I suspect that gabapentin is causing me to gain weight despite my many efforts to lose. are there alternatives that don't have that side effect?

Not true side-effect: While there can be edema (fluid retention) with Gabapentin which results in weight gain, the medicine itself does not likely cause increased appetite or reduced metabolism. If you are sedated, your activity level may have been reduced, thus burning less Cal. Please visit with your doctor to see about a dose change, if you have edema, and other options. Best wishes