Gabapentin 1600 mg helps to relieve chronic pain and seizures by limiting the ability of nerve cells in the brain and spinal cord, which is something that a person experiences when individuals have epilepsy. Gabapentin has also been successful in studies with individuals who suffer from atypical neuropathic pain. Gabapentin works by enhancing the effect of GABA, a neurotransmitter that suppresses neuronal excitability. When combined with other medications, it may reduce some adverse effects related to drugs like diazepam (Valium).