Restless legs syndrome (RLS) is a common sleep-related neurological disorder that is characterized by the urge to move, worsening at rest, improvement with activity, and worsening in the evening and night. Dopamine agonists are usually the first-line therapy. Other agents including benzodiazepines, narcotics, and anticonvulsants have been used to treat RLS. Gabapentin has been shown to improve RLS in a small number of clinical studies, but is limited by its short half-life and variable bioavailability. Gabapentin enacarbil is a novel prodrug of gabapentin designed to overcome these pharmacokinetic limitations. In vitro and in vivo studies have demonstrated that gabapentin enacarbil has improved absorption, bioavailability and pharmacokinetics compared with gabapentin. Phase II and III studies have demonstrated that gabapentin enacarbil is generally well tolerated and is useful in the treatment of RLS.
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