Long-term safety and efficacy of rotigotine transdermal patch for moderate-to-severe idiopathic restless legs syndrome: a 5-year open-label extension study

Translation from Preclinical Research to Clinical Trials: Transdermal Drug Delivery for Neurodegenerative and Mental Disorders

Neurodegenerative diseases (NDs), particularly dementia, provide significant problems to worldwide healthcare systems. The development of therapeutic materials for various diseases has a severe challenge in the form of the blood-brain barrier (BBB). Transdermal treatment has recently garnered widespread favor as an alternative method of delivering active chemicals to the brain. This approach has several advantages, including low invasiveness, self-administration, avoidance of first-pass metabolism, preservation of steady plasma concentrations, regulated release, safety, efficacy, and better patient compliance. Topics include the transdermal method for therapeutic NDs, their classification, and the mechanisms that allow the medicine to enter the bloodstream through the skin. The paper also discusses the obstacles and potential outcomes of transdermal therapy, emphasizing the benefits and drawbacks of different approaches.

A comprehensive update on the ADMET considerations for α2δ calcium channel ligand medications for treating restless legs syndrome

INTRODUCTION

Restless legs syndrome/Willis-Ekbom disease (RLS/WED) is a sleep-related sensory-motor disorder associated with poor sleep quality and impaired daily functioning. In patients affected by chronic RLS/WED, a pharmacological therapy is recommended. International guidelines suggest to start the treatment with a α2δ calcium channel ligand in most cases, unless contraindicated.

AREAS COVERED

The present review is based on an extensive Internet and PubMed search from 1986 to 2024. Our purpose is to describe the absorption, distribution, metabolism, and toxicology (ADMET) of the α2δ ligands, with common consideration for the therapeutic class, specificities of different compounds, efficacy, and safety in relation to other treatment options.

EXPERT OPINION

α2δ ligands are quite similar in their ADMET profiles, sharing most of the pharmacokinetics and potential adverse effects. However, we highlight the linear kinetic of gabapentin enacarbil and pregabalin, differently from gabapentin. α2δ ligands are safe and effective for the treatment of RLS/WED. Additional benefits can be obtained in comorbid insomnia, chronic pain syndromes, history of impulse control disorder, and comorbid anxiety. The use of α2δ ligands is associated with poor risk of augmentation. We still need new long-term safe and effective treatments, which could be developed along with our knowledge of RLS/WED pathophysiology.

The Park Sleep subtype in Parkinson's disease: from concept to clinic

INTRODUCTION

The heterogeneity of Parkinson's disease (PD) is evident from descriptions of non-motor (NMS) subtypes and Park Sleep, originally identified by Sauerbier et al. 2016, is one such clinical subtype associated with the predominant clinical presentation of sleep dysfunctions including excessive daytime sleepiness (EDS), along with insomnia.

AREAS COVERED

A literature search was conducted using the PubMed, Medline, Embase, and Web of Science databases, accessed between 1 February 2023 and 28 March 2023. In this review, we describe the clinical subtype of Park Sleep and related 'tests' ranging from polysomnography to investigational neuromelanin MRI brain scans and some tissue-based biological markers.

EXPERT OPINION

Cholinergic, noradrenergic, and serotonergic systems are dominantly affected in PD. Park Sleep subtype is hypothesized to be associated primarily with serotonergic deficit, clinically manifesting as somnolence and narcoleptic events (sleep attacks), with or without rapid eye movement behavior disorder (RBD). In clinic, Park Sleep recognition may drive lifestyle changes (e.g. driving) along with therapy adjustments as Park Sleep patients may be sensitive to dopamine D3 active agonists, such as ropinirole and pramipexole. Specific dashboard scores based personalized management options need to be implemented and include pharmacological, non-pharmacological, and lifestyle linked advice.

Pharmacologic and Nonpharmacologic Treatment of Restless Legs Syndrome

Restless legs syndrome (RLS) is a sleep-related disorder defined by an urgency to move the legs, usually combined with uncomfortable or unpleasant sensations, which occurs or worsens during rest, usually in the evening or at night, and disappears with the movement of the legs. RLS can be classified as idiopathic or primary, and secondary to comorbid conditions (eg, renal disease, polyneuropathy). The pathophysiology of RLS is still unclear. This article provides an updated practical guide for the treatment of primary RLS in adults.

How effective are treatment guidelines for augmented RLS?

Study Objectives

The objective of this study was to assess the effectiveness of current treatment guidelines for restless legs syndrome (RLS) augmentation in patients on dopamine agonists (DAs) which recommend a cross-titration strategy to an alpha-2-delta ligand (A2D) and/or opioid.

Methods

Consecutive new consultations for RLS with both augmentation and active treatment with DAs at the time of initial assessment were included if followed >5 months. Clinical information from the semi-structured initial consultation, and subsequent visits until their most recent/final visit was extracted. Clinical Global Impression-Severity (CGI-S) and Clinical Global Impression-Improvement (CGI-I) scores were retrospectively determined by two independent evaluators.

Results

In the 63 patients with augmented RLS on DAs, followed for 5–59 months (mean = 28, SD = 14), the average age was 67.6 (SD = 9.8) and 63% were female. Mean duration of prior dopaminergic therapy was 11.6 years (SD = 6.7) and average pramipexole equivalent dose was 1.23 mg (SD = 1.22 mg). At baseline, RLS was “moderate-markedly” severe (CGI-S = 4.9). At the final/most recent visit, 78% (49/63) were classified as Responders (CGI-I ≤ 2, “Much” or “Very Much Improved”) with an average CGI-S of 2.4 (“borderline-mildly ill”). Responders (59%) were more likely to have discontinued DAs than Non-Responders (40%), and mean opioid doses were higher in Responders (39 vs 20 MME). No differences in baseline DA dose, final A2D dose, or iron therapy were observed between groups. Responders did have significantly more severe RLS, more sleep maintenance insomnia, and greater subjective daytime sleepiness at baseline (p < 0.05).

