A long-term follow-up study of cinnarizine- and flunarizine-induced parkinsonism

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.

Reduction of neuronal hyperexcitability with modulation of T-type calcium channel or SK channel in essential tremor

Essential tremor is one of the most prevalent movement disorders. Propranolol and primidone are the first-line pharmacological therapies. They provide symptomatic control in less than 50% of patients. Topiramate, alprazolam, clonazepam, gabapentin, and botulinum toxin injections are the next line of treatments. These medications lead to modest improvements and are therefore commonly used as add-on agents. Surgical therapies, including deep brain stimulation (DBS) surgery and focused ultrasound beam targeted to the thalamus, are considered for treating tremor refractory to medications and lead to greater than 75% improvements in tremor symptoms. However, DBS is a costly and an invasive procedure; some patients report tolerance to benefits. Focused ultrasound therapy leading to brain lesions is associated with a possibility for permanent clinical deficits. Therefore, research efforts to develop the next generation of oral medications with greater benefits and lesser adverse effects are warranted. There is considerable evidence that the increased functions of calcium channels (P/Q-type and T-type channels) and reduced functions of calcium-activated potassium channels (SK channels) located in the neuronal membranes lead to tremor oscillations. Consequently, many new pharmacological studies have targeted these channels to leverage better clinical outcomes. The current review will discuss the pathophysiology, the specific importance of these channels, and the early clinical experience of using compounds targeting these channels to treat essential tremor.

Cinnarizine- and flunarizine-associated movement disorder: a literature review

Introduction

Cinnarizine (CNZ) and flunarizine (FNZ) belong to the calcium channel blockers class of medication.

Main text

The aim of this literature review is to evaluate the clinical epidemiological profile, pathological mechanisms, and management of CNZ/FNZ-associated movement disorder (MD). Relevant reports in six databases were identified and assessed by two reviewers without language restriction. One hundred and seventeen reports containing 1920 individuals who developed a CNZ/FNZ-associated MD were identified. The MD encountered were 1251 parkinsonism, 23 dyskinesias, 11 akathisia, 16 dystonia, and 5 myoclonus, and in the group not clearly defined, 592 extrapyramidal symptoms, 19 tremors, 2 bradykinesia, and 1 myokymia. The predominant sex was female with a percentage of 72.69% (466/641). The mean age was 74.49 (SD, 7.88) years. The mean CNZ dose was 148.19 mg (SD, 42.51) and for the FNZ dose, 11.22 mg (5.39). The mean MD onset and recovery were 1.83 years (SD, 1.35) and 3.71 months (SD, 1.26). In the subgroup of subjects that had improvement of the symptoms, the complete recovery was achieved within 6 months of the drug withdrawal in almost all subjects (99%). The most common management was drug withdrawal. A complete recovery was observed in 93.77% of the patients (437/466).

Conclusions

CNZ/FNZ-associated MD was extensively reported in the literature. Parkinsonism was the most well described. Myoclonus (MCL) was the poorest described MD with missing data about the neurological examination and electrodiagnostic studies. The knowledge of this disorder probably can contribute to the understanding of the other drug-induced MDs.

Cinnarizine as an alternative recommendation for migraine prophylaxis: a narrative review

INTRODUCTION

Despite the available prophylactic and acute drugs for migraine management, this disabling disorder remains undertreated especially among pediatrics. In this review, the authors aim at assessing the preventive role cinnarizine plays in treating migraine based on previously published studies.

AREAS COVERED

Randomized clinical trials, randomized controlled trials, non-randomized open-label trials, and retrospective studies concerning cinnarizine in migraine prevention in children and adults were reviewed. Especial attention was given to the response rate, migraine characteristics, and tolerability.

EXPERT OPINION

The majority of reviewed trials demonstrated that cinnarizine is comparable to the conventional drugs used in migraine prophylaxis. However, most of the reviewed studies were limited by a non-controlled open-label design. Due to poor planning and possibility of high placebo responses, particularly in children and adolescents, the interpretation of open-label studies' results should be done cautiously. The evidence shows that cinnarizine's effectiveness was more promising in pediatric migraineurs and adults with migraine-associated vertigo such as vestibular migraine. Therefore, while the efficacy of cinnarizine cannot be dismissed, before reaching a definite conclusion on its effectiveness, it is necessary to do further high-quality RCTs among both children and adults.

