Advances in the Therapeutic Use of Non-Ergot Dopamine Agonists in the Treatment of Motor and Non-Motor Symptoms of Parkinson's Disease

Comparative safety signals of dopamine agonists: psychiatric and cardiovascular risks derived from FDA adverse event reporting system (FAERS) data

BACKGROUND

Dopamine receptor agonists (DAs) are widely used as first-line therapeutic agents for Parkinson's disease. However, comparative clinical trials assessing their safety profiles are limited. This study aims to compare adverse event (AE) data across various DAs to inform personalized treatment strategies.

METHODS

AE reports with DAs as the "primary suspicion (PS)" were extracted from the FDA Adverse Event Reporting System (FAERS) database, covering 67 quarters from the second quarter of 2007 to the fourth quarter of 2023. Four disproportionality analysis methods, including the reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian confidence propagation neural network (BCPNN) and multi-item gamma Poisson shrinker (MGPS), were employed to evaluate the risk of AEs.

RESULTS

A total of 19,745,533 DA-related AEs reports were analyzed. The six DAs-pramipexole, ropinirole, cabergoline, rotigotine, bromocriptine and apomorphine-generated 269, 246, 202, 163, 146, and 135 preferred terms positive signals, respectively. Non-ergot DAs (pramipexole, ropinirole, rotigotine and apomorphine) were primarily associated with psychiatric disorders and reported more hallucinations than ergot-derived dopamine agonists (ergot-DAs), with ropinirole showing a slightly higher signal intensity than pramipexole (ROR = 15.76 vs. 11.23). Pramipexole demonstrated the most significant signal for impulse control disorders (ICDs). Compared with pramipexole and ropinirole, rotigotine generally exhibits milder signals in terms of psychiatric disorders such as hallucinations, ICDs, and sleep-related AEs. Administration site-related AEs were more prominent in rotigotine and apomorphine users. Ergot-DAs exhibited higher signal intensities for cardiac disorders, with cabergoline also showing a notable signal for amnestic symptoms (ROR = 340.54), which is not mentioned in the drug label.

CONCLUSION

This study elucidates the distinct safety profiles of six DAs. Non-ergot DAs are primarily associated with psychiatric AEs, while administration-related AEs are more notable for rotigotine and apomorphine. Ergot-DAs present a higher risk for cardiac valvulopathies. These findings highlight the importance of individualized treatment considerations in clinical practice, emphasizing the need to formulate appropriate treatment plans on patients' specific conditions.

Advances in the study of depression and anxiety in Parkinson's disease: A review

Motor symptoms are central to diagnosing Parkinson's disease (PD), but depression and anxiety significantly impact the prognosis and course of PD. For many PD patients, these mental health issues may be the most crucial determinants of quality of life. This study uses an interdisciplinary approach to provide an in-depth understanding of the pathogenesis, diagnostic methods, and therapeutic strategies for depression and anxiety in PD, incorporating neuroscience, psychiatry, and psychology. It aims to offer theoretical support for developing personalized medicine and precise treatments, as well as insights into future research directions. The objective of this study was to systematically sort out the research progress of PD with depression and anxiety and to provide a basis for clinical optimization of treatment strategies. Extensive searches of relevant domestic and international databases, including PubMed, Web of Science, Embase, Cochrane Library, CNKI, etc., were conducted to screen the high-quality research literature on the treatment of PD depression and anxiety in the last decade and to conduct comprehensive analyses and generalizations. Pharmacological treatments, including 5-hydroxytryptamine reuptake inhibitors, norepinephrine system agents, and dopamine agonists, showed some efficacy but with individual differences and side effects. Psychotherapies such as cognitive-behavioral therapy and group counseling improved patient mood. Neuromodulation techniques like deep brain stimulation also showed promise in refractory cases. The combined application of multiple therapeutic approaches shows good prospects in the treatment of depression and anxiety in PD, but in-depth studies are still needed to determine the optimal treatment plan while focusing on individual patient differences to achieve precise treatment.

