Ropinirole treatment for restless legs syndrome

Ropinirole-Associated Orthostatic Hypotension as Cause of a Prescribing Cascade in an Elderly Man

Ropinirole is an overall well-tolerated antiparkinsonian medication that is also used to treat restless leg syndrome (RLS). The incidence of side effects is low, with orthostatic hypotension (OH) only anecdotally reported. Additionally, it is known that the elderly population is very susceptible to adverse drug effects and the prevalence of prescribing cascades that these can trigger is unknown.

A 71-year-old male with history of atrial fibrillation, well-controlled diabetes on oral agents, hyperlipidemia, hypertension, ischemic heart failure status post (s/p) implantable cardioverter-defibrillator (ICD) placement with improved ejection fraction (EF), transient ischemic attack (TIA), rheumatoid arthritis, RLS, aortic stenosis s/p mechanical aortic valve replacement on anticoagulation, deep venous thrombosis (DVT), and right knee replacement, presented to the ED with generalized weakness, with difficulty standing from seated position, followed by a fall without head trauma. Over the eight months prior to this presentation, the patient had had similar symptoms that resulted in four falls, two hospital admissions, and new prescriptions of midodrine and compression stockings.

On admission, vital signs were remarkable for positive orthostatics with blood pressure (BP) 110/74 mmHg, heart rate (HR) of 86 bpm in supine position and BP 87/51 mmHg, HR of 70 bpm while in standing position. Physical exam was unremarkable except for a known ejection murmur and dry oral mucous membranes. Labs included a creatinine 3.6 mg/dl, blood urea nitrogen (BUN) 66 mg/dl, international normalized ration (INR) of 4.1, B-natriuretic peptide (BNP) of 313 pg/mL, troponin <0.03 ng/mL. A kidney ultrasound was normal, and a transthoracic echocardiogram showed left ventricle ejection fraction (LVEF) of 55-65%, improved compared to a prior study. Furosemide, carvedilol and canagliflozin were discontinued and IV fluids were administered. In the subsequent days, his creatinine improved, and so did the patient's volume status, but he continued to be orthostatic despite midodrine and stockings. On further interview, the patient disclosed starting ropinirole 0.25 mg three times daily approximately 10 months prior to this admission, due to asymptomatic RLS that was reported in a sleep study. Decision was made to discontinue this medication, which resulted in improvement of symptoms. We were able to discontinue IV fluids, midodrine and stockings, and reintroduce carvedilol, furosemide and canagliflozin in a stepwise manner. In a follow-up visit one month after discharge, the patient was symptom-free.

This case illustrates two major points. First, this prescribing cascade potentially induced by ropinirole, as well as the increase in health care costs associated to iatrogenic admissions, is major preventable problem faced mostly by the geriatric population. Second, although OH associated with ropinirole has only been reported in patients treated for Parkinson’s disease, this side effect should be considered when prescribing ropinirole for other indications, with cautious assessment of risks and benefits. Further studies need to be conducted to establish the frequency of OH related to ropinirole.

Motor restlessness, sleep disturbances, thermal sensory alterations and elevated serum iron levels in Btbd9 mutant mice

Restless legs syndrome (RLS), also known as Willis-Ekbom disease, is a sensory-motor neurological disorder with a circadian component. RLS is characterized by uncomfortable sensations in the extremities, generally at night or during sleep, which often leads to an uncontrollable urge to move them for relief. Recently, genomic studies identified single-nucleotide polymorphisms in BTBD9, along with three other genes, as being associated with a higher risk of RLS. Little is known about the function of BTBD9 or its potential role in the pathophysiology of RLS. We therefore examined a line of Btbd9 mutant mice we recently generated for phenotypes similar to symptoms found in RLS patients. We observed that the Btbd9 mutant mice had motor restlessness, sensory alterations likely limited to the rest phase, and decreased sleep and increased wake times during the rest phase. Additionally, the Btbd9 mutant mice had altered serum iron levels and monoamine neurotransmitter systems. Furthermore, the sensory alterations in the Btbd9 mutant mice were relieved using ropinirole, a dopaminergic agonist widely used for RLS treatment. These results, taken together, suggest that the Btbd9 mutant mice model several characteristics similar to RLS and would therefore be the first genotypic mouse model of RLS. Furthermore, our data provide further evidence that BTBD9 is involved in RLS, and future studies of the Btbd9 mutant mice will help shine light on its role in the pathophysiology of RLS. Finally, our data argue for the utility of Btbd9 mutant mice to discover and screen novel therapeutics for RLS.

Update on the management of restless legs syndrome: existing and emerging treatment options

Restless legs syndrome (RLS) is a sensorimotor disorder, characterized by a circadian variation of symptoms involving an urge to move the limbs (usually the legs) as well as paresthesias. There is a primary (familial) and a secondary (acquired) form, which affects a wide variety of individuals, such as pregnant women, patients with end-stage renal disease, iron deficiency, rheumatic disease, and persons taking medications. The symptoms reflect a circadian fluctuation of dopamine in the substantia nigra. RLS patients have lower dopamine and iron levels in the substantia nigra and respond to both dopaminergic therapy and iron administration. Iron, as a cofactor of dopamine production and a regulator of the expression of dopamine type 2-receptor, has an important role in the RLS etiology. In the management of the disease, the first step is to investigate possible secondary causes and their treatment. Dopaminergic agents are considered as the first-line therapy for moderate to severe RLS. If dopaminergic drugs are contraindicated or not efficacious, or if symptoms are resistant and unremitting, gabapentin or other antiepileptic agents, benzodiazepines, or opioids can be used for RLS therapy. Undiagnosed, wrongly diagnosed, and untreated RLS is associated with a significant impairment of the quality of life.

Restless legs syndrome: differential diagnosis and management with pramipexole

Restless legs syndrome (RLS) is a condition characterized by discomfort at rest and urge to move focused on the legs. RLS may occur as an idiopathic, often hereditary condition (primary RLS), or in association with medical conditions (secondary RLS) including iron deficiency, uremia, and polyneuropathy. Current understanding of the pathophysiology of RLS points to the involvement of three interrelated components: dopaminergic dysfunction, impaired iron homeostasis, and genetic mechanisms. The diagnosis of RLS is made according to the consensus criteria by a National Institutes of Health panel: 1) an urge to move the legs, usually accompanied by uncomfortable sensations; 2) beginning or worsening during rest; 3) relieved by movement; and 4) worse, or only occurring, in the evening or at night. The differential diagnosis of RLS aims to: 1) distinguish RLS from other disorders with RLS-like symptoms and 2) identify secondary forms, with investigation of underlying diseases. The treatment of RLS demands a clinical evaluation to rule out and cure causes of secondary RLS, including iron supplementation when deficient, and to eliminate the triggering factors. The presence of neuropathy should be especially investigated in nonhereditary, late-onset RLS, in view of a possible treatment of the underlying disease. The first line treatment for idiopathic RLS is represented by dopamine agonists, in particular nonergot-derived ropinirole and pramipexole, whereas ergot dopamine agonists (cabergoline and pergolide) are no longer in first-line use given the risks of cardiac valvulopathy. Although no comparative trials have been published, a meta-analysis of pramipexole versus ropinirole suggests differences in efficacy and tolerability favoring pramipexole.