Flunarizine Induced Parkinsonism in Migraine Group: A Nationwide Population-Based Study

Background: Flunarizine (Fz) is a first-line prophylactic medication that is widely used in migraine. However, Fz has been recognized as a potential cause of drug-induced parkinsonism for a long time. However, to our knowledge, there has been no population-based subgroup analyses for Fz-induced parkinsonism (FIP) in migraine patients. Methods: Data were obtained from the Taiwan's National Health Insurance Research Database. The study comprised 6,470 migraine patients who were divided into two groups, based on their exposure or non-exposure to Fz. Results: During the study period (2000-2012), the incidence rate of parkinsonism was 1.92 and 8.72 per 1,000 person-years in the control and Fz -treated groups, respectively. In the study population, the adjusted hazard ratio was 4.07 (95% confidence interval CI: 2.84-5.85). In 45-64-year old subjects and ≥ 65-year old subjects, the risk of FIP was 3.18 times (95% CI = 1.63-6.20) and 4.89 times (95% CI = 3.09-7.72) more than that in the controls. The Fz-treated subjects with comorbidities also had a higher risk (4.54, 95% CI: 3.14-6.57). An average annual cumulative Fz dose > 445 mg was accompanied by the greatest risk of FIP; Fz use for >60 days is a cut-off point for predicting future FIP. Conclusion: At the population level, this study showed a complete picture of FIP in migraine patients. FIP is associated with older age, history of comorbidities, exposure to high-dose of Fz, and longer duration of exposure to Fz.

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.

Flunarizine related movement disorders: a nationwide population-based study

Flunarizine (fz) causes side effects such as movement disorders (MDs). We investigated risk factors associated with fz-related MDs. Participants were recruited from the longitudinal health insurance databases and included patients who took fz for more than 1 month. Patients with one of the underlying diseases, or with concomitant drug use (antipsychotics, metoclopramide or reserpine), and those diagnosed with MDs before fz use were excluded. Fz-related MD was defined as a new diagnosis of parkinsonism or hyperkinetic syndrome including dyskinesia or secondary dystonia during fz use or within 3 months after drug discontinuation. After exposure, 288 individuals had fz-related MDs (parkinsonism, n = 240; hyperkinesia, n = 48). Risk factors associated with these disorders were higher-dose exposure (cumulative defined daily dose [cDDD] ≥87.75, odds ratio [OR]: 3.80; 95% CI: 2.61–5.52), older age (OR: 1.07; 95% CI: 1.06–1.09), history of essential tremor (OR: 6.39; 95% CI: 2.29–17.78) and cardiovascular disease (CVD) (OR: 1.47; 95% CI: 1.14–1.9). The optimal value of cDDD to predict MDs was 58.5 (sensitivity: 0.67, specificity: 0.60), indicating an overall exposure of 585 mg. Higher exposure dose and duration, older age, history of essential tremor, and CVD were associated with fz-associated MDs. Clinicians ought to watch for extrapyramidal side effects when prescribing fz.

Flunarizine and the risk of parkinsonism in a newly diagnosed type 2 diabetic population in Taiwan: A nested case-control study

Previous studies demonstrated that both diabetes and flunarizine use can increase the risk of parkinsonism. The aim of the current study was to investigate the risk of developing parkinsonism after flunarizine treatment, in a cohort of patients newly diagnosed with type 2 diabetes. We conducted a nested case-control study of a type 2 diabetic cohort from the Taiwan Longitudinal Health Insurance Database 2005 (LHID 2005). Each incident case of parkinsonism, during the period from 2001 to 2013, was randomly matched with 3-10 controls, according to age, sex, calendar year of cohort entry, and the duration of follow-up. Conditional logistic regression was used to estimate the odds ratio (OR) of parkinsonism associated with flunarizine use. The cohort consisted of 44,644 patients with newly diagnosed type 2 diabetes from 2001 to 2013, of whom 464 patients had a parkinsonism event during the follow-up period. The adjusted OR of parkinsonism with relation to flunarizine use was 2.75 (95% confidence interval: 2.26-3.36). There were also duration- and dose-response effects. Compared to those who had not used it, the OR for developing parkinsonism was 1.77 for patients who used flunarizine for less than 1 month. When the exposure period expanded over 3 months, the OR increased to 7.03. Our findings suggested that flunarizine use is a potential risk factor for parkinsonism in patients with newly diagnosed type 2 diabetes, especially when the drug is persistently used for over 3 months.