Conclusions

Guideline-based management is effective in most patients with augmented RLS on DAs.

The prevalence and potential aetiological factors associated with restless legs syndrome in patients with chronic kidney disease: a cross-sectional study

BACKGROUND

There is limited understanding of aetiological factors of and treatment options for restless leg syndrome (RLS) in patients with chronic kidney disease (CKD). This study aimed to estimate the prevalence of RLS in CKD patients and identify factors that may contribute to RLS.

METHODS

A questionnaire-based cross-sectional study of patients with CKD stage 4 (CKD 4), pre-dialysis stage 5 (CKD-5ND) and haemodialysis-dependent stage 5 (CKD-5D) was conducted. Eligible patients were enrolled from the local dialysis units and renal clinics. The International RLS Study Group rating scale was used to establish the diagnosis of RLS and quantify its severity.

RESULTS

212 patients with CKD 4 (n = 92), CKD-5ND (n = 14) and CKD-5D (n = 106) were included. The overall prevalence of RLS was 32.1%. Women had a significantly higher odds of having RLS despite adjustment for age, diabetes, cardiovascular disease and whether patients were on dialysis (odds ratio 2.8 [95% confidence intervals 1.5-5.2]). In pre-dialysis groups, patients with RLS had significantly higher serum ferritin (323.9 [SD 338.1] vs 177.5 [SD 178.5] µg/L, p = 0.020) compared to non-RLS patients. In dialysis patients (CKD-5D), those with RLS had significantly higher total white cell (8.0 [SD 3.5] vs 6.8 [SD 1.9] × 10⁹/L, p = 0.026) and neutrophil (6.4 [SD 3.9] vs 4.6 [SD1.7] × 10⁹/L, p = 0.002) counts compared to patients without RLS.

CONCLUSION

RLS remains a significant problem in patients with CKD and may be related to underlying inflammation. Targeting this pathway may be useful. Prevalence of RLS, diagnosed using validated measures, is higher than previous reports.

TRIAL REGISTRATION

N/A (the current study is not a trial).

D3 Receptors and Restless Legs Syndrome

Restless Legs Syndrome (RLS) is a sensorimotor disorder that severely affects sleep. It is characterized by an urge to move the legs that is often accompanied by periodic limb movements during sleep (PLMS). RLS has a high prevalence in the population and is usually a life-long condition. While its origins remain unclear, RLS is initially highly responsive to treatment with dopaminergics that target the D3 receptor. However, over time patients often develop a gradual tolerance that can lead to the emergence of adverse effects and the augmentation of the symptoms. While the basal ganglia and the striatum control leg movements, the lumbar spinal cord is the gateway for the sensory processing of the symptoms and critical for the associated leg movements. D3 receptors are highly expressed in nucleus accumbens (NAc) of the striatum and the sensory-processing areas of the spinal dorsal horn. In contrast, D1 receptors are strongly expressed throughout the entire striatum and in the ventral horn of the spinal cord. Long-term treatment with D3 receptor full agonists is associated with an upregulation of the D1 receptor subtype, and D3 and D1 receptors can form functional heteromers, in which the D3R controls the D1R function. It is conceivable that the switch from beneficial treatment to augmentation observed in RLS patients after prolonged D3R agonist exposure may be the result of unmasked D1-like receptor actions.

The Efficacy and Safety of Pharmacological Treatments for Restless Legs Syndrome: Systemic Review and Network Meta-Analysis

Although various drugs are currently used for restless legs syndrome (RLS) in clinic, selecting appropriate drugs for patients is difficult. This network meta-analysis (NMA) aimed to compare the efficacy and safety of different drugs. After literature searching and screening, 46 trials, including 10,674 participants are included in this NMA. The pooled results showed that, compared with placebo, only levodopa is inefficient to relieve symptoms of RLS. Cabergoline decreases IRLS scores to the greatest extent among all drugs (MD −11.98, 95% CI −16.19 to −7.78). Additionally, pramipexole is superior to ropinirole in alleviating symptoms of RLS (MD −2.52, 95% CI −4.69 to −0.35). Moreover, iron supplement alleviates RLS symptoms significantly compared with placebo in patient with iron deficiency (MD −5.15, 95% CI −8.99 to −1.31), but not for RLS patients with normal serum ferritin level (MD −2.22, 95% CI −6.99 to 2.56). For primary RLS, these drugs are also effective, while there is insufficient data to analyze drug efficacy in secondary RLS. We analyzed risk of common adverse effects of drugs including nausea, somnolence, fatigue, headache and nasopharyngitis. Alpha-2-delta ligands and DAs are favorable choices for both primary and secondary RLS because of their significant efficacy and good tolerability. Iron supplement can significantly alleviate symptoms of RLS patients with iron deficiency than placebo. We recommend gabapentin, gabapentin enacarbil, and pregabalin for clinicians for first consideration mainly because that they rarely cause augmentation. Oxycodone-naloxone could be considered in patients with severe or very severe RLS who failed in treatment with above drugs.

Association of Decreased Serum BDNF With Restless Legs Syndrome in Parkinson's Disease Patients

Objective: To objective of the study was to investigate whether serum brain-derived neurotrophic factor (BDNF) levels are associated with the severity of restless legs syndrome (RLS) in Parkinson's disease (PD). Methods: A total of 249 PD patients with (n = 53) and without RLS (n = 196) and 326 age-matched controls were included in this study. All the serum BDNF levels of the participants were measured. The International Restless Legs Syndrome Study Group Rating Scale (IRLSSG-RS) was administered for the severity of RLS. The severity of PD patients were assessed by the Unified PD Rating Scale (UPDRS) and the Hoehn and Yahr (H-Y) stage. Results: The prevalence of RLS was significantly higher in PD patients (21.3%) than in the controls group (7.4%) (p < 0.05). The IRLSSG-RS score in PD patients with RLS (16.25 ± 5.24) was significantly increased than in controls with RLS (12.08 ± 3.99) (p < 0.01). The serum BDNF levels were significantly decreased in PD patients with RLS than in PD patients without RLS, controls without RLS, and controls with RLS (p < 0.001). BDNF levels were negatively associated with IRLSSG-RS in both PD patients with RLS and controls with RLS group (both p < 0.01). Multiple regression analysis confirmed that in either PD with RLS or controls with RLS group, BDNF was an independent contributor to IRLSSG-RS (both p < 0.01). Conclusions: Decreased serum BDNF levels may be involved in the pathophysiology of RLS in PD, suggesting that it may serve as a potential blood biomarker of diagnostic value for RLS in PD.

