Ropinirole 24-hour prolonged release and ropinirole immediate release in early Parkinson's disease: a randomized, double-blind, non-inferiority crossover study

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.

The Interplay of Mitochondrial Bioenergetics and Dopamine Agonists as an Effective Disease-Modifying Therapy for Parkinson's Disease

Parkinson's disease (PD) is a progressive neurological ailment with a slower rate of advancement that is more common in older adults. The biggest risk factor for PD is getting older, and those over 60 have an exponentially higher incidence of this condition. The failure of the mitochondrial electron chain, changes in the dynamics of the mitochondria, and abnormalities in calcium and ion homeostasis are all symptoms of Parkinson's disease (PD). Increased mitochondrial reactive oxygen species (mROS) and an energy deficit are linked to these alterations. Levodopa (L-DOPA) is a medication that is typically used to treat most PD patients, but because of its negative effects, additional medications have been created utilizing L-DOPA as the parent molecule. Ergot and non-ergot derivatives make up most PD medications. PD is successfully managed with the use of dopamine agonists (DA). To get around the motor issues produced by L-DOPA, these dopamine derivatives can directly excite DA receptors in the postsynaptic membrane. In the past 10 years, two non-ergoline DA with strong binding properties for the dopamine D2 receptor (D2R) and a preference for the dopamine D3 receptor (D3R) subtype, ropinirole, and pramipexole (PPx) have been developed for the treatment of PD. This review covers the most recent research on the efficacy and safety of non-ergot drugs like ropinirole and PPx as supplementary therapy to DOPA for the treatment of PD.

Comparative efficacy and safety of six non-ergot dopamine-receptor agonists in early Parkinson's disease: a systematic review and network meta-analysis

Background

Non-ergot dopamine agonists (NEDAs) have been used as monotherapy or as an adjunctive therapy to levodopa for many years. Novel long-acting formulations of NEDAs including pramipexole extended-release (ER), ropinirole prolonged-release (PR), and rotigotine transdermal patch have been developed. However, there is no strong evidence that a given NEDA is more potent than another. We performed a systematic review and network meta-analysis to evaluate the efficacy, tolerability and safety of six commonly used NEDAs in early Parkinson's disease (PD).

Methods

Six NEDAs including piribedil, rotigotine transdermal patch, pramipexole immediate-release (IR)/ER, and ropinirole IR/PR were investigated. The efficacy outcomes including Unified Parkinson's Disease Rating Scale activities in daily life (UPDRS-II), motor function (UPDRS-III), and their subtotal (UPDRS-II + III), tolerability and safety outcomes were analyzed.

Results

A total of 20 RCTs (5,355 patients) were included in the current study. The result indicated that compared with placebo, all six investigated drugs had statistically significant differences in the improvement of UPDRS-II, UPDRS-III, and UPDRS-II + III (except ropinirole PR in UPDRS-II). There were no statistically significant differences between six NEDAs for the UPDRS-II and UPDRS-III. For UPDRS-II + III, the improvement of ropinirole IR/PR and piribedil were higher than that of rotigotine transdermal patch, and piribedil was higher than that of pramipexole IR. The surface under the cumulative ranking curve (SUCRA) indicated that piribedil resulted in best improvement in UPDRS-II and UPDRS-III (0.717 and 0.861, respectively). For UPDRS-II + III, piribedil and ropinirole PR exhibited similar improvement and both had high rates (0.858 and 0.878, respectively). Furthermore, piribedil performed better as monotherapy, ranking first in the improvement of UPDRS-II, III, and II + III (0.922, 0.960, and 0.941, separately). With regard to tolerability, there was a significant increase in overall withdrawals with pramipexole ER (0.937). In addition, the incidence of adverse reaction of ropinirole IR was relatively high (nausea: 0.678; somnolence: 0.752; dizziness: 0.758; fatigue: 0.890).

Conclusions

In this systematic review and network meta-analysis of six NEDAs, piribedil exhibited better efficacy, especially as monotherapy, and ropinirole IR was associated with a higher incidence of adverse events in patients with early PD.

The complex molecular pharmacology of the dopamine D2 receptor: Implications for pramipexole, ropinirole, and rotigotine

With L-DOPA, dopamine agonists such as pramipexole, ropinirole and rotigotine constitute key therapeutic options for the management of motor symptoms of Parkinson's disease. These compounds exert their beneficial effect on motor behaviours by activating dopamine D₂-class receptors and thereby compensating for the declining dopaminergic transmission in the dorsal striatum. Despite a strong similarity in their mechanism of action, these three dopamine agonists present distinct clinical profiles, putatively underpinned by differences in their pharmacological properties. In this context, this review aims at contributing to close the gap between clinical observations and data from molecular neuropharmacology by exploring the properties of pramipexole, ropinirole and rotigotine from both the clinical and molecular perspectives. Indeed, this review first summarizes and compares the clinical features of these three dopamine agonists, and then explores their binding profiles at the different dopamine receptor subtypes. Moreover, the signalling profiles of pramipexole, ropinirole and rotigotine at the D₂ receptor are recapitulated, with a focus on biased signalling and the potential therapeutic implications. Overall, this review aims at providing a unifying framework of interpretation for both clinicians and fundamental pharmacologists interested in a deep understanding of the pharmacological properties of pramipexole, ropinirole and rotigotine.

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

Dopamine (DA) agonists, as an excellent dopamine replacement therapy for patients with early and advanced Parkinson's disease (PD), play a vital role in controlling motor and several nonmotor symptoms. Besides, the application of DA agonists may delay levodopa therapy and the associated risk of motor complications. Indeed, each DA agonist has unique pharmacokinetic and pharmacodynamic characteristics and therefore has different therapeutic efficacy and safety profile. The comorbidities, significant non-motor manifestations, concomitant medications, and clinical features of PD individuals should guide the selection of a specific DA agonist to provide a more patient-tailored treatment option. Thorough knowledge of DA agonists helps clinicians better balance clinical efficacy and side effects. Therefore, this review refers to recent English-written articles on DA agonist therapy for PD patients and summarizes the latest findings on non-ergot DA agonists as well as the advantages and disadvantages of each compound to help clinicians in the selection of a specific DA agonist. In addition, novel D1/D5 partial agonists and new formulations of DA agonists are also discussed.

