Current Methods for the Treatment and Prevention of Drug-Induced Parkinsonism and Tardive Dyskinesia in the Elderly

Central Nervous System Medications: Pharmacokinetic and Pharmacodynamic Considerations for Older Adults

Most drugs have not been evaluated in the older population. Recognizing physiological alterations associated with changes in drug disposition and with the ultimate effect, especially in central nervous system-acting drugs, is fundamental. While considering pharmacokinetics, it should be noted that the absorption of most drugs from the gastrointestinal tract does not change in advanced age. There are only few data about the effect of age on the transdermal absorption of medications such as fentanyl. Absorption from an intramuscular injection may be similar in older adults as in younger patients. The distribution of lipophilic drugs (such as diazepam) is increased owing to a relative increase in the percentage of body fat, causing drug accumulation and prolonged drug elimination following cessation. Phase I drug biotransformation is variably decreased in aging, impacting elimination, and hepatic drug clearance has been shown to decrease in older individuals by 10-40% for most drugs studied. Lower doses of phenothiazines, butyrophenones, atypical antipsychotics, antidepressants (citalopram, mirtazapine, and tricyclic antidepressants), and benzodiazepines (such as diazepam) achieve the same extent of exposure. For renally cleared drugs with no prior metabolism (such as gabapentin), the glomerular filtration rate appropriately estimates drug clearance. Important pharmacodynamic changes in older adults include an increased sedative effect of benzodiazepines at a given drug exposure, and a higher sensitivity to mu opiate receptor agonists and to opioid adverse effects. Artificial intelligence, physiologically based pharmacokinetic modeling and simulation, and concentration-effect modeling enabling a differentiation between the pharmacokinetic and the pharmacodynamic effects of aging might help to close some of the gaps in knowledge.

Prevention of Parkinson's Disease: From Risk Factors to Early Interventions

Parkinson's disease (PD) is a debilitating neurological disorder characterized by progressively worsening motor dysfunction. Currently, available therapies merely alleviate symptoms, and there are no cures. Consequently, some researchers have now shifted their attention to identifying the modifiable risk factors of PD, with the intention of possibly implementing early interventions to prevent the development of PD. Four primary risk factors for PD are discussed including environmental factors (pesticides and heavy metals), lifestyle (physical activity and dietary intake), drug abuse, and individual comorbidities. Additionally, clinical biomarkers, neuroimaging, biochemical biomarkers, and genetic biomarkers could also help to detect prodromal PD. This review compiled available evidence that illustrates the relationship between modifiable risk factors, biomarkers, and PD. In summary, we raise the distinct possibility of preventing PD via early interventions of the modifiable risk factors and early diagnosis.

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.

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.

Pharmacological Management of Dysphagia in Patients with Alzheimer's Disease: A Narrative Review

Alzheimer's disease (AD) and dysphagia are important health and socioeconomic problems in the aging population. Currently, the medical treatment of dysphagia in AD patients remains insufficient, and there are significant gaps in the management and clinical needs to postpone tube feeding. Literatures published over the last 30 years were searched in the PubMed and Embase databases. All relevant and promising pharmacological management studies were included. Because of the heterogeneity in design and methodology, only narrative reports were mentioned. Nine studies were included with two case reports, two case series, and two observational and three randomized controlled trials. The key approaches and clinical problems related to dysphagia include onset pattern, dementia stage, review of offending drugs and polypharmacy, and comorbidities (cerebrovascular disease, hypertension, parkinsonism, depression, and anorexia). The corresponding strategies of pharmacological treatments are further proposed and discussed comprehensively, with transient receptor potential channel modulators as promising treatment. With the integration of adequate and potential pharmacomanagement, AD patients with dysphagia can achieve a good prognosis and postpone tube feeding to maintain a better quality of life. More rigorous studies are needed to verify the effectiveness of innovative strategies and develop targets for neurostimulation.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Treatable Hyperkinetic Movement Disorders Not to Be Missed

Hyperkinetic movement disorders are characterized by the presence of abnormal involuntary movements, comprising most notably dystonia, chorea, myoclonus, and tremor. Possible causes are numerous, including autoimmune disorders, infections of the central nervous system, metabolic disturbances, genetic diseases, drug-related causes and functional disorders, making the diagnostic process difficult for clinicians. Some diagnoses may be delayed without serious consequences, but diagnosis delays may prove detrimental in treatable disorders, ranging from functional disabilities, as in dopa-responsive dystonia, to death, as in Whipple's disease. In this review, we focus on treatable disorders that may present with prominent hyperkinetic movement disorders.

