Gabapentin is not an analgesic (pain killer). It is a medication used to treat epilepsy, neuropathic pain, hot flashes, and restless legs syndrome. In epilepsy it may be used for those with partial seizures. Gabapentin works in your brain and nervous system. It stabilises the electrical activity in your brain, and affects the way your nerves send messages to your brain. The exact way in which gabapentin works is not fully understood. Gabapentin appears to affect the build up of electrical signals in the nerve cells, as well as affecting the activity of various neurotransmitters in the brain and nervous system. Neurotransmitters are natural body chemicals that are involved in transmitting messages between nerve cells. GABA is a neurotransmitter that acts as a natural 'nerve-calming' agent. It helps keep the nerve activity in the brain in balance. Gabapentin appears to increase production of GABA. Glutamate is a neurotransmitter that acts as a natural 'nerve-exciting' agent. It's released when electrical signals build up in nerve cells and subsequently excites more nerve cells. It is thought to play a key role in causing epileptic seizures and transmitting pain signals to the brain. Gabapentin appears to reduce the release of glutamate. This information was obtained from NetDoctor Another similar drug is pregabalin, marketed as Lyrica. Gabapentin and pregabalin are different drugs but they rather like cousins. Lyrica has one less carbon atom in the molecule. This makes the structure more open. It is absorbed more quickly and lasts longer than gabapentin. However, they both work much the same way by attaching themselves to a specific sub-unit protein and thereby buffer the calcium ions in the voltage gated calcium channels. This is where nerves are activated. This results in the chemically excited nerves being calmed down.