Intraoral stimulation of salivary secretion with the cholinesterase inhibitor physostigmine as a mouth spray: a pilot study in healthy volunteers.

Dry mouth produces a deterioration in oral health and impairs quality of life. There is a need for a novel approach to the pharmacological treatment of dry mouth. With a view to enhancing the cholinergic drive on minor salivary glands, whilst at the same time minimising adverse systemic effects, the cholinesterase inhibitor physostigmine was therefore sprayed, in a fixed volume, onto the oral mucosa of seven healthy subjects. Three concentrations (0.5%, 1% and 2%) were tested. The mean salivary output over time (0-105 min) was higher than that of placebo (p<0.05), as the area under the curve increased by 61%, 91% and 66% at physostigmine 0.5%, 1% and 2%, respectively. Two subjects experienced nausea at the highest physostigmine concentration, thus reflecting systemic effects. Heart rate, blood pressure and respiration were unaffected by the physostigmine treatment.