Gabapentin enacarbil (XP-13512) is a prodrug of Gabapentin designed to be absorbed throughout the intestine by high-capacity nutrient transporters. Gabapentin is a potent, orally active P/Q type Ca2+ channel blocker. Gabapentin enacarbil can be used for the study of Restless Legs Syndrome (RLS) and postherpetic neuralgia (PHN)[2].