Gabapentin Enacarbil in Restless Legs Syndrome

Restless legs syndrome (RLS) is a sleep-related movement disorder with a high prevalence in the general population. Patients affected by a severe form of the disorder may develop comorbidities, such as psychological distress, cognitive dysfunction and cardiovascular diseases; these patients require pharmacotherapy. Dopamine agonists represent the first line treatment for RLS patients but, if adverse events such as compulsive behaviors and augmentation occur, the pharmacological approach should be modified. Gabapentin is a GABA analogue used in the treatment of seizures and pain syndromes. This drug has an unfavorable pharmacokinetic profile; the prodrug gabapentin enacarbil was developed to overcome this limitation. Unlike oral gabapentin, gabapentin enacarbil shows no evidence of saturation and exposure to gabapentin is dose proportional. The extended release formulation of gabapentin enacarbil has the characteristics of an optimal drug therapy. Doses from 1200 to 1800 mg/day of gabapentin enacarbil appear effective in treating RLS after only a few days of treatment. The most frequently reported adverse events associated with gabapentin enacarbil are dizziness and somnolence, which are transient and of mild intensity. Further studies are required to confirm the long term efficacy and safety of gabapentin enacarbil on the symptoms of RLS.