Gabapentin is an anticonvulsant medication. It can reduce unusual levels of electrical activity in the brain, so it’s useful for treating conditions like epilepsy and restless leg syndrome. A doctor might also prescribe gabapentin to treat chronic pain conditions, such as fibromyalgia and migraines, or mental health conditions, including bipolar disorder, anxiety, and PTSD. The medication comes in multiple forms, such as tablets and liquids, and it can cause side effects like drowsiness, blurred vision, and nausea.