There are many drugs that cause dry mouth. Sometimes they add up together...so you should look at all the drugs you take RX and OTC. If you get stuffed up at night, try the Breathe Right strips to open your nose up, as you may be sleeping with your mouth open. A shot of Afrin nasal spray at night can also open up your nostrils some, but use very sparingly as you can get hooked on it.

This is the post from the Subforum here on the relationship of gabapentin and Lyrica:
http://neurotalk.psychcentral.com/post829091-8.html

There is much useful information on the subforum that you could benefit from reading.