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.

Functional Improvement of Tacrolimus-Induced Parkinsonism With Amantadine After Liver Transplantation: A Case Report

ABSTRACT

Drug-induced parkinsonism is the most common type of drug-induced movement disorder, whose symptoms can decrease patient quality of life and reduce medication compliance. Tacrolimus is a routinely used immunosuppressant agent after liver transplantation, with a well-known neurotoxic profile. There have been rare reports of tacrolimus-induced parkinsonism, but its pharmacologic management and functional impact remain poorly characterized in the literature. We present a case of tacrolimus-induced parkinsonism in a 62-year-old man after a liver transplant, resulting in significant neurologic impairments and multiple barriers to hospital discharge. His tremor, rigidity, bradykinesia, gait dysfunction, dysphonia, and dysphagia significantly improved after starting low-dose amantadine, with increased functional independence that allowed for a safe discharge. This is the first case in the literature detailing tacrolimus-induced parkinsonism's functional impairments improving with amantadine monotherapy.

Tardive Dyskinesia in Older Persons Taking Antipsychotics

Tardive dyskinesia (TD) is a hyperkinetic movement disorder caused by the use of dopamine receptor-blocking agents (DRBAs), a category of medications that includes first- and second-generation antipsychotics (APs) and agents such as metoclopramide that are used for the treatment of nausea and gastrointestinal dysmotility. While TD can affect people of all ages, older age is associated with increased risk of TD and also with the emergence of TD occurring after shorter treatment durations and lower dosages of DRBAs. TD is characterized by involuntary movements that include the face, limbs, and trunk, and is associated with increased comorbidities, social stigmatization, and impaired physical and mental health. Once present, TD tends to persist despite AP dose adjustment or discontinuation. Even with the use of US Food and Drug Administration (FDA)-approved medications for TD, symptoms may persist. Because the leading hypothesis for the pathophysiology of TD has been dysregulation of dopamine transmission due to treatment with DRBAs, APs that avoid postsynaptic dopamine receptor blockade may provide an alternative therapeutic approach for patients who require an AP. In this review, we discuss the risks, burdens, prevention, and management of TD, with a focus on older people.

Amiodarone and Parkinsonism: a pharmacovigilance study

BACKGROUND

Some case reports have described parkinsonism with amiodarone. We investigated a putative association between parkinsonism and exposure to amiodarone.

METHODS

We used the WHO pharmacovigilance database (VigiBase^® ). All adverse drug reactions with 'Parkinson-like events' and amiodarone were included. Four disproportionality analyses were performed: 1/after inclusion of all reports, 2/according to sex, 3/for the twenty last years (2000-2019), and 4/after exclusion of concomitant drugs known to induce parkinsonism (antipsychotic, antivertigo, antiemetic antinauseant drugs, flunarizine). Results are expressed as reporting odds ratios (ROR; 95% CI) and information component (IC).

RESULTS

No significant association was found in the whole population [ROR = 0.83 (0.65-1.06), IC = -0.7 (IC₀₂₅  = -0.65)], in men, in women, for the 2000-2019 years, or after exclusion of drugs inducing parkinsonism.

CONCLUSION

We failed to find any signal of parkinsonism with amiodarone. We suggest that reports of parkinsonism with amiodarone could be mainly explained by other underlying causes.

Drug-Induced Movement Disorders and Its Associated Factors Among Patients Attending Treatment at Public Hospitals in Eastern Ethiopia

BACKGROUND

Antipsychotic medications have both beneficial and undesired effects at a dose used for treatment purposes. Among undesired effects caused by antipsychotics, movement disorders are prevalent. However, there is no study done to determine the prevalence of movement disorders that occurred due to antipsychotics and their determinants in eastern Ethiopia.

