^I disagree with this advice. I hope the OP is ok and didn't have a crazy black out or anything. "Very experienced user" doesn't give us much to go on, for future reference Wholmes1276 it's a lot more helpful if you are specific, like say how much of each drug you would normally take on it's own and tell us how long it's been since you took the gabapentin and drank the beer. Also it's not very wise to mix alcohol + gabapentin + benzos. I would really just stick to one or the other.
I'm going to close this since it's from yesterday but if you want to discuss things further or let us know if it ended up being ok please feel free to PM me and I can re-open it.