The aim of this study is to obtain the basic knowledge for safer clinical use of oxymetazoline, one of nasal decongestants, by observing changes of ciliary activity and histopa-thologic findings after topical application of oxymetazoline to the cultured human basak mucosa.

The nasal mucosa, obtained from the inferior tubinates in healthy non-smokers without any nasal symptoms or signs, was cultured and then, exposed to oxymetazoline solu-tion at different concentrations from 0.0123% to 0.25%, containing no preservatives. Ciliary activity was observed under an inverted microscope and the histopathology of the mucosa was examined by light microscopy 1,3,6,12,24 and 48 hours after exposure, respectively.

Oxymetazoline impaired ciliary activity and induced mucosal injury at dose- and time-dependent patterns. Once the ciliary activity disappeared, it was not restored at least for the next 48 hours. Furthermore, these functional and morphologic changes resulted from applying oxymetazoline at the concentration of clinical use.

Oxymetazoline as a topical vasoconstrictor should be administered for the minimal period even at clinical dose.