Extrapyramidal symptoms after exposure to calcium channel blocker-flunarizine or cinnarizine

Purpose

Flunarizine (fz) and cinnarizine (cz) have well-known extrapyramidal side effects (EPSEs). The aim of this study was to evaluate the incidence and occurrence time of cz- and fz-related EPSEs.

Method

Patients who took fz or cz for more than 1 month were identified from the longitudinal health insurance database 2005 and 2010. Excluded were patients with any of the underlying diseases that may cause parkinsonism. Drug-induced EPSEs were defined as the new diagnosis of parkinsonism, dyskinesia, or secondary dystonia during drug use or within 3 months after discontinuing the medication. Age- and sex-matched controls were included in this study.

Results

Recruited for analysis were individuals who took fz (n = 26,133) and cz (n = 7186). The incidence rates of fz- and cz-induced EPSEs were 21.03 and 10.3 per 10,000 person-months, respectively. The hazard ratios (HRs) of EPSEs among fz and cz subjects were 8.03 (95% CI 6.55–9.84) and 3.41 (95% CI 2.50–4.63) when compared with the control individuals. Both fz and cz patients had a higher cumulative incidence of EPSEs than their control individuals (p < 0.001). Among subjects who took fz, the incidence of EPSEs was higher in the second than first year of drug exposure (45.59 vs 21.03 per 10,000 person-months).

Conclusions

Fz and cz significantly increased the risk of parkinsonism, dyskinesia, and dystonia. Potential benefits and risks should be weighed when considering long-term use of these drugs especially fz.

Electronic supplementary material

The online version of this article (doi:10.1007/s00228-017-2247-x) contains supplementary material, which is available to authorized users.

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.

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.

Viewpoint: challenges in our understanding of neuroleptic induced parkinsonism

Parkinsonism remains a common and often overlooked adverse effect of almost all neuroleptic drugs, including the "atypical," or "second generation" antipsychotics. While neuroleptic induced parkinsonism (NIP) is often thought to be well understood in terms of its clinical course, pathophysiology, and treatment, this is clearly not the case, and almost all our current beliefs are based on data published decades ago of dubious merit, and recent studies which are confounded by design conflicts. This article attempts to highlight gaps in our knowledge. While there are data on the stigma associated with idiopathic Parkinson's disease, there are none on NIP, where the problem is most likely much greater. The natural course of NIP remains unknown, including the question of whether this is a risk factor for the later development of tardive dyskinesia. While treatment with anticholinergics or amantadine is the norm, there are weak and conflicting data on whether these have much value. Why quetiapine and clozapine do not worsen motor function in people with idiopathic PD, while all other neuroleptic do, remains uncertain. Neuroleptics are among the most widely prescribed medications in the United States, with 20% of nursing home residents taking them, with an increasing use for treating depression as well as psychosis, underscoring the importance of understanding NIP, the most important adverse motor effect of this class of drugs.

Cinnarizine for the prophylaxis of migraine associated vertigo: a retrospective study

Objective

To assess the efficacy and safety of cinnarizine for the prophylaxis of migraine associated vertigo in the vestibular migraine and migraine with brainstem aura.

Background

Vestibular migraine and migraine with brainstem aura are two principal clinical syndromes that frequently are associated with vertigo. Since cinnarizine is a well-tolerated calcium channel blocker which has acceptable effect on both vertigo and migraine headache, we carried out this study to evaluate the efficacy and safety of this medication in vestibular migraine and also migraine with brainstem aura associated with vertigo.

Methods

This was a retrospective, single-center, open-label, investigation of the effects of cinnarizine on vestibular migraine and migraine with associated with vertigo. We assessed the change in monthly frequency of vertigo and also frequency, duration and intensity of migraine attacks after one, two and three months of cinnarizine administration.

Results

The mean frequency of vertigo and also the mean frequency, duration and intensity of migraine headaches per month were reduced significantly after three months of cinnarizine therapy (all p < 0.001).

Conclusion

This study suggests that cinnarizine is safe and effective in reducing both headache and vertigo aspects of “migraine plus vertigo” among the patients who suffer from either vestibular migraine or migraine with brainstem aura associated with vertigo.

Drug-induced parkinsonism

INTRODUCTION

Drug-induced parkinsonism (DIP) is the second most common cause of parkinsonism after idiopathic Parkinson's disease (iPD). Initially reported as a complication of antipsychotics, it was later recognized as a common complication of antidepressants, calcium channel antagonists, gastrointestinal prokinetics, antiepileptic drugs and many other compounds. Despite being a major health problem in certain populations, it seems to be frequently overlooked by the medical community.

