Inhibitory effects of nasal drops components on granulocyte chemotaxis.

A possible toxic effect of components in nasal drops on chemotaxis by human granulocytes was studied. The vasoactive substances oxymetazoline chloride and xylometazoline chloride gave a successive reduction of chemotaxis down to zero for a concentration of 500 mg/l which is around that used in commercial preparations. The preservative benzalkonium chloride which is used in nasal drops in a concentration of 200 mg/l was deleterious for chemotaxis at a concentration of 0.8 mg/l. Thiomersal was deleterious for chemotaxis at a concentration of 1 mg/l which should be compared with a concentration of 24 mg/l used as preservative in nasal drops. Together with previous studies the present results indicate that the addition of preservatives in nasal drops should be questioned especially as they can be safely distributed without any risk of bacterial contaminations nowadays.