Dopamine agonists for the treatment of restless legs syndrome

Dopamine agonists and risk of lung cancer in patients with restless legs syndrome

PURPOSE

To examine the association between long-term use of dopamine agonists (DAs) and the risk of lung cancer in patients with restless legs syndrome (RLS).

METHODS

We conducted a retrospective cohort study using Optum Clinformatics® database. We included adults ≥40 years diagnosed with RLS during the study period (1/2006-12/2016). Follow-up started with the first RLS diagnosis and ended on the earliest of: incident diagnosis of lung cancer, end of enrollment in the database or end of the study period. The exposure of interest was cumulative duration of DAs use, measured in a time-varying manner. We constructed a multivariable Cox regression model to estimate HRs and 95% CIs for the association between lung cancer and cumulative durations of DA use, adjusting for potential confounding variables.

RESULTS

We identified 295 042 patients with a diagnosis of RLS. The mean age of the cohort was 62.9; 66.6% were women and 82.3% were white. The prevalence of any DA exposure was 40.3%. Compared to the reference group (no use and ≤1 year), the crude HRs for lung cancer were 1.16 (95% CI 0.99-1.36) and 1.14 (95% CI 0.86-1.51) for 1-3 years and >3 years of cumulative DA use, respectively. The adjusted HR for lung cancer was 1.05 (95% CI 0.88-1.25) for 1-3 years and 1.02 (95% CI 0.76-1.37) for >3 years of cumulative DA use, respectively.

CONCLUSIONS

At typical doses for the clinical management of RLS, long-term DA use was not associated with risk of lung cancer.

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.

Current Evidence on Diagnostic Criteria, Relevant Outcome Measures, and Efficacy of Nonpharmacologic Therapy in the Management of Restless Legs Syndrome (RLS): A Scoping Review

OBJECTIVE

The aim of this scoping review is to outline the current evidence regarding the management of restless legs syndrome (RLS) with nonpharmacologic approaches. To categorize the efficacy of conservative approaches in reducing symptoms of RLS, we have identified and summarized the current data regarding diagnostic criteria and relevant outcome measures, to inform future research and to guide clinical practice.

METHODS

A scoping review was conducted using the National Center for Biotechnology Information; EBSCO; the Manual, Alternative and Natural Therapy Index System; the Cumulative Index to Nursing & Allied Health Literature; and Scopus. All literature related to RLS was extracted, screened, and reviewed based on titles and abstract contents. The authors then extracted data from the 24 admissible studies, that is, the ones about manual therapy, exercises, and alternative treatments for RLS. The Physiotherapy Evidence Database scale was used to rate the methodological quality of the included randomized controlled trials by 2 independent readers.

RESULTS

In the 24 articles fulfilling the selection criteria, there was a consistent trend in the findings showing positive results in lowering RLS symptom severity. Most clinical studies based their diagnosis on the International Restless Legs Syndrome Study Group diagnostic criteria; the International Restless Legs Syndrome Study Group rating scale was the most often used outcome measure. The efficacy of exercise, yoga, massage, acupuncture, traction straight leg raise, cryotherapy, pneumatic compression devices, whole-body vibration, transcranial and transcutaneous stimulation, and near-infrared lights showed different effects on RLS symptom severity, and the level of evidence was evaluated.

CONCLUSION

Our results showed clinically significant effects for exercises, acupuncture, pneumatic compression devices, and near-infrared light. Short-lasting effects were identified with whole-body cryotherapy, repetitive transcranial stimulation, and transcutaneous stimulation. More studies are necessary to investigate efficacy of yoga, massage, traction straight leg raise, and whole-body vibration. No adverse effects were identified for moderate-intensity exercise, yoga, massage, and pneumatic compression devices.

Small fiber function in drug naïve patients with idiopathic restless legs syndrome

To assess whether idiopathic restless legs syndrome (RLS) is associated with small fiber abnormalities, we evaluated somatic and autonomic small fiber function in 56 patients with idiopathic RLS and 36 age-matched and sex-matched healthy controls using quantitative sensory testing and quantitative sudomotor axon reflex tests. The warm detection thresholds (WDT) of the hands (p=0.017) and feet (p=0.008) were higher in patients with RLS than in controls. Cooling detection thresholds (CDT) were higher in the feet of patients with RLS than controls (p<0.001), but CDT in the hands did not differ between groups (p=0.161). There were no significant between-group differences in total sweat volume and sweat production in the forearms, proximal legs, distal legs, and feet (p>0.1 each). These findings suggest that abnormal sensory perception in patients with idiopathic RLS may result from impairment of central somatosensory processing rather than small fiber neuropathy.

Cutaneous silent period in patients with restless leg syndrome

OBJECTIVE

To investigate the pathophysiological relationship between RLS and small fiber neuropathy using the cutaneous silent period (CSP), which is a spinal reflex mediated by Adelta cutaneous afferents and is useful for the evaluation of small-diameter nerve function.