Recent advances in nanotechnology for Parkinson's disease: diagnosis, treatment, and future perspectives

Parkinson's disease is a progressive neurodegenerative disease that destroys substantia nigra dopaminergic neurons, causing tremors, bradykinesia, rigidity, and postural instability. Current treatment approaches primarily focus on symptom management, employing pharmacological, non-pharmacological, and surgical methods. However, these treatments often result in fluctuating symptoms, side effects, and disease progression. Here, the authors have reviewed the emerging field of nanomedicine as a promising path for Parkinson's disease treatment, emphasizing its potential to overcome the limitations of traditional therapies. Nanomedicine utilizes nanoparticles for targeted drug delivery, leveraging their small size and high surface area to volume ratio to cross the blood-brain barrier and deliver therapeutic agents directly to affected brain regions. Various nanoparticles, including lipid-based, polymeric, metallic, and carbon-based, have shown potential in Parkinson's disease treatment. Additionally, nanocarrier systems like liposomes, nanogels, dendrimers, and solid lipid nanoparticles offer controlled and sustained release of therapeutic agents, enhancing their bioavailability and reducing side effects. This review provides insights into the pathophysiology of Parkinson's disease, highlighting the mechanisms of neurodegeneration, the role of alpha-synuclein, and the disruption of dopaminergic pathways. It further discusses the application of gene therapy in conjunction with nanomedicine for targeted therapeutic interventions.

Alternative Therapies for Non-Motor Symptoms in Parkinson's Disease: A Mini Review

Parkinson's disease (PD) is primarily recognized for its motor symptoms, yet non-motor symptoms (NMS) such as neuropsychiatric disturbances, sleep disorders, autonomic dysfunction, and sensory abnormalities significantly contribute to the disease's overall burden. While traditional pharmacological and surgical treatments have primarily targeted motor symptoms, alternative therapies such as acupuncture, cognitive therapy, and Traditional Chinese Medicine (TCM) are gaining attention for managing NMS. This review provides a comprehensive analysis of alternative therapies for NMS in PD, drawing on evidence from international guidelines and TCM. The review highlights the current gaps in research, emphasizing the need for high-quality randomized controlled trials (RCTs) and standardized protocols, particularly in the evaluation of TCM therapies. Additionally, it underscores the potential of integrated treatment approaches that combine traditional and modern medicine, offering a personalized strategy for managing NMS in PD. By addressing these challenges, this review aims to enhance the understanding and application of alternative therapies, ultimately improving the quality of life for PD patients. These therapies, particularly those emphasizing holistic and individualized approaches, such as cognitive therapy and TCM, offer potential solutions to the unmet needs in PD management without causing side effects associated with medications or fluctuations in drug plasma levels.

Advanced Parkinson's disease treatment patterns in Italy: an observational study interim analysis

BACKGROUND

Oral levodopa remains the mainstay of treatment for Parkinson's disease (PD). However, as PD progresses, response to treatment may fluctuate. Managing fluctuations can be demanding for clinicians and patients. There is a paucity of real-world studies reporting on PD management in patients with fluctuations in treatment response, especially in patients with advanced stages of PD. The multicentre, observational Parkinson's Disease Fluctuations treatment PAthway (PD-FPA) study describes the real-life management of response fluctuations in Italian patients with advanced PD.

PATIENTS AND METHODS

PD-FPA had a retrospective and prospective phase; herein, retrospective results are presented. Ten Italian centres enrolled patients with a PD diagnosis from 10-15 years prior to study entry (T0) and who had ≥2-year history of fluctuations. Data on patient demographics, medical history, PD stage, fluctuation characteristics, symptoms, and prescribed treatments were collected at T0 and retrospectively (2 years prior to T0) via patient chart review/interview.

