Gabapentin has been licensed to treat nerve pain (neuralgia) caused by nerve injury. Gabapentin is a medication that is used to treat neuralgia caused by the herpes zoster virus, also known as shingles. Post-herpetic neuralgia (PHN) is a type of pain that can be severe and long-lasting. Gabapentin is also used to treat diabetic neuropathy, which occurs when diabetes damages nerves in the foot, resulting in severe burning pain.