Neurontin is an anticonvulsant that is used to combat epilepsy and postherpetic neuralgia. Neurontin works by altering the chemicals and nerves that cause seizures and pain. Neurontin (gabapentin) is a medication that is used to prevent and control seizures. It is an anticonvulsant or anti-epileptic medicine. It works by reducing seizure activities in the brain to restore the normal brain function. Gabapentin is the main agent in this medication, and it affects chemicals and nerves in the body that are responsible for causing seizures. In adult patients, Neurontin can be used for the treatment of nerve pain caused by shingles (herpes zoster). Patients who are allergic to Neurontin or any of its ingredients should not use it. You will experience drowsiness and loss of coordination, but they are just some of the common side effects. Neurontin is in the form of an oral solution, tablets, and capsules and thus, it should be administered by mouth.