RESULTS

Overall, 296 patients (60% male, mean age 68 years, 84% with Hoehn and Yahr scores 2-3) were enrolled. At T0, most patients (99.3%) were on oral levodopa therapy. All patients used dopaminergic medications; adjunctive medications included dopamine agonists (56%) and monoamine oxidase B (60%) and catechol-O-methyltransferase enzyme inhibitors (41%). At T0, 51% of patients had changed therapy, with response fluctuations being the most common reason (74%); wearing-off was the most common fluctuation (83%).

CONCLUSION

This interim analysis of PD-FPA suggests that adequate levodopa dosing and adjunctive medications can stabilize advanced PD and provide patients with a good quality of life.

Therapeutic potential of Canna edulis RS3-resistant starch in alleviating neuroinflammation and apoptosis in a Parkinson's disease rat model

This study aimed to investigate the effects of Miao medicinal Canna edulis RS3-resistant starch on behavioral performance and substantia nigra neuron apoptosis-related indicators in a rat model of Parkinson's disease (PD). Among the experimental groups, except for the control group, we induced PD rat models by subcutaneous injection of rotenone in the neck and back. After model induction, a 28-day drug intervention was conducted. Various techniques have been employed, including behavioral analysis, Real-time Polymerase Chain Reaction (RT-PCR), western blotting, enzyme-linked immunosorbent assay (ELISA), immunofluorescence, and terminal deoxynucleotidyltransferase-mediated UTP nick-ends. labeling (TUNEL) and Nissl staining to investigate the effect of Canna edulis RS3-resistant starch on the substantia nigra and neuronal apoptosis-related markers in the brains of PD model rats. Our study revealed that Canna edulis RS3, a resistant starch, significantly reduced the climbing time of PD model rats, prolonged their hanging time, lowered the expression levels of the inflammatory factors IL-1β, IL-6, and TNF-α, increased the number of TH-positive neurons in the substantia nigra, and decreased the levels of IL-1β, IL-6, and TNF-α. Furthermore, Canna edulis RS3 elevated the protein expression levels of tyrosine hydroxylase (TH) and Bcl-2 while reducing those of Bax, TLR4, NLRP3,and p-P65, and mitigated apoptosis and morphological changes in dopaminergic neurons in the substantia nigra region. Our results suggest that Canna edulis RS3-resistant starch may offer therapeutic benefits for PD patients with PD by potentially influencing inflammation and apoptosis in the dopaminergic system.

The role of central neurotransmitters in appetite regulation of broilers and layers: similarities and differences

The importance of feeding as a vital physiological function, on the one hand, and the spread of complications induced by its disorder in humans and animals, on the other hand, have led to extensive research on its regulatory factors. Unfortunately, despite many studies focused on appetite, only limited experiments have been conducted on avian, and our knowledge of this species is scant. Considering this, the purpose of this review article is to examine the role of central neurotransmitters in regulating food consumption in broilers and layers and highlight the similarities and differences between these two strains. The methodology of this review study includes a comprehensive search of relevant literature on the topic using appropriate keywords in reliable electronic databases. Based on the findings, the central effect of most neurotransmitters on the feeding of broilers and laying chickens was similar, but in some cases, such as dopamine, ghrelin, nitric oxide, and agouti-related peptide, differences were observed. Also, the lack of conducting a study on the role of some neurotransmitters in one of the bird strains made it impossible to make an exact comparison. Finally, it seems that although there are general similarities in appetite regulatory mechanisms in meat and egg-type chickens, the long-term genetic selection appropriate to breeding goals (meat or egg production) has caused differences in the effect of some neurotransmitters. Undoubtedly, conducting future studies while completing the missing links can lead to a comprehensive understanding of this process and its manipulation according to the breeding purposes of chickens.

