Both gabapentin and pregabalin have weight gain as a side effect for some people. You can’t compare the two directly though because the max dose for gabapentin is 3600mg a day and the max dose for pregabalin is 600mg a day. So 450mg of pregabalin is roughly equivalent to 2700mg of gabapentin FOR THE SAME PERSON. The capitals are because we all metabolise different drugs differently. That’s why some people need very low doses to get the same effect as another person who needs high doses, but also why one drug might work while an alternative doesn’t.
There’s no doubt that some people struggle with their weight while on these meds, but there’s also no doubt that decreasing levels of activity often contributes too. Let’s face it, pain and fatigue + exercise do not exactly go together!
If your weight is a problem, then it might be worth trying a different drug, but if the pregabalin is working, it might mean a return of pain It’s a tricky balance
Sorry, this is not a terribly optimistic reply!