Dopaminergic Therapy for Motor Symptoms in Early Parkinson Disease Practice Guideline Summary: A Report of the AAN Guideline Subcommittee

BACKGROUND AND OBJECTIVES

To review the current evidence on the options available for initiating dopaminergic treatment of motor symptoms in early-stage Parkinson disease and provide recommendations to clinicians.

METHODS

A multidisciplinary panel developed practice recommendations, integrating findings from a systematic review and following an Institute of Medicine-compliant process to ensure transparency and patient engagement. Recommendations were supported by structured rationales, integrating evidence from the systematic review, related evidence, principles of care, and inferences from evidence.

RESULTS

Initial treatment with levodopa provides superior motor benefit compared to treatment with dopamine agonists, whereas levodopa is more likely than dopamine agonists to cause dyskinesia. The comparison of different formulations of dopamine agonists yielded little evidence that any one formulation or method of administration is superior. Long-acting forms of levodopa and levodopa with entacapone do not appear to differ in efficacy from immediate-release levodopa for motor symptoms in early disease. There is a higher risk of impulse control disorders associated with the use of dopamine agonists than levodopa. Recommendations on initial therapy for motor symptoms are provided to assist the clinician and patient in choosing between treatment options and to guide counseling, prescribing, and monitoring of efficacy and safety.

An Update on the Critical Role of α-Synuclein in Parkinson's Disease and Other Synucleinopathies: from Tissue to Cellular and Molecular Levels

The aggregation of alpha-synuclein (α-Syn) plays a critical role in the development of Parkinson's disease (PD) and other synucleinopathies. α-Syn, which is encoded by the SNCA gene, is a lysine-rich soluble amphipathic protein normally expressed in neurons. Located in the cytosolic domain, this protein has the ability to remodel itself in plasma membranes, where it assumes an alpha-helix conformation. However, the protein can also adopt another conformation rich in cross-beta sheets, undergoing mutations and post-translational modifications, then leading the protein to an unusual aggregation in the form of Lewy bodies (LB), which are cytoplasmic inclusions constituted predominantly by α-Syn. Pathogenic mechanisms affecting the structural and functional stability of α-Syn - such as endoplasmic reticulum stress, Golgi complex fragmentation, disfunctional protein degradation systems, aberrant interactions with mitochondrial membranes and nuclear DNA, altered cytoskeleton dynamics, disrupted neuronal plasmatic membrane, dysfunctional vesicular transport, and formation of extracellular toxic aggregates - contribute all to the pathogenic progression of PD and synucleinopathies. In this review, we describe the collective knowledge on this topic and provide an update on the critical role of α-Syn aggregates, both at the cellular and molecular levels, in the deregulation of organelles affecting the cellular homeostasis and leading to neuronal cell death in PD and other synucleinopathies.

An Update on Medical and Surgical Treatments of Parkinson's Disease

Parkinson’s disease (PD) is characterized by degeneration of dopaminergic neurons in the substantia nigra pars compacta and other neuronal populations. The worldwide prevalence of PD is over 7 million and has been increasing more rapidly than many other neurodegenerative disorders. PD symptoms can be broadly divided into motor (slowness, stiffness, tremor) and non-motor symptoms (such as depression, dementia, psychosis, orthostatic hypotension). Patients can also have prodromal symptoms of rapid eye movement sleep behavior disorder, hyposmia, and constipation. The diagnosis of PD is mainly clinical, but dopamine transporter single-photon emission computed tomography can improve the accuracy of the diagnosis. Dopamine based therapies are used for the treatment of motor symptoms. Non-motor symptoms are treated with other medications such as selective serotonin reuptake inhibitors (depression/anxiety), acetylcholinesterase inhibitors (dementia), and atypical antipsychotics (psychosis). Patients with motor fluctuations or uncontrolled tremor, benefit from deep brain stimulation. Levodopa-carbidopa intestinal gel is an alternative to deep brain stimulation for uncontrolled motor fluctuations. Rehabilitative therapies such as physical, occupational, and speech therapy are important during all stages of the disease. Management of PD is complex but there have been significant advancements in the treatment of motor and non-motor symptoms over the past few years. This review discusses the updates in the medical and surgical management of PD.

Detecting placebo and drug effects on Parkinson's disease symptoms by longitudinal item-score models

This study tested the hypothesis that analyzing longitudinal item scores of the Unified Parkinson's Disease Rating Scale could allow a smaller trial size and describe a drug's effect on symptom progression. Two historical studies of the dopaminergic drug ropinirole were analyzed: a cross-over formulation comparison trial in 161 patients with early-stage Parkinson's disease, and a 24-week, parallel-group, placebo-controlled efficacy trial in 393 patients with advanced-stage Parkinson's disease. We applied item response theory to estimate the patients' symptom severity and developed a longitudinal model using the symptom severity to describe the time course of the placebo response and the drug effect on the time course. Similarly, we developed a longitudinal model using the total score. We then compared sample size needs for drug effect detection using these two different models. Total score modeling estimated median changes from baseline at 24 weeks (90% confidence interval) of -3.7 (-5.4 to -2.0) and -9.3 (-11 to -7.3) points by placebo and ropinirole. Comparable changes were estimated (with slightly higher precision) by item-score modeling as -2.0 (-4.0 to -1.0) and -9.0 (-11 to -8.0) points. The treatment duration was insufficient to estimate the symptom progression rate; hence the drug effect on the progression could not be assessed. The trial sizes to detect a drug effect with 80% power on total score and on symptom severity were estimated (at the type I error level of 0.05) as 88 and 58, respectively. Longitudinal item response analysis could markedly reduce sample size; it also has the potential for assessing drug effects on disease progression in longer trials.

