scholarly journals Dopaminergic stimulants and risk of Parkinson’s disease

Author(s):  
Michael Wainberg ◽  
Dipender Gill ◽  
Bowen Su ◽  
Mike A. Nalls ◽  
Robert R. Graham ◽  
...  

Parkinson’s disease is characterized by dopaminergic neurodegeneration in the substantia nigra. Although dopaminergic drugs are the mainstay of Parkinson’s treatment, their putative disease-modifying properties remain controversial. We explored whether prescription of dopaminergic stimulants for attention-deficit hyperactivity disorder (ADHD) might affect Parkinson’s incidence. We performed Cox survival analyses for outpatient Parkinson’s diagnosis among ADHD-diagnosed seniors in the Optum Clinformatics™ Data Mart de-identified administrative claims database, correcting for diverse demographic and socio-economic status covariates. We compared 5,683 sustained users (≥ 90 days) of dopaminergic stimulants to 252 sustained users of atomoxetine, a noradrenergic first-line ADHD medication. Parkinson’s incidence was reduced among sustained dopaminergic stimulant users compared to atomoxetine users (adjusted hazard ratio [HR] 0.15, 95% confidence interval [CI] 0.04-0.56, p = 0.005). Effect sizes were comparable between derivatives of amphetamine (adjusted HR 0.12, 95% CI 0.03-0.48, p = 0.003) and methylphenidate (adjusted HR 0.27, 95% CI 0.04-1.76, p = 0.2). In sensitivity analyses, similar trends were observed when other psychotropics (SSRIs, gabapentin) were used as comparators instead of atomoxetine, or when the threshold for sustained use was defined as 45, 180 or 360 days instead of 90. Thus, sustained dopaminergic stimulant use was associated with lower Parkinson’s incidence among seniors with ADHD. Our results are consistent with a protective effect of dopaminergic stimulants on the development of Parkinson’s, and support a re-examination of certain dopaminergics, particularly rasagiline and other selective monoamine oxidase B inhibitors, as potential disease-modifying agents.

Author(s):  
Richard J. Beninger

Schizophrenia, Parkinson’s disease, and attention deficit hyperactivity disorder (ADHD) discusses how hyperactive dopaminergic neurotransmission appears to underlie schizophrenia’s positive symptoms, loss of dopaminergic neurons in adulthood leads to Parkinson’s disease, and dopamine neuron hypofunction in childhood and adolescence may underlie ADHD. Positive schizophrenia symptoms may arise from excessive incentive learning that is gradually lost with antipsychotic treatment. Declarative learning and memory may contribute to delusions based on excessive incentive learning. Loss of responsiveness to environmental stimuli in Parkinson’s may result from a decrease of their conditioned incentive value and inverse incentive learning. Conditioned incentive stimuli not encountered while in a state of decreased dopaminergic neurotransmission may retain their incentive value, producing apparent kinesia paradoxa. Dopamine hypofunction in juveniles does not lead to hypokinesia but may result in loss of incentive learning that focuses attention. Pro-dopaminergic drugs have a calming effect in ADHD, presumably because they reinstate normal incentive learning.


BMJ Open ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. e047993
Author(s):  
Nirosen Vijiaratnam ◽  
Christine Girges ◽  
Grace Auld ◽  
Marisa Chau ◽  
Kate Maclagan ◽  
...  

IntroductionParkinson’s disease (PD) is a common neurodegenerative disorder with substantial morbidity. No disease-modifying treatments currently exist. The glucagon like peptide-1 receptor agonist exenatide has been associated in single-centre studies with reduced motor deterioration over 1 year. The aim of this multicentre UK trial is to confirm whether these previous positive results are maintained in a larger number of participants over 2 years and if effects accumulate with prolonged drug exposure.Methods and analysisThis is a phase 3, multicentre, double-blind, randomised, placebo-controlled trial of exenatide at a dose of 2 mg weekly in 200 participants with mild to moderate PD. Treatment duration is 96 weeks. Randomisation is 1:1, drug to placebo. Assessments are performed at baseline, week 12, 24, 36, 48, 60, 72, 84 and 96 weeks.The primary outcome is the comparison of Movement Disorders Society Unified Parkinson’s Disease Rating Scale part 3 motor subscore in the practically defined OFF medication state at 96 weeks between participants according to treatment allocation. Secondary outcomes will compare the change between groups among other motor, non-motor and cognitive scores. The primary outcome will be reported using descriptive statistics and comparisons between treatment groups using a mixed model, adjusting for baseline scores. Secondary outcomes will be summarised between treatment groups using summary statistics and appropriate statistical tests to assess for significant differences.Ethics and disseminationThis trial has been approved by the South Central-Berkshire Research Ethics Committee and the Health Research Authority. Results will be disseminated in peer-reviewed journals, presented at scientific meetings and to patients in lay-summary format.Trial registration numbersNCT04232969, ISRCTN14552789.