AREAS COVERED

This paper approaches the concept of DIP, reviews its epidemiology, clinical features and ancillary tests recommended for a correct diagnosis. The authors discuss the different drugs and its pathogenic mechanisms. The relevance of an early recognition and recommendations for a correct management are commented.

EXPERT OPINION

Prescribers need to remain vigilant for DIP, particularly in the elderly, patients taking multiple drugs and those with genetic risk factors involved in iPD. Cessation of the causing agent is the main treatment and there is no evidence of benefit for the use of anticholinergics or levodopa. If the medication cannot be withdrawn, it should be switched to agents with a lower risk of DIP.

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.

Cognitive dysfunction in drug induced parkinsonism (DIP)

Several studies have suggested that the presence of dementia increases the risk of developing DIP. However, these prior studies exclusively focused on the underlying conditions before the development of DIP and there are no studies about the characteristics and prognosis of the cognitive status associated with DIP. We investigate the cognitive impairments associated with DIP by comparing neuro-psychological test results in patients with Parkinson's disease (PD) and normal controls and the longitudinal outcome of cognition in DIP. The cohort in this study included 13 consecutive patients with DIP and 91 patients with PD; all subjects completed a clinical assessment, neuropsychological investigation, and magnetic resonance imaging of brain. All patients with DIP were followed closely for more than six months after withdrawal of the offending drug. The cognitive function in DIP was significantly worse than in controls for most domains; however, there were no significant differences found in the comparisons with the PD patients. In addition, the severity of motor impairment was in part associated with cognitive function. Some patients had transient and reversible cognitive impairment, similar to other Parkinsonian motor features, and others experienced persistence and eventual worsening of their cognitive dysfunction after discontinuation of the offending drug. The results of this study suggest that cognitive impairment in patients with DIP reflects the toxic/metabolic symptoms associated with the offending drug in addition to being a risk factor for DIP.

Ameliorative effect of flunarizine in cisplatin-induced acute renal failure via mitochondrial permeability transition pore inactivation in rats

This study was aimed to evaluate the protective effect of flunarizine on cisplatin-induced acute renal failure. Administration of cisplatin (6 mg/kg, i.p. on day 6) significantly increased serum blood urea nitrogen and creatinine, urinary N-acetyl β-D-glucosaminidase, tissue thiobarbituric acid reactive substances and total calcium whereas, decreased body weight, fractional excretion of sodium, creatinine clearance tissue-reduced glutathione, mitochondrial cytochrome c oxidase, and ATP levels were observed in acute renal failure rats. Moreover, cisplatin produced histopathological changes in the renal tissue. Furthermore, flunarizine (100, 200, and 300 μM/kg, p.o., for six consecutive days) was administered to evaluate its therapeutic potential in acute renal failure, and the results were compared with cyclosporin A (50 μM/kg, p.o., for six consecutive days) as a reference drug. Flunarizine resulted in the attenuation of cisplatin-induced renal dysfunction, oxidative stress marker, mitochondrial damage, and histopathological changes in rats. Medium and higher doses of flunarizine produced significant renal protective effect which was comparable to cyclosporin A. The results of this study clearly revealed that flunarizine protected the kidney against the nephrotoxic effect of cisplatin via mitochondrial permeability transition pore inactivation potential.

Parkinsonism in patients with chronic hepatitis C treated with interferon-alpha2b: a report of two cases

Details of two patients with chronic hepatitis C infection who developed features of Parkinsonism when treated with IFN-alpha2b and ribavirin are reported. The symptoms resolved when treatment was discontinued in one patient but not in the other. Physicians should be alert to the possibility that drug-related Parkinsonism may complicate treatment of hepatitis C infection with antiviral agents; the agent most likely responsible is IFN-alpha2b. Prompt withdrawal of treatment is mandatory but does not always guarantee reversal of the Parkinsonian features.

Diabetes mellitus and drug-induced Parkinsonism: a case-control study

To investigate if diabetes is more common in drug-induced parkinsonism patients. We performed a hospital-based retrospective case-control study on 44 drug-induced parkinsonism (DIP) patients, 177 Parkinson disease patients, and 176 acute stroke patients matched for age and sex who were seen over the same period at the same hospital. The frequency of diabetes, age-at onset and sex were compared between DIP and IPD or acute stroke. Multivariate analysis showed that patients with diabetes are more frequent in DIP compared with IPD (p<0.001, adjusted OR 5.48; 95% CI, 2.52-11.94). The frequency of diabetes in DIP was comparable to that in acute stroke patients (p=0.16, adjusted OR 0.62; 95% CI, 0.32-1.21). These data suggest that diabetes may be a risk factor for DIP. Drugs with dopamine receptor blocking potency should be avoided in elderly with diabetes.

