Levosulpiride-induced movement disorders

Development and validation of a reversed-phase HPLC-UV method for simultaneous determination of levosulpiride and omeprazole in human plasma: Applicability of the method for evaluation of pharmacokinetic drug-drug interactions

Levosulpiride and omeprazole are co-prescribed for gastrointestinal disorders associated with depression and anxiety. Objective of the study was to develop a sensitive, robust and simple method for simultaneous analysis of levosulpiride and omeprazole in human plasma and applicability of the method in determination of pharmacokinetics drug-drug interaction. In the presented study, a reversed-phase HPLC-UV method was developed for the simultaneous determination of levosulpiride and omeprazole using pantoprazole as the internal standard. Experimental conditions were optimized and the developed method was validated as per standard guidelines (USP and ICH). Furthermore, the developed method was applied for evaluation of pharmacokinetics drug-drug interaction between levosulpiride (50 mg) and omeprazole (40 mg) in healthy human volunteers. Sharpsil C8 column (4.6 × 250 mm, 5 μm), Ultisil C8 column (4.6 mm × 150 mm, 5 μm) and Agilent C18 column (4.6 × 250 mm, 5 μm) were evaluated as stationary phase. The best resolution was achieved with Agilent C18 (4.6 x 250 mm, 5 μm) column and was selected for further study. The mobile phase consisted of a mixture of acetonitrile and phosphate buffer (pH 7.2) in 60:40 by volume, and was pumped at a flow rate of 1 mL/min. Detector wavelength was set at 280 nm. Levosulpiride and omeprazole were extracted from human plasma with ethyl acetate and dichloromethane (4:1, v/v). The calibration curves for both levosulpiride (5-150 ng/mL) and omeprazole (10-1500 ng/mL) were linear. The lower limit of quantification and limit of detection for levosulpiride were 5 and 2 ng/mL, while for omeprazole these were 10 and 3 ng/mL, respectively. Pharmacokinetics analysis showed that co-administration of omeprazole increased the AUC and Cmax of levosulpiride, while the clearance was reduced. Both the changes were insignificant. Similarly, no significant change in the pharmacokinetic parameters of omeprazole was observed with co-administration of levosulpiride.

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.

Phenomenology, quality of life, and predictors of reversibility in patients with drug-induced movement disorders: a prospective study

BACKGROUND

Drug-induced movement disorders (DIMDs) form an important subgroup of secondary movement disorders, which despite conferring a significant iatrogenic burden, tend to be under-recognized and inappropriately managed.

OBJECTIVE

We aimed to look into phenomenology, predictors of reversibility, and its impact on the quality of life of DIMD patients.

METHODS

We conducted the study in the Department of Neurology at a tertiary-care centre in India. The institutional ethics-committee approved the study. We assessed 55-consecutive DIMD patients at presentation to our movement disorder clinic. Subsequently, they followed up to evaluate improvement in severity-scales (UPDRS, UDRS, BARS, AIMS) and quality of life (EuroQol-5D-5L). Wilcoxan-signed-rank test compared the scales at presentation and follow-up. Binary-logistic-regrerssion revealed the independent predictors of reversibility.

RESULTS

Fourteen patients (25.45%) had acute-subacute DIMD and 41 (74.55%) had tardive DIMD. Tardive-DIMD occurred more commonly in the elderly (age 50.73±16.92 years, p<0.001). Drug-induced-Parkinsonism (DIP) was the most common MD, followed by tardivedyskinesia. Risperidone and levosulpiride were the commonest culprit drugs. Patients in both the groups showed a statistically significant response to drug-dose reduction /withdrawal based on follow-up assessment on clinical-rating-scales and quality of life scores (EQ-5D-5L). DIMD was reversible in 71.42% of acute-subacute DIMD and 24.40% of patients with chronic DIMD (p=0.001). Binary-logistic-regression analysis showed acute-subacute DIMDs and DIP as independent predictors of reversibility.

CONCLUSION

DIP is the commonest and often reversible drug-induced movement disorder. Levosulpiride is notorious for causing DIMD in the elderly, requiring strict pharmacovigilance.

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.

Prokinetic Agents

Gastrointestinal (GI) prokinetic agents are drugs that increase GI motility and promote the movement of contents in the GI tract by amplifying and controlling the contraction of GI smooth muscle. Currently used prokinetics increase GI motility by acting as a dopamine D₂ receptor antagonist (e.g., metoclopramide, domperidone, levosulpiride) and 5-HT₄ receptor agonist (e.g., mosapride, prucalopride). Some prokinetics also have a cholinesterase inhibitory property (e.g., itopride), and herb-derived prokinetics (e.g., motilitone) affect multiple receptors. Depending on the type and distribution of receptors on which the prokinetics bind, the effect(s) may be regional or throughout the GI tract. Most prokinetics have been used for functional dyspepsia and gastroparesis because they mainly affect upper GI motility. However, prucalopride, a highly selective 5-HT₄ receptor agonist, is used primarily to treat chronic constipation and pseudo-obstruction. Dopamine D₂ receptor antagonists also inhibit the D₂ receptor in the medulla oblongata chemoreceptor trigger zone; therefore, they can treat nausea and vomiting. However, short term use of dopamine D₂ antagonists at an appropriate dose is recommended because of their potential for central nervous system side effects by penetrating the blood-brain barrier. It is necessary to know the mechanism of action, each clinical trial’s characteristics, and the side effects of prokinetics to obtain the best clinical outcomes. This article aims to summarize the results of clinical studies related to the impact of currently available prokinetic agents in Korea on GI motility.

