statistics

INTRODUCTION

This research aimed to investigate the pathophysiological mechanism of how drug-induced parkinsonism (DIP) affects the integrity of the white matter (WM) fiber microstructure as measured by magnetic resonance diffusion tensor image (DTI) fractional anisotropy (FA) and mean diffusivity (MD).

METHODS

We recruited 17 participants diagnosed with DIP, 20 Parkinson's disease (PD) patients, and 16 normal controls (NCs) with a similar age, gender, and years of education. Subsequently, all participants underwent DTI magnetic resonance imaging scanning. To analyze the data, we utilized the software packages Functional MRI of the Brain Centre (FMRIB) Diffusion Toolbox (FDT), developed by the FMRIB laboratory at Oxford University, and tract-based spatial statistics (TBSS).

RESULTS

The Argentina Hyposmia Rating Scale (AHRS) scores of patients in DIP group were markedly higher than those in PD patients group. Compared with the NC group, the FA values in the genu and body of the corpus callosum (CC), anterior limb of the right internal capsule, bilateral anterior corona radiata, bilateral superior corona radiata, right external capsule, and right superior fronto-occipital fasciculus (could be a part of the anterior internal capsule) were significantly decreased in the DIP group; however, no significant cluster was found in MD.

CONCLUSIONS

The present study provides novel insights into the alterations in WM microstructure among DIP patients, suggesting that these methodologies have the potential to aid in the early diagnosis and treatment of DIP.

Outcome of Drug-Induced Parkinsonism in the Elderly: A Permanent Nonprogressive Parkinsonian Syndrome May Occur Following Discontinuation of Cinnarizine and Flunarizine

Parkinsonism induced by dopamine receptor antagonists, traditionally considered completely reversible following offending drug withdrawal, may unmask a degenerative parkinsonism in the patients with an underlying subclinical disease. In elderly patients, parkinsonism induced by the calcium channel blockers such as piperazine derivates cinnarizine and flunarizine may persist following drug discontinuation resulting in a permanent nonprogressive syndrome fulfilling the criteria for tardive parkinsonism. Whether this outcome occurs also following exposure to dopamine receptor antagonists such as neuroleptics and benzamide derivates or represents a class effect of the voltage-gated L-type calcium channel blockers, such as cinnarizine and flunarizine, due to their complex pharmacodynamic properties remains to be established.

Statistical integration of multi-omics and drug screening data from cell lines

Data integration methods are used to obtain a unified summary of multiple datasets. For multi-modal data, we propose a computational workflow to jointly analyze datasets from cell lines. The workflow comprises a novel probabilistic data integration method, named POPLS-DA, for multi-omics data. The workflow is motivated by a study on synucleinopathies where transcriptomics, proteomics, and drug screening data are measured in affected LUHMES cell lines and controls. The aim is to highlight potentially druggable pathways and genes involved in synucleinopathies. First, POPLS-DA is used to prioritize genes and proteins that best distinguish cases and controls. For these genes, an integrated interaction network is constructed where the drug screen data is incorporated to highlight druggable genes and pathways in the network. Finally, functional enrichment analyses are performed to identify clusters of synaptic and lysosome-related genes and proteins targeted by the protective drugs. POPLS-DA is compared to other single- and multi-omics approaches. We found that HSPA5, a member of the heat shock protein 70 family, was one of the most targeted genes by the validated drugs, in particular by AT1-blockers. HSPA5 and AT1-blockers have been previously linked to α-synuclein pathology and Parkinson's disease, showing the relevance of our findings. Our computational workflow identified new directions for therapeutic targets for synucleinopathies. POPLS-DA provided a larger interpretable gene set than other single- and multi-omic approaches. An implementation based on R and markdown is freely available online.

Use of gastrointestinal prokinetics and the risk of parkinsonism: A population-based case-crossover study

BACKGROUND

The disease burden of parkinsonism is extremely costly in the United States. Unlike Parkinson's disease, drug-induced parkinsonism (DIP) is acute and reversible; exploring the causative drug is important to prevent DIP in patients at high-risk of parkinsonism.

OBJECTIVE

To examine whether the use of gastrointestinal (GI) prokinetics is associated with an increased risk of parkinsonism.

METHODS

We conducted a case-crossover study using nationally representative data. We included patients who were newly diagnosed with parkinsonism (ICD-10 G20, G21.1, G25.1) between January 1, 2007 and December 1, 2015. The first prescription date of G20, G21.1, or G25.1 diagnoses was defined as the index date (0 day). Patients with prior extrapyramidal and movement disorders or brain tumors were excluded. We assessed the exposure within the risk (0-29 days) and control periods (60-89 days), before or on the index date. Conditional logistic regression estimated the adjusted odds ratio (aOR) for parkinsonism.

RESULTS

Overall, 2268 and 1674 patients were exposed to GI prokinetics during the risk and control periods, respectively. The use of GI prokinetics significantly increased the occurrence of parkinsonism (aOR = 2.31; 95% Confidence Interval [CI], 2.06-2.59). The use of GI prokinetics was associated with a higher occurrence of parkinsonism in elderly patients (≥65 years old; aOR = 2.69; 95% CI, 2.30-3.14) than in younger patients (aOR = 1.90; 95% CI, 1.59-2.27).

CONCLUSIONS

The use of GI prokinetics was significantly associated with higher occurrences of parkinsonism, necessitating close consideration when using GI prokinetics.

Effects of defoliant exposure and medication use on the development of Parkinson's disease in veterans

BACKGROUND

Vietnam-era veterans were exposed to Agent Orange (AO), which is associated with a high prevalence of Parkinson's disease (PD). However, little is known about the development of PD-like symptoms caused by drug-induced parkinsonism (DIP) in such populations. This study aimed to investigate PD incidence and PD risk following exposure to AO or DIP-risk drugs in veterans.

METHODS

A retrospective cohort study was conducted using 12 years (2009-2020) of electronic medical records of the Veterans Health Service Medical Center, the largest Veterans Affairs hospital in South Korea (n = 37,246; 100% male; age, 65.57 ± 8.12 years). Exposure to AO or DIP-risk drugs, including antipsychotic, prokinetic, anti-epileptic, dopamine-depleting and anti-anginal agents, was assessed in veterans with PD, operationally defined as having a PD diagnosis and one or more prescriptions for PD treatment. The PD risk was calculated using multiple logistic regression analysis adjusted for age and comorbidities.

RESULTS

The rates of DIP-risk drug use and AO exposure were 37.92% and 62.62%, respectively. The PD incidence from 2010 to 2020 was 3.08%; 1.30% with neither exposure, 1.63% with AO exposure, 4.38% with DIP-risk drug use, and 6.33% with both. Combined exposure to AO and DIP-risk drugs increased the PD risk (adjusted odds ratio = 1.68, 95% confidence interval, 1.36-2.08, P < 0.001).

