MY MOTHER CAN´T EAT. Please if you have so info that can help.

Hello, my mother has gastric cancer, metastasis and in the NY Hospital, they told us yesterday that there is nothing else to do for her. No more treatment. She´s only 48. 

The thing is that she has EXCESS OF SALIVATION that doesn't allow her to eat or even sleep because she needs to spit very often. Can you help me with any recommendation on what to do to STOP SALIVATION? Thanks.