Therapeutic Strategies to Treat or Prevent Off Episodes in Adults with Parkinson's Disease

Parkinson's disease is a chronic, neurodegenerative disease, which manifests with a mixture of motor, cognitive and behavioural symptoms. Levodopa is the most effective antiparkinsonian treatment to date, although chronic use engenders a mixture of complications in a substantial proportion of patients. Amongst these is the occurrence of episodes of worsening symptoms-'off' phenomena. These episodes can manifest with either motor or non-motor symptoms or a combination of these features and have been found to have profound impacts on patients' quality of life. Although preventative measures are poorly evidenced, avoiding excessive total daily levodopa intake in selected populations that are deemed to be of a higher risk for developing these episodes warrants further exploration. Methods to improve levodopa bioavailability and delivery to the brain are currently available and are of value in addressing these episodes once they have become established. These include modifications to levodopa formulations as well as the use of complimentary agents that improve levodopa bioavailability. The deployment of device-assisted approaches is a further dimension that can be considered in addressing these debilitating episodes. This review summarises the clinical manifestations of 'off' phenomena and the current approaches to treat them. Although we briefly discuss clinical advances on the horizon, the predominant focus is on existing, established treatments.

Pharmacological Treatment of Early Motor Manifestations of Parkinson Disease (PD)

Parkinson disease (PD), as a slowly progressive neurodegenerative disorder, undergoes six neuropathological stages. The earliest clinical manifestation presents in the middle stage of the disorder pathologically, when 50% or more of the dopaminergic neurons have degenerated in the substantia nigra. This discrepancy between the early stage clinically and that pathologically has, in part, spurred the debate as to when it is best to initiate symptomatic therapy. The most well-studied monotherapeutic agents for PD in its early course include levodopa (the cornerstone of PD therapy), dopamine agonists, and monoamine oxidase inhibitors (MAOIs). With several options for initiating pharmacologic therapy, along with the heterogenous presentation of the disorder, an individualized approach is warranted. Careful deliberation must be done to optimize risk reduction while providing effective symptom control, taking the chronological age, comorbidities, social and financial disposition, work status, and both immediate- and long-term goals into consideration. Generally, treatment can be delayed in patients with mild symptoms and minimal functional impairment at any age. If treatment must be initiated, dopamine agonists and monoamine oxidase type B inhibitors can be used, especially in younger patients with milder disease. However, for older patients, those with moderate to severe PD symptoms, regardless of age, or for patients with greater comorbidities, levodopa generally remains the better choice. Eventually, regardless of initial therapy, studies have shown that most will eventually require levodopa therapy when symptoms become more disabling.

Safety considerations when using non-ergot dopamine agonists to treat Parkinson's disease

INTRODUCTION

Nonergot dopamine agonists (NEDA) represent an excellent treatment option for Parkinson's disease (PD) patients, in both early and advanced stages of the disease. The post-marketing phase of NEDA has highlighted, though, the occurrence of important long-term adverse events.

AREAS COVERED

This review reports recent updates on NEDA adverse events, analyzing neurobiological bases and risk factors of these complications. A literature search has been performed using Medline and reviewing the bibliographies of selected articles.

EXPERT OPINION

NEDA represents a very important option in the treatment of PD. Criticisms on their use can be overcome through a better knowledge of these molecules and of the risk factors for adverse events which allow specialists to prevent the occurrence of undesired complications and consent a tailor-based approach. Abbreviations: PD: Parkinson's disease, DA: dopamine agonists, NEDA: non-ergot dopamine agonists, ICD: impulse control disorders, DAWS: dopamine agonist withdrawal syndrome, CYP: Cytochrome P, PK: pharmacokinetic, AUC: area under the curve, HRT: hormone replacement therapy, AV: atrioventricular, HF: heart failure, OH: orthostatic hypotension, RBD: REM behavior disorders, PDP: Parkinson's disease psychosis, DRT: dopamine replacement therapy, DDS: dopamine dysregulation syndrome, MMSE: Mini-Mental state examination, EDS: excessive daytime somnolence.

Lipid-based nanodelivery approaches for dopamine-replacement therapies in Parkinson's disease: From preclinical to translational studies

The incidence of Parkinson's disease (PD), the second most common neurodegenerative disorder, has increased exponentially as the global population continues to age. Although the etiological factors contributing to PD remain uncertain, its average incidence rate is reported to be 1% of the global population older than 60 years. PD is primarily characterized by the progressive loss of dopaminergic (DAergic) neurons and/or associated neuronal networks and the subsequent depletion of dopamine (DA) levels in the brain. Thus, DA or levodopa (l-dopa), a precursor of DA, represent cardinal targets for both idiopathic and symptomatic PD therapeutics. While several therapeutic strategies have been investigated over the past decade for their abilities to curb the progression of PD, an effective cure for PD is currently unavailable. Even DA replacement therapy, an effective PD therapeutic strategy that provides an exogenous supply of DA or l-dopa, has been hindered by severe challenges, such as a poor capacity to bypass the blood-brain barrier and inadequate bioavailability. Nevertheless, with recent advances in nanotechnology, several drug delivery systems have been developed to bypass the barriers associated with central nervous system therapeutics. In here, we sought to describe the adapted lipid-based nanodrug delivery systems used in the field of PD therapeutics and their recent advances, with a particular focus placed on DA replacement therapies. This work initially explores the background of PD; offers descriptions of the most recent molecular targets; currently available clinical medications/limitations; an overview of several lipid-based PD nanotherapeutics, functionalized nanoparticles, and technical aspects in brain delivery; and, finally, presents future perspectives to enhance the use of nanotherapeutics in PD treatment.

Item Response Model Adaptation for Analyzing Data from Different Versions of Parkinson's Disease Rating Scales

Purpose

The aim of this work was to allow combination of information from recent and historical trials in Parkinson’s Disease (PD) by developing bridging methodology between two versions of the clinical endpoint.