CONCLUSIONS

The PD incidence was 1.31 times higher with AO exposure alone and 1.68 times higher with AO exposure and DIP-risk drug use. The results suggest the necessity for careful monitoring and DIP-risk drug prescription in patients with AO exposure.

Prevalence and causative drugs of drug-induced Parkinsonism in pediatric patients

Although several studies provided evidence on the epidemiology of drug-induced Parkinsonism (DIP) and its causative drugs, it is still limited in pediatrics. This study aimed to investigate the prevalence and risk of DIP in pediatrics. We used the Health Insurance Review and Assessment Service-Pediatric Patients Sample in Korea between 2010 and 2017 to estimate the annual prevalence of DIP and causative drug use using a cross-sectional design. The risk of DIP associated with causative drugs was evaluated using a case-crossover design. Adjusted odds ratios (aOR) with 95% confidence intervals (CI) were calculated using a conditional logistic regression. A total of 2925 pediatric patients had diagnosed with DIP from 2010 to 2017. Most patients were aged between 12 and19 years old, and 99.8% had any diagnosis of mental health disorder (MHD). During the study period, the prevalence of DIP increased by 10.0-fold from 2010 to 2017. All causative drugs showed a corresponding increase in their use, with atypical antipsychotics being the most prominent (increase ratio, 2.07). For both in the prevalence of DIP and atypical antipsychotic use, the increment was much bigger in patients with non-psychotic MHD than that in patients with psychotic MHD. In the case-crossover study, antipsychotics showed the largest aOR with DIP. Risperidone among antipsychotics showed the highest risk for DIP (aOR = 7.09, 95% CI = 3.83-13.09), followed by aripiprazole (aOR = 5.03, 95% CI = 2.88-8.80). This study suggests that the increase in DIP prevalence in pediatric patients might be because of the increased use of atypical antipsychotics.

A Case of Long-Term Exposure to Valproic Acid Mimicking Tremor-Dominant Parkinson's Disease

Background

Valproic acid is associated with increased risks of tremor and parkinsonism.

Case Report

A 67-year-old man with a diagnosis of epilepsy who had been treated with valproic acid (VPA) for 32 years noticed right-dominant upper-limb resting tremor accompanied by mild rigidity and bradykinesia. He was initially diagnosed with tremor-dominant Parkinson's disease (TDPD), but dopamine transporter single-photon emission computed tomography demonstrated no nigrostriatal degeneration. At 3 months after discontinuing VPA, his symptoms dramatically improved.

Discussion

VPA-induced tremor usually consists of postural or kinetic tremor without asymmetry. Our case indicated that careful evaluation is needed, even in cases of asymmetrical resting tremor and mild parkinsonism resembling TDPD after long term exposure to VPA.

Highlights

We report an atypical case of valproic acid-induced tremor and parkinsonism that mimics tremor-dominant Parkinson's disease. Physicians should not exclude the possible relation to valproic acid in patients presenting unilateral resting tremor and parkinsonism even in the absence of long-term side effects.

Treatment Changes and Prognoses in Patients with Incident Drug-Induced Parkinsonism Using a Korean Nationwide Healthcare Claims Database

This retrospective cohort study assessed treatment changes and prognoses after incident drug-induced parkinsonism (DIP). We used the National Health Insurance Service's National Sample Cohort database in South Korea. We selected patients diagnosed with incident DIP and given prescriptions to take offending drugs (antipsychotics, gastrointestinal (GI) motility drugs, or flunarizine) for a period of time that overlapped with the time of DIP diagnosis during 2004-2013. The proportion of patients experiencing each type of treatment change and prognosis was assessed for 2 years after DIP diagnosis. We identified 272 patients with incident DIP (51.9% of patients were aged ≥ 60 years and 62.5% of them were women). Switching (38.4%) and reinitiation (28.8%) were the most common modifications in GI motility drug users, whereas dose adjustment (39.8%) and switching (23.0%) were common in antipsychotic users. The proportion of persistent users was higher among antipsychotic users (7.1%) than that among GI motility drug users (2.1%). Regarding prognosis, 26.9% of patients experienced DIP recurrence or persistence, the rate being the highest in persistent users and the lowest in patients who discontinued the drug. Among patients with incident DIP diagnoses, the patterns of treatment change and prognosis differed across the types of offending drugs. Over 25% of patients experienced DIP recurrence or persistence, highlighting the need for an effective strategy to prevent DIP.

Permanent non-progressive cinnarizine and flunarizine-induced parkinsonism: An under-recognized tardive syndrome in the elderly?

Secondary parkinsonism induced by exposure to dopamine (DA) receptor antagonists as first and second generation antipsychotics, DA storage depleters, calcium channel blockers, benzamides substituted and other classes of drugs is traditionally believed to be completely reversible in most of patients following withdrawal of the offending drug even though after a variable time delay. The lack of recovery or initial full recovery with subsequent development of progressive parkinsonism has been regarded to result from an underlying subclinical degenerative process like PD unmasked by the inducing drug. These well-recognized clinical outcomes of drug-induced parkinsonism (DIP) have disregarded the existence of another outcome, characterized by permanent non-progressive parkinsonism. This syndrome may fullfil the criteria of tardive parkinsonism, a controversial entity currently referred to as a persistent condition without indication of its long-term course and clinical features. On reviewing the published literature on DIP, we have identified two prospective long-term follow-up of elderly patients in which parkinsonism induced by the calcium channel antagonists cinnarizine and flunarizine became permanent and non-progressive following drug discontinuation in a non-negligible proportion of patients, consistent with the clinical concept of a true tardive syndrome, according to currently accepted criteria. The authors hypothesize that the development of tardive parkinsonism might be due to a neurotoxic effect of the pharmacodynamic proprieties of the calcium channel blockers and their metabolites, exerted on post-synaptic striatal neurons and/or a neurotoxic damage on presynaptic DA neurons in patients without an underlying subclinical degenerative parkinsonism, so accounting for the stable and non-progressive course over time.