Restless legs syndrome

Restless legs syndrome (RLS) is a common sensorimotor disorder characterized by an urge to move that appears during rest or is exacerbated by rest, that occurs in the evening or night and that disappears during movement or is improved by movement. Symptoms vary considerably in age at onset, frequency and severity, with severe forms affecting sleep, quality of life and mood. Patients with RLS often display periodic leg movements during sleep or resting wakefulness. RLS is considered to be a complex condition in which predisposing genetic factors, environmental factors and comorbidities contribute to the expression of the disorder. RLS occurs alone or with comorbidities, for example, iron deficiency and kidney disease, but also with cardiovascular diseases, diabetes mellitus and neurological, rheumatological and respiratory disorders. The pathophysiology is still unclear, with the involvement of brain iron deficiency, dysfunction in the dopaminergic and nociceptive systems and altered adenosine and glutamatergic pathways as hypotheses being investigated. RLS is poorly recognized by physicians and it is accordingly often incorrectly diagnosed and managed. Treatment guidelines recommend initiation of therapy with low doses of dopamine agonists or α₂δ ligands in severe forms. Although dopaminergic treatment is initially highly effective, its long-term use can result in a serious worsening of symptoms known as augmentation. Other treatments include opioids and iron preparations.

High National Rates of High-Dose Dopamine Agonist Prescribing for RLS

Study Objectives

Long-term dopamine agonist (DA) use in restless legs syndrome (RLS) is associated with augmentation, a dose-related symptom worsening leading to further dose escalation to manage RLS. This study investigated rates and factors of high-dose DA prescribing in US RLS patients.

Methods

This retrospective analysis examined data from a US longitudinal prescriptions database (October 2017–September 2018). Patients diagnosed with RLS (ICD-10 G255.81) without Parkinson’s disease who were prescribed ropinirole, pramipexole, and/or rotigotine were included. Daily DA dosage was categorized: LOW/MID (US Food and Drug Administration [FDA]-approved/guideline or slightly above FDA-approved [pramipexole]); HIGH (101%–149%); VERY HIGH (>150%). Patient counts were converted to US national estimates. Logistic regression of patient counts evaluated factors associated with HIGH/VERY HIGH DA dosing.

Results

Of 670,404 RLS patients (131,289,331 therapy days), 58.8% were prescribed DA therapy. Overall, 19.1% of RLS patients were prescribed DAs above maximum FDA-approved/guideline daily doses—over half of these were >150% maximum recommended doses; 67.6% of HIGH/VERY HIGH-dose prescriptions were pramipexole (OR [95% CI] pramipexole vs ropinirole, 5.8 [5.7 to 6.0]). The highest 1% of DA prescriptions were ≥10× the FDA-recommended maximum daily dose. Rates of HIGH/VERY HIGH DA dosing increased with patient age. Twice as many neurologists (31.1%) prescribed HIGH/VERY HIGH doses vs other specialties (OR [95% CI], 2.1 [1.2 to 2.0]).

Conclusions

Approximately 20% of DA-treated RLS patients were prescribed doses above the approved and guideline daily maximum. Pramipexole, Neurology as specialty, and patient age were independently associated with HIGH/VERY HIGH DA dosing. Increased education is warranted regarding risks of high-dose DA exposure in RLS.

The Management of Restless Legs Syndrome: An Updated Algorithm

Restless legs syndrome (RLS) is a common disorder. The population prevalence is 1.5% to 2.7% in a subgroup of patients having more severe RLS with symptoms occurring 2 or more times a week and causing at least moderate distress. It is important for primary care physicians to be familiar with the disorder and its management. Much has changed in the management of RLS since our previous revised algorithm was published in 2013. This updated algorithm was written by members of the Scientific and Medical Advisory Board of the RLS Foundation based on scientific evidence and expert opinion. A literature search was performed using PubMed identifying all articles on RLS from 2012 to 2020. The management of RLS is considered under the following headings: General Considerations; Intermittent RLS; Chronic Persistent RLS; Refractory RLS; Special Circumstances; and Alternative, Investigative, and Potential Future Therapies. Nonpharmacologic approaches, including mental alerting activities, avoidance of substances or medications that may exacerbate RLS, and oral and intravenous iron supplementation, are outlined. The choice of an alpha₂-delta ligand as first-line therapy for chronic persistent RLS with dopamine agonists as a second-line option is explained. We discuss the available drugs, the factors determining which to use, and their adverse effects. We define refractory RLS and describe management approaches, including combination therapy and the use of high-potency opioids. Treatment of RLS in pregnancy and childhood is discussed.