Methods

A previously developed Item Response Model (IRM), that described longitudinal changes in Movement Disorder Society (MDS) sponsored revision of Unified Parkinson’s Disease Rating Scale (UPDRS) [MDS–UPDRS] data from the De Novo PD cohort in Parkinson’s Progression Markers Initiative, was first adapted to describe baseline UPDRS data from two clinical trials, one in subjects with early PD and another in subjects with advanced PD. Assuming similar IRM structure, items of the UPDRS version were mapped to those in the MDS-UPDRS version. Subsequently, the longitudinal changes in the placebo arm of the advanced PD study were characterized.

Results

The parameters reflecting differences in the shared items between endpoints were successfully estimated, and the model diagnostics indicated that mapping was better for early PD subjects (closer to De Novo cohort) than for advanced PD subjects. Disease progression for placebo in advanced PD patients was relatively shallow.

Conclusion

An IRM able to handle two variants of clinical PD endpoints was developed; it can improve the utilization of data from diverse sources and diverse disease populations.

Electronic supplementary material

The online version of this article (10.1007/s11095-019-2668-6) contains supplementary material, which is available to authorized users.

Molecular basis of dopamine replacement therapy and its side effects in Parkinson's disease

There is currently no cure for Parkinson's disease. The symptomatic therapeutic strategy essentially relies on dopamine replacement whose efficacy was demonstrated more than 50 years ago following the introduction of the dopamine precursor, levodopa. The spectacular antiparkinsonian effect of levodopa is, however, balanced by major limitations including the occurrence of motor complications related to its particular pharmacokinetic and pharmacodynamic properties. Other therapeutic strategies have thus been developed to overcome these problems such as the use of dopamine receptor agonists, dopamine metabolism inhibitors and non-dopaminergic drugs. Here we review the pharmacology and molecular mechanisms of dopamine replacement therapy in Parkinson's disease, both at the presynaptic and postsynaptic levels. The perspectives in terms of novel drug development and prediction of drug response for a more personalised medicine will be discussed.

Nanotechnology-based drug delivery of ropinirole for Parkinson's disease

A new drug delivery system is developed for ropinirole (RP) for the treatment of Parkinson's disease (PD) consisting of biodegradable poly (D,L-lactide-co-glycolide) (PLGA) nanoparticles (NPs). The formulation selected was prepared with 8 mg RP and 50 mg PLGA 502. This formulation exhibited mean encapsulation efficiency of 74.8 ± 8.2%, mean particle size lower than 155 nm, the zeta potential of -14.25 ± 0.43 mV and zero-order in vitro release of RP (14.13 ± 0.17 μg/h/10 mg NPs) for 5 d. Daily doses of the neurotoxin rotenone (2 mg/kg) given i.p. to male Wistar rats induced neuronal and behavioral changes similar to those of PD. Once neurodegeneration was established (15 d) animals received RP in saline (1 mg/kg/d for 35 d) or encapsulated within PLGA NPs (amount of NPs equivalent to 1 mg/kg/d RP every 3 d for 35 d). Brain histology and immunochemistry (Nissl-staining, glial fibrillary acidic protein and tyrosine hydroxylase immunohistochemistry) and behavioral testing (catalepsy, akinesia, rotarod and swim test) showed that RP-loaded PLGA NPs were able to revert PD-like symptoms of neurodegeneration in the animal model assayed.

Comparison for Efficacy and Tolerability among Ten Drugs for Treatment of Parkinson's Disease: A Network Meta-Analysis

Parkinson’s disease (PD) is a long term disorder affects the central nervous system and we aim to determine the relative efficacy of the current available drugs used in PD. Firstly, we performed a systematic review in current literature and eligible studies were retrieved from online databases, relevant data were extracted. Efficacy of these medications was assessed by different Unified Parkinson’s Disease Rating Scales (UPDRS). Mean difference (MD) and odds ratio (OR) were produced by pairwise or network meta-analysis (NMA). Finally, we performed a cluster analysis for the included medications with respect to their surface under the cumulative ranking curve (SUCRA). Pairwise meta-analysis suggests that selegiline had a higher ranking in UPDRS II, UPDRS III and UPDRS total than bromocriptine and levodopa. Selegiline was more tolerable than bromocriptine (OR = 0.62, CI: 0.39 to 0.98) and pramipexole was less tolerable than levodopa (OR = 1.43, CI = 1.00 to 2.04). Results of NMA indicate that patients with levodopa, pramipexole, ropinirole and selegiline exhibited a significantly improved UPDRS III than those with lazabemide. To sum up, levodopa, selegiline, ropinirole and rotigotine were recommended for PD patients as they appeared relatively high efficacy and tolerability.

A fixed-dose, dose-response study of ropinirole prolonged release in early stage Parkinson's disease

AIM

This Phase IV, double-blind, randomized, parallel-group study characterized the dose-response and tolerability of fixed doses of ropinirole prolonged release (PR).

PATIENTS & METHODS

Subjects with early Parkinson's disease (PD) received placebo or ropinirole PR 2, 4, 8, 12 or 24 mg once daily, up-titrated to randomized or highest tolerated dose, maintained for 4 weeks.

RESULTS

The primary end point was not met (change from baseline in Unified PD Rating Scale motor score). However, because the data were not normally distributed, prespecified nonparametric analysis of covariance suggested ropinirole PR (8 and 12 mg/day) was effective in treating motor symptoms. The adverse event profile was consistent with the known safety profile of ropinirole PR. There was no impulse control disorder reported. Although a higher than previously reported rate of sudden onset of sleep events was reported, these were not dose dependent and were likely to have been influenced by the method of data collection.

CONCLUSION

The adverse event profile was consistent with the known safety profile of ropinirole PR and ropinirole PR (8 or 12 mg/day) improved motor symptoms of early PD.