Direct Medical Costs of Parkinson's Disease in Southern China: A Cross-Sectional Study Based on Health Insurance Claims Data in Guangzhou City

Background: Parkinson’s disease (PD) is the second most common neurodegenerative disorder. This study aims to evaluate the direct medical costs of patients with PD using a large sample from an entire city and to identity the potential factors correlating with their inpatient costs in Guangzhou City, Southern China. Methods: This retrospective cross-sectional study uses data obtained from the Urban Employee-based Basic Medical Insurance (UEBMI) and the Urban Resident-based Basic Medical Insurance (URBMI) administrative claims databases in Guangzhou City from 2008 to 2012. The total sample was comprised of 2660 patients with PD. Costs were evaluated for the total sample and by types of insurance. The composition of costs was compared between the UEBMI and URBMI subgroups. The extended estimating-equations model was applied to identify the potential impact factors influencing the inpatient costs. Results: The direct medical costs per patient with PD were CNY 14,514.9 (USD 2299.4) in 2012, consisting of inpatient costs of CNY 13,551.4 and outpatient costs of CNY 963.5. The medication costs accounted for the largest part (50.3%). The inpatient costs of PD patients under the UEBMI scheme (CNY 13,651.0) were significantly higher than those of patients in the URBMI subgroup (CNY 12,402.2) (p < 0.05). The proportion of out-of-pocket spending out of inpatient and outpatient costs for UEBMI beneficiaries (24.3% and 56.1%) was much lower than that for patients under the URBMI scheme (47.9% and 76.2%). The regression analysis suggested that types of insurance, age, hospital levels, length of stay (LOS) and comorbidities were significantly correlated with the inpatient costs of patients with PD. Conclusions: The direct medical costs of patients with PD in China were high compared to the GDP per capita in Guangzhou City and different between the two evaluated types of insurance. Patients with the UEBMI scheme, of older age, with comorbidities, staying in tertiary hospitals and with longer LOS had significantly higher inpatient costs. Thus, policymakers need to reduce the gaps between the two urban insurance schemes in benefit levels, provide support for the development of a comprehensive long-term care insurance system and promote the use of telemedicine in China.

Diagnostic accuracy of brain stem auditory evoked response in distinguishing drug-induced parkinsonism from Parkinson'sdisease

OBJECTIVES

Brainstem auditory evoked response (BAER) is a non-invasive modality that can be used to investigate brainstem neuronal function in movement disorders. The differentiation between drug-induced parkinsonism (DIP) and Parkinson's disease (PD) can be very challenging. Although PD and DIP to some extent display similar clinical symptoms, the underlying pathophysiologic mechanisms are entirely different. Given these differences in pathogenesis, and the diagnostic utility of BAER for detecting brainstem function, BAER may help to distinguish between PD and DIP. This study aimed to assess the accuracy and predictive values of BAER parameters in differentiating DIP from PD.

METHODS

We prospectively studied143 participants classified within three groups, including 50 controls, 57 PD, and 36 DIP. BAER was performed on all patients in the study. Patients in the DIP group were followed up for at least one year after discontinuation of the causative drug and examined for final diagnosis. We compared BAER latencies of the three groups and measured sensitivity, specificity, predictive values, likelihood ratios, and accuracy of BAER in diagnosing DIP.

RESULT

Waves V, I-V, and III-V latencies were significantly prolonged among the PD patients compared to the DIP and the control group; however, there were no significant differences in BAER latencies between the DIP and the control group. Waves V and I-V latencies revealed the highest accuracy (86% and 79%, respectively) in distinguishing DIP from PD with high negative predictive value(89% and 83%, respectively) as well as a high negative likelihood ratio (0.2and 0.3, respectively).

CONCLUSION

This study showed that waves V and I-V latencies are significantly prolonged in PD patients compared to those with DIP, consistent with the proposed mechanisms of neurodegeneration in PD, particularly in the midbrain and pons. Consequently, BAER could be used as a useful diagnostic tool for differentiating DIP from PD.

Use of antipsychotics and long-term risk of parkinsonism

INTRODUCTION

Few epidemiological studies have assessed the risk of parkinsonisms after prolonged use of neuroleptics. We aimed to examine the long-term risk of degenerative parkinsonisms (DP) associated with previous use of neuroleptics.

METHODS

All residents in Piedmont, Northern-west Italy, older than 39 years (2,526,319 subjects), were retrospectively followed up from 2013 to 2017. Exposure to neuroleptics was assessed through the regional archive of drug prescriptions. The development of DP was assessed using the regional archives of both drug prescriptions and hospital admissions. We excluded prevalent DP cases at baseline as well as those occurred in the first 18 months (short-term risk). The risk of DP associated with previous use of neuroleptics was examined through Cox regression, using a matched cohort design.

RESULTS

The risk of DP was compared between 63,356 exposed and 316,779 unexposed subjects. A more than threefold higher risk of DP was observed among subjects exposed to antipsychotics, compared to those unexposed (HR = 3.27, 95% CI 3.00-3.57), and was higher for exposure to atypical than typical antipsychotics. The risk decreased after 2 years from therapy cessation but remained significantly elevated (HR = 2.38, 95% CI 1.76-3.21).

CONCLUSIONS

These results indicate a high risk of developing DP long time from the start of use and from the cessation for both typical and atypical neuroleptics, suggesting the need of monitoring treated patients even after long-term use and cessation.

Recognition and Management of Antipsychotic-Induced Parkinsonism in Older Adults: A Narrative Review

Background: Parkinsonism is a common side-effect of antipsychotic drugs especially in older adults, who also present with a higher frequency of neurodegenerative disorders like Idiopathic Parkinson’s disease (IPD). Distinguishing between antipsychotic-induced parkinsonism (AIP) and IPD is challenging due to clinical similarities. Up to 20% of older adults may suffer from persisting parkinsonism months after discontinuation of antipsychotics, suggesting underlying neurodegeneration. A review of the literature on AIP in older adults is presented, focusing on epidemiology, clinical aspects, and management. Methods: A literature search was undertaken on EMBASE, MEDLINE and PsycINFO, for articles on parkinsonism induced by antipsychotic drugs or other dopamine 2 receptor antagonists in subjects aged 65 or older. Results: AIP in older adults is the second most common cause of parkinsonism after IPD. Older age, female gender, exposure to high-potency first generation antipsychotics, and antipsychotic dosage are the main risk factors. The clinical presentation of AIP resembles that of IPD, but is more symmetrical, affects upper limbs more, and tends to have associated motor phenomena such as orofacial dyskinesias and akathisia. Presence of olfactory dysfunction in AIP suggests neurodegeneration. Imaging of striatal dopamine transporters is widely used in IPD diagnosis and could help to distinguish it from AIP. There is little evidence base for recommending pharmacological interventions for AIP, the best options being dose-reduction/withdrawal, or switching to a second-generation drug. Conclusions: AIP is a common occurrence in older adults and it is possible to differentiate it from IPD. Further research is needed into its pathophysiology and on its treatment.

Neuromelanin-sensitive magnetic resonance imaging in disease differentiation for parkinsonism or neurodegenerative disease affecting the basal ganglia

INTRODUCTION

Several reports have shown that neuromelanin-sensitive magnetic resonance imaging (NMI) using 3T magnetic resonance imaging is useful for the differential diagnosis of Parkinson's disease (PD), progressive supranuclear palsy (PSP), and other neurological diseases. However, the number of cases in previous studies has been insufficient. We aimed to determine the relationship between NMI and severity of PD and related disorders, and thereby establish the diagnostic utility of NMI for diagnosing neurological diseases.

