The Gabapentin does have a s/e of edema (fluid retention/swelling)
for some patients-especially in the lower extremities.
You should see your doc about taking a diuretic for the edema.
Do not drink pop (carbonated beverages-even plain,
carbonated, or mineral, waters) and keep all of your fluid intake very low.
If this doesn't help, or If the swelling doesn't respond to a diuretic,
a change in meds may be in order.