2021 ◽  
pp. 1-12
Author(s):  
Julie Chandler ◽  
Radhika Nair ◽  
Kevin Biglan ◽  
Erin A. Ferries ◽  
Leanne Munsie ◽  
...  

Background: Characterizing patients with Parkinson’s disease (PD) and cognitive impairment is important toward understanding their natural history. Objective: Understand clinical, treatment, and cost characteristics of patients with PD pre- and post-cognitive impairment (memory loss/mild cognitive impairment/dementia or dementia treatment) recognition. Methods: 2,711 patients with PD newly diagnosed with cognitive impairment (index) were identified using administrative claims data. They were matched (1:1) on age and gender to patients with PD and no cognitive impairment (controls). These two cohorts were compared on patient characteristics, healthcare resource utilization, and total median costs for 3 years pre- and post-index using Chi-square tests, t-tests, and Wilcoxon rank-sum tests. Logistic regression was used to identify factors predicting cognitive impairment. Results: Comorbidity indices for patients with cognitive impairment increased during the 6-year study period, especially after the index. Enrollment in Medicare Advantage Prescription Drug plans vs. commercial (OR = 1.60), dual Medicare/Medicaid eligibility (OR = 1.36), cerebrovascular disease (OR = 1.24), and PD medication use (OR = 1.46) were associated with a new cognitive impairment diagnosis (all p <  0.05). A greater proportion of patients with cognitive impairment had hospitalizations and emergency department visits and higher median total healthcare costs than controls for each year pre- and post-index. Conclusion: In patients with PD newly diagnosed with cognitive impairment, comorbidity burden, hospitalizations, emergency department visits, and total costs peaked 1-year pre- and post-identification. These data coupled with recommendations for annual screening for cognitive impairment in PD support the early diagnosis and management of cognitive impairment in order to optimize care for patients and their caregivers.


2020 ◽  
Vol 29 (8) ◽  
pp. 864-872
Author(s):  
Laura C. Maclagan ◽  
Naomi P. Visanji ◽  
Yi Cheng ◽  
Mina Tadrous ◽  
Alix M. B. Lacoste ◽  
...  

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Liang Song ◽  
Meng-Bei Xu ◽  
Xiao-Li Zhou ◽  
Dao-pei Zhang ◽  
Shu-ling Zhang ◽  
...  

To date, no drug has been proven to be neuroprotective or disease-modifying for Parkinson’s disease (PD) in clinical trials. Here, we aimed to assess preclinical evidence of Ginsenosides-Rg1 (G-Rg1), a potential neuroprotectant, for experimental PD and its possible mechanisms. Eligible studies were identified by searching six electronic databases from their inception to August 2016. Twenty-five eligible studies involving 516 animals were identified. The quality score of these studies ranged from 3 to 7. Compared with the control group, two out of the 12 studies of MPTP-induced PD showed significant effects of G-Rg1 for improving the rotarod test (P<0.01), two studies for improving the swim-score values (P<0.01), six studies for improving the level of TH protein expression (P<0.01), and two studies for increasing the expression of TH mRNA in the substantia nigra of mice (P<0.01). The studies reported that G-Rg1 exerted potential neuroprotective effects on PD model through different mechanisms as antineuroinflammatory activities (n=10), antioxidant stress (n=3), and antiapoptosis (n=11). In conclusion, G-Rg1 exerted potential neuroprotective functions against PD largely by antineuroinflammatory, antioxidative, and antiapoptotic effects. G-Rg1 as a promising neuroprotectant for PD needs further confirmation by clinical trials.


2015 ◽  
Vol 73 (7) ◽  
pp. 1365-1379 ◽  
Author(s):  
Dan Lindholm ◽  
Johanna Mäkelä ◽  
Valentina Di Liberto ◽  
Giuseppa Mudò ◽  
Natale Belluardo ◽  
...  

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