METHODS

We enrolled 591 patients (531 subjects after removal of duplicates) with parkinsonism who underwent NMI. The contrast ratio of the locus coeruleus (LC-CR) and the area of the substantia nigra pars compacta (SNc) were analyzed in each patient.

RESULTS

The patients' clinical diagnoses were as follows: 11 patients in the disease control group (DCG), 244 patients with PD, 49 patients with PSP, and 19 patients with multiple system atrophy with predominant parkinsonism. Additionally, some patients were diagnosed with dementia with Lewy bodies, vascular parkinsonism, and drug-induced parkinsonism. SNc in the patients with PD and PSP was significantly smaller than that in DCG. LC-CR in the patients with PD was lower than that in DCG; furthermore, LC-CR in the patients with PD was significantly lower than that in the patients with PSP. We found that an area under the receiver-operating characteristic curve, indicating diagnostic efficacy, of 0.85 for LC-CR is a promising biomarker for differentiating PD from PSP.

CONCLUSION

NMI effectively contributes to differentiating neurodegenerative diseases, such as PD and PSP.

A case series of serious and unexpected adverse drug reactions under treatment with cariprazine

Reporting of new or unexpected adverse drug reactions of medicines that are subject to additional monitoring ("black triangle" label), such as the antipsychotic drug cariprazine, is of paramount importance to improve pharmacotherapy safety.

Drug-induced Parkinsonism: A strong predictor of idiopathic Parkinson's disease

Background

Although Idiopathic Parkinson’s disease (IPD) develops in considerable patients with drug-induced Parkinsonism (DIP), the association hasn’t been well defined. We aimed to evaluate the underlying association and risk factors of DIP and IPD.

Methods

A retrospective cohort study using National Health Insurance Claims data in 2011–2016 was conducted. New-onset DIP patients in 2012 were selected and matched with active controls having diabetes mellitus at a 1:4 ratio by age, sex, and Charlson’s Comorbidity Index score. Comorbidity, causative drugs, and prescription days were evaluated as covariates.

Results

A total of 441 DIP were selected. During the 4-year follow up, 14 IPD events in the DM group but 62 events in the DIP group were observed (adjusted hazard ratio, HR: 18.88, 95% CI, 9.09–39.22, adjusting for comorbidities and causative drugs). IPD diagnosis in DIP was observed high in males compared to females (15.58/13.24%). The event was the most within the 1^st year follow-up, mean days 453 (SD 413.36). Subgroup analysis in DIP showed calcium channel blocker (verapamil, diltiazem, and flunarizine) was significantly associated with increased IPD risk (HR: 2.24, 95% CI, 1.27–3.93).

Conclusion

Increased IPD in DIP patients might not be from the causal toxicity of antidopaminergic effects but from a trigger by the causative drugs on the DIP patients who already had subclinical IPD pathology. DIP can serve as a strong proxy for IPD incidence. Subjects who develop DIP should be monitored carefully for potential IPD incidence.

Prevalence of Extrapyramidal Symptoms in In-Patients With Severe Mental Illnesses: Focus on Parkinsonism

Patients with severe mental illnesses may present extrapyramidal symptoms as part of a concomitant neurological disorder or secondary to medications. Extrapyramidal symptoms are frequently unrecognized, have negative consequences for adherence to treatment, negatively affect quality of life and can induce stigma. We estimated and correlated with demographic and clinical variables prevalence of extrapyramidal symptoms in in-patients with severe mental illnesses. Additionally we evaluated ¹²³I-FP-CIT SPECT binding to striatal dopamine transporter in subjects with clinical manifestations suggestive of Parkinson's Disease and recorded therapeutic management and clinical evolution for 6-months. Extrapyramidal symptoms were present in 144 out of 285 patients (50.5%), mainly tremor (94 patients, 33%). There were 38 patients (13.3%) with parkinsonism and they had older age, more medical comorbidities and medical treatments. In 15/38 patients striatal dopamine transporter binding was abnormal resulting in dose reduction or change of psychotropic drugs as well as combination with antiparkinson therapy. Our study confirmed the clinical and epidemiological relevance of extrapyramidal symptoms among inpatients with severe mental illnesses. A small percentage of patients with extrapyramidal symptoms had features compatible with possible diagnosis of Parkinson's Disease. ¹²³I-FP-CIT SPECT was useful to identify dopaminergic dysfunction and initiate dopamine replacement therapy.

Trimetazidine Use and the Risk of Parkinsonism: A Nationwide Population-Based Study

An association between trimetazidine (TMZ), an anti-anginal drug, and parkinsonism has been reported in a number of studies. However, evidence from studies with long-term follow-up and better validity is lacking. We investigated the risk of TMZ-associated parkinsonism, specifically the incidence rate, cumulative dose–response relationship, and combined effects with other parkinsonism-inducing medications. This propensity score-matched retrospective cohort study was conducted using 14-year health insurance claims data in South Korea. The risk of parkinsonism was evaluated using multivariate Cox proportional hazard regression analysis, adjusted for comorbidities and concurrent medications. A total of 9712 TMZ users and 29,116 matched non-TMZ users were included. TMZ users had a significantly higher incidence rate of parkinsonism than non-TMZ users (9.34 vs. 6.71 per 1000 person-years; p < 0.0001). TMZ use significantly increased the risk of parkinsonism (adjusted hazard ratio = 1.38; 95% confidence interval = 1.26–1.51). Increased risks were observed with accumulated doses of TMZ, as well as concurrent use of other parkinsonism-inducing medications. The findings indicate that TMZ use significantly increases the risk of parkinsonism in the South Korean population. Closer monitoring should be considered for TMZ users, especially for those who are older, using TMZ at high cumulative doses and other parkinsonism-inducing medications.

Prevalence of Extrapyramidal Symptoms in Cancer Patients Referred to Palliative Care: A Multicenter Observational Study (JORTC PAL12)

BACKGROUND

Neuroleptics are commonly used in palliative care settings. However, adverse events of neuroleptics, known as extrapyramidal symptoms (EPSs), might be overlooked in clinical practice. We conducted this study to explore the prevalence of EPSs in palliative care setting.

METHODS

This multicenter, prospective, observational study included patients who 1) were referred to either a specialist palliative care team or a palliative care unit, 2) had a diagnosis of cancer, and 3) were ≥20 years of age. We investigated the prevalence of EPSs and medications used. The primary outcome was the overall Drug-Induced Extrapyramidal Symptom Scale (DIEPSS) score.