Drug-induced parkinsonism in the elderly

Drug-induced parkinsonism is primarily caused by drugs that interfere with dopamine stimulation. Antipsychotic drugs are the most common offenders, but drug-induced parkinsonism may be seen with many other drugs, such as antiemetics and certain calcium-channel blockers. These medications are widely used in the elderly. Unlike the first generation of antipsychotic drugs, all of which cause parkinsonism and other extrapyramidal side effects, atypical antipsychotics have motor side effects that are not uniform. Among the atypicals, only quetiapine and clozapine are not associated with drug-induced parkinsonism. Since drug-induced parkinsonism is frequently under-recognized, it may be devastating in an elderly person with already compromised gait.

Drug-induced parkinsonism

Drug-induced parkinsonism (DIP) is the second cause of akinetic rigid syndrome in the Western world and its prevalence is increasing and approaching that of idiopathic Parkinson's disease due to the ageing of the population and to the rising of polypharmacotherapy. DIP was initially reported as a complication of neuroleptics in psychiatric patients, but it has also been described with a great diversity of compounds such as antiemetics, drugs used for the treatment of vertigo, antidepressants, calcium channel antagonists, antiarrythmics, antiepileptics, cholinomimetics and other drugs. Although traditionally considered reversible, DIP may persist after drug withdrawal. At least 10% of patients with DIP develop persistent and progressive parkinsonism in spite of the discontinuation of the causative drug. Irreversible or progressive DIP has been considered as an indication of presymptomatic parkinsonian deficit, unmasked but not caused by the offending drug, but it could be explained by persistent toxicity of the responsible pharmacological agents on the nigrostriatal dopamine pathway. The best treatment of DIP is prevention, including the avoidance of prescription of causative drugs whenever it is not strictly necessary. In patients who require potentially risky medication, it is necessary to perform adequate monitoring for early parkinsonian deficits and early discontinuation if these deficits appear. Atypical neuroleptics are associated with lower risk than first generation antipsychotic drugs. Special precautions are needed in elderly subjects, in patients treated with multiple drugs for prolonged periods of time and in those with familial risk factors including familial parkinsonism or tremor, or in those with genetic variants of genes involved in idiopathic Parkinson's disease.

Practical considerations for the treatment of elderly patients with migraine

Treatment of migraine presents special problems in the elderly. Co-morbid diseases may prohibit the use of some medications. Moreover, even when these contraindications do not exist, older patients are more likely than younger ones to develop adverse events. Managing older migraine patients, therefore, necessitates particular caution, including taking into account possible pharmacological interactions associated with the greater use of drugs for concomitant diseases in the elderly. Paracetamol (acetaminophen) is the safest drug for symptomatic treatment of migraine in the elderly. Use of selective serotonin 5-HT(1B/1D) receptor agonists ('triptans') is not recommended, even in the absence of cardiovascular or cerebrovascular risk, and NSAID use should be limited because of potential gastrointestinal adverse effects. Prophylactic treatments include antidepressants, beta-adrenoceptor antagonists, calcium channel antagonists and antiepileptics. Selection of a drug from one of these classes should be dictated by the patient's co-morbidities. Beta-adrenoceptor antagonists are appropriate in patients with hypertension but are contraindicated in those with chronic obstructive pulmonary disease, diabetes mellitus, heart failure and peripheral vascular disease. Use of antidepressants in low doses is, in general, well tolerated by elderly people and as effective, overall, as in young adults. This approach is preferred in patients with concomitant mood disorders. However, prostatism, glaucoma and heart disease make the use of tricyclic antidepressants more difficult. Fewer efficacy data in the elderly are available for selective serotonin reuptake inhibitors, which can be tried in particular cases because of their good tolerability profile. Calcium channel antagonists are contraindicated in patients with hypotension, heart failure, atrioventricular block, Parkinson's disease or depression (flunarizine), and in those taking beta-adrenoceptor antagonists and monoamine oxidase inhibitors (verapamil). Antiepileptic drug use should be limited to migraine with high frequency of attacks and refractoriness to other treatments. Promising additional strategies include ACE inhibitors and angiotensin II type 1 receptor antagonists because of their effectiveness and good tolerability in patients with migraine, particularly in those with hypertension. Because of its favourable compliance and safety profile, botulinum toxin type A can be considered an alternative treatment in elderly migraine patients who have not responded to other currently available migraine prophylactic agents. Pharmacological treatment of migraine poses special problems in regard to both symptomatic and prophylactic treatment. Contraindications to triptan use, adverse effects of NSAIDs, and unwanted reactions to some antiemetics reduce the list of drugs available for the treatment of migraine attacks in elderly patients. The choice of prophylactic treatment (beta-adrenoceptor antagonists, calcium channel antagonists, antiepileptics, and more recently, some antihypertensive drugs) is influenced by co-morbidities and should be directed at those drugs that are believed to have fewer adverse effects and a better safety profile. Unfortunately, for most of these drugs, efficacy studies are lacking in the elderly.