Multicenter, Randomized, Placebo-controlled Trial to Evaluate the Efficacy and Safety of a Controlled-release, Once-daily UIC201609/UIC201610 Combination Therapy for Functional Dyspepsia: Preliminary Study

Backgrounds/Aims

Functional dyspepsia is a disease involving a range of upper gastrointestinal symptoms derived from various pathophysiologies. Tablets containing a combination of rabeprazole and controlled-release (CR) mosapride were recently developed. To investigate a more effective treatment, this trial evaluated the efficacy and safety of UIC201609/UIC201610 as a preliminary study.

Methods

A multicenter, double-blind, randomized study was performed on 30 subjects. UIC201609/UIC201610 (combination of rabeprazole and CR mosapride) was the case group, and the two control groups were rabeprazole 10 mg once a day and mosapride 15 mg CR tablet once a day. As a primary efficacy endpoint of the study, the changes in the total score of eight items of the Nepean Dyspepsia Index-Korean version were analyzed at 2 weeks and 4 weeks. The outcomes regarding safety were collected.

Results

The total symptom score of Nepean Dyspepsia Index-Korean decreased in the rabeprazole single group (29.4±17.1), mosapride CR single group (33.4±15.6), and UIC201609/UIC201610 group (33.4±11.8) at 4 weeks without significant differences. On the other hand, the UIC201609/UIC201610 combination group showed more score reduction of pain in the upper abdomen, burning in the upper abdomen compared to each control group, but it did not reach statistical significance. No difference was found in safety analysis.

Conclusions

UIC201609/UIC201610 once daily showed some improvement in epigastric pain and dyspepsia in patients with functional dyspepsia, but there was no significance. Further study based on the advanced clinical trial design will be needed to confirm the efficacy of UIC201609/UIC201610 combination therapy in the future.

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.

Levosulpiride-Induced Neurological Adverse Effects: A Prospective Study from a Tertiary Care Center

Background

Levosulpiride (LS) is a prokinetic drug increasingly used for the gastric motility disorders. Despite its common use for the gastric motility disorder, the tendency to cause parkinsonism and acute dystonias are under-recognized as the major adverse effects. This study was aimed to evaluate the adverse effects of this drug in patients attending neurology clinics.

Methods

Patients presenting with new-onset extrapyramidal symptoms with respect to LS therapy were selected for the study. A detailed history had been taken using a questionnaire. All the patients were tested for neurological manifestations. The number of cases was then statistically analyzed.

Results

A total of 30 patients were diagnosed with LS-induced movement disorders. The average age of patients was 65 ± 12 years with 17 males and remaining females. Major presentations were tremor, stiffness, dystonia, neck or back pain, dysarthria, and abnormal feelings. Stiffness, tremor, or both were among the most common signs. A statistically significant (P = 0.0154) positive correlation (r = 0.8295) was found between the duration of LS treatment and incidence of tremor/stiffness. Among them, 19 patients were started with dopaminergic drugs and five were given symptomatic measures. Six patients had no follow-up.

Conclusion

The LS treatment was found to produce adverse effects such as tremor and stiffness. Early recognition of this condition is essential for its complete cure and better prognosis. Therefore, one should be cautious about the LS as one of the etiologies for acute recent-onset extrapyramidal syndromes while working up patients.

Clinical Practice Guidelines for Functional Dyspepsia in Korea

Functional dyspepsia (FD) is a chronic upper gastrointestinal (GI) symptom complex that routine diagnostic work-up, such as endoscopy, blood laboratory analysis, or radiological examination, fails to identify a cause. It is highly prevalent in the World population, and its response to the various available therapeutic strategies is only modest because of the heterogenous nature of its pathogenesis. Therefore, FD represents a heavy medical burden for healthcare systems. We constituted a guideline development committee to review the existing guidelines on the management of functional dyspepsia. This committee drafted statements and conducted a systematic review and meta-analysis of various studies, guidelines, and randomized control trials. External review was also conducted by selected experts. These clinical practice guidelines for FD were developed based on evidence recently accumulated with the revised version of FD guidelines released in 2011 by the Korean Society of Neurogastroenterology and Motility. These guidelines apply to adults with chronic symptoms of FD and include the diagnostic role of endoscopy, Helicobacter pylori screening, and systematic review and meta-analyses of the various treatment options for FD (proton pump inhibitors, H.pylori eradication, and tricyclic antidepressants), especially according to the FD subtype. The purpose of these new guidelines is to aid the understanding, diagnosis, and treatment of FD, and the targets of the guidelines are clinicians, healthcare workers at the forefront of patient care, patients, and medical students. The guidelines will continue to be revised and updated periodically.