RESULTS

Between November 2015 and October 2016, 149 patients from 5 centers in Japan were enrolled. The median age was 67 years (range: 21-88 years) and the study population included 81 men (54.4%). The cancer types included lung (55 patients, 36.9%), upper gastrointestinal tract (5, 3.3%), hepatobiliary (19, 12.8%); breast (12, 8.1%); head and neck (10, 6.7%), gynecologic (10, 6.7%), genitourinary (10, 6.7%), and others (28, 18.8%). The median Karnofsky performance status was 60 (20-100). Most patients (86.6%) did not experience delirium. Thirty-nine (26.2%) patients received one or more EPS-inducing medications. EPSs occurred in 4 (2.7%) patients with a cutoff score of 5 points for 5 parkinsonism items in DIEPSS.

CONCLUSION

A lower frequency (<3%) of patients than expected in this population had EPSs. Therefore, we concluded that an interventional study is not feasible. However, medications that cause EPSs are often used in palliative care; therefore, a longitudinal study is warranted.

TRIAL REGISTRATION

This study was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) (UMIN000019810) on 16, November, 2015.

Iatrogenesis and neurological manifestations in the elderly

Older people are often exposed to polypharmacy in a multimorbidity context. Inappropriate polypharmacy is often harmful, increasing the risk of inappropriate prescriptions and therefore adverse drug events (ADEs). Five to 20% of all hospital admissions are related to ADE in older people, among which 40 to 70% could be prevented. However, identifying ADEs and drug-related admissions in the elderly is challenging because ADEs often present as common geriatric problems such as falls, delirium, which might be due to the aging process, underlying diseases, and/or medications. In the pharmacovigilance database of the World Health Organization, drug-related neurological manifestations are the third reported cause of ADEs in the elderly, and neurological drugs are the third leading class of medications involved in ADEs. We must therefore be particularly vigilant, both in our prescriptions but also in our diagnoses to avoid prescribing inappropriate treatments and detect ADEs. Even though multiple pharmacologic changes occur in the elderly (absorption, distribution, drug metabolism and excretion), most of medications are still often prescribed at the same daily dosage as in young adults. When prescribing any drug for old patients, we should remember that daily intake should be adapted to these specificities, keeping in mind the old well-known aphorism "start low, go slow". In this review, we describe the main drug-related neurological manifestations (drug-induced movement disorders, falls, seizures, delirium, hypoglycemia, stroke, hyponatremia, peripheral neuropathy and myopathy, and serotonin syndrome) and the main drugs associated with neurological manifestations (dopamine receptor blocking agents, antithrombotics, anticholinergics, beta-lactams, antidepressants, benzodiazepines, mood stabilizers).

Parkinsonism in the psychiatric setting: an update on clinical differentiation and management

Parkinsonism is seen frequently in patients with psychiatric conditions. Drug-induced parkinsonism (DIP) is the second most common cause of parkinsonism in the general population after Parkinson’s disease (PD) but a range of rarer aetiologies, some of them reversible, should also be considered in patients of all ages. DIP is more common in older patients, as are neurodegenerative diseases that may produce parkinsonism and it is relatively more likely that drug exposure could be unmasking an underlying process in this population. There is an extensive literature on differentiating DIP from PD but clinical features can be indistinguishable and many proposed investigations are not readily available. Aside from cessation of the responsible medication, there is no clear consensus on treatment strategies or duration of treatment. Practically, a delicate balance must be achieved between ameliorating parkinsonism and avoiding recurrent psychosis. Long-term prognosis in the setting of DIP remains unclear. We review the features that may differentiate DIP from other causes of parkinsonism in patients with psychiatric illness, provide an update on relevant investigations and discuss management strategies. The use of atypical antipsychotics for a broad range of indications highlights the ongoing relevance of DIP.

Evidence-based guidelines for the pharmacological treatment of schizophrenia: Updated recommendations from the British Association for Psychopharmacology

These updated guidelines from the British Association for Psychopharmacology replace the original version published in 2011. They address the scope and targets of pharmacological treatment for schizophrenia. A consensus meeting was held in 2017, involving experts in schizophrenia and its treatment. They were asked to review key areas and consider the strength of the evidence on the risk-benefit balance of pharmacological interventions and the clinical implications, with an emphasis on meta-analyses, systematic reviews and randomised controlled trials where available, plus updates on current clinical practice. The guidelines cover the pharmacological management and treatment of schizophrenia across the various stages of the illness, including first-episode, relapse prevention, and illness that has proved refractory to standard treatment. It is hoped that the practice recommendations presented will support clinical decision making for practitioners, serve as a source of information for patients and carers, and inform quality improvement.

Secondary parkinsonism due to drugs, vascular lesions, tumors, trauma, and other insults

In addition to neurodegenerative disorders, there are many secondary forms of parkinsonism. The most common cause for secondary parkinsonism is the intake of distinct drugs. Neuroleptics and calcium channel blockers have been mainly described to induce parkinsonism, but also other drugs were suspected to cause or worsen parkinsonism. Another common cause for secondary parkinsonism are vascular lesions (i.e. vascular parkinsonism). Furthermore, also brain tumors have been described as rare causes for parkinsonism. Moreover, parkinsonism can be caused by chronic traumatic encephalopathy, which is a special case, since secondary insults to the brain leads to the occurrence of a neuropathologically defined disease. Other rare causes for secondary parkinsonism are lesions caused by infectious or immunological diseases as well as toxins or street drugs.

Metoclopramide and Levosulpiride Use and Subsequent Levodopa Prescription in the Korean Elderly: The Prescribing Cascade

The aim of this study was to investigate the prescribing cascade phenomenon of dopaminergic drugs such as levodopa in the management of gastroprokinetic drugs induced parkinsonism. Based on the Korea National Health Insurance Service (NHIS)-Senior Cohort Database, we analyzed patients aged ≥65 years, between 2009 and 2013, who obtained new prescriptions for levodopa through the NHIS during this period. Those who were prescribed levodopa from 2002 to 2008 were excluded, only patients who were prescribed metoclopramide and levosulpiride within 90 days of receiving the levodopa prescription were included. Those who did not receive levodopa were used as a control group for 1:3 age and sex matching. We assessed 1824 and 1197 levodopa cases for metoclopramide and levosulpiride use, respectively. The matched controls for each levodopa case were 5472 and 3591, respectively. We used conditional logistic regression to determine the odds ratio (OR) for initiation of levodopa therapy in patients using metoclopramide and levosulpiride, relative to nonusers, after adjusting for age, sex, and exposure to antipsychotic medication. Both metoclopramide (OR = 3.04; 95% confidence interval, CI, 2.46-3.77) and levosulpiride (OR = 3.32; 95% CI, 2.56-4.3) users were three times more likely to begin using medication containing levodopa, compared to nonusers. Metoclopramide and levosulpiride were frequently prescribed within 90 days of receiving a prescription for levodopa. Before prescribing levodopa, it should be considered whether the adverse event is actually a side effect caused by metoclopramide and levosulpiride.