Diagnostic considerations in juvenile parkinsonism

Juvenile parkinsonism (JP) describes patients in whom the clinical features of parkinsonism manifest before 21 years of age. Many reported cases that had a good response to levodopa have proved to have autosomal recessive juvenile parkinsonism (AR-JP) due to mutations in the parkin gene. With the exception of parkin mutations and dopa-responsive dystonia, most causes are associated with the presence of additional neurological signs, resulting from additional lesions outside of the basal ganglia. Lewy body pathology has only been reported in one case, suggesting that a juvenile form of idiopathic Parkinson's disease may be extremely rare.

[Drug-induced parkinson syndromes]

Parkinsonism is defined by the association of akinesia with one of the following symptoms: extrapyramidal rigidity, tremor at rest, or postural instability. A drug-induced aetiology must always be suspected when parkinsonian symptoms appear, or increase in a patient receiving drug treatment. Indeed drug-induced is the more frequent aetiology of secondary parkinsonism. The main treatments involved are antipsychotic and other neuroleptic drugs (accounting for up to two-thirds of drug-induced parkinsonism), and calcium-channel entry blockers. The risk associated with antipsychotics is often dose dependent and related to dopamine D2 striatal receptor occupancy induced by the antipsychotic drug. This risk is inferior for the second generation antipsychotics. The other treatments more rarely involved are antidepressants (tricyclic and selective serotonin reuptake inhibitors), lithium, valproic acid, and others. The main criterium for imputability is chronological, regression of symptoms being observed in 40-74% of cases, after a mean delay of 3 months from cessation of treatment. However, 15% of cases persist after drug withdrawal, leading to a diagnosis of underlying idiopathic Parkinson's disease.

Flunarizine and cinnarizine-induced parkinsonism: a historical and clinical analysis

BACKGROUND

Drug-Induced Parkinsonism (DIP) represents the second leading cause of Parkinsonism (PK) in several countries. Flunarizine and cinnarizine are some of the most common drugs that cause DIP. This paper reviews the first description of Flunarizine and Cinnarizine-Induced Parkinsonism (FCIP), as well as the subsequent literature, emphasizing epidemiological, clinical and diagnostic aspects.

METHODS

We reviewed the literature on the subject, with special emphasis on the first description and the later definition of the clinical syndrome that results from chronic use of flunarizine and cinnarizine.

RESULTS

In 1984, De Melo-Souza reported the first description of flunarizine-induced PK in five patients. Other reports followed on FCIP, emphasizing the clinical features, which are symmetrical parkinsonism, and depression, affecting mainly elderly women.

CONCLUSIONS

Eighteen years after the original description, FCIP is a recognized condition with specific clinical features, and is the second most common cause of parkinsonism in many countries.

DAT imaging in drug-induced and psychogenic parkinsonism

Parkinson's syndrome (PS) is frequently encountered in disorders associated with prominent degeneration of the nigrostriatal pathway as in Parkinson's disease, multisystem atrophy, and progressive supranuclear palsy (presynaptic PS). Drug-induced parkinsonism, a common, underdiagnosed health problem and psychogenic parkinsonism are causes of Parkinson's syndrome which, evidence suggests, occurs without degeneration of nigrostriatal structures. We review clinical features and results of DAT imaging in drug-induced parkinsonism and psychogenic parkinsonism. These two conditions normally give normal striatal DAT imaging results; an abnormal result in either case could exclude both conditions, corroborating a diagnosis of organic parkinsonism in uncertain cases.

