Gabapentin 100 mg is a medicine used to treat partial seizures, nerve pain from shingles, and restless leg syndrome. It works on the chemical messengers in your brain and nerves. Gabapentin is from a group of medicines called anticonvulsants. Different brands of gabapentin are not interchangeable, and they are FDA-approved for different conditions. Use only the brand and form of Gabapentin 100 mg pills your doctor has prescribed. Check your medicine each time you get a refill to make sure you receive the correct form.