Prevalence and incidence of Parkinson's disease and drug-induced parkinsonism in Korea

Background

Parkinson’s disease (PD) and drug-induced parkinsonism (DIP) are the major diseases of parkinsonism. To better understand parkinsonism, we aimed to assess the prevalence and incidence of PD and DIP in Korea from 2012 to 2015.

Methods

We used the Health Insurance Review and Assessment Service database, which covers the entire population in Korea. We used claims during 2011–2015 to assess epidemiology of PD and DIP during 2012–2015. Retrospective cross-sectional study design was employed to assess prevalence, whereas retrospective cohort study design was used to determine incidence. Patients with at least one claim with ICD-10 G20 and who received antiparkinsonian drugs for at least 60 days were classified as having PD. We excluded patients with antiparkinsonian drugs that can be used for indications other than PD. Patients with at least one claim with ICD-10 G211 or G251 during the prescription period of drugs that are frequently related with DIP were classified as having DIP. Incident cases had a disease-free period of 1 year before diagnosis. To evaluate the significance of changes in the prevalence or incidence over time, Poisson regression was used to determine p for trend.

Results

The prevalence of PD increased from 156.9 per 100,000 persons in 2012 to 181.3 per 100,000 persons in 2015 (p for trend< 0.0001). The incidence of PD decreased steadily from 35.4 per 100,000 person-years in 2012 to 33.3 per 100,000 person-years in 2015 (p for trend< 0.0001). The prevalence of DIP increased from 7.3 per 100,000 persons in 2012 to 15.4 per 100,000 persons in 2015 (p for trend< 0.0001) and the incidence of DIP increased from 7.1 per 100,000 person-years in 2012 to 13.9 per 100,000 person-years in 2015 (p for trend< 0.0001).

Conclusions

Our study suggests that the incidence of PD has gradually decreased whereas, the incidence of DIP increased from 2012 to 2015. Further studies are warranted to examine possible causes of increased DIP incidence in order to develop management strategy for parkinsonism.

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.

[Functional Dyspepsia]

Dyspepsia is a common problem, and when dyspeptic symptoms develop within a short period of time, organic diseases such as gastroesophageal reflux disease, peptic ulcer diseases, pancreatoduodenal diseases, and gastrointestinal cancers should be suspected. Furthermore, functional dyspepsia (FD) should be considered if chronic or recurrent symptoms persist after eliminating underlying disease. FD is classified as epigastric pain syndrome (EPS) or postprandial distress syndrome (PDS), but these two conditions may overlap. Patients with the EPS subtype can be treated with proton pump inhibitors (PPIs), whereas patients with the PDS subtype may be managed primarily with prokinetics, and patients with EPS and PDS can be co-administered PPIs and prokinetics. Helicobacter pylori eradication therapy can be administered on a test-and-treat basis when PPIs and prokinetics are ineffective or to younger patients with chronic dyspepsia, and tricyclic antidepressants can be used as a secondary treatment because they are effective in patients with the EPS subtype. In addition, because the pathophysiology of FD is diverse, dietary education and stress management are required in addition to medical therapy, and should substantially aid treatment and long-term management. Here, we introduce and summarize recently published guidelines for the treatment of FD.

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.

Association between preoperative use of antithrombotic medications and intraoperative transfusion in older patients undergoing cancer surgery

BACKGROUND

Management of antiplatelet agents and other chronic anticoagulation medications in patients scheduled for surgery can reduce intraoperative bleeding complications. However, few studies on the association of antithrombotics, relative to their duration of action, with intraoperative transfusion have been conducted. We aimed to determine the association of recent use of antithrombotics, relative to their duration of action, with intraoperative transfusion in elderly people undergoing cancer surgery.

METHODS

The study subjects were patients aged 65 years or older who were scheduled for cancer surgery and presented for comprehensive geriatric assessment. We reviewed the baseline patient characteristics obtained from electronic medical records and the patients' preoperative medication history, including anticoagulants, antiplatelet agents, and streptokinase/streptodornase.

RESULTS

A total of 475 cancer patients were included. Multivariate analysis showed that long-acting anticoagulant therapy before surgery was a significant risk factor for intraoperative transfusion. Long-acting anticoagulants increased the risk of transfusion approximately 15.9-fold (95% CI 1.9-136.2). The attributable risk of long-acting anticoagulants to transfusion was approximately 93.7%. Also, low body mass index (BMI) and hepato-pancreato-biliary (HPB) surgery were significantly associated with intraoperative transfusion. The adjusted odds ratios for low BMI (<18.5 kg/m²) and HPB surgery (reference: lower gastrointestinal surgery) were 5.3 (95% CI 1.8-15.4) and 4.9 (95% CI 1.9-12.5), respectively.

CONCLUSIONS

It was found that the perioperative use of long-acting anticoagulants was associated with an increased risk of intraoperative transfusion, further highlighting the importance of medication optimization for elderly patients with cancer surgery.

Association of pre-operative medication use with unplanned 30-day hospital readmission after surgery in oncology patients receiving comprehensive geriatric assessment

BACKGROUND

This study aimed to determine whether pre-operative medication use is associated with unplanned 30-day readmission in elderly people undergoing cancer surgery.

METHODS

Patients aged 65 years or older who were scheduled for cancer surgery and presented for comprehensive geriatric assessment were included. Comparisons of variables between patients with readmission and those without readmission were performed by univariate and multivariate analyses.