Tyrosine Hydroxylase Inhibitors and Dopamine Receptor Agonists Combination Therapy for Parkinson's Disease

There are currently no disease-modifying therapies for Parkinson's disease (PD), a progressive neurodegenerative disorder associated with dopaminergic neuronal loss. There is increasing evidence that endogenous dopamine (DA) can be a pathological factor in neurodegeneration in PD. Tyrosine hydroxylase (TH) is the key rate-limiting enzyme for DA generation. Drugs that inhibit TH, such as alpha-methyltyrosine (α-MT), have recently been shown to protect against neurodegeneration in various PD models. DA receptor agonists can activate post-synaptic DA receptors to alleviate DA-deficiency-induced PD symptoms. However, DA receptor agonists have no therapeutic effects against neurodegeneration. Thus, a combination therapy with DA receptor agonists plus TH inhibitors may be an attractive therapeutic approach. TH inhibitors can protect and promote the survival of remaining dopaminergic neurons in PD patients' brains, whereas DA receptor agonists activate post-synaptic DA receptors to alleviate PD symptoms. Additionally, other PD drugs, such as N-acetylcysteine (NAC) and anticholinergic drugs, may be used as adjunctive medications to improve therapeutic effects. This multi-drug cocktail may represent a novel strategy to protect against progressive dopaminergic neurodegeneration and alleviate PD disease progression.

Mild Behavioral Impairment in Parkinson's Disease: An Updated Review on the Clinical, Genetic, Neuroanatomical, and Pathophysiological Aspects

Neuropsychiatric symptoms (NPS), including depression, anxiety, apathy, visual hallucinations, and impulse control disorders, are very common during the course of Parkinson's disease (PD), occurring even at the prodromal and premotor stages. Mild behavioral impairment (MBI) represents a recently described neurobehavioral syndrome, characterized by the emergence of persistent and impactful NPS in later life, reflecting arisk of dementia. Accumulating evidence suggests that MBI is highly prevalent in non-demented patients with PD, also being associated with an advanced disease stage, more severe motor deficits, as well as global and multiple-domain cognitive impairment. Neuroimaging studies have revealed that MBI in patients with PD may be related todistinct patterns of brain atrophy, altered neuronal connectivity, and distribution of dopamine transporter (DAT) depletion, shedding more light on its pathophysiological background. Genetic studies in PD patients have also shown that specific single-nucleotide polymorphisms (SNPs) may be associated with MBI, paving the way for future research in this field. In this review, we summarize and critically discuss the emerging evidence on the frequency, associated clinical and genetic factors, as well as neuroanatomical and neurophysiological correlates of MBI in PD, aiming to elucidate the underlying pathophysiology and its potential role as an early "marker" of cognitive decline, particularly in this population. In addition, we aim to identify research gaps, and propose novel relative areas of interest that could aid in our better understanding of the relationship of this newly defined diagnostic entity with PD.

Electro-acupuncture on Vascular Parkinsonism with multiple sleep disorders: A Case Report

Vascular Parkinsonism (VP) is a kind of rare secondary Parkinsonism caused by vascular lesions. Patients with VP experience not only movement disorders but also sleep disorders. But treatment options are limited and often associated with undesirable adverse effects. Electro-acupuncture (EA) is a safe, rapid work, easy operation, and convenient complementary replacement therapy. We report a case of a 51-year-old man who presented with VP and multiple sleep disorders. Based on clinical evaluation and nocturnal hospital-based polysomnography (PSG), the patient had severe PLMD (PSG showed severe periodic leg movements), excessive daytime sleepiness (EDS, the score of the ESS is 16), and probable rapid eye movement sleep disorder (RBD). Parkinson's disease sleep scale (PDSS) score, Pittsburgh sleep quality index (PSQI), and periodic leg movements index were 93, 11, and 135.2, respectively. After 8 weeks of EA treatment, the patient reported that the symptoms of subjective and objective sleep disturbance were significantly alleviated without any discomfort. This case report may provide a new alternative and complementary therapy for VP patients with sleep disturbance but more definitive and robust evidence is needed to support its efficacy.