A randomized, fixed-dose, dose-response study of ropinirole prolonged release in advanced Parkinson's disease

AIM

This Phase IV, double-blind, randomized, parallel-group study characterized the dose-response and tolerability of fixed doses of ropinirole prolonged release (PR) in subjects with advanced Parkinson's disease.

PATIENTS & METHODS

Subjects receiving concomitant l-dopa received once-daily ropinirole PR 4, 8, 12, 16 or 24 mg, or placebo, up-titrated for 13 weeks, maintained for 4 weeks.

RESULTS

At maintenance period week 4, ropinirole PR significantly reduced total awake 'Off-time' (16 mg; p = 0.027); increased absolute awake time spent 'On' without troublesome dyskinesia from baseline versus placebo (8 mg; p = 0.036); improved Unified Parkinson's Disease Rating Scale motor scores versus placebo (all doses; p = 0.005-0.016). Incidence of adverse events was similar between treatment groups; no dose-related trends were observed.

CONCLUSION

Ropinirole PR (16 mg) reduced 'Off-time' with 8 mg the likely lowest maximally effective dose, and the safety profile was consistent with previous studies.

Analysis of pramipexole dose-response relationships in Parkinson's disease

BACKGROUND

Pramipexole (PPX), a non-ergot dopamine receptor agonist, is a first-line treatment for Parkinson's disease (PD). A critical dose level above which a better benefit-to-harm ratio exists has not been examined.

METHODS

Chinese PD patients (n=464) were retrospectively analyzed by PPX maintenance dose, PD stage, combined levodopa dose, and baseline tremor contribution. The sum score of Baseline Activities of Daily Living (part II) and Motor Examination (III) of the Unified Parkinson's Disease Rating Scale (UPDRS II+III) was used as a covariate for final score adjustment.

RESULTS

Sustained-release (SR) and immediate-release (IR) PPX showed similar efficacy based on score changes at 18 weeks, with comparable tolerability. Approximately two-third of patients received PPX at ≥1.5 mg/d, and one fourth of patients had ≥20% tremor contribution to UPDRS II+III. After treatment, patients receiving PPX ≥1.5 mg/d showed better improvement in UPDRS II+III scores (P=0.0025), with similar trends with the IR and SR formulations. Patients with ≥20% tremor contribution showed better improvement in UPDRS II+III scores (P=0.0017). No differences were seen based on PD stage or combined levodopa dose. The overall proportions of adverse events (AEs) were similar. More patients discontinued because of intolerable side effects, and more investigator-defined drug-related AEs were recorded in the <1.5 mg/d subgroup.

CONCLUSION

UPDRS II+III improvement was better with PPX ≥1.5 than with <1.5 mg/d in Chinese PD patients after 18 weeks of treatment, with similar trends seen with IR and SR formulations. The frequency of AEs in PPX ≥1.5 and <1.5 mg/d subgroups was similar.

Advances in dopamine receptor agonists for the treatment of Parkinson's disease

INTRODUCTION

Dopamine agonists (DA) are a class of agents which directly stimulate dopamine receptors mimicking the endogenous neurotransmitter dopamine. At first used as adjunctive therapy in the advanced phases of the disease, over the years a significant role was found for DA monotherapy as a first approach in the initial stage of Parkinson's disease (PD). Several reviews have already reported efficacy and safety of DA in PD and differences between DA and levodopa. Therefore the objective of this review is to gather recent updates in DA therapy. A thorough knowledge of recent literature evidences, would help clinician in the management of treatment with DA.

AREAS COVERED

Our review investigates recent updates on DA therapy, the role of these compounds in controlling non-motor symptoms (NMS) as well as new formulations under clinical evaluation and newly emerged post-marketing safety considerations. A literature search has been performed using Medline and reviewing the bibliographies of selected articles.

EXPERT OPINION

DA represents a very important option in the treatment of PD, even though there are still some criticisms and unmet needs. A better knowledge of dopamine receptors could lead to identification of new compounds able to better balance clinical efficacy and side effects.

Initial treatment of Parkinson's disease in 2016: The 2000 consensus conference revisited

In 2000, a French consensus conference proposed guidelines for the treatment of Parkinson's disease (PD). Since then, new drugs have been concocted, new studies have been published and clinicians have become aware of some drug-induced adverse effects that were little known in the past. This has led us to reconsider the recommendations published 16 years ago. Thus, the aim of the present review is to present the recent data related to the different medications and non-pharmacological approaches available for PD, with a special focus on early-stage PD. Levodopa (LD), dopamine agonists (DAs), catechol-O-methyltransferase inhibitors (COMT-Is), anticholinergics, monoamine oxidase inhibitors (MAOB-Is) and amantadine have been considered, and their efficacy and safety for both motor as well as non-motor aspects are reported here. This has led to our proposal for a revised therapeutic strategy for the initiation of treatment in newly diagnosed PD patients, based on the available literature and the relative benefits/side effects balance.

Efficacy of rasagiline in early Parkinson's disease: a meta-analysis of data from the TEMPO and ADAGIO studies

AIM OF THE STUDY

To evaluate the efficacy of rasagiline versus placebo in a pooled population of patients with early Parkinson's disease (PD).

MATERIALS AND METHODS

TEMPO and ADAGIO were Phase III studies that evaluated the symptomatic efficacy of rasagiline versus placebo in patients with early PD. This meta-analysis included Unified Parkinson's Disease Rating Scale (UPDRS) observations from weeks 12, 24 and 36 in ADAGIO and from weeks 14 and 26 in TEMPO; TEMPO visits were recoded to weeks 12 and 24, respectively. The present analysis includes all patients who received rasagiline 1 mg/day, 2 mg/day or placebo, and had ≥1 post-baseline observations and a subgroup of patients whose baseline UPDRS Total scores were ≥27 (Upper Quartile population). Change from baseline in UPDRS scores were evaluated using mixed models repeated measures analyses.

