Your mouth can become dry from radiation therapy, some types of chemotherapy, or some medications. The saliva glands can become irritated and produce less saliva, or your saliva can become very thick, sticky, or stringy. For some people, dryness is mild and can be managed with drinking more water and fluids. For others, dryness is more severe and can cause problems with eating, talking, and sleeping. A dry mouth also increases your chance for developing dental cavities or mouth infections. If you smoke, chew tobacco, or drink alcoholic beverages, the dryness will be worse.
You do not need a prescription for items recommended in this section. However, many drugstores keep them behind the pharmacists' counter, instead of on drugstore shelves.
Article from American Dietetic Association.