Trends in the Prevalence of Drug-Induced Parkinsonism in Korea

PURPOSE

Discontinuation of offending drugs can prevent drug-induced parkinsonism (DIP) before it occurs and reverse or cure it afterwards. The aim of this study was to investigate the prevalence of DIP and the utilization of offending drugs through an analysis of representative nationwide claims data.

MATERIALS AND METHODS

We selected DIP patients of ages ranging from 40 to 100 years old with the G21.1 code from the Korean National Service Health Insurance Claims database from 2009 to 2015. The annual standardized prevalence of DIP was explored from 2009 to 2015. Trends were estimated using the compound annual growth rate (CAGR) and the Cochran-Armitage test for DIP over the course of 6 years. Additionally, the utilization of offending drugs was analyzed.

RESULTS

The annual prevalence of DIP was 4.09 per 100000 people in 2009 and 7.02 in 2015 (CAGR: 9.42%, p<0.001). Levosulpiride use before and after DIP diagnosis showed a clear trend for decreasing utilization (CAGR: -5.4%, -4.3% respectively), whereas the CAGR for itopride and metoclopramide increased by 12.7% and 6.4%, respectively. In 2015, approximately 46.6% (858/1840 persons) of DIP patients were prescribed offending drugs after DIP diagnosis. The most commonly prescribed causative drug after DIP diagnosis was levosulpiride.

CONCLUSION

The prevalence of DIP has increased. To prevent or decrease DIP, we suggest that physicians reduce prescriptions of benzamide derivatives that have been most commonly used, and that attempts be made to find other alternative drugs. Additionally, the need for continuing education about offending drugs should be emphasized.

Recent developments in drug-induced movement disorders: a mixed picture

A large and ever-growing number of medications can induce various movement disorders. Drug-induced movement disorders are disabling but are often under-recognised and inappropriately managed. In particular, second generation antipsychotics, like first generation agents, are associated with potentially debilitating side-effects, most notably tardive syndromes and parkinsonism, as well as potentially fatal acute syndromes. Appropriate, evidence-based management is essential as these drugs are being prescribed to a growing population vulnerable to these side-effects, including children and elderly people. Prevention of the development of drug-induced movement disorders is an important consideration when prescribing medications that can induce movement disorders. Recent developments in diagnosis, such as the use of dopamine transporter imaging for drug-induced parkinsonism, and treatment, with the approval of valbenazine and deutetrabenazine, the first drugs indicated for tardive syndromes, have improved outcomes for many patients with drug-induced movement disorders. Future research should focus on development of safer antipsychotics and specific therapies for the different tardive syndromes and the treatment of drug-induced parkinsonism.

Metoclopramide as a prokinetic agent for diabetic gastroparesis: revisiting the risk of Parkinsonism

Background:

Metoclopramide is used to relieve gastrointestinal symptoms, however, it could cause adverse reactions of motor disorders. The aim of this study was to investigate whether metoclopramide treatment has a duration–response or dose–response effect and to estimate the risk of developing Parkinsonism following different and specific durations of treatment.

Methods:

A cohort study of newly diagnosed type 2 diabetes mellitus in 45- to 79-year-old patients, between 1999 and 2008, was selected using the Longitudinal Health Insurance Database 2005. A nested case–control study was conducted in the diabetes cohort in which all incident cases of Parkinsonism were identified. We randomly matched each case with up to 10 controls from the risk set. Conditional logistic regression was utilized to estimate odds ratio of Parkinsonism associated with metoclopramide use.

Results:

A total of 34,685 patients with diabetes were assembled as the cohort, and 541 incident Parkinsonism cases were identified. There were duration–response and dose–response effects on the risk of developing Parkinsonism. Compared with never-use patients, the adjusted odds ratios (ORs) of continuing therapy for 0–1 month, 1–2 months, 2–3 months, 3–5 months, and more than 5 months were 1.17 [95% confidence interval (CI) 0.93–1.45], 1.44 (95% CI 1.04–2.00), 1.74 (95% CI 1.14–2.65), 1.90 (95% CI 1.23–2.93), and 2.17 (95% CI 1.50–3.12), respectively.

Conclusions:

With metoclopramide treatment, regardless of less or more than 3 months of use, the risk of developing Parkinsonism in patients with newly diagnosed diabetes escalated with the duration of therapy. Therefore, we recommend close monitoring for the development of Parkinsonism in patients treated with metoclopramide, particularly (but not limited to) those with prolonged exposure.

Association Between Drug Exposure and Occurrence of Parkinsonism in Korea: A Population-Based Case-Control Study

Background: Although drug-induced parkinsonism is reversible in most cases, some patients can suffer from persistent/recurrent symptoms. Therefore, prevention is the most efficient way to manage drug-induced parkinsonism. However, there is a paucity of studies exploring the relationship between parkinsonism and drug exposure. Objective: To examine the association between drug exposure and the risk of parkinsonism using Korean population-based data. Methods: We conducted a matched case-control study using the National Health Insurance Service-National Sample Cohort database. Cases and controls were defined as individuals with and without parkinsonism, respectively, between 2007 and 2013. Cases and controls were matched for sex, age group, income, type of insurance, and Charlson comorbidity index. Drug exposures, including propulsives, antipsychotics, and flunarizine, were identified at 1 year before the first date of parkinsonism and stratified by recency and cumulative dose. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% CIs. Results: We identified 5496 cases and 5496 controls. ORs for current use group of propulsives, antipsychotics, and flunarizine compared with those of the never use group were 2.812 (95% CI = 2.466-3.206), 3.009 (95% CI = 1.667-5.431), and 4.950 (95% CI = 2.711-9.037), respectively. ORs were greater in those more recently exposed and those exposed to higher cumulative doses. Conclusion and Relevance: At the population level, use of propulsives, antipsychotics, and flunarizine had a significant association with the increased risk of parkinsonism, depending on recency and cumulative dose. Drugs associated with parkinsonism should be used with careful monitoring to prevent drug-induced parkinsonism.

The Dopamine Receptor Antagonism of Opipramol: Relevance to Parkinsonism?

Drug-induced Parkinsonism (DIP) represents the second most-frequent etiology of Parkinson syndromes after neurodegenerative disorders. It has been described mainly for antipsychotics, Ca-channel blockers, antiemetics, and gastrointestinal prokinetics. In this article, we present a clinical case series of 10 patients, retrieved within our movement disorders hospital, with DIP under intake of opipramol. Symptoms completely resolved after drug withdrawal, and associated risk factors were old age, high doses, and presence of cortical atrophy. This frequently prescribed anxiolytic drug has so far not been associated with DIP. Our objective is to raise awareness of DIP as an adverse effect of opipramol.