RESULTS

Of the 1578 patients randomized to the two studies, 1546 patients met criteria for inclusion in the meta-analysis. Effects on UPDRS Total, motor and activities of daily living scores were significantly better for both doses of rasagiline compared with placebo at all time periods. The Upper Quartile population included 402 patients with a UPDRS Total score ≥27 at baseline. These patients generally demonstrated a larger magnitude of treatment effect than was seen in the full population.

CONCLUSIONS

This meta-analysis confirms the efficacy of rasagiline monotherapy over 36 weeks. Although TEMPO and ADAGIO are considered studies of "very early" PD, both contained a sizeable pool of patients with more severe disease. In addition, the meta-analysis showed a larger magnitude of effect in patients with more severe baseline disease.

A review of adverse events linked to dopamine agonists in the treatment of Parkinson's disease

INTRODUCTION

Dopamine agonists are highly effective as adjunctive therapy to levodopa in advanced Parkinson's disease. These drugs have rapidly gained popularity as a monotherapy in the early stages of Parkinson's disease for patients less than 65-70 years old since they are about as effective as levodopa but patients demonstrate a lower tendency to develop motor complications. However, dopamine agonists could have peripheral and central side-effects which are often the reason for the discontinuation of the treatment.

AREAS COVERED

This article presents an overview of the efficacy and the potential negative effects related to the use of dopamine agonists in the treatment of Parkinson's disease.

EXPERT OPINION

Beyond the new generation non ergot dopamine agonists, no strong evidences allow the choice of a specific dopamine agonists for Parkinson 's disease treatment and by now dopamine agonists treatment should be tailored on specific adverse events profile.

Early versus delayed initiation of pharmacotherapy in Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease and pathologically is characterised by a progressive loss of dopaminergic cells of the nigrostriatal pathway. Clinically, PD is mainly defined by the presence of the motor symptoms of bradykinesia, rigidity, rest tremor and postural instability, but non-motor symptoms such as depression, dementia and autonomic disturbances are recognised as integral parts of the disease. Although pharmacotherapy for PD was introduced almost 50 years ago, and has improved significantly over the intervening period, the timing of initiation of treatment in newly diagnosed PD remains controversial. While some physicians favour an early start of pharmacotherapy at or soon after diagnosis, others prefer to delay pharmacological treatment until a certain degree of disability has developed. This article aims to discuss the advantages and disadvantages of both strategies by exploring their effects on symptoms, disease progression and quality of life. Although the data on putative disease-modifying effects of early pharmacological intervention in PD are still inconclusive, we believe that the most important indication for an early initiation of anti-parkinsonian treatment should be to maintain the quality of life of PD patients and to secure their socioeconomic status as long as possible.

An open-label extension study to evaluate the safety of ropinirole prolonged release in Chinese patients with advanced Parkinson's disease

OBJECTIVE

This open-label extension (OLE) study evaluated the safety profile of ropinirole prolonged release (PR) administered for 24 weeks as adjunctive to levodopa in Chinese patients with advanced Parkinson's disease (PD).

METHODS

This was a 24 week, flexible-dose, OLE study in Chinese patients with advanced PD who received 24 week treatment with ropinirole PR in the preceding double-blind (DB), phase III study (NCT01154166) and had no break in receiving study treatment while switching from the DB study to the OLE study. In the OLE study, patients received ropinirole PR once daily, starting with 2 mg/d and increasing up to 8 mg/d at week 4 (2 mg increment/week); if tolerable, the dose could be further increased in 4 mg increments up to 24 mg/d according to clinical judgment. There were no efficacy assessments. Safety assessments included monitoring adverse events (AEs), neurological examination, Gambling Symptom Assessment Scale questionnaire, liver chemistry, and laboratory tests.

RESULTS

Of the 295 enrolled patients, 282 completed the study. The most common reason for withdrawal was AEs (n = 9, 3.1%). The mean duration to ropinirole PR treatment was 173.1 days and an overall median daily dose of ropinirole was 8 mg (range: 2-24 mg). Overall, 114 (38.6%) patients experienced on-treatment AEs; the most frequent reported AEs ( ≥ 2%) were dyskinesia (6.1%), dizziness (4.1%), nausea (3.4%), hallucinations (3.4%), somnolence (2.7%) and decreased weight (2.4%). Sixty-eight patients (23.1%) experienced treatment-related AEs. Six patients experienced serious AEs (SAEs), of which hallucination was determined to be a treatment-related SAE. There were no other significant safety findings. No new safety signals for ropinirole were identified.

CONCLUSION

The safety profile of ropinirole was consistent with the preceding DB study and also with the established safety profile for ropinirole. Results support the long-term use of ropinirole PR as an adjunctive to levodopa in Chinese patients with advanced PD. ClinicalTrials.gov identifier: NCT 1536574.

How to optimize the treatment of early stage Parkinson's disease

The approach to early Parkinson's disease denotes the communication of the diagnosis and important decisions, such as when and how to start treatment. Evidence based medicine and guidelines indicate which drugs have robust evidence of efficacy and tolerability in this specific population. However, de-novo patients may show different characteristics and they may be in a different phase of their disease. In this review, we will give an insight into the appropriate time therapy should be started and the actual knowledge about disease modification therapies. Moreover, the drugs indicated for early treatment will be considered and an indication for the use of these drugs will be given with the support of the actual knowledge.

Treatment of early Parkinson's disease

PURPOSE OF REVIEW

This review summarizes currently available treatment options and treatment strategies, investigational treatments, and the importance of exercise for early Parkinson's disease.

RECENT FINDINGS

The available treatment options for early Parkinson's disease have changed little in the past decade and include carbidopa/levodopa, dopamine agonists, and monoamine oxidase type B (MAO-B) inhibitors. However, we discuss changes in treatment strategies, including dosing and the use of combination therapy used in an attempt to reduce or delay the appearance of motor complications and other adverse events. We will also review several investigational treatments that have shown promise for the treatment of early Parkinson's disease, including a new extended release formulation of carbidopa/levodopa (IPX066), safinamide which inhibits MAO-B, dopamine uptake and glutamate and pardoprunox which is a 5HT-1A agonist and a partial dopamine agonist. Finally, we discuss recent studies focusing on exercise as an important component in the management of early Parkinson's disease.