Neuronal Dopamine D3 Receptors: Translational Implications for Preclinical Research and CNS Disorders

Dopamine (DA), as one of the major neurotransmitters in the central nervous system (CNS) and periphery, exerts its actions through five types of receptors which belong to two major subfamilies such as D1-like (i.e., D1 and D5 receptors) and D2-like (i.e., D2, D3 and D4) receptors. Dopamine D3 receptor (D3R) was cloned 30 years ago, and its distribution in the CNS and in the periphery, molecular structure, cellular signaling mechanisms have been largely explored. Involvement of D3Rs has been recognized in several CNS functions such as movement control, cognition, learning, reward, emotional regulation and social behavior. D3Rs have become a promising target of drug research and great efforts have been made to obtain high affinity ligands (selective agonists, partial agonists and antagonists) in order to elucidate D3R functions. There has been a strong drive behind the efforts to find drug-like compounds with high affinity and selectivity and various functionality for D3Rs in the hope that they would have potential treatment options in CNS diseases such as schizophrenia, drug abuse, Parkinson’s disease, depression, and restless leg syndrome. In this review, we provide an overview and update of the major aspects of research related to D3Rs: distribution in the CNS and periphery, signaling and molecular properties, the status of ligands available for D3R research (agonists, antagonists and partial agonists), behavioral functions of D3Rs, the role in neural networks, and we provide a summary on how the D3R-related drug research has been translated to human therapy.

Restless Legs Syndrome: Contemporary Diagnosis and Treatment

Restless legs syndrome (RLS) is characterized by an uncomfortable urge to move the legs while at rest, relief upon movement or getting up to walk, and worsened symptom severity at night. RLS may be primary (idiopathic) or secondary to pregnancy or a variety of systemic disorders, especially iron deficiency, and chronic renal insufficiency. Genetic predisposition with a family history is common. The pathogenesis of RLS remains unclear but is likely to involve central nervous system dopaminergic dysfunction, as well as other, undefined contributing mechanisms. Evaluation begins with a thorough history and examination, and iron measures, including ferritin and transferrin saturation, should be checked at presentation and with worsened symptoms, especially when augmentation develops. Augmentation is characterized by more intense symptom severity, earlier symptom occurrence, and often, symptom spread from the legs to the arms or other body regions. Some people with RLS have adequate symptom control with non-pharmacological measures such as massage or temperate baths. First-line management options include iron-replacement therapy in those with evidence for reduced body-iron stores or, alternatively, with prescribed gabapentin or pregabalin, and dopamine agonists such as pramipexole, ropinirole, and rotigotine. Second-line therapies include intravenous iron infusion in those who are intolerant of oral iron and/or those having augmentation with intense, severe RLS symptoms, and opioids including tramadol, oxycodone, and methadone. RLS significantly impacts patients' quality of life and remains a therapeutic area sorely in need of innovation and a further pipeline of new, biologically informed therapies.

[Restless legs syndrome in Parkinson's disease]

Disturbances in sleep and wakefulness are important symptoms of Parkinson's disease (PD) and are associated with negative effects on patients' quality of life. The analysis of literature on the relationship between RLS and PD revealed three main hypotheses explaining the relatively high incidence of RLS in PD: (1) RLS can be considered as an early (prodromal) manifestation or a predictor of PD that can outpace its main symptoms by several years (by analogy with conduct disorder during sleep with REM); (2) the high incidence of RLS in the advanced stage of PD may be associated with augmentation of previously latent RLS symptoms during prolonged dopaminergic therapy of PD; (3) a significant proportion of RLS cases in PD patients are not «classical» RLS, but represent, for example, manifestations of motor or non-motor fluctuations or a special form of stereotypy in the legs. Further research is needed to determine if any of these statements are true.

Pharmacologic and Nonpharmacologic Treatment of Restless Legs Syndrome

This article provides an updated practical guide for the treatment of primary restless legs syndrome (RLS). Articles that appeared after the American Academy of Neurology guideline search were reviewed according to the same evidence rating schedule. We found limited evidence for nonpharmacologic treatment options. In moderate to severe primary RLS, pharmacologic options may be considered, including iron suppletion, an α2δ ligand, a dopamine agonist, a combination of an α2δ ligand and a dopamine agonist, or oxycodone/naloxone. This article includes treatment options in case of augmentation.

Pharmacological treatments of augmentation in restless legs syndrome patients

Augmentation, a treatment-induced paradoxical worsening of the symptoms of restless legs syndrome (RLS) that is caused by long-term dopaminergic therapy, in particular with higher doses, remains the major challenge of RLS treatment. The mainstay of treatment continues to be preventing augmentation, either by starting RLS therapy with alternative drugs or by sensitizing physicians about the absolute necessity of respecting approved dosages of dopaminergic drugs when treating RLS and never exceeding the maximum recommended dosages. In the case of a positive diagnosis of augmentation, treatment consists of reducing or eliminating dopaminergic therapy, ensuring that serum ferritin is clearly higher than the level assumed to be necessary from a hematological point of view and/or switching treatment to alternative drugs such as α2δ ligands, opiates, or to combination therapy.

Switching from an oral dopamine receptor agonist to rotigotine transdermal patch: a review of clinical data with a focus on patient perspective

INTRODUCTION

Dopamine receptor agonists (DAs) are commonly used to treat Parkinson's disease (PD) and restless legs syndrome (RLS). In certain situations, switching from oral DAs to rotigotine transdermal patch may be beneficial for the patient (e.g., optimal symptom control/side effects/perioperative management, preference for once-daily/non-oral administration, RLS augmentation treatment). Areas covered: This narrative review summarizes available data on DA dose equivalency, dose conversions, switching schedules, safety, tolerability, efficacy and patient treatment preferences of switching from oral DAs to rotigotine (and vice versa) in patients with PD/RLS. The studies were identified in a PubMed search (up to 8 November 2016) using terms ('dopamine receptor agonist' OR 'rotigotine') AND 'switch'. Expert commentary: Randomized controlled studies often do not address the challenges clinicians face in practice, e.g., switching medications within the same class when dosing is not a one-to-one ratio. The authors describe three open-label studies in PD where oral DAs were successfully switched to rotigotine, and review three studies in RLS where oral DAs/levodopa were switched to rotigotine. Finally, the authors provide a suggested tool for switching from oral DAs to rotigotine, which includes dose conversion factors and switching schedules. The authors' view is that low-dose oral DAs (equivalent to ≤8 mg/24 h rotigotine) may be switched overnight.

