Objective: To determine if the use of toothpicks infused with flavoring and flavoring plus the food additive spilanthol (Xerosticks™) improve saliva flow in people with opioid-induced dry mouth.
Design: Time series, nonrandomized, double-blind within-subject design.
Setting: Private practice/academic multidisciplinary pain and palliative care clinic.
Participants: Ten subjects with opioid-induced dry mouth were recruited, and all finished the study.
Methods: Salivary flow and pH were measured consecutively at baseline, following use of a mango-flavored toothpick, and again after use of a mango-flavored toothpick infused with spilanthol. Salivary flow rates and saliva pH were compared between flavored and baseline, between flavored + spilanthol and baseline, and between the flavored and flavored + spilanthol. Mouthfeel of each toothpick was assessed using the Bluestone Mouthfeel Questionnaire.
Outcomes: The primary measure was salivary flow, and the secondary measures were salivary pH and mouthfeel.
Results: Saliva flow increased 440 percent over baseline with use of a flavored toothpick and 628 percent over baseline with similarly flavored toothpicks infused with spilanthol, and these differences are significant (p = 0.00002). Saliva pH increased with both toothpicks (p = 0.04). The addition of spilanthol produced a greater increase in salivary flow (p = 0.05) compared to control toothpicks with flavoring alone. Furthermore, addition of spilanthol improved the "mouthfeel" of the toothpick (p = 0.00001).
Conclusions: Toothpicks infused with either flavoring or flavoring plus spilanthol are likely to be an effective remedy for opioid-induced dry mouth. Addition of spilanthol may improve effectiveness over flavoring alone and may be better ac-cepted because spilanthol appears to improve mouthfeel.