Ipratropium bromide delivered orally by metered dose inhaler does not decrease salivary flow in normal subjects

A randomised placebo-controlled cross-over group study was conducted to ascertain the occurrence and duration of xerostomia induced by 240 micrograms (high dose) and 120 micrograms (low dose) of ipratropium bromide (IPB) delivered by metered dose inhaler (MDI) into the mouth in normal subjects. Salivary output was higher with both doses of IPB than with placebo though the differences were not statistically significant. IPB was less palatable than placebo as indicated on visual analogue scale (VAS) and the taste of the drug may have caused a reflex increase in salivary output from the major salivary glands which would have masked any possible local effect of the drug on the smaller submucosal glands of the mouth. IPB delivered into the oral cavity by MDI is therefore not a suitable treatment for hypersalivation.