Restless Legs Syndrome and Other Movement Disorders of Sleep-Treatment Update

PURPOSE OF REVIEW

The purpose of this review article is to summarize and discuss the recent advances in the treatment of restless legs syndrome (RLS), as well as REM sleep behavior disorder (RBD), and periodic leg movement disorder (PLMD).

RECENT FINDINGS

Traditionally, dopaminergic therapy has been considered the sole option for first-line treatment of RLS due to their impressive acute efficacy. Dopamine agonists such as oral pramipexole and ropinirole, as well as transdermal rotigotine are all effective treatment options. However, augmentation of the RLS symptoms is a major limitation of oral dopaminergic therapy. Recently, gabapentinoid agents such as gabapentin enacarbil and pregabalin have shown comparable short-term efficacy to dopaminergics with lower risk of augmentation of the RLS symptoms. Recent evidence on the efficacy of oxycodone-naloxone in treatment-resistant RLS provides an additional therapeutic avenue. The increasing understanding of the role of iron in RLS pathophysiology has led to new options in iron supplementation therapy in RLS, including treatment with ferric carboxymaltose. With emerging evidence of augmentation being a side effect specific to dopaminergic treatment, gabapentinoids are considered a safer option as initial treatment. In severe refractory RLS, oxycodone-naloxone can be used. If iron stores are low, IV iron formulations should be the initial treatment choice. New treatment options are needed to address issues with current therapies.

Comorbidities, treatment, and pathophysiology in restless legs syndrome

Restless legs syndrome, also known as Willis-Ekbom disease, is a common neurological condition whose manifestation is affected by complex environmental and genetic interactions. Restless legs syndrome can occur on its own, mostly at a young age, or with comorbidities such as cardiovascular disease, diabetes, and arterial hypertension, making it a difficult condition to properly diagnose. However, the concept of restless legs syndrome as being two entities, primary or secondary to another condition, has been challenged with genetic data providing further insight into the pathophysiology of the condition. Although dopaminergic treatment was formerly the first-line therapy, prolonged use can result in a serious worsening of symptoms known as augmentation. Clinical studies on pregabalin, gabapentin enacarbil, oxycodone-naloxone, and iron preparations have provided new treatment options, but most patients still report inadequate long-term management of symptoms. Studies of the hypoxic pathway activation and iron deficiency have provided valuable information about the pathophysiology of restless legs syndrome that should now be translated into new, more effective treatments for restless legs syndrome.

Pharmacologic and Nonpharmacologic Treatment of Restless Legs Syndrome

This article provides an updated practical guide for the treatment of primary restless legs syndrome (RLS). Articles that appeared after the American Academy of Neurology guideline search were reviewed according to the same evidence rating schedule. We found limited evidence for nonpharmacologic treatment options. In moderate to severe primary RLS, pharmacologic options may be considered, including iron suppletion, an α2δ ligand, a dopamine agonist, a combination of an α2δ ligand and a dopamine agonist, or oxycodone/naloxone. This article includes treatment options in case of augmentation.

French consensus: Treatment of newly diagnosed restless legs syndrome

Treatment of restless legs syndrome (RLS) must only be considered after a definite positive diagnosis. The RLS phenotype must be characterised precisely, iron deficiency always tested for, and aggravating factors eliminated when possible. Medical treatment is considered for severe or very severe forms and based on dopaminergic agonists, α2δ-1 ligands and/or opioids. First line treatment will be a low-dose monotherapy and the choice of treatment depends on the results of the clinical examination and investigations.

Rate of augmentation and risk factors with long-term follow-up in Japanese patients with restless legs syndrome

OBJECTIVES

Preventing augmentation is the critical clinical issue for RLS treatment. As for augmentation in Asian RLS patients, there have been only four studies and the follow-up durations of these studies were not long. We investigated Japanese RLS patients with longer duration of treatment in a clinical setting.

METHODS

This study is a retrospective assessment of 42 RLS patients with follow-up durations of longer than 18 months (78.4 ± 29.2, range 19-139) at two urban sleep centers in Osaka, Japan from May 2004 to April 2014.

RESULTS

The mean age of first visit was 63.5 ± 14.1 years old and the estimated age of RLS onset was 47.9 ± 16.5 years old. Twenty-eight out of 42 patients were female. At initial evaluation, the mean International Restless Legs Scale score (IRLS score) was 22.0 ± 5.9. Thirty-one of 42 had already visited other clinics before coming to our sleep centers, and the number of clinics visited was 1.3 ± 0.6. Augmentation developed in two patients (4.8%), and the dosage of dopamine equivalent in patients with and without augmentation was 12.5 and 18.8 mg vs. 15.8 ± 17.7 mg. In the two RLS patients with augmentation, ferritin was 113.1 and 114.1 ng/mL, respectively, and the number of clinics before coming to our sleep centers was both three.

CONCLUSIONS

The augmentation rate of Japanese RLS patients from our study is low compared with previous Western and Asian studies. It might be attributable to racial difference, lower dosage of dopaminergic treatment, and the level of ferritin.

The efficacy and tolerability of rotigotine on patients with periodic limb movement in sleep: A systematic review and meta-analysis

OBJECTIVE

There is still no consensus on the treatment for periodic limb movement in sleep (PLMS). This study aimed to determine the efficacy and tolerability of rotigotine in patients suffering from PLMS.

METHODS

Publications listed in PubMed, ScienceDirect, The Cochrane Library, and ClinicalTrials.gov were reviewed to assess the efficacy of rotigotine on PLMS. Analyses of PLMS frequency before and after rotigotine treatments (pre- and post-intervention studies) and PLMS frequency between placebo and rotigotine treatments (placebo-controlled trial studies) were included in our study. A systematic review and meta-analysis was conducted.

