Are there any medicines to help dry up the excessive saliva?

Do you have a spitter that is driving you nutty? My mom was one. She always had a tissue in her hand for something to spit into. Gross! I think it may have been partially due to dehydration, nothing to thin the mucus. There may be a med but it wouldn't work properly without fluid consumption. There were enough other meds mom was taking would not have added another to try to address something that was just a nuisance and gross.