Therapeutic Utility of Opioids for Restless Legs Syndrome.

Restless legs syndrome (RLS) is a sensorimotor neurologic disorder characterized by an unpleasant urge to move the legs, often accompanied by leg dysesthesias. Symptoms predominate in the evening or at night and often cause significant distress and disruption of sleep. Several non-opioid classes of drugs provide initial relief from the symptoms of RLS. Among these, however, the efficacy of dopamine agonists can wane over time or even paradoxically 'augment' the severity of symptoms during the course of long-term treatment. Opioids can alleviate RLS symptoms, even in patients who have become refractory to, or do not tolerate, other drugs. In a carefully selected group of patients with severe RLS that has not been effectively managed with other therapies, opioids may be an appropriate treatment.