International Group for Reducing Inappropriate Medication Use & Polypharmacy (IGRIMUP): Position Statement and 10 Recommendations for Action

Globally, the number of drug prescriptions is increasing causing more adverse drug events, which is now a significant cause of mortality, morbidity, and disability that has reached epidemic proportions. The risk of adverse drug events is correlated to very old age, multiple co-morbidities, dementia, frailty, and limited life expectancy, with the major contributor being polypharmacy. Each characteristic alters the risk-benefit balance of medications, typically reducing anticipated benefits and amplifying risk. Current clinical guidelines are based on evidence proven in younger/healthier adult populations using a single disease model and their application to older adults with multimorbidity, in whom testing has not been conducted, yields a different risk-benefit prospect and makes inappropriate medication use and polypharmacy inevitable. Applying inappropriate clinical practice guidelines to older adults is antithetical to good healthcare, is likely to increase health inequity, and is associated with substantial negative clinical, economic, and social implications for health systems. The casualties are on the scale of a war or epidemic, yet are usually invisible in measures of healthcare quality and formal recommendations. Radical and rapid action is required to achieve a better quality of life for older populations and to remain true to the principles of medical professionalism and evidence-based medicine that place patients' interests and autonomy at the fore. This first International Group for Reducing Inappropriate Medication Use & Polypharmacy position statement briefly details the causes, consequences, and extent of inappropriate medication use and polypharmacy. This article outlines current strategies to reduce inappropriate medication use, provides evidence for their effect, and then proposes recommendations for moving forward with 10 recommendations for action and 12 recommendations for research. We conclude that an urgent integrated effort to reduce inappropriate medication use and polypharmacy should be a leading global target of the highest priority. The cornerstone of this position statement from the International Group for Reducing Inappropriate Medication Use & Polypharmacy is the understanding that without evidence of definite relevant benefit, when it comes to prescribing, for many older patients 'less is more'. This approach differs from most other current recommendations and guidance in medical care, as the focus is on what, when, and how to stop, rather than on when to start medications/interventions. Disrupting the framework that indiscriminately applies standard guidelines to older adults requires a new approach that better serves patients with multimorbidity. This transition requires a shift in medical education, research, and diagnostic frameworks, and re-examination of the measures used as quality indicators. In achieving this objective, we promote a return to some of the original concepts of evidence-based medicine: which considers scientific data (where it exists), clinical judgment, patient/family preference, and context. A shift is needed: from the current model that focuses on single conditions to one that simultaneously considers multiple conditions and patient priorities. This approach reframes the clinician's role as a professional providing care, rather than a disease technician.

Clinical features of drug-induced Parkinsonism

Drug-induced Parkinsonism is often reversible after withdrawal of the causative drug. Its clinical course, however, is not well understood, as the majority of cases are caused by drugs prescribed by departments outside of neurology. We reviewed 21 cases of drug-induced parkinsonism for several factors, including age, sex, causative drug and reason for prescription, department by which it was prescribed, and outcome. The age at onset ranged from 40 to 87 years, with an average Hoehn and Yahr Scale score of 4, indicating severe disability. Sulpiride was the most commonly observed causative drug (71.4%). All causative drugs were prescribed in non-neurological departments and over one half were prescribed in non-psychiatric departments; most were prescribed to treat depression or abdominal discomfort. Ten patients (48%) were previously diagnosed with a neuromuscular disease, including cerebrovascular diseases and Parkinson's disease. Recovery was observed in 15 cases (71%) after withdrawal of the causative drug, but lingering symptoms were observed in the remaining cases. It is suggested that physicians should be more cautious of Parkinsonian side effects when prescribing such drugs.

Tramadol-induced parkinsonism: a case report of a 75-year-old woman

Adverse drug reaction (ADR) is a form of unwanted reaction and is the crucial reason for illness and death. Tramadol-induced parkinsonism is a kind of ADR that occurs after the repeated intake of tramadol. Long-term exposure to tramadol has been known to induce tremor and alter the functioning of dopamine. This case report introduces a 75-year-old woman diagnosed with tramadol-induced parkinsonism due to the administration of tramadol for the treatment of post-operated (breast cancer) acute onset of severe pain on the left side of the chest. The assessment of the offending drug was carried out via Naranjo probability scale. A score of 6 was reported for this patient, defining tramadol as a probable cause of this reaction. For the management of the drug-induced parkinsonism, levodopa/carbidopa was prescribed and the symptoms related to parkinsonism resolved within a week. The age of the patient and the female gender is considered to be the main risk factor for the occurrence of such reaction. This case report is an attempt to spread awareness about the negative consequences of long-term use of tramadol in old patients. Thus, the medical practitioners must be very careful while administering tramadol to the old aged population.

Antipsychotic-Related Movement Disorders: Drug-Induced Parkinsonism vs. Tardive Dyskinesia-Key Differences in Pathophysiology and Clinical Management

Introduction

Drug-induced parkinsonism (DIP) and tardive dyskinesia (TD) are stigmatizing movement disorders associated with exposure to dopamine receptor blocking agents such as antipsychotics, but they differ in their pathophysiology and clinical management. Treatment for one may worsen the other, and there are important diagnostic clues that assist in making an accurate assessment and instituting a rational treatment plan.

Methods

A literature review was executed to identify articles relating to the presentation, pathophysiology, epidemiology, and management of DIP and TD.

Results

DIP and TD prevalence estimates range from approximately 20 to 35% among antipsychotic users, but may be higher in select populations. DIP often presents as bradykinesia and rigidity, as well as rhythmic tremor, and the majority of cases appear within hours to weeks of initiation of therapy with an antipsychotic, or if dosage of the antipsychotic is increased. TD onset is delayed, typically appearing after at least 3 months or longer of treatment, and patients will commonly present with involuntary, abnormal facial movements such as lip smacking, puckering, chewing, or tongue protrusion. DIP often resolves with discontinuation of the causative agent, but TD may be permanent. Broadly, proposed mechanisms underlying these adverse events include decreased dopamine concentrations in the nigrostriatal pathway of the striatum and dopamine hypersensitivity, for DIP and TD, respectively. Pharmacologic treatment approaches for DIP have commonly included anticholinergic agents such as benztropine; however, anticholinergic medications can make TD worse. Switching the antipsychotic medication to one with lower propensity for DIP is an option for some patients. Amantadine, a non-anticholinergic agent used for the treatment of DIP, may be preferred in patients with comorbid DIP and TD. In TD, treatment options include the new reversible vesicular monoamine 2 transporter inhibitors, valbenazine and deutetrabenazine.

Conclusions

It is important for clinicians to be able to recognize DIP and TD in patients using antipsychotics so that they can minimize the impact of these adverse events on their patients’ quality of life. Accurate diagnosis will drive the selection of the correct treatment.

Plain Language Summary

Plain language summary available for this article.