METHODS

The CSP was measured from the extensor digitorum brevis in 157 patients with RLS and 60 healthy controls. The CSP measurement was repeated in the RLS patients after dopamine agonist treatment for one month. The RLS rating scale for clinical severity was used to evaluate each patient before and after treatment. The measured CSP variables were compared between the patient group and the control group. In addition, the possible correlation between the CSP variables and the RLS rating scale score related to treatment was analyzed.

RESULTS

The mean CSP latencies did not differ between the RLS patients and the healthy controls; however, the mean CSP duration was significantly longer in the RLS patients than in the controls, and this prolonged CSP duration improved to the level of the control subjects after dopamine agonist treatment (p=0.003). The mean RLS rating scale score also significantly decreased after medication (p=0.000). However, the changes in the CSP variables did not correlate with the decrement in the RLS rating scale score.

CONCLUSIONS

Although our results do not support the role of Adelta fiber dysfunction in RLS, the observed change in CSP duration may be useful as a clinical measure of the improvement with dopamine agonist treatment in patients with RLS.

SIGNIFICANCE

Further study is needed to elucidate the exact mechanism involved in the prolonged CSP duration in response to treatment.

Efficacy and tolerability of ropinirole in patients with restless legs syndrome and a baseline IRLS total score > or = 24 points--data from the ropinirole clinical trial programme

OBJECTIVE

Results from one of the largest clinical trial programmes to date of a dopamine agonist in patients with primary restless legs syndrome (RLS) have demonstrated that ropinirole, 0.25-4.0 mg once daily 1-3 hours before bedtime, is associated with significant improvements in RLS symptoms, sleep parameters and quality-of-life measures, compared with placebo. Analyses were conducted in a subpopulation of patients with a baseline score on the International Restless Legs Scale (IRLS) of at least 24 points.

RESEARCH DESIGN AND METHODS

Data was pooled from four, 12-week, pivotal studies: RESET PLM and TREAT RLS 1, 2 and US.

MAIN OUTCOME MEASURES

Covariate analysis demonstrated that the magnitude of treatment difference between ropinirole and placebo for change in IRLS total score (a measure of RLS symptom severity) increased with increasing baseline IRLS total score. Mean treatment difference was > 3 points in patients with a baseline total score > or = 24. Among this population, ropinirole treatment was associated with significant reduction in RLS symptom severity compared with placebo, along with significant improvements in global symptoms and sleep measures. A treatment benefit was also observed for measures of quality of life. Ropinirole is well tolerated in this patient population.

CONCLUSIONS

Patients with primary RLS and baseline IRLS total score > or = 24 gain clinically meaningful benefits from ropinirole treatment. As with the overall population in the ropinirole clinical trial programme, ropinirole was associated with improvements in RLS symptoms, global symptoms, sleep and quality of life and was well tolerated in patients with a baseline IRLS total score > or = 24.

Use of Sleep-Promoting Medications in Nursing Home Residents

This paper reviews the use of sleep-promoting medications in nursing home residents with reference to risks versus benefits. Up to two-thirds of elderly people living in institutions experience sleep disturbance. The aetiology of sleep disturbance includes poor sleep hygiene, medical and psychiatric disorders, sleep apnoea, periodic limb movements and restless leg syndrome. One key factor in the development of sleep disturbance in the nursing home is the environment, particularly with respect to high levels of night-time noise and light, low levels of daytime light, and care routines that do not promote sleep. Clinical assessment should include a comprehensive medical, psychiatric and sleep history including a review of prescribed medications. Nonpharmacological interventions for insomnia are underutilised in many clinical settings despite evidence that they are often highly effective. International studies suggest that 50-80% of nursing home residents have at least one prescription for psychotropic medication. Utilisation rates vary dramatically from country to country and from institution to institution. The most commonly prescribed medications for sleep are benzodiazepines and nonbenzodiazepine hypnotics (Z-drugs). The vast majority of studies of these medications are short-term, i.e. < or =2 weeks, although some longer extension trials have recently been carried out. Clinicians are advised to avoid long-acting benzodiazepines and to use hypnotics for as brief a period as possible, in most cases not exceeding 2-3 weeks of treatment. Patients receiving benzodiazepines are at increased risk of daytime sedation, falls, and cognitive and psychomotor impairment. Zaleplon, zolpidem, zopiclone and eszopiclone may have some advantages over the benzodiazepines, particularly with respect to the development of tolerance and dependence. Ramelteon, a novel agent with high selectivity for melatonin receptors, has recently been approved in the US. Use of the antidepressant trazodone for sleep in nondepressed patients is somewhat controversial. Atypical antipsychotics should not be used to treat insomnia unless there is also evidence of severe behavioural symptoms or psychosis.