Re: Saliva glands killed during Radiation on throat cancer.
My doctor prescribed a pill to stimulate my saliva - it's called "salagen" and comes in 5mg pills. I have not suffered with dry throat and mouth, on the contrary, I have thick mucus. But the doctor said the mucus was so thick because I had no saliva, and that salagen would increase saliva to loosen the mucus. Also he said he didn't want my saliva glands to "atrophy."
It seems that your brother has a symptom that is opposite of mine (dryness), but possibly the result of a similar malfunction (decreased saliva).
Hopefully this is good info for you and your brother. Good luck.