Extreme Dry Mouth

I have extreme dry mouth.  My blood has been checked for obvious things.  I have seen an ENT specialist who can see no problem.  He has prescribed Sialor for saliva stimulation.  It has only helped slightly but has given me gastrointestinal problems.  Therefore, I may have to discontinue using it.  I am very concerned about dental problems because of my lack of saliva.  I wake up about every two hours all night because of extreme dry mouth. Even though I am using Biotene for dry mouth, both the mouthwash and Oralbalance (the oralbalance is for moderate to severe dry mouth and supposed to give up to 8 hours relief) , the dry mouth still awakens me every two hours.

I am a 58 year old female and have no other health problems that I am aware of.   I have been on conjugated estrogens for 10 years for hot flashes.  I would be forever greatful if you could figure out this horrible problem.  Thank you very much in advance for any suggestions you may be able to offer.

Rosemary Walter