I had two cups of coffee yesterday with four teaspoons of sugar and the dry mouth has not left yet. Sugar and salt both keep my mouth dry all day long. I couldn't lick an envelope wet. I always drink my eight glasses of water daily. When I woke up this morning the middle of my tongue was like sandpaper, hard, rough, and dry. I read that drinks don't all refresh, some hydrate and others dehydrate.
While adults average 12.8-ounce beverages daily, the net gain equals three glasses of water (eight recommended) because some drinks dehydrate. Daily average:
no-caffeine soda .6
hydrating total 7.9
caffeine soda 1.3
dehydrating total 4.9