High exposure compared with standard exposure to metoclopramide associated with a higher risk of parkinsonism: a nationwide population-based cohort study

AIMS

We conducted a cohort study utilizing a nationwide health insurance database to assess the European Medicines Agency's restrictions on using metoclopramide and its association with the risk of parkinsonism.

METHODS

New oral metoclopramide users aged ≥20 years, and age- and gender-matched non-users were recruited between 2001 and 2011. Users were divided into high-exposure (dose >30 mg day^-1 and/or duration >5 days) and standard-exposure (dose ≤30 mg day^-1 and duration ≤5 days) groups. The adjusted hazard ratio (aHR) with 95% confidence interval (CI) estimated the risk of parkinsonism.

RESULTS

During a 1-year period, 122 of 218 931 (0.06%) users of metoclopramide vs. 56 of 218 931 (0.03%) non-users developed parkinsonism (P < 0.001). Among the 122 cases of parkinsonism in users, 64 (0.04%) were from 168 566 standard-exposure users and 58 (0.12%) from 50 365 high-exposure users. Compared with non-users, the risk of parkinsonism was higher in users (aHR 2.16; 95% CI 1.54, 3.02), including standard-exposure (aHR 1.73; 95% CI 1.11, 2.70), and high-exposure (aHR 3.15; 95% CI 1.78, 5.57) users. High-exposure users had a higher risk of parkinsonism than standard-exposure users (aHR 1.83; 95% CI 1.28, 2.63). Within the high-exposure group, 45 233 of 50 365 (89.81%) users and 55 of 58 (94.83%) parkinsonism were from long-duration exposure; 5 132 of 50 365 (10.19%) users and 3 of 58 (5.17%) parkinsonism were from high-dose exposure and long-duration + high-dose exposure.

CONCLUSIONS

The risk of parkinsonism in metoclopramide users, although extremely low (0.06%), is 2.16-fold greater than in non-users. High-exposure users have a 1.83-fold higher risk than standard-exposure users. As users in high-exposure group had a higher risk of parkinsonism than in standard-exposure group, and the majority of users and parkinsonism in high-exposure group were from long-duration exposure; thus, physician are advised to avoid prescribing metoclopramide for >5 days, even if the daily dose is ≤30 mg.

Asymmetric Drug-Induced Parkinsonism and Psychopathology: A Prospective Naturalistic Study in Long-Stay Psychiatric Patients

BACKGROUND

Drug-induced parkinsonism (DIP) is the most common movement disorder induced by antipsychotics. Although DIP is mostly symmetric, asymmetric DIP is reported in a substantial part of the patients. We investigated the frequency of motor asymmetry in DIP and its relationship to the severity of psychopathology in long-stay psychiatric patients.

METHODS

We obtained data from a cohort study of 207 long-stay psychiatric patients on the frequency and risk factors of tardive dyskinesia, akathisia, tardive dystonia, and DIP. From July 2003 to May 2007 (mean follow-up, 1.1 year) drug-induced movement disorders were assessed at least two times in each patient, with a frequency of persistent DIP of 56.2%. All patients who had at least one time parkinsonism in the upper/lower limb(s) were included for analyses (190 patients, 79 women; mean age, 48.0 ± 12.9 years). The Unified Parkinson Disease Rating Scale motor scale was used to calculate the frequency of asymmetric parkinsonism. Multilevel mixed models were built to explore the relationship between asymmetry in parkinsonism and the severity of psychopathology, measured on the Clinical Global Impression-Schizophrenia scale severity index (CGI-SCH SI).

RESULTS

The frequency of asymmetric parkinsonism was 20.8%. Asymmetry in parkinsonism was associated with symptom severity on all CGI-SCH SI scales (β range, 0.37-3.74) and significantly associated with the positive symptom scale (β, 3.74; 95% CI, 0.35-7.31).

CONCLUSION

DIP is asymmetric in a substantial part of patients. Asymmetric presentation of DIP is of clinical relevance as it is related to the severity of psychopathology and may alert the clinician of more severe psychopathology. Future research is recommended to provide insight into the neuropsychopathology and clinical value of asymmetric parkinsonism for psychiatric patients.

Current Status of Parkinsonism-Related Adverse Events and Associated Drugs in Korea

OBJECTIVE

The aim of the study was to explore the current status of drug-induced parkinsonism and drugs possibly related to drug-induced parkinsonism in Korea.

METHODS

We conducted a cross-sectional study using the Korea Adverse Event Reporting System database between July 1, 2010, and June 30, 2015. We identified all adverse event reports associated with parkinsonism.

RESULTS

There were 1402 adverse event reports associated with parkinsonism. The number of adverse event reports has increased annually. Among the 1499 drugs associated with parkinsonism, the most common were metoclopramide (49.77%) and paliperidone (16.14%). The major therapeutic groups (the third level of the Anatomical Therapeutic Chemical code) were propulsives (53.87%) and antipsychotics (35.58%). The mean time of onset of parkinsonism was 34.9 days. However, the time of onset of parkinsonism varied by drug, for example, it was 4.6 days for metoclopramide and 37.2 days for paliperidone.

CONCLUSIONS

Metoclopramide and antipsychotics were reported in most adverse event reports associated with parkinsonism in Korea.

Not all drug-induced parkinsonism are the same: the effect of drug class on motor phenotype

Drug-induced parkinsonism (DIP) is classically described as acute/subacute, bilateral symmetric syndrome in which tremor is infrequent compared to Parkinson's disease. Most DIP cases are caused by classic (CN) and second-generation neuroleptics (SN), and calcium channel blockers (CCB). We evaluated potentially distinctive demographic and clinical features in DIP among different drug classes. This was a prospective study of reversible DIP related to single selected drugs on each class. Baseline assessment included demographic, clinical data, and scales for staging, severity of motor signs of parkinsonism, tremor, and other involuntary movements. Six months after medication withdrawal, patients were reassessed. Those with no parkinsonian signs were included in the final sample. 157 cases were included after strict criteria were applied. Most common agents were haloperidol, levomepromazine, and chlorpromazine for the CN-DIP group, flunarizine and cinnarizine for the CCB-DIP group, and risperidone and olanzapine for the SN-DIP group. Drug exposure was shorter for CN-DIP cases; duration of parkinsonism was longer in the CCB-DIP group. CN-DIP had worse bradykinesia, rigidity, axial, total motor, and disease stage scores, with higher frequency of rigid-akinetic parkinsonism. Tremor scores were worse for CCB-DIP cases. SN-DIP presented as a less severe but similar form of CN-DIP. Tardive-type involuntary movements were less common in the SN-DIP group. DIP profile differs significantly depending on drug class involved, not only in terms of severity, but also regarding the differential combination of signs. These findings may help guiding clinicians in screening and diagnosing DIP in patients exposed to these drugs.