OBJECTIVE

This study aimed to find out the prevalence of drug-induced movement disorders and its determinants among patients who had been on follow-up at public hospitals in eastern Ethiopia.

METHODS

A cross-sectional study was conducted from May to June 2018 at HFSUH and Jugal hospital. Extrapyramidal symptom rating scale (ESRS) was used to identify patients with drug-induced movement disorders in a sample of 411 outpatients. A systematic random sampling method was used to select the sample. Logistic regression was done to identify factors associated.

RESULTS

A drug-induced movement disorder was found in 44% of the participants: Of this, 27.3% had drug-induced pseudo-Parkinsonism, 21.2% had drug-induced akathisia, 9.5% had drug-induced tardive dyskinesia, and 3.4% had drug-induced tardive dystonia. Being female was associated with pseudo-Parkinsonism (AOR=3.6, 95% CI: 2.03, 6.35), akathisia (AOR=4.9, 95% CI: 2.73, 8.78), and tardive dyskinesia (AOR=2.51, 95% CI: 1.08, 5.86) and being male with tardive dystonia (AOR=4.6, 95% CI: 1.8, 18.5). Alcohol use was associated with tardive dyskinesia (AOR= 5.89, 95% CI: 2.20, 15.69).

CONCLUSION

Drug-induced movement disorder in this study was high and nearly half of patients on antipsychotic treatment were experiencing it. Age, sex, and doses of antipsychotics were factors associated with all of the types of drug-induced movement disorders.

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.

Drug-induced parkinsonism: Revisiting the epidemiology using the WHO pharmacovigilance database

INTRODUCTION

Drug-Induced Parkinsonism (DIP) is the second most common cause of parkinsonism after idiopathic Parkinson's disease. Little is known about DIP epidemiology. Using VigiBase®, the objective of this study was to assess the main characteristics of DIP reporting around the world.

METHODS

We described reports recorded in the WHO pharmacovigilance database, Vigibase® and classified as "Parkinsonism" between 2000 and 2017. Differences of reporting between geographical locations and characteristics of reports were investigated using disproportionality analysis with calculation of Reporting Odds Ratios (ROR) and its 95% confidence interval.

RESULTS

Among the 9,009,107 reports recorded in VigiBase®, 4565 (0.05%) were DIP. Co reported terms were mainly "tremor" (n = 408, 8.9%), "gait disturbance" (n = 209, 4.6%) and "extrapyramidal disorders" (n = 180, 3.9%). DIP reports were significantly more frequent in men (ROR = 1.4; 95% CI 1.3-1.5) and in patients aged 75 and over (ROR = 2.12; 95% CI 1.98-2.26). Compared to all other continents, risk of reporting drug-induced parkinsonism was higher in Europe (ROR = 2.89; 95% CI 2.73-3.07), Africa (ROR = 1.81; 95% CI 1.46-2.25) and Oceania (ROR = 1.50; 95% CI 1.27-1.77). The risk was lower in Asia (ROR = 0.55; 95% CI 0.51-0.59) and America (ROR = 0.55 95% CI 0.51-0.59). The highest risk of DIP reporting was found with sulpiride and haloperidol followed by risperidone, aripiprazole, paliperidone, metoclopramide, olanzapine, quetiapine and clozapine.

CONCLUSION

Risk of DIP reports was higher in men, in people aged 75 and over and in Europe. Main drugs involved are antipsychotics not only drugs from the first generation but also those from the second one.

[Tardive dyskinesia following discontinuation of neuroleptic therapy in 87-year-old patient]

In the absence of a therapeutic alternative, the use of neuroleptics in geriatrics should be limited to the bare minimum, given their potentially serious deleterious effects in frail elderly patients. Dyskinesia is one of their most common side effects. Case of an elderly patient in whom the dyskinesia was revealed following abrupt cessation of a neuroleptic taken in the long term with discussions of the etiological hypotheses of this rare situation, which nevertheless deserve to be known.

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.