Inhibition of Human Neutrophil Actin Polymerization, Phagocytosis and Oxidative Burst by Components of Decongestive Nosedrops

Human neutrophil functions have been examined after exposure of leukocytes to components of decongestive nosedrops in vitro. Both the vasoactive components oxymethazoline chloride and xylomethazoline chloride, as well as the preservative benzalkonium chloride, showed a concentration- and time-dependent deleterious effect on neutrophil actin polymerization, phagocytosis and oxidative burst. The most toxic of the drug components was benzalkonium chloride, which in the commercial nosedrops tested was present in concentrations about 20 times higher than that compatible with intact neutrophil functions. These findings suggest possible inhibition of mucosal neutrophil activity following exposure to nosedrops in vivo, and support earlier reports that have questioned the use of preservatives in decongestive nosedrops.