Oxycodone/Naloxone PR: A Review in Severe Refractory Restless Legs Syndrome

Use of α2δ Ligands for Restless Legs Syndrome/Willis Ekbom Disease

Restless legs syndrome is a common neurological condition affecting a substantial portion of the population. It can be an idiopathic disorder, or one that is secondary to another cause. Given that the underlying pathophysiology of restless legs syndrome is not well understood, several drug classes have been studied for symptom control. While dopamine agonists have long been the mainstay of first-line treatment for restless legs syndrome, recently, the α2δ ligands have been increasingly used. These agents have proven both efficacious and safe in a number of clinical trials. Additionally, compared with the dopamine agonists, they have been associated with less augmentation, a phenomenon whereby symptoms emerge earlier in the day, become more severe, and may spread to areas of the body previously unaffected. Newer clinical guidelines for restless legs syndrome are increasingly recommending the α2δ ligands as a logical first-choice medication for patients needing drug therapy for symptom control.

Oxycodone/Naloxone Prolonged Release: A Review in Severe Chronic Pain

Oral oxycodone/naloxone prolonged release (PR) [Targin^®, Targinact^®, Targiniq^®] is a 12-hourly opioid receptor agonist and opioid receptor antagonist fixed-dose combination product that is approved in countries in the EU for the management of severe pain (adequately manageable only with opioid analgesics) in adults. Oral naloxone prevents oxycodone from binding to μ-receptors in the gastrointestinal (GI) tract, thereby counteracting opioid-induced constipation (OIC). In short-term (5- to 12-week) clinical trials of adults with moderate to severe, chronic pain and OIC (OXN3001, OXN3006, OXN3506), oxycodone/naloxone PR significantly improved OIC while providing noninferior analgesia relative to oxycodone PR; results were consistent between cancer and non-cancer patients in OXN3506. Analgesia and improvements in bowel function were sustained with an additional 24-52 weeks of oxycodone/naloxone PR treatment in long-term extension studies. Results in real-world studies were consistent with those in clinical trials. Oxycodone/naloxone PR was generally well tolerated, with nausea, hyperhidrosis, and diarrhoea (generally transient) reported as the most commonly occurring adverse events. Thus, oxycodone/naloxone PR is a useful treatment option to consider in adults with severe chronic pain that can be adequately managed only with opioid analgesics, particularly in those with OIC.

Targinact for restless legs syndrome

Idiopathic restless legs syndrome (RLS)--also known as Willis-Ekbom disease--is a neurological condition characterised by an overwhelming urge to move the legs, occurring during rest or inactivity, especially at night. Symptoms are highly variable in frequency and severity, and can affect sleep and quality of life. First-line management includes addressing precipitating or aggravating factors and providing explanation, reassurance and advice on self-help strategies. Drug therapy (e.g. a dopamine agonist) is used for patients with more severe symptoms. In December 2014, the marketing authorisation for a modified-release preparation containing oxycodone and naloxone (Targinact-Napp Pharmaceuticals) was expanded to include use in the treatment of severe to very severe RLS after failure of dopaminergic therapy.(10)Here we review the management of adults with RLS, including the place of oxycodone/naloxone.

Intractable restless legs syndrome: role of prolonged-release oxycodone-naloxone

Restless legs syndrome (RLS) is a common neurological disorder characterized by an irresistible urge to move the legs accompanied by uncomfortable sensations that occur at night or at time of rest. Pharmacological therapy should be limited to patients who suffer from clinically relevant symptoms. Chronic RLS is usually treated with either a dopamine agonist (pramipexole, ropinirole, rotigotine) or an α2δ calcium-channel ligand (gabapentin, gabapentin enacarbil, pregabalin). Augmentation is the main complication of long-term dopaminergic treatment, and frequently requires a reduction of current dopaminergic dose or a switch to non-dopaminergic medications. Opioids as monotherapy or add-on treatment should be considered when alternative satisfactory regimens are unavailable and the severity of symptoms warrants it. In a recent Phase III trial, oxycodone-naloxone prolonged release (PR) demonstrated a significant and sustained effect on patients with severe RLS inadequately controlled by previous treatments. The adverse-event profile was consistent with the safety profile of opioids. The most frequent adverse events were fatigue, constipation, nausea, headache, hyperhidrosis, somnolence, dry mouth, and pruritus. Adverse events were usually mild or moderate in intensity. No cases of augmentation were reported. Oxycodone-naloxone PR is approved for the second-line symptomatic treatment of adults with severe to very severe idiopathic RLS after failure of dopaminergic treatment. Further studies are needed to evaluate if oxycodone-naloxone PR is equally efficacious as a first-line treatment. Moreover, long-term comparative studies between opioids, dopaminergic drugs and α2δ ligands are needed.