pregabalin vs gabapentin

Gabapentin only for 6 1/2 years. I’ve never had edema. I take it to help manage the nerve pain I get from PN as well as the extreme cold & heat sensitivity I get in my extremities. I don’t have any known underlying conditions that would contribute to edema (thank God). I am now late 50’s and worked my way up to 800 mg 3x.
A Neurologist 2 years ago sent in a prescription for Pregabalin for no reason or new symptoms after a visit but just a comment “a lot of people take it too”. I kept the bottle but decided not to take it since I was unclear on the expected outcome and the side effects and drug interactions alarmed me. He didn’t offer an explanation when I wrote to ask about the expected benefit. But I have read how it has helped some people on here.