RESULTS

A total of 473 patients were included. Multivariate analysis showed that pre-operative discontinuation-requiring medications (PDRMs) and gastrointestinal/hepato-pancreato-biliary (GI/HPB) cancer were significant factors for 30-day readmission. PDRM increased the risk of readmission by about 2.2-fold. Attributable risk of PDRM to readmission was around 55%. The adjusted odds ratio and attributable risk for GI/HPB surgery was 3.4 (95% CI 1.0-11.5) and 70.8%, respectively.

CONCLUSIONS

Medication use has an impact on unplanned 30-day readmission in geriatric oncology patients, further highlighting the importance of medication optimization for elderly patients with cancer surgery.

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.

Re-emergent Tongue Tremor in Neuroleptic-induced Parkinsonism

Background

A re-emergent tremor is suggested to be specific to Parkinson’s disease and although a tongue tremor has been reported in levosulpiride-induced parkinsonism (LIP), re-emergence has never been reported.

Case Report

A 59-year-old female presented with a 3-month history of bradykinesia, 2-week history of right-leg tremor, and 10-day history of lip and tongue tremor. A review of the medication revealed a 15-month history of levosulpiride consumption. On examination, asymmetric bradykinesia, rigidity, rest tremor of the right leg, and re-emergent tongue tremor were observed. The parkinsonism subsided after levosulpiride was stopped.

Discussion

This is the first report of re-emergent tongue tremor in LIP.

An Unusual Cause of Camptocormia

Background

Camptocormia is defined as forward flexion of the spine that manifests during walking and standing and disappears in recumbent position. The various etiologies include idiopathic Parkinson’s disease, multiple system atrophy, myopathies, degenerative joint disease, and drugs.

Case Report

A 67-year-old diabetic female presented with bradykinesia and camptocormia that started 1 year prior to presentation. Evaluation revealed levosulpiride, a dopamine receptor blocker commonly used for dyspepsia, to be the culprit.

Discussion

It is well known that dopamine receptor blockers cause parkinsonism and tardive syndromes. We report a rare and unusual presentation of camptocormia attributed to this commonly used gastrointestinal drug in the Asian population.

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.

Levosulpiride-induced neuroleptic malignant syndrome in rheumatoid arthritis

A 53-year-old woman, known case of diabetes mellitus and rheumatoid arthritis, presented with a 4-day history of hyperthermia, rigidity, tremor and altered sensorium. She developed these symptoms after having been administered parenteral levosulpiride to control vomiting due to secondary adrenal insufficiency. We managed her as a case of life-threatening neuroleptic malignant syndrome (NMS) requiring mechanical ventilation, bromocriptine and other supportive care. She subsequently recovered and was discharged in a stable condition. To the best of our knowledge, this is the first documented case report describing levosulpiride-induced NMS.

DAT-SPECT imaging in cases of drug-induced parkinsonism in a specialty movement disorders practice

OBJECTIVE

Compare clinical characteristics and outcomes in cases where DAT-SPECT imaging is used to distinguish Parkinson's disease from Drug-Induced Parkinsonsim.

BACKGROUND

Clinical uncertainty in diagnosing Parkinson's disease is common when patients are on dopamine-blocking medications. DAT-SPECT imaging can improve diagnostic certainty but little data are available on clinical characteristics and outcomes associated with normal and abnormal scan results.

METHODS

Retrospective chart review of patients seen at a movement disorders center between 2011 and 2017 where DAT-SPECT was ordered to distinguish Parkinson's disease from Drug-induced Parkinsonism. Descriptive statistics were calculated for variables of interest and compared by scan result. Chi-squared analyses was carried out for categorical variables and students' t-tests for continuous values.

RESULTS

51 patients met inclusion criteria with 36 normal scans and 15 abnormal scans. Those with greater than 2 cardinal manifestations (tremor, rigidity, akinesia, postural instability) were more likely to have an abnormal scan (63.89% vs 93.33%, p = 0.04). No other clinical characteristics assessed were associated with scan results. Atypical antipsychotics (aripiprazole 39.21%, olanzapine 31.37%) and mood stabilizers (valproic acid 33.33%, lithium 17.65%) were most commonly associated with suspected Drug-induced Parkinsonism cases. A post-scan change in management occurred in 41.18% of patients. 55.56% of patients with normal scans responded to changes in the offending medication, with 16.66% taking over 3 months to show improvement.

CONCLUSIONS

Many DAT-SPECT scans at our institution are ordered to distinguish Parkinson's disease from Drug-induced Parkinsonism because clinical characteristics alone are unreliable. DAT-SPECT results lead to changes in management and the outcomes of these changes are consistent with scan results.

