Gabapentin is a medication that is primarily used to treat seizures and certain types of nerve pain (neuropathic pain). It is also sometimes prescribed off-label for other conditions such as anxiety, restless leg syndrome, and fibromyalgia. It works by affecting the chemicals and nerves involved in the transmission of pain signals in the brain. Gabapentin works effectively, it can relieve you from your pain within 2 to 3 hours after medication.