Transdermal rotigotine: a new non-ergot dopamine agonist for the treatment of Parkinson’s disease

Management of Motor Symptoms for Patients with Advanced Parkinson's Disease without Safe Oral Access: A Scoping Review

Context: Parkinson's disease (PD) is the second most common neurodegenerative disorder worldwide. Oral medications for control of motor symptoms are the mainstay of treatment. However, as the disease progresses, patients with PD may develop dysphagia that prohibits them from safely taking oral medications. Currently there are no clinical guidelines for managing distressing motor symptoms in patients with PD and severe dysphagia, which can therefore be quite challenging. Objectives: To provide an exhaustive summary of current literature on pharmacological interventions for patients with PD who do not have safe oral access in managing distressing motor symptoms. Indication, route, doses, frequency, outcome, and adverse effects will be discussed. Methods: A scoping review using Medline, Embase, CENTRAL, CINAHL, AgeLine, and PsycINFO databases (1946-2021) was conducted. Articles examining patients with PD and dysphagia who are eligible to receive palliative care or at end of life were included. Studies that included patients who were also on oral PD medications or received device-aided therapy were excluded from this review. Results: A total of 3821 articles were screened for title and abstract, 259 were selected for full-text review, and 20 articles were selected for data extraction. These included five case reports, one retrospective cohort study, one book chapter, and 13 narrative reviews. There are very few articles addressing the issue of treatment of patients with advanced PD who are unable to take oral medications. Although rotigotine patch and apormorphine injections are most frequently recommended, there are no clinical trials in this patient population to support those recommendations. Conclusion: This study highlights a need for further research examining the efficacy and dosing of nonoral medications in advanced PD with dysphagia.

Controlled iontophoretic delivery of pramipexole: electrotransport kinetics in vitro and in vivo

The objective of the study was to investigate the anodal iontophoretic delivery of pramipexole (PRAM), a dopamine agonist used for the treatment of Parkinson's disease, in order to determine whether therapeutic amounts of the drug could be delivered across the skin. Preliminary iontophoretic experiments were performed in vitro using porcine ear and human abdominal skin. These were followed by a pharmacokinetic study in male Wistar rats to determine the drug input rate in vivo. Stability studies revealed that after current application (0.5 mA/cm(2) for 6h), the solution concentration of PRAM was only 60.2 ± 5.3% of its initial value. However, inclusion of sodium metabisulfite (0.5%), an antioxidant, increased this to 97.2 ± 3.1%. Iontophoretic transport of PRAM across porcine skin in vitro was studied as a function of current density (0.15, 0.3, 0.5 mA/cm(2)) and concentration (10, 20, 40 mM). Increasing the current density from 0.15 to 0.3 and 0.5 mA/cm(2), resulted in 2.5- and 4-fold increases in cumulative permeation, from 309.5 ± 80.2 to 748.8 ± 148.1 and 1229.1 ± 138.6 μg/cm(2), respectively. Increasing the PRAM concentration in solution from 10 to 20 and 40 mM resulted in a 2-fold increase in cumulative permeation (816.4 ± 123.3, 1229.1 ± 138.6 and 1643.6 ± 201.3 μg/cm(2), respectively). Good linearity was observed between PRAM flux and both the applied current density (r(2)=0.98) and drug concentration in the formulation (r(2)=0.99). Co-iontophoresis of acetaminophen showed that electromigration was the dominant electrotransport mechanism (accounting for >80% of delivery) and that there was no inhibition of electroosmotic flow at any current density. Cumulative iontophoretic permeation across human and porcine skin (after 6h at 0.5 mA/cm(2)) was also shown to be statistically equivalent (1229.1 ± 138.6 and 1184.8 ± 236.4 μg/cm(2), respectively). High transport and delivery efficiencies were achieved for PRAM (up to 7% and 58%, respectively). The plasma concentration profiles obtained in the iontophoretic studies in vivo (20 mM PRAM; 0.5 mA/cm(2) for 5h) were modelled using constant and time-variant input models; the latter gave a superior quality fit. The drug input rate in vivo suggested that PRAM electrotransport rates would be sufficient for therapeutic delivery and the management of Parkinsonism.

Animal models of Parkinson's disease: a gateway to therapeutics?

Parkinson's disease (PD) is a progressive, neurodegenerative disorder of unknown etiology, although a complex interaction between environmental and genetic factors has been implicated as a pathogenic mechanism of selected neuronal loss. A better understanding of the etiology, pathogenesis, and molecular mechanisms underlying the disease process may be gained from research on animal models. While cell and tissue models are helpful in unraveling involved molecular pathways, animal models are much better suited to study the pathogenesis and potential treatment strategies. The animal models most relevant to PD include those generated by neurotoxic chemicals that selectively disrupt the catecholaminergic system such as 6-hydroxydopamine; 1-methyl-1,2,3,6-tetrahydropiridine; agricultural pesticide toxins, such as rotenone and paraquat; the ubiquitin proteasome system inhibitors; inflammatory modulators; and several genetically manipulated models, such as α-synuclein, DJ-1, PINK1, Parkin, and leucine-rich repeat kinase 2 transgenic or knock-out animals. Genetic and nongenetic animal models have their own unique advantages and limitations, which must be considered when they are employed in the study of pathogenesis or treatment approaches. This review provides a summary and a critical review of our current knowledge about various in vivo models of PD used to test novel therapeutic strategies.

