Objective: To investigate the influence of dry mouth on the incidence and severity of inhalation
therapy-induced hoarseness. Methods: The volume of saliva secreted without stimulation was
measured in patients with asthma or chronic obstructive pulmonary disease (COPD) who also
answered a questionnaire on subjective ratings for hoarseness. The relationship between
salivary secretion and hoarseness was analyzed by the Pearson correlation and multiple linear
regression. The prediction accuracy of salivary secretion for the grade of hoarseness was
evaluated using a receiver-operating characteristic (ROC) analysis. Results: A total of 232
patients participated in this study. The subjective rating score of hoarseness was negatively
correlated with the volume of saliva secreted (r¼0.273, p50.001). A stepwise multiple linear
regression analysis revealed that salivary secretion (p50.001) and the dose of fluticasone
administered (p50.05) were significant variables for predicting hoarseness. The ROC analysis
for predicting severe hoarseness by salivary secretion showed significant prediction accuracy
(AUC¼0.690, 95% CI: 0.614–0.766, p50.001) and was higher in patients administered
fluticasone (AUC¼0.732, 95% CI: 0.644–0.821, p50.001). Conclusions: Hyposalivation is a
significant prediction factor of hoarseness induced by inhaled corticosteroids (ICS). The
prediction accuracy was higher in patients administered fluticasone than in those administered
another inhalation drug. Although the pharmaceutical efficacy of fluticasone is high, patients
with hyposalivation should be prescribed other inhalation drugs