Treatment of autonomic dysfunction in Parkinson disease and other synucleinopathies

Dysfunction of the autonomic nervous system afflicts most patients with Parkinson disease and other synucleinopathies such as dementia with Lewy bodies, multiple system atrophy, and pure autonomic failure, reducing quality of life and increasing mortality. For example, gastrointestinal dysfunction can lead to impaired drug pharmacodynamics causing a worsening in motor symptoms, and neurogenic orthostatic hypotension can cause syncope, falls, and fractures. When recognized, autonomic problems can be treated, sometimes successfully. Discontinuation of potentially causative/aggravating drugs, patient education, and nonpharmacological approaches are useful and should be tried first. Pathophysiology-based pharmacological treatments that have shown efficacy in controlled trials of patients with synucleinopathies have been approved in many countries and are key to an effective management. Here, we review the treatment of autonomic dysfunction in patients with Parkinson disease and other synucleinopathies, summarize the nonpharmacological and current pharmacological therapeutic strategies including recently approved drugs, and provide practical advice and management algorithms for clinicians, with focus on neurogenic orthostatic hypotension, supine hypertension, dysphagia, sialorrhea, gastroparesis, constipation, neurogenic overactive bladder, underactive bladder, and sexual dysfunction. © 2018 International Parkinson and Movement Disorder Society.

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.

Levosulpiride-induced Movement Disorders

We reported a series of patients who presented with LSP-induced movement disorders specifically, dyskinetic movements. We have presented one case of LSP-induced parkinsonism and summarized ten cases of LSP-induced dyskinesia. The causality of the adverse drug reaction was assessed systematically using a validated rating system, and we extensively qualified the clinical presentation of each case of dyskinesia using a clinical rating scale. We described an unusual case of acute onset LSP-induced parkinsonism in a 56-year-aged female. The mean age of ten patients of LSP-induced dyskinesia was 65.3 years (standard deviation 10.4), and 25% of patients were female. They were consuming suspected medication for a median duration of 13 months (range 1-60 months). We noted LSP-induced dyskinesia was challenging to treat as its resolution is often incomplete even with adequate treatment.

Prokinetics in the Management of Functional Gastrointestinal Disorders

PURPOSE OF REVIEW

The goal of this review is to review the current status of prokinetics and to place it in historical context. Impaired motility and thus propulsion have long been thought to play important roles in the pathogenesis of a number of gastrointestinal disorders including gastroesophageal reflux disease (GERD), gastroparesis, chronic idiopathic pseudo-obstruction, and constipation. Historically, disordered motility was also thought to contribute to a number of functional gastrointestinal disorders such as functional dyspepsia (FD) and irritable bowel syndrome (IBS).

RECENT FINDINGS

As we learn more of the pathophysiology of FD, IBS, GERD, constipation, and gastroparesis, the limitations of a therapeutic strategy based on the stimulation of motility (i.e., the use of a prokinetic) have become apparent and the disappointments of the past explained. The development of prokinetic drugs has also been hampered by the non-selective nature of many of the agents studied to date which resulted in some unexpected side effects. There is still an unmet need for an effective and safe prokinetic, but drug development in this area must be mindful of the challenges of the area and the need for selectivity for a given target receptor.

Preoperative medication use and its association with postoperative length of hospital stay in surgical oncology patients receiving comprehensive geriatric assessment

AIM

The present study aimed to investigate whether preoperative medication use is associated with postoperative length of hospital stay in older adults undergoing cancer surgery.

METHODS

Patients aged ≥65 years who were scheduled for cancer surgery and presented for preoperative comprehensive geriatric assessment were included in the present study. Cognitive function evaluation and preoperative medication review were carried out, as well as baseline characteristics of participants collected from electronic medical records. The primary efficacy variable was the postoperative length of stay (LOS) in hospital.

RESULTS

A total of 475 cancer patients were included for the analysis. Baseline characteristics of participants including older age, lower body mass index (BMI) and male sex were associated with longer postoperative stay. Among the clinical variables, cancer type, number of medications, potentially inappropriate medication (PIM) and delirium-inducing medication were found as statistically significant factors for postoperative LOS. In multivariate analysis, variables independently associated with postoperative LOS were cancer type, PIM use, BMI, and the number of medications after controlling for age, BMI, sex, cancer type, the number of medications, PIM, and delirium-inducing medication. In subgroup analysis of gastrointestinal cancer, multiple linear regression analysis showed that PIM use and BMI were significantly associated with LOS after adjustment for age, sex, and number of medication.

CONCLUSIONS

The present study supports the impact of medication use on postoperative LOS in geriatric oncology patients. The results add a further aspect to medication optimization in older patients undergoing cancer surgery. Geriatr Gerontol Int 2018; 18: 12-19.

Prokinetics for the treatment of functional dyspepsia: Bayesian network meta-analysis

BACKGROUND

Controversies persist regarding the effect of prokinetics for the treatment of functional dyspepsia (FD). This study aimed to assess the comparative efficacy of prokinetic agents for the treatment of FD.

METHODS

Randomized controlled trials (RCTs) of prokinetics for the treatment of FD were identified from core databases. Symptom response rates were extracted and analyzed using odds ratios (ORs). A Bayesian network meta-analysis was performed using the Markov chain Monte Carlo method in WinBUGS and NetMetaXL.

