My 89 year old mother has had this for years. She now takes Evoxac, a prescription, that has helped her tremendously. There are 2-3 prescriptions to treat dry mouth, but this one has worked the best. Before she was prescribed this med, sucked on hard candies which was not good for her teeth. She also bought from Amazon, SalivaSure 90 Lozenges, which helped somewhat. It did produce some saliva. But, by far, Evoxac has helped the most. Her mouth is never dry anymore.
Also, her eye doctor has her wash her eyes everyday with baby shampoo because she has gotten eye infections due to lack of tears. And, he plugged up her tear ducts so what tears she did produce did not get drained away. She also puts GenTeal Eye Lubricant in her eyes because it lasts longer than regular eye drops.
I hope any of this helps. The Evoxac, baby shampoo, and GenTeal Eye Lubricant has made life so much better for my mother.