The effects of the dopamine agonist rotigotine on hemispatial neglect following stroke

Hemispatial neglect following right-hemisphere stroke is a common and disabling disorder, for which there is currently no effective pharmacological treatment. Dopamine agonists have been shown to play a role in selective attention and working memory, two core cognitive components of neglect. Here, we investigated whether the dopamine agonist rotigotine would have a beneficial effect on hemispatial neglect in stroke patients. A double-blind, randomized, placebo-controlled ABA design was used, in which each patient was assessed for 20 testing sessions, in three phases: pretreatment (Phase A1), on transdermal rotigotine for 7-11 days (Phase B) and post-treatment (Phase A2), with the exact duration of each phase randomized within limits. Outcome measures included performance on cancellation (visual search), line bisection, visual working memory, selective attention and sustained attention tasks, as well as measures of motor control. Sixteen right-hemisphere stroke patients were recruited, all of whom completed the trial. Performance on the Mesulam shape cancellation task improved significantly while on rotigotine, with the number of targets found on the left side increasing by 12.8% (P = 0.012) on treatment and spatial bias reducing by 8.1% (P = 0.016). This improvement in visual search was associated with an enhancement in selective attention but not on our measures of working memory or sustained attention. The positive effect of rotigotine on visual search was not associated with the degree of preservation of prefrontal cortex and occurred even in patients with significant prefrontal involvement. Rotigotine was not associated with any significant improvement in motor performance. This proof-of-concept study suggests a beneficial role of dopaminergic modulation on visual search and selective attention in patients with hemispatial neglect following stroke.

Excessive daytime sleepiness in patients with Parkinson's disease

Excessive daytime sleepiness (EDS) is described as inappropriate and undesirable sleepiness during waking hours and is a common non-motor symptom in Parkinson's disease, affecting up to 50% of patients. EDS has a large impact on the quality of life of Parkinson's disease patients as well as of their caregivers, in some cases even more than the motor symptoms of the disease. Drug-induced EDS is a particular problem as many dopamine agonists used for the treatment of Parkinson's disease have EDS as an adverse effect. Dopaminergic treatment may also render a subset of Parkinson's disease patients at risk for sudden-onset sleep attacks that occur without warning and can be particularly hazardous if the patient is driving. This demonstrates the need for early recognition and management not only to increase health-related quality of life but also to ensure patient safety. There are many assessment tools for EDS, including the Epworth Sleepiness Scale (ESS) and the Multiple Sleep Latency Test (MSLT), although only the Parkinson's Disease Sleep Scale (PDSS) and the SCales for Outcomes in PArkinson's Disease-Sleep (SCOPA-S) are specifically validated for Parkinson's disease. Polysomnography can be used when necessary. Management comprises non-pharmacological and pharmacological approaches. Non-pharmacological approaches can be the mainstay of treatment for mild to moderate EDS. Advice on good sleep hygiene is instrumental, as pharmacological approaches have yet to provide consistent and reliable results without significant adverse effects. The efficacy of pharmacological treatment of EDS in Parkinson's disease using wakefulness-promoting drugs such as modafinil remains controversial. Further areas of research are now also focusing on adenosine A(2A) receptor antagonists, sodium oxybate and caffeine to promote wakefulness. A definitive treatment for the highly prevalent drug-induced EDS has not yet been found.

One year open-label safety and efficacy trial with rotigotine transdermal patch in moderate to severe idiopathic restless legs syndrome

BACKGROUND

Long-term efficacy and tolerability data are not yet available for patch formulations of dopamine agonists in restless legs syndrome.

METHODS

Efficacy and safety of rotigotine (0.5-4mg/24h), formulated as a once-daily transdermal system (patch), were investigated in an open extension (SP710) of a preceding 6-week placebo-controlled trial (SP709, 341 randomized patients) in patients with idiopathic restless legs syndrome. For efficacy assessment the international RLS severity scale (IRLS), the RLS-6 scales, the clinical global impressions (CGI) and the QoL-RLS questionnaire were administered. In addition, long-term tolerability and safety were assessed.