RESULTS

In total, 25 RCTs, which included 4473 patients with FD who were treated with 6 different prokinetics or placebo, were identified and analyzed. Metoclopramide showed the best surface under the cumulative ranking curve (SUCRA) probability (92.5%), followed by trimebutine (74.5%) and mosapride (63.3%). However, the therapeutic efficacy of metoclopramide was not significantly different from that of trimebutine (OR:1.32, 95% credible interval: 0.27-6.06), mosapride (OR: 1.99, 95% credible interval: 0.87-4.72), or domperidone (OR: 2.04, 95% credible interval: 0.92-4.60). Metoclopramide showed better efficacy than itopride (OR: 2.79, 95% credible interval: 1.29-6.21) and acotiamide (OR: 3.07, 95% credible interval: 1.43-6.75). Domperidone (SUCRA probability 62.9%) showed better efficacy than itopride (OR: 1.37, 95% credible interval: 1.07-1.77) and acotiamide (OR: 1.51, 95% credible interval: 1.04-2.18).

CONCLUSIONS

Metoclopramide, trimebutine, mosapride, and domperidone showed better efficacy for the treatment of FD than itopride or acotiamide. Considering the adverse events related to metoclopramide or domperidone, the short-term use of these agents or the alternative use of trimebutine or mosapride could be recommended for the symptomatic relief of FD.

Cardiovascular Autonomic Dysfunction in Patients with Drug-Induced Parkinsonism

BACKGROUND AND PURPOSE

Recent studies have shown that several nonmotor symptoms differ between Parkinson's disease (PD) and drug-induced parkinsonism (DIP). However, there have been no reports on cardiovascular autonomic function in DIP, and so this study investigated whether cardiovascular autonomic function differs between PD and DIP patients.

METHODS

This study consecutively enrolled 20 DIP patients, 99 drug-naïve PD patients, and 25 age-matched healthy controls who underwent head-up tilt-table testing and 24-h ambulatory blood pressure monitoring.

RESULTS

Orthostatic hypotension was more frequent in patients with PD or DIP than in healthy controls. In DIP, orthostatic hypotension was associated with the underlying psychiatric diseases and neuroleptics use, whereas prokinetics were not related to orthostatic hypotension. The supine blood pressure, nighttime blood pressure, and nocturnal blood pressure dipping did not differ significantly between the DIP and control groups. Supine hypertension and nocturnal hypertension were more frequent in PD patients than in controls.

CONCLUSIONS

The included DIP patients frequently exhibited orthostatic hypotension that was associated with the underlying diseases as well as the nature of and exposure time to the offending drugs. Clinicians should individualize the manifestations of DIP according to underlying diseases as well as the action mechanism of and exposure time to each offending drug.

Association of pre-operative medication use with post-operative delirium in surgical oncology patients receiving comprehensive geriatric assessment

BACKGROUND

Older patients undergoing surgery tend to have a higher frequency of delirium. Delirium is strongly associated with poor surgical outcomes. This study evaluated the association between pre-operative medication use and post-operative delirium (POD) in surgical oncology patients receiving comprehensive geriatric assessment (CGA).

METHODS

A total of 475 patients who were scheduled for cancer surgery and received CGA from January 2014 to June 2015 were included. Pre-operative medication review through CGA was conducted on polypharmacy (≥5 medications), delirium-inducing medications (DIMs), fall-inducing medications (FIMs), and potentially inappropriate medications (PIMs). POD was confirmed by psychiatric consultation, and DSM-V criteria were used for diagnosing delirium. The model fit of the prediction model was assessed by computing the Hosmer-Lemeshow goodness-of-fit test. Effect size was measured using the Nagelkerke R(2). Discrimination of the model was assessed by an analysis of the area under receiver operating curve (AUROC).

RESULTS

Two models were constructed for multivariate analysis based on univariate analysis; model I included dementia and DIM in addition to age and sex, and model II included PIM instead of DIM of model I. Every one year increase of age increased the risk of POD by about 1.1-fold. DIM was a significant factor for POD after adjusting for confounders (AOR 12.78, 95 % CI 2.83-57.74). PIM was also a significant factor for POD (AOR 5.53, 95 % CI 2.03-15.05). The Hosmer-Lemeshow test results revealed good fits for both models (χ(2) = 3.842, p = 0.871 for model I and χ(2) = 8.130, p = 0.421 for model II). The Nagelkerke R(2) effect size and AUROC for model I was 0.215 and 0.833, respectively. Model II had the Nagelkerke R(2)effect size of 0.174 and AUROC of 0.819.

CONCLUSIONS

These results suggest that pharmacists' comprehensive review for pre-operative medication use is critical for the post-operative outcomes like delirium in older patients.

Cognitive Dysfunction in Drug-induced Parkinsonism Caused by Prokinetics and Antiemetics

