I doubt it's the baclofenor gabapentin - if anything they cause drowsiness. I'm pretty certain alcohol should be avoided with baclofen so it's probably a good idea to try & avoid that as a solution.
I went to a sleep clinic at my hospital, as I'd have trouble getting off to sleep. They recommended a book by Colin Espie (search for his name in Amazon and you'll find the book - if you don't want to buy it you may find it in your local library). One of the techniques he says to use is to only go to bed when you're sleepy. If you're not asleep after 15 minutes, get up and don't go to bed again until you're sleepy (not just tired but actually sleepy). Keep repeating this until you fall alseep. This sorted the problem for me. Now I don't go to bed until I'm sleepy, and I almost always fall asleep pretty quickly.
There's a whole load of other things I do that help. Lower the lights in the evening. Don't drink caffeine after 6pm, and don't eat late either (I try to eat my main meal no later than half six or 7). When (if) you get up in the night, read or do a puzzle rather than go on the comnputer or watch telly, as they can over stimulate your brain. Try a variation on counting sheep - count backwards from 1000 in steps of 3 (i.e. 1000, 997, 994 etc). I find listening to talk radio or audio books can be good too - I have the volume very low so I have to concentrate to hear them (I use headphones so as not to disturb my wife). Turn the clock around too - clock watching never helped me, as knowing it was 3am and I was still awake would just get my head worrying.
Hope they all help.