Sialagogues

Sialagogues are substances which increase the secretion of saliva. They may do so by stimulating the secretory nerves of the salivary glands reflexly through the sensory nerves of the mouth, stomach, eye, or nose. Thus, sweet or slightly irritating substances in the mouth provoke a secretion of saliva, while the sight or smell of savoury eatables 'makes the teeth water.' These are known as topical sialagogues, and include such substances as mustard, ginger, pellitory-root, dilute acids, &c. Dilute acids and pellitory-root are the only ones which are much used in medicine to increase the flow of saliva and keep the mouth moist; a small piece of the latter is chewed from time to time. Sialagogues also act after absorption into the blood by a direct stimulating action on the secretory nerves. Jaborandi and mercurial compounds are well-known examples of this class. The former, or its alkaloid, pilocarpine, may cause the secretion of a pint or more of saliva within a short time after administration. This class is known as remote or general sialagogues.