RESULTS

Of 310 patients who finished the controlled trial, 295 (mean age 58+/-10 years, 66% females) with a mean IRLS score of 27.8+/-5.9 at baseline of SP709 were included. We report results after one year of this ongoing long-term trial. Two hundred twenty patients (retention rate=74.6%) completed the 12-month follow-up period. The mean daily dose was 2.8+/-1.2mg/24h with 4mg/24h (40.6%) being the most frequently applied dose; 14.8% were sufficiently treated with 0.5 or 1.0mg/24h. The IRLS total score improved by ?17.4+/-9.9 points between baseline and end of Year 1 (p<0.001). The other measures of severity, sleep satisfaction and quality of life supported the efficacy of rotigotine (p<0.001 for pre-post-comparisons of all efficacy variables). The tolerability was described as "good" or "very good" by 80.3% of all patients. The most common adverse events were application site reactions (40.0%), which led to withdrawal in 13.2%. Further relatively frequent adverse events were nausea (9.5%) and fatigue (6.4%). Two drug-related serious adverse events, nausea and syncope, required hospitalization. Symptoms of augmentation were not reported by the patients.

CONCLUSION

Rotigotine provided a stable, clinically relevant improvement in all efficacy measures throughout one year of maintenance therapy. The transdermal patch was safe and generally well tolerated by the majority of patients. Comparable to any transdermal therapy, application site reactions were the main treatment complication.

Intranasal dopamine application increases dopaminergic activity in the neostriatum and nucleus accumbens and enhances motor activity in the open field

Dopamine (DA) plays an important role in a number of behavioral processes and neurological disorders. The intranasal administration of DA provides improved brain penetrability in comparison to systemic administration. We investigated the effects of intranasal administration of DA on the activity of dopaminergic neurons of the mesostriatal and mesolimbic systems and on motor activity. Rats previously implanted with guide-cannulae in the neostriatum (NS) and nucleus accumbens (NAc) were submitted to microdialysis procedure under urethane anesthesia. Vehicle or DA (0.03, 0.3, or 3.0 mg/kg) was administered bilaterally into the nostrils. In a separate study, animals received an intraperitoneal (i.p.) injection of vehicle or DA (0.03, 0.3, 3.0, or 30.0 mg/kg). Samples were collected every 10 min and analyzed for the content of DA and metabolites using high-performance liquid chromatography. For the open field study, rats were given intranasal vehicle or DA (0.03, 0.3, or 3.0 mg/kg) and placed into the field for 30 min. Motor activity (locomotion and rearing) and grooming were analyzed in blocks of 10 min using Ethovision. Intranasal DA (3.0 mg/kg) significantly increased DA levels in the NS and NAc immediately after administration. A comparable effect was obtained only after i.p. administration of 30 mg/kg DA. In the open field, the 3.0 mg/kg dose significantly decreased grooming behavior in the second 10 min interval and significantly increased locomotor activity in the third 10 min interval. The data indicate that intranasal administration of DA can influence dopaminergic functions and motor activity, and has a potential application in the therapy of diseases affecting the dopaminergic system.

Rotigotine transdermal patch: a review of its use in the management of Parkinson's disease

A transdermal patch formulation of the non-ergolinic dopamine agonist rotigotine (Neupro) is indicated for use as monotherapy in the treatment of early-stage Parkinson's disease or, in the EU, as an adjunct to levodopa across all disease stages. Transdermal rotigotine is an effective and generally well tolerated addition to the armamentarium for the control of Parkinson's disease, with the once-daily transdermal patch system offering several practical advantages and the possible benefits of avoiding pulsatile dopaminergic stimulation. Transdermal rotigotine was superior to placebo in patients with early-stage and advanced Parkinson's disease, although noninferiority to the oral dopamine agonists ropinirole or pramipexole was not consistently demonstrated. Additional active comparator trials would be of interest. In the meantime, transdermal rotigotine offers a convenient new treatment option for patients with Parkinson's disease.

Molecular pathways and genetic aspects of Parkinson's disease: from bench to bedside

Idiopathic Parkinson's disease (PD) is a progressive neurodegenerative disease characterized by dopaminergic neuronal loss within the substantia nigra. The incidence and prevalence of PD is rising with an increasing aging population. PD is a slowly progressive condition and patients can develop debilitating motor and functional impairment. Current research has implicated oxidative stress, alpha-synucleinopathy and dysfunction of the ubiquitin-proteasome system in the pathogenesis of PD. A number of gene mutations have also been linked to the development of PD. The elucidation of these new molecular pathways has increased our knowledge of PD pathophysiology. This article reviews important molecular mechanisms and genetic causes implicated in the pathogenesis of PD, which has led to new areas of therapeutic drug research.

Rotigotine transdermal patch in the treatment of Parkinson’s disease and restless legs syndrome

Dopamine agonists are effective in delaying levodopa-induced dyskinesia in early Parkinson's disease (PD) and reducing motor fluctuations in advanced PD. Rotigotine, a novel dopamine receptor agonist, improves motor function in both early and advanced PD using a transdermal route of administration. A smaller, but convincing body of data, supports its ability to ameliorate the symptoms of restless legs syndrome as well. The side-effect profile mimics other dopamine agonists, with the addition of application-site reactions, most of which are mild-to-moderate. Advantages over existing dopamine agonists include once-daily administration, absence of food interactions, maintenance of stable plasma levels and utility in patients with swallowing difficulties.