SUMMARY

Advances in the management of early Parkinson's disease include evolving treatment strategies, new investigational treatments, and earlier implementation of various forms of exercise.

Medication adherence in patients with Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder, after Alzheimer's disease, affecting the elderly worldwide. Current therapy for PD is largely based on prescription of drugs that act as either dopamine precursors, dopamine agonists or agents that inhibit key enzymes in the dopamine catabolic pathways. Most of these drugs are administered in tablet or capsule form and can involve multiple daily doses in complex dosing regimens, which contributes to sub-optimal compliance amongst patients. There is evidence to suggest that non-compliance with medications results in perceived poor response to therapy and may ultimately increase direct and indirect health care costs. Medication compliance in PD assumes a particularly important role, given that PD is a progressive, debilitating condition, and once medication is instituted for ameliorating the symptoms of PD, it is lifelong. We included nine research studies in our review of the medical literature, which report the prevalence of significant medication non-compliance in PD, using standard definitions, varies between 10 and 67%. This variation partly reflects differences in defining what clinically significant medication adherence is, the methods used to estimate the scale of the problem and the underlying population heterogeneity. Nevertheless, medication adherence is related to health costs and to the quality of life of patients affected by PD and, indirectly, their carers. Educating patients and their carers is one method of improving patient adherence to therapy. Simplifying drug regimens can also aid in this effort.

Long-acting versus standard non-ergot dopamine agonists in Parkinson's disease: a meta-analysis of randomized controlled trials

AIMS

To evaluate the efficacy, tolerability, and safety of long-acting versus standard non-ergot dopamine agonists (NEDAs) in Parkinson's disease (PD), we performed a meta-analysis of randomized controlled trials (RCTs).

MATERIALS AND METHODS

The PubMed, EMBASE, Cochrane Library databases, and Web of Knowledge were searched up to November 20th 2013. The pooled weighted mean differences (WMDs) and relative risks (RRs) with 95% confidence intervals (CIs) were calculated.

RESULTS

Eight large-scale RCTs, involving 2402 patients, were included in this meta-analysis. Compared with the standard NEDAs, long-acting NEDAs exhibited similar improvements in Unified Parkinson's Disease Rating Scale activities of daily living (ADL) score (WMD 0.09, 95% CI -0.33 to 0.50), motor score (WMD -0.35, 95% CI -1.60 to 0.90), and "off" time (WMD 0.18, 95% CI -0.14 to 0.50). No differences were found in overall withdrawals (RR 1.11, 95% CI 0.94 to 1.32), withdrawals due to adverse events (RR 1.19, 95% CI 0.91 to 1.56), or the ten commonly reported adverse events between the two formulations.

CONCLUSIONS

Our meta-analysis showed long-acting NEDAs were noninferior to standard NEDAs in efficacy, tolerability, and safety in the treatment of PD.

Drug safety evaluation of ropinirole prolonged release

INTRODUCTION

The need for multiple administrations and a difficult titration schedule has always represented a limit in the use of dopamine agonists in the treatment of early Parkinson's disease. To avoid these problems, Ropinirole prolonged release (RPR), a non-ergoline dopamine receptor agonist that can be taken once a day, has been formulated. The prolonged release formulation has higher patient compliance due to a simpler and fastest titration schedule; the once-a-day administration makes this molecule especially suitable for young Parkinsonian patients who are still working and having an active lifestyle.

AREAS COVERED

In this paper, we will review ropinirole's mechanism of action including pharmacokinetics and pharmacodynamic data and the results of the main clinical studies in early and advanced PD patients. We will also discuss safety data shown during the experimental phase and after RPR commercialization. This article reviews the use of RPR in early and advanced Parkinsonian patients. Medical literature on the use of RPR in Parkinson's disease was identified using MEDLINE and the reference lists of published articles.

EXPERT OPINION

RPR is effective in the treatment of patients with early Parkinson's disease; in advanced Parkinsonian patients, the amount of daily off-time significantly decreases, improving the mean on time. RPR has also demonstrated to be effective in ameliorating the quality of sleep without increasing the occurrence of daily sleepiness and nocturnal psychosis. RPR was generally well tolerated in both early and advanced Parkinsonian patients.

The impact of extended release dopamine agonists on prescribing patterns for therapy of early Parkinson's disease: an observational study

Background

Dopamine agonists (DA) are the first-choice drug for treatment of the early stage of Parkinson’s disease (PD) in subjects younger than 70 years. Recently, a number of third generation DA have been marketed, including transdermal patch of rotigotine and extended release oral formulation of ropinirole and pramipexole.

We investigated the impact of third generation DA on management of the early stage of PD in an outpatient service for Movement Disorders in Italy.

Methods

Two 12-month observation periods were selected (January - December, 2007, and January - December, 2011) as representative for prescription of immediate and extended release formulations of DA respectively. Within each period, PD patients were divided into subgroups according to age (<65 years; 65–75 years; >75 years) or functional requirement (high; moderate; low). For each period, the number of subjects receiving monotherapy with DA, monotherapy with levodopa (LD), or combined DA/LD therapy and the relative doses were calculated. The severity of parkinsonian motor symptoms was calculated by means of the Unified Parkinson’s Disease Rating Scale part III (UPDRS-III) score. The frequency and severity of side-effects leading to discontinuation or reduction of DA drugs at each time point were also calculated.

Results

We found a significant reduction of daily LD dose (both as mono- and combined therapy) between the second and the first observation period. There was also a significant increase of monotherapy with DA and corresponding reduction of monotherapy with LD in patients aged 65–75 years, as well as in PD patients with moderate functional requirements. A significant reduction of frequency of side-effects was measured with extended release DA as compared to immediate release formulations. There were no significant differences of the UPDRS-III scores between the 2 observation periods in any subgroup.