Parkinsonian syndrome induced by amlodipine: case report

An elderly patient who developed marked symptoms of parkinsonism in response to amlodipine for the treatment of arterial systemic hypertension is described. She had a complete reversal of her motor symptoms after discontinuation of the drug.

Influence of benzodiazepines on antiparkinsonian drug treatment in levodopa users

OBJECTIVES

Animal studies showed that benzodiazepines decrease the concentration of dopamine in the striatum. Benzodiazepines may therefore affect the treatment of Parkinson's disease. This study determined whether start of a benzodiazepine in patients on levodopa was followed by a faster increase of antiparkinsonian drug treatment.

METHODS

Data came from the PHARMO database, which includes information on drug dispensing for all residents of six Dutch cities. Selected were all patients aged 55 years and older who used levodopa for at least 360 days. The rate of increase of antiparkinsonian drug treatment was compared between starters of a benzodiazepine and controls who did not start a benzodiazepine with the use of Cox's proportional hazard model.

RESULTS

Identified were 45 benzodiazepine starters (27 women, mean age 76.4 years) and 169 controls (83 women, 74.3 years). Antiparkinsonian drug treatment increased faster in the benzodiazepine group; relative risk was 1.44 (95% confidence interval 0.80-2.59).

CONCLUSION

This study has not found any statistically significant increase in antiparkinsonian drug treatment when a benzodiazepine was started in a small population of chronic levodopa users.

The effects of dimenhydrinate, cinnarizine and transdermal scopolamine on performance

We assessed the influence of dimenhydrinate, cinnarizine and transdermal scopolamine on the ability to perform simulated naval crew tasks. The effect of single doses of dimenhydrinate, 100 mg, cinnarizine, 50 mg, and one transdermal scopolamine patch on psychomotor performance was evaluated using a double-blind, placebo-controlled, randomized, crossover design in three separate studies. A total of 60 young naval crew (20 for dimenhydrinate, 15 for cinnarizine and 25 for transdermal scopolamine) underwent a battery of computerized and paper and pencil performance tests, and filled out a questionnaire on side-effects and well-being self-assessment. Dimenhydrinate significantly impaired decision reaction time and auditory digit span. Most of the subjects who took dimenhydrinate also reported a subjective decrease in well-being and general performance abilities. Cinnarizine and transdermal scopolamine did not affect performance abilities. Cinnarizine was free of significant side-effects. Dry mouth was the only significant side-effect of transdermal scopolamine. These findings could be explained by the well-known sedative properties of dimenhydrinate and not by a specific effect on any particular cognitive or motor function. Our results suggest that dimenhydrinate, 100 mg, adversely affects psychomotor function, whereas single doses of cinnarizine, 50 mg, and transdermal scopolamine appear to be free of side-effects on performance and seem to be a preferable anti-seasickness drug for use by a naval crew.

Diagnosis and differential diagnosis of Parkinson's disease and parkinsonism

In the clinic setting, most cases represent either Parkinson's disease (PD) or one of the other neurodegenerative disorders that make up the parkinsonism-plus syndromes. The major parkinsonism-plus syndromes include progressive supranuclear palsy, multiple system atrophy, corticobasal degeneration, as well as parkinsonism occurring in the context of Alzheimer's disease or one of the other primary dementing disorders. There are a variety of other conditions, however, that occasionally come into the differential diagnosis. These fall into the categories of secondary parkinsonism (due to drugs, toxins, structural lesions, etc.), another tremor syndrome such as essential tremor, or a hereditary disorder with parkinsonism. This broad differential diagnosis is reviewed.

Calcium channel agonists and dystonia in the mouse

Systemic administration of the L-type calcium channel agonists +/-Bay K 8644 or FPL 64176 causes a characteristic pattern of motor dysfunction in normal C57BL/6J mice that resembles generalized dystonia. There is no associated change in the electroencephalogram, confirming that the motor disorder does not reflect epileptic seizures. However, the electromyogram reveals an increase in baseline motor unit activity with prolonged phasic discharges consistent with dystonia. The duration and severity of dystonia is dependent on the dose administered and the age of the animal at testing. The effects are transient, with the return of normal motor behavior 1-4 hours after treatment. Similar effects can be provoked by intracerebral administration of small amounts of the drugs, indicating a centrally mediated response. Dystonia can be attenuated by co-administration of dihydropyridine L-type calcium channel antagonists (nifedipine, nimodipine, and nitrendipine) but not by non-dihydropyridine antagonists (diltiazem, verapamil, and flunarizine). These results implicate abnormal function of L-type calcium channels in the expression of dystonia in this model.