RESULTS

Five publications involving 197 participants were included in this study. Among these articles, pre- and post-intervention data involving 55 participants were available from three articles, while placebo-controlled trial data from 107 participants receiving rotigotine and 70 participants receiving a placebo were available from an additional three articles. In the pre- and post-intervention studies, the periodic limb movement index was significantly decreased after therapy with rotigotine with a difference in means of -5.866/h (95% CI, -10.570 to -1.162, p = 0.015). In comparison with the placebo, the use of rotigotine significantly lowered the periodic limb movement index, with a difference in means of -32.105/h (95% CI, -42.539 to -21.671, p < 0.001), reduced the PLMS with arousal index, with a difference in means of -7.160/h (95% CI, -9.310 to -5.010, p < 0.001), and increased the withdrawal rate, with an odds ratio of 3.421 (95% CI, 1.230 to 9.512, p = 0.018).

CONCLUSIONS

This meta-analysis revealed the considerable efficacy of rotigotine in alleviating the frequency of PLMS. However, the high withdrawal rate should be taken into account.

Restless Legs Syndrome: clinical features, diagnosis and a practical approach to management

Restless legs syndrome (RLS) is a chronic neurological disorder that interferes with rest and sleep. It has a wide spectrum of symptom severity, and treatment is started when symptoms become bothersome. Dopamine agonists and calcium channel apha-2-delta antagonists (gabapentin, gabapentin enacarbil and pregabalin) are first-line treatments; calcium channel alpha-2-deltas are preferred over dopamine agonists because they give less augmentation, a condition with symptom onset earlier in the day and intensification of RLS symptoms. Dopamine agonists can still be used as first-line therapy, but the dose should be kept as low as possible. Iron supplements are started when the serum ferritin concentration is ≤75 µg/L, or if the transferrin saturation is less than 20%. For severe or resistant RLS, a combined treatment approach can be effective. Augmentation can be very challenging to treat and lacks evidenced-based guidelines.

Rotigotine, a dopamine receptor agonist, increased BDNF protein levels in the rat cortex and hippocampus

Brain-derived neurotrophic factor (BDNF) critically controls the fate and function of the neuronal network and has received much attention as a target of many brain diseases. Dopaminergic system dysfunction has also been implicated in a variety of neuropsychiatric diseases. Rotigotine, a non-ergot dopamine receptor agonist, is used in the treatment of Parkinson's disease and restless legs syndrome. To investigate the effects of rotigotine on neuronal functions both in vivo and in vitro, rats and primary cortical neurons were administered rotigotine, and the mRNA and protein expression levels of BDNF, its receptor TrkB and downstream signaling molecules, and synaptic proteins were determined. We found that BDNF protein was increased in the cortex and hippocampus of rats after 7days of rotigotine treatment. In contrast, BDNF mRNAs were reduced 6h after rotigotine treatment in cultured neurons presumably through the transient suppression of neuronal activity. We identified differential expression of D1, D2, and D3 receptors in the rat brain and cultured neurons. The observed increase in the expression of BDNF protein in the cortex and hippocampus after subchronic administration of rotigotine suggests that it may exert its medical effect in part through improving BDNF function in the brain. In addition, our results highlight the complex relationships between rotigotine and BDNF expression, which depend on the brain region, time course, and dose of the drug.

Restless Legs Syndrome: From Pathophysiology to Clinical Diagnosis and Management

Restless legs syndrome (RLS), a common neurological sensorimotor disorder in western countries, has gained more and more attention in Asian countries. The prevalence of RLS is higher in older people and females. RLS is most commonly related to iron deficiency, pregnancy and uremia. The RLS symptoms show a significant circadian rhythm and a close relationship to periodic limb movements (PLMs) in clinical observations, while the pathophysiological pathways are still unknown. The diagnostic criteria have been revised in 2012 to improve the validity of RLS diagnosis. Recent studies have suggested an important role of iron decrease of brain in RLS pathophysiology. Dopaminergic (DA) system dysfunction in A11 cell groups has been recognized long ago from clinical treatment and autopsy. Nowadays, it is believed that iron dysfunction can affect DA system from different pathways and opioids have a protective effect on DA system. Several susceptible single nucleotide polymorphisms such as BTBD9 and MEIS1, which are thought to be involved in embryonic neuronal development, have been reported to be associated with RLS. Several pharmacological and non-pharmacological treatment are discussed in this review. First-line treatments of RLS include DA agents and α2δ agonists. Augmentation is very common in long-term treatment of RLS which makes prevention and management of augmentation very important for RLS patients. A combination of different types of medication is effective in preventing and treating augmentation. The knowledge on RLS is still limited, the pathophysiology and better management of RLS remain to be discovered.

A method to switch from oral dopamine agonists to rotigotine in patients with restless legs syndrome and mild augmentation

BACKGROUND

We examined the short- and long-term efficacy and tolerability of a cross-titration algorithm from oral dopamine agonists to the rotigotine transdermal patch in patients dissatisfied with their restless legs syndrome (RLS) treatment, predominantly with mild augmentation.

METHODS

Patients with RLS (n = 20) were recruited at a single site. The cross-titration consisted of decreasing oral dopaminergic agents (ropinirole by 1 mg or pramipexole by 0.25 mg) and increasing rotigotine by 1 mg every two days. Efficacy and adverse events (AEs) were assessed at one, three, six and 12 months after the switch.

RESULTS

Patients had moderate-severe RLS symptoms at the baseline (mean international restless legs syndrome (IRLS) score 19.4 ± 5.5); 85% had augmentation and 45% reported afternoon RLS symptoms. The baseline mean pramipexole equivalent dose was 0.6 ± 0.3 mg. At Week 5, 85% (17/20) had successfully switched from their oral dopamine agonist to rotigotine (mean dose 2.5 ± 0.6 mg; change in IRLS score: -6.7 ± 8.4, p = 0.002); 14 patients were CGI-I responders (much or very much improved). Three patients withdrew due to lack of efficacy. Twelve months after cross-titration, 10 patients continued on rotigotine, of whom four required either higher doses of rotigotine or supplemental RLS medication compared with their optimal Week 5 dose; five patients withdrew due to AEs and two due to lack of efficacy.

