Here is some additional information:

http://neurotalk.psychcentral.com/post829091-8.html

It has been shown over time, that only about 30% of people get success from gabapentin. It is thought that its major effects on pain occur in the spinal cord by blocking signals from going to the brain. Over time there appears to be a tolerance factor, and relief may occur, and then wear off and require higher doses, until there is a plateau and relief is gone.

Avoid magnesium orally in any form (antacids and supplements) as magnesium complexes gabapentin and prevents absorption from the GI tract. That warning should be on your pharmacy handout that came with your medication.

Report any major side effects to your doctor.

I made this post just before the gabapentin link above to be an overview of how neurons work. You might find it helpful for understanding how gabapentin (and other pain drugs) may or may not help.

http://neurotalk.psychcentral.com/post828704-7.html