Quantitative prediction of catalepsy induced by amoxapine, cinnarizine and cyclophosphamide in mice

Parkinsonism can be a side effect of antipsychotic drugs, and has recently been reported with peripherally acting drugs such as calcium channel blockers, antiarrhythmic agents and so on. In this study, we examined the quantitative prediction of drug-induced catalepsy by amoxapine, cinnarizine and cyclophosphamide, which have been reported to induce parkinsonism. Dose-dependent catalepsy was induced by these drugs in mice. In vivo dopamine D(1), D(2) and muscarinic acetylcholine (mACh) receptor occupancies by these drugs in the striatum were also examined. The in vitro binding affinities (K(i) values) of amoxapine and cinnarizine to dopamine D(1), D(2) and mACh receptors in rat striatal synaptic membrane were 200 and 2900 nM, 58.4 and 76.4 nM and 379 and 290 nM, respectively. Cyclophosphamide did not bind to these receptors at concentrations up to 100 microM. Twenty drugs, including those mentioned above, showed a significant correlation between the observed intensity of catalepsy and the values predicted with a pharmacodynamic model (Haraguchi K, Ito K, Kotaki H, Sawada Y, Iga T. Prediction of drug-induced catalepsy based on dopamine D(1), D(2), and muscarinic acetylcholine receptor occupancies. Drug Metab Disp 1997; 25: 675-684) based on in vivo occupancy of dopamine D(1), D(2) and mACh receptors. We conclude that occupancy of dopamine D(1) and D(2) receptors contributes to catalepsy induction by amoxapine and cinnarizine.

Differential diagnosis of parkinsonism

The diagnosis of Parkinson's disease is predominantly clinical, based on a combination of the cardinal features of tremor, bradykinesia and rigidity. The differential essentially lies between other conditions resulting in tremor, of which essential tremor is the commonest, and other akinetic-rigid syndromes. These include progressive supranuclear palsy, multiple system atrophy, toxins and other degenerative disorders, including diffuse Lewy body disease and corticobasal degeneration. The key clinical features of these disorders and a practical diagnostic approach are briefly reviewed in this article.

Dose-related inversion of cinnarizine and flunarizine effects on mitochondrial permeability transition

We investigated the effects of cinnarizine and flunarizine on mitochondrial permeability transition, ATP synthesis, membrane potential and NAD(P)H oxidation. Both drugs were effective in inhibiting the mitochondrial permeability transition induced either by Ca2+ alone or in the presence of tert-butylhydroperoxide. This protective effect occurred at low concentrations (< 50 microM) of these drugs and was accompanied by the inhibition of NAD(P)H oxidation and the restoration of the mitochondrial membrane potential decreased by a high concentration of Ca2+ (25 microM). However, at higher concentrations (> 50 microM) of cinnarizine and flunarizine and in the absence of both tert-butylhydroperoxide and Ca2+, their effects on the mitochondria were reversed as follows: mitochondrial permeability transition was generated, mitochondrial NAD(P)H was oxidized and membrane potential collapsed. These deleterious effects were not antagonized by cyclosporine A, the most potent inhibitor of the mitochondrial permeability transition, but by 2,6-di-tert-butyl-4-methylphenol, a known antioxidant agent. This mitochondrial effect was neither accompanied by an increase in malondialdehyde production nor by an increase in H2O2 generation, which attested that the effect of both drugs was not due to an increase in reactive oxygen species production. The dual effects of both cinnarizine and flunarizine on mitochondrial functions is discussed with regard to both the protective effect afforded by these drugs against ischemia-reperfusion injury and their side effect observed in some therapeutic situations where an overdosage seems likely.

Drug-induced movement disorders

Drug-induced movement disorders are often unrecognized, especially when not due to dopamine receptor blockers. This review discusses acute, subacute, and chronic syndromes. Pathophysiology relates almost always to dopaminergic transmission. Patient-dependent vulnerability and drug-dependent sensitivity are contributing factors. Young patients are more prone to acute reactions, and tardive or chronic conditions are more frequent in the elderly. Subclinical Parkinsonism can be unmasked by medication exposure. Treatment of tardive dyskinesia remains a challenging task for the clinician, but novel antipsychotics and dopamine depleting agents can be beneficial.