CONCLUSION

A cross-titration to rotigotine was efficacious after five weeks in 70% of patients dissatisfied with RLS treatment, most of whom had mild augmentation. At one year following the medication switch, 50% had discontinued rotigotine due to lack of continued efficacy or side effects.

Guidelines for the first-line treatment of restless legs syndrome/Willis-Ekbom disease, prevention and treatment of dopaminergic augmentation: a combined task force of the IRLSSG, EURLSSG, and the RLS-foundation

A Task Force was established by the International Restless Legs Syndrome Study Group (IRLSSG) in conjunction with the European Restless Legs Syndrome Study Group (EURLSSG) and the RLS Foundation (RLS-F) to develop evidence-based and consensus-based recommendations for the prevention and treatment of long-term pharmacologic treatment of dopaminergic-induced augmentation in restless legs syndrome/Willis-Ekbom disease (RLS/WED). The Task Force made the following prevention and treatment recommendations: As a means to prevent augmentation, medications such as α2δ ligands may be considered for initial RLS/WED treatment; these drugs are effective and have little risk of augmentation. Alternatively, if dopaminergic drugs are elected as initial treatment, then the daily dose should be as low as possible and not exceed that recommended for RLS/WED treatment. However, the physician should be aware that even low dose dopaminergics can cause augmentation. Patients with low iron stores should be given appropriate iron supplementation. Daily treatment by either medication should start only when symptoms have a significant impact on quality of life in terms of frequency and severity; intermittent treatment might be considered in intermediate cases. Treatment of existing augmentation should be initiated, where possible, with the elimination/correction of extrinsic exacerbating factors (iron levels, antidepressants, antihistamines, etc.). In cases of mild augmentation, dopamine agonist therapy can be continued by dividing or advancing the dose, or increasing the dose if there are breakthrough night-time symptoms. Alternatively, the patient can be switched to an α2δ ligand or rotigotine. For severe augmentation the patient can be switched either to an α2δ ligand or rotigotine, noting that rotigotine may also produce augmentation at higher doses with long-term use. In more severe cases of augmentation an opioid may be considered, bypassing α2δ ligands and rotigotine.

Incidence of Augmentation in Primary Restless Legs Syndrome Patients May Not Be That High: Evidence From A Systematic Review and Meta-Analysis

Augmentation is a common complication of primary restless legs syndrome (RLS) during treatment; however, its incidence rate remains unclear.The aim of this study is investigate the rate of augmentation during RLS treatment.We searched 6 databases, including PubMed, OVID, Embase, Wiley citations, Web of Science research platform (including SciELO Citation Index, Medline, KCI Korean Journal Database, the Web of Science™ Core Collection), and the Cochrane library, and screened the reference lists of the included trials and recently published reviews.Randomized controlled trials and observational studies that reported augmentation events during RLS treatment.Primary RLS patients older than 18 years.No restrictions regarding intervention types were applied.Three investigators independently extracted and pooled the data to analyze the augmentation rate of the total sample and of patient subgroups with different interventions, treatment durations and drug regimens and different geographic origins. Fixed-effects or random-effects model was used for pooled analysis.A total of 60 studies involving 11,543 participants suggested an overall augmentation rate of 5.6% (95% confidence intervals (CI), 4.0-7.7). The augmentation incidence was 6.1% (95% CI, 4.1-9.1) for long-term treatment and 3.3% (95% CI, 1.4-7.3) for short-term treatment. In addition, 27.1% (95% CI, 12.3-49.5) of the levodopa-treated patients, 6.0% (95% CI, 4.1-8.8) of the patients treated with dopamine agonists, and 0.9% (95% CI, 0.2-3.3) of the patients taking pregabalin or gabapentin developed augmentation. Augmentation occurred in 7.2% (95% CI, 5.0-10.3) of the patients taking immediate-release drugs and in 1.7% (95% CI, 0.6-5.0) of the patients taking transdermal application.The main limitations are that the augmentation rates were not evaluated according to drug dosage, gender, and age and symptom severity.Approximately 5 to 6 in 100 RLS patients developed augmentation during treatment.

Effects of rotigotine on daytime symptoms in patients with primary restless legs syndrome: a randomized, placebo-controlled study

OBJECTIVE

This 12 week double-blind, placebo-controlled study (ClinicalTrials.gov: NCT01569464) was conducted to evaluate the effects of rotigotine transdermal patch on daytime symptoms in patients with idiopathic restless legs syndrome (RLS).

METHODS

Adult patients with moderate-to-severe RLS were randomized to rotigotine (optimal dose: 1-3 mg/24 h) or placebo. A modified four-assessment version (4:00 pm, 6:00 pm, 8:00 pm, and 10:00 pm) of the Multiple Suggested Immobilization Test (m-SIT) was performed at baseline and end of 4 week maintenance (EoM). Primary study outcomes were change from baseline to EoM in International Restless Legs Syndrome Rating Scale (IRLS) and in average of means for the m-SIT Discomfort Scale (m-SIT-DS) (combined average of mean values from each of the individual assessments). Secondary outcomes included average of means of Periodic Limb Movement during Wakefulness Index (PLMWI; PLM/hour) for the combination of m-SIT.

