Reply to boconn89, @yellowdoggirl , when the worst of my nerve pain was raging and I built up to 1900 mg/ day in multiple doses, the gabapentin did make me feel really "stupid" and tired, but my body, old thing that it is, adjusted. Then it was a trick to wean down, and after about 7 years I am still on it for residual nerve pain caused by the initial infection. I am just glad it works and now I only take 400 before bed, but without it there is no sleeping!
I read that about only 60% of people are helped by gabapentin so I am still grateful that I am one of them.