Nasal Sprays Not Equally Effective
Those Without Preservative Clear Stuffiness Best
Sept. 24, 2002 -- Allergy nasal sprays that contain a germ-killing preservative may not work as well as other formulations, according to a new study. Researchers found that the preservative may limit the drugs' nose-clearing effects.
Research had already shown that the preservative -- called benzalkonium -- could interfere with how well over-the-counter saline and decongestant nasal sprays work. It's effect on specialized hair cells in the nose may be to blame.
Steroid nasal sprays are commonly used to calm inflammation and prevent the runniness and stuffiness that comes with hay fever. So researchers tested whether benzalkonium may also interfere with the effectiveness of these prescription sprays.
In a study presented at the recent meeting of the American Academy of Otolaryngology, University of Chicago researchers Robert M. Naclerio, MD, and colleagues compared two different steroid nasal sprays. Both are FDA-approved for the treatment of allergic rhinitis: the stuffy, runny nose, and sneezing that comes with hay fever. Rhinocort Aqua doesn't contain benzalkonium. Nasonex does. The study was funded in part by a grant from Rhinocort manufacturer AstraZeneca.
The researchers treated 10 allergy sufferers with Rhinocort and 10 with Nasonex. Both drugs helped. But the group treated with Rhinocort had clearer noses after treatment.
Why? This study was too small to show for sure. But earlier studies have shown that benzalkonium is toxic to tiny hairs in the nose. In the normal nose, these little hairs work together in waves. They push gunk to the back of the nose and out into the throat, where swallowing carries it away. Damage to these hairs increases nasal stuffiness -- and increases the risk of new infections.
Most nasal sprays contain benzalkonium, because it kills germs that might get sucked back into the spray bottle. New bottle designs can keep this from happening, so some products no longer contain benzalkonium. Some researchers have called for the removal of benzalkonium from asthma inhalers. When used only for a few days -- as their labels suggest -- benzalkonium-containing products are safe. But even short-term use appears to affect the lining of the nose.