RESULTS

A total of 150 patients were randomized and 137 (rotigotine: 92/101 [91.1%]; placebo: 45/49 [91.8%]) completed maintenance. All 150 randomized patients were assessed for efficacy. At EoM, mean change in IRLS was -14.9 ± 9.3 with rotigotine vs. -12.7 ± 7.6 with placebo (ANCOVA, LS mean treatment difference [95% CI]: -0.27 [-2.96, 2.42]; p = 0.8451). Changes in average of means of m-SIT-DS values of each individual SIT were comparable with rotigotine (-2.68 ± 2.31) vs. placebo (-2.62 ± 2.61) (ANCOVA, LS mean treatment difference [95% CI]: 0.07 [-0.61, 0.75]; p = 0.8336) and comparable reductions in PLMWI were observed in both treatment groups (8.34 [-8.50, 25.17]; p = 0.3290). Rotigotine was generally well tolerated. Application site reactions (rotigotine: 20 patients [19.8%]; placebo: 4 [8.2%]) and nausea (16 [15.8%]; 3 [6.1%]) were the most common AEs.

CONCLUSIONS

Rotigotine was beneficial in improving overall RLS symptom severity (assessed by IRLS) and RLS symptom severity at various times of the day (m-SIT-DS); however, superiority to placebo was not established.

In the Clinic. Restless Legs Syndrome

This issue provides a clinical overview of restless legs syndrome, focusing on diagnosis, treatment, and practice improvement. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of additional science writers and physician writers.

Restless legs syndrome-current therapies and management of augmentation

Idiopathic restless legs syndrome (RLS) can severely affect quality of life and disturb sleep, so that pharmacological treatment is necessary, especially for elderly patients. Treatment guidelines recommend initiation of therapy with dopamine agonists (pramipexole, ropinirole or the rotigotine transdermal patch, all approved in most countries) or α-2-δ ligands (gabapentin enacarbil, approved in the USA and Japan), depending on the country and availability. Where approved, opioids (prolonged release oxycodone-naloxone, approved in Europe) are also recommended as a second-line therapy for severe RLS. Several iron formulations can be effective but are not yet approved for RLS therapy, whereas benzodiazepines and other anticonvulsants are not recommended or approved. Less is known about effective management of RLS that is associated with other conditions, such as uraemia or pregnancy. Furthermore, very little data are available on the management of RLS when first-line treatment fails or patients experience augmentation. In this Review, we summarize state-of-the-art therapies for RLS in the context of the diagnostic criteria and available guidelines, based on knowledge ranging from Class I evidence for the treatment of idiopathic RLS to Class IV evidence for the treatment of complications such as augmentation. We consider therapies, including combination therapies, that are used in clinical practice for long-term management of RLS, despite a lack of trials and approval, and highlight the need for practical long-term evaluation of current trials.

An update on pharmacological, pharmacokinetic properties and drug-drug interactions of rotigotine transdermal system in Parkinson's disease and restless legs syndrome

This narrative review reports on the pharmacological and pharmacokinetic properties of rotigotine, a non-ergolinic D₃/D₂/D₁ dopamine receptor agonist approved for the treatment of early- and advanced-stage Parkinson’s disease (PD) and moderate to severe restless legs syndrome (RLS). Rotigotine is formulated as a transdermal patch providing continuous drug delivery over 24 h, with a plasma concentration profile similar to that of administration via continuous intravenous infusion. Absolute bioavailability after 24 h transdermal delivery is 37 % of the applied rotigotine dose. Following a single administration of rotigotine transdermal system (24-h patch-on period), most of the absorbed drug is eliminated in urine and feces as sulphated and glucuronidated conjugates within 24 h of patch removal. The drug shows a high apparent volume of distribution (>2500 L) and a total body clearance of 300–600 L/h. Rotigotine transdermal system provides dose-proportional pharmacokinetics up to supratherapeutic dose rates of 24 mg/24 h, with steady-state plasma drug concentrations attained within 1–2 days of daily dosing. The pharmacokinetics of rotigotine transdermal patch are similar in healthy subjects, patients with early- or advanced-stage PD, and patients with RLS when comparing dose-normalized area under the plasma concentration–time curve (AUC) and maximum plasma drug concentration (C_max), as well as half-life and other pharmacokinetic parameters. Also, it is not influenced in a relevant manner by age, sex, ethnicity, advanced renal insufficiency, or moderate hepatic impairment. No clinically relevant drug–drug interactions were observed following co-administration of rotigotine with levodopa/carbidopa, domperidone, or the CYP450 inhibitors cimetidine or omeprazole. Also, pharmacodynamics and pharmacokinetics of an oral hormonal contraceptive were not influenced by rotigotine co-administration. Rotigotine was generally well tolerated, with an adverse event profile consistent with dopaminergic stimulation and use of a transdermal patch. These observations, combined with the long-term efficacy demonstrated in clinical studies, support the use of rotigotine as a continuous non-ergot D₃/D₂/D₁ dopamine receptor agonist in the treatment of PD and RLS.

Dopaminergic Augmentation in Restless Legs Syndrome/Willis-Ekbom Disease: Identification and Management

Augmentation is the main clinical complication of long-term dopaminergic treatment of restless legs syndrome (RLS)/Willis-Ekbom disease and also the main reason for treatment failure of this class of drugs. It involves an increase in the severity (or frequency) of RLS symptoms during treatment. There is some preliminary evidence that the incidence of augmentation is higher when short-acting dopamine agonists are used. Prevention strategies include managing lifestyle changes and keeping dopaminergic load low. This might include, whenever feasible, to postpone any dopaminergic medication and perform a treatment trial with nondopaminergic agents (ie, alpha-2 delta ligand) first. Treatment of augmentation might require switching to longer-acting dopaminergic agents, to alpha-2 delta ligands or to opiates.

Restless Leg Syndrome/Willis-Ekbom Disease Pathophysiology

Restless leg syndrome/Willis-Ekbom disease has brain iron deficiency that produces excessive dopamine and known genetic risks, some of which contribute to the brain iron deficiency. Dopamine treatments work temporarily but may eventually produce further postsynaptic down-regulation and worse restless leg syndrome. This article includes sections focused on pathophysiologic findings from each of these areas: genetics, cortical-spinal excitability, and iron and dopamine.