The use of prokinetics/antiemetics is one of the leading causes of drug-induced parkinsonism (DIP) observed in neurology clinics. Cognitive dysfunction in DIP has recently been recognized, but pathologies related with cognitive dysfunction is unknown. Among our retrospective cohort of 385 consecutive parkinsonian patients enrolled in our parkinsonism registry, 14 patients were identified who satisfied our inclusion criteria: parkinsonism caused by prokinetics/antiemetics, existing T1-weighted 3D volumetric MR images, and normal [(18)F]-N-3-fluoropropyl-2-β-carboxymethoxy-3-β-(4-iodophenyl) nortropane PET scan images. For the comparison of volumetric MR data, 30 age- and sex-matched healthy individuals were included in this study. Among 14 patients with DIP, 4 patients were diagnosed with dementia, and all other patients had mild cognitive impairment (MCI). Comparisons of MR volumetric data between DIP patients with MCI and controls show that cortical gray matter volumes are reduced bilaterally in DIP (P=0.041) without changes in either total white matter volume or total intracranial volume. Among subcortical structures, the volume of the right hippocampus is reduced in DIP patients compared with controls (P=0.011, uncorrected). In DIP, cortical thickness is reduced in the bilateral lingual (P=0.002), right fusiform (P=0.032) and part of the left lateral occipital gyri (P=0.007). Our results suggests that cognitive dysfunction in DIP caused by prokinetics/antiemetics is common. Structural changes in the brain by 3D MRI may be associated with cognitive decline in DIP.

Herbal medicine treatment for drug-induced parkinsonism

OBJECTIVES

To evaluate the role of herbal medicine in drug-induced parkinsonism (DIP) and identify an optimal treatment approach.

DESIGN

Retrospective review of DIP cases treated with herbal medicine.

SETTINGS/LOCATION

The Parkinson's clinic at Kyung Hee Traditional Korean Medicine Hospital, Korea.

PATIENTS

Twenty-one patients whose clinical outcome and offending drug could be identified.

OUTCOME MEASURES

Clinical features, treatments, and outcomes and summarized the clinical course and treatment in each case.

RESULTS

Twelve patients had levosulpiride-induced parkinsonism and 9 had parkinsonism induced by another drug. The offending drugs were discontinued in all patients, and all patients received herbal medications during treatment. Nine of 12 patients with parkinsonism from levosulpiride and 4 of 9 patients with parkinsonism from other drugs had complete reversal of symptoms. The most frequently used herbal formula was Ukgansan (Yigansan). DIP in the levosulpiride group tended to improve faster with herbal medicine, and the percentage of improvement was higher.

CONCLUSIONS

Optimal herbal medicine treatments chosen after a careful history and evaluation for risk factors may be helpful in reversing DIP.

Pharmacokinetics of levosulpiride after single and multiple intramuscular administrations in healthy Chinese volunteers

The main purpose of this study was to evaluate the pharmacokinetics of levosulpiride in humans after single and multiple intramuscular injections. Six males and six females received single dose of either 25 mg or 50 mg levosulpiride, or multiple doses of 25 mg every 12 h for 5 consecutive days. In the single 25 mg study, the mean peak plasma concentration (C_max) was 441 ng/mL, the mean area under the concentration–time curve from 0 to 36 h (AUC_0–36) was 1724 ng h/mL, and the mean elimination half-life (t_1/2) was 7.0 h. In the single 50 mg study, the mean C_max was 823 ng/mL, the mean AUC_0–36 was 3748 ng·h/mL, and the mean t_1/2 was 6.8 h. After multiple doses of 25 mg levosulpiride, the average plasma concentration (C_av) was 136 ng/mL, the fluctuation index (DF) was 3.60, and the accumulation ratio (R) was 1.2. Levosulpiride injections appeared to be well tolerated by the subjects, and can be used for successive administration.

Clinical features of drug-induced parkinsonism based on [18F] FP-CIT positron emission tomography

Drug-induced parkinsonism (DIP) is the common cause of parkinsonism. It is difficult to make a differentiation between DIP and Parkinson's disease (PD) because there are no notable differences in the clinical characteristics between the two entities. In this study, we examined the relationship between the characteristics of [(18)F] fluorinated-N-3-fluoropropyl-2-β-carboxymethoxy-3-β-(4-iodophenyl)nortropane (FP-CIT) positron emission tomography (PET) images and clinical features in DIP patients. We retrospectively studied 76 patients with DIP who underwent [(18)F] FP-CIT PET. We also enrolled 16 healthy controls who underwent it. We compared the clinical characteristics between the DIP patients with normal [(18)F] FP-CIT PET scans and those with abnormal ones. Symmetric parkinsonism was more frequent in the patients with normal [(18)F] FP-CIT PET scans as compared with those with abnormal ones. Interval from drug intake to onset of parkinsonism was longer in the patients with abnormal [(18)F] FP-CIT PET scans as compared with those with normal ones. A semi-quantitative analysis showed that specific to non-specific binding ratios in the putamen was lower in the patients with abnormal [(18)F] FP-CIT PET scans as compared with those with normal ones and the age-matched control group. Our results suggest that symmetric parkinsonism was more prevalent, and the duration of drug exposure before the onset of parkinsonism was shorter in the patients with normal [(18)F] FP-CIT PET scans as compared with those with abnormal ones.