Conclusions

Our results suggest that extended release DA might optimize therapeutic management of the early stages of PD even in patients older than 70 years of age.

Comparison of once-daily versus twice-daily combination of ropinirole prolonged release in Parkinson's disease

Background

Ropinirole prolonged release (RPR) is a once-daily formulation. However, there may be individual pharmacokinetic differences so that multiple dosing may be preferred in some individuals. This study compares once-daily and twice-daily RPR in patients with Parkinson’s disease.

Methods

This study was an open-label crossover study. We enrolled Parkinson’s disease patients on dopamine agonist therapy with unsatisfactory control such as motor fluctuation, dyskinesia and sleep-related problems. Agonists were switched into equivalent dose of RPR. Subjects were consecutively enrolled into either once-daily first or twice-daily first groups, and received the same amount of RPR in a single and two divided dosing for 8 weeks respectively in a crossover manner without a washout period.

The primary outcome was a questionnaire of the preference completed by patients in the last visit. The secondary outcome measures included the Unified Parkinson’s Disease Rating Scale part 3 (mUPDRS), Hoehn and Yahr stage (H&Y); sleep questionnaire including overall quality of sleep, nocturnal off symptoms and early morning symptoms; Epworth Sleep Scale (ESS); compliances and patient global impression (PGI).

Results

A total of 82 patients were enrolled and 61 completed the study. 31 patients preferred twice-daily regimen, 17 preferred the once-daily regimen, and 13 had no preference. Their mean mUPDRS, H&Y, ESS, sleep quality, compliance and adverse events were not statistically different in both regimens. PGI-improvement on wearing off defined was better in twice-daily dosing regimen.

Conclusions

RPR is a once-daily formulation, but multiple dosing was preferred in many patients. Multiple dosing of RPR might be a therapeutic option if once-daily dosing is unsatisfactory.

Trial registration

This study is registered with ClinicalTrials.gov, number NCT00986245.

Summary of the recommendations of the EFNS/MDS-ES review on therapeutic management of Parkinson's disease

OBJECTIVE

To summarize the 2010 EFNS/MDS-ES evidence-based treatment recommendations for the management of Parkinson's disease (PD). This summary includes the treatment recommendations for early and late PD.

METHODS

For the 2010 publication, a literature search was undertaken for articles published up to September 2009. For this summary, an additional literature search was undertaken up to December 2010. Classification of scientific evidence and the rating of recommendations were made according to the EFNS guidance. In cases where there was insufficient scientific evidence, a consensus statement ('good practice point') is made.

RESULTS AND CONCLUSIONS

For each clinical indication, a list of therapeutic interventions is provided, including classification of evidence.

The management of orthostatic hypotension in Parkinson's disease

Orthostatic hypotension (OH) is a common and disabling symptom affecting Parkinson's disease (PD) patients. We present the effect of the different therapies commonly used to manage PD on this clinical manifestation. For this purpose, we describe the relationship between OH and the current treatments employed in PD, such as L-DOPA, dopaminergic agonists, and continuous dopaminergic stimulation therapies. Additionally, we review the therapeutic measures that could be used to ameliorate OH. There are different approaches to deal with this manifestation, including pharmacological and non-pharmacological treatments, although none of them is specifically aimed for treating OH in PD.

Motor and nonmotor complications in Parkinson's disease: an argument for continuous drug delivery?

The complications of long-term levodopa therapy for Parkinson’s disease (PD) include motor fluctuations, dyskinesias, and also nonmotor fluctuations—at least equally common, but less well appreciated—in autonomic, cognitive/psychiatric, and sensory symptoms. In seeking the pathophysiologic mechanisms, the leading hypothesis is that in the parkinsonian brain, intermittent, nonphysiological stimulation of striatal dopamine receptors destabilizes an already unstable system. Accordingly, a major goal of PD treatment in recent years has been the attainment of continuous dopaminergic stimulation (CDS)—or, less theoretically (and more clinically verifiable), continuous drug delivery (CDD). Improvements in the steadiness of the plasma profiles of various dopaminergic therapies may be a signal of progress. However, improvements in plasma profile do not necessarily translate into CDS, or even into CDD to the brain. Still, it is reassuring that clinical studies of approaches to CDD have generally been positive. Head-to-head comparative trials have often failed to uncover evidence favoring such approaches over an intermittent therapy. Nevertheless, the findings among recipients of subcutaneous apomorphine infusion or intrajejunal levodopa/carbidopa intestinal gel suggest that nonmotor PD symptoms or complications may improve in tandem with motor improvement. In vivo receptor binding studies may help to determine the degree of CDS that a dopaminergic therapy can confer. This may be a necessary first step toward establishing whether CDS is, in fact, an important determinant of clinical efficacy. Certainly, the complexities of optimal PD management, and the rationale for an underlying strategy such as CDS or CDD, have not yet been thoroughly elucidated.

Diagnosis and initiation of treatment in Parkinson's disease

Parkinson's disease (PD) is the most common cause of parkinsonism, yet the diagnosis and management can be a challenge. The United Kingdom Parkinson's Disease Society Brain Bank Clinical Diagnostic Criteria and dopamine transporter/single-photon emission computed tomography (DaT-SPECT) are diagnostic aids that can improve diagnostic accuracy. Even though PD is a progressive disease, for years, physicians and patients have delayed treatment until functional disability occurs. However, studies of monoamine oxidase-type B (MAO-B) inhibitors, dopamine agonists, and levodopa, all of which can be used as initial therapy, have demonstrated that PD patients receiving treatment do better than those who do not receive treatment, and some studies have shown that those receiving treatment earlier do better long term. Therefore, the management strategy for PD has moved toward earlier initiation of treatment. Although treatment for each patient should be individualized and based on their specific symptoms, severity, and lifestyle, in general MAO-B inhibitors may be used initially to treat mild symptoms, adding a dopamine agonist in younger patients or levodopa in older patients, as symptoms become more severe.