Commonly used gastrointestinal drugs

This chapter reviews the spectrum and mechanisms of neurologic adverse effects of commonly used gastrointestinal drugs including antiemetics, promotility drugs, laxatives, antimotility drugs, and drugs for acid-related disorders. The commonly used gastrointestinal drugs as a group are considered safe and are widely used. A range of neurologic complications are reported following use of various gastrointestinal drugs. Acute neurotoxicities, including transient akathisias, oculogyric crisis, delirium, seizures, and strokes, can develop after use of certain gastrointestinal medications, while disabling and pervasive tardive syndromes are described following long-term and often unsupervised use of phenothiazines, metoclopramide, and other drugs. In rare instances, some of the antiemetics can precipitate life-threatening extrapyramidal reactions, neuroleptic malignant syndrome, or serotonin syndrome. In contrast, concerns about the cardiovascular toxicity of drugs such as cisapride and tegaserod have been grave enough to lead to their withdrawal from many world markets. Awareness and recognition of the neurotoxicity of gastrointestinal drugs is essential to help weigh the benefit of their use against possible adverse effects, even if uncommon. Furthermore, as far as possible, drugs such as metoclopramide and others that can lead to tardive dyskinesias should be used for as short time as possible, with close clinical monitoring and patient education.

Nonmotor symptoms in drug-induced parkinsonism and drug-naïve Parkinson disease

BACKGROUND

The clinical manifestations of drug-induced parkinsonism (DIP) and Parkinson disease (PD) are nearly indistinguishable, making it difficult to differentiate DIP from PD, especially in the early stages. We compared non-motor symptoms between patients with DIP and those with drug-naïve PD in the early stages using the Non Motor Symptoms Scale (NMSS).

METHODS

We prospectively enrolled 28 patients with DIP, 35 patients with drug-naïve PD, and 32 controls with no history of neurological diseases or related medical problems. We investigated demographic characteristics, medical and drug history, parkinsonian motor symptoms, and non-motor symptoms. We used the NMSS to evaluate non-motor symptoms in all patients.

RESULTS

The total NMSS scores were higher in patients with PD than those with DIP, as were the scores for certain domains, including the cardiovascular, sleep/fatigue, urinary, sexual, and miscellaneous domains. When controlling for age and gender, the correlation analysis revealed that scores for urinary symptoms (urgency, frequency and nocturia), sleep disturbances (daytime sleep, restless legs), concentration, taste or smell were significantly associated with PD.

CONCLUSIONS

Our data suggest that non-motor symptoms, particularly urinary symptoms, excessive daytime sleepiness, restless leg syndrome, attention deficit and hyposmia may be helpful to differentiate between DIP and PD in the early stages.

Diagnostic accuracy of 123 I-FP-CIT SPECT in diagnosing drug-induced parkinsonism: a prospective study

INTRODUCTION

Drug-induced parkinsonism is a major type of parkinsonism in our setting. Symptoms usually disappear after discontinuation of the drug. However, they may persist in patients with a variant known as subclinical drug-exacerbated parkinsonism; early identification of this entity has important prognostic and therapeutic implications. The most widely used complementary test in this diagnosis is single-photon emission computed tomography with ioflupane ((123)I), also known as (123)I-FP-CIT SPECT. The aim of our study is to verify its diagnostic accuracy.

METHODS

We designed a prospective study of patients with drug-induced parkinsonism in which, after discontinuing the drug and undergoing a (123)I-FP-CIT SPECT scan, patients would be monitored for at least 6 months. Patients were categorised as having iatrogenic parkinsonism if symptoms disappeared, or as having subclinical drug-exacerbated parkinsonism if they persisted. Lastly, we verified concordance between the clinical diagnosis and results from the (123)I- FP-CIT SPECT scan.

RESULTS

The sample included 19 patients. The most commonly prescribed drug class was neuroleptic agents. For the diagnosis of both subgroups, (123)I-FP-CIT SPECT showed a sensitivity of 66.7%, specificity and positive predictive value of 100%, a negative predictive value of 86.7%, and a negative likelihood ratio of 0.33.

CONCLUSIONS

Although the study needs to be repeated in a larger sample of patients, (123)I-FP-CIT SPECT is useful in the diagnosis of drug-induced parkinsonism since it is a very precise tool for identifying patients with that illness.

Drug-induced parkinsonism

Drug-induced parkinsonism (DIP) is the second-most-common etiology of parkinsonism in the elderly after Parkinson's disease (PD). Many patients with DIP may be misdiagnosed with PD because the clinical features of these two conditions are indistinguishable. Moreover, neurological deficits in patients with DIP may be severe enough to affect daily activities and may persist for long periods of time after the cessation of drug taking. In addition to typical antipsychotics, DIP may be caused by gastrointestinal prokinetics, calcium channel blockers, atypical antipsychotics, and antiepileptic drugs. The clinical manifestations of DIP are classically described as bilateral and symmetric parkinsonism without tremor at rest. However, about half of DIP patients show asymmetrical parkinsonism and tremor at rest, making it difficult to differentiate DIP from PD. The pathophysiology of DIP is related to drug-induced changes in the basal ganglia motor circuit secondary to dopaminergic receptor blockade. Since these effects are limited to postsynaptic dopaminergic receptors, it is expected that presynaptic dopaminergic neurons in the striatum will be intact. Dopamine transporter (DAT) imaging is useful for diagnosing presynaptic parkinsonism. DAT uptake in the striatum is significantly decreased even in the early stage of PD, and this characteristic may help in differentiating PD from DIP. DIP may have a significant and longstanding effect on patients' daily lives, and so physicians should be cautious when prescribing dopaminergic receptor blockers and should monitor patients' neurological signs, especially for parkinsonism and other movement disorders.