Vicks VapoRub may put infants at risk, study finds

Published 10:27 pm Monday, January 12, 2009

Many parents slather Vicks VapoRub on a child who has a cough or the sniffles — because, by gosh, that’s what their parents did to them. But for children younger than 2, the folksy remedy could be dangerous, researchers warned today.

Reporting in Chest, the journal of the American College of Chest Physicians, the researchers said that using the ointment to ease coughing and congestion in children of this age might lead to severe breathing problems by increasing mucus production and inflammation.

The product’s label cautions against using Vicks VapoRub on children younger than 2, but many parents do so anyway, putting their infants at risk, experts said.

“People don’t read warnings on prescription medications, so to (read a warning for) a salve on the outside of the body that has been around for 100 years … I think it would be a rare parent who would do that,” said lead author Dr. Bruce Rubin of Wake Forest University Baptist Medical Center in Winston-Salem, N.C.

Vicks VapoRub, whose active ingredients are camphor, menthol and eucalyptus oil, was first formulated in 1891 in Greensboro, N.C. National marketing began in 1905, and it gained popularity during the Spanish flu epidemic of 1918.

Several small studies have failed to show any medicinal benefit from the ointment, Rubin said. He suspects that the menthol in it binds to cold receptors in the throat, giving the impression that the patient is breathing more easily even when that is not the case.

The ointment’s risks came to the attention of Rubin and his colleagues when they treated an otherwise healthy 18-month-old girl who was brought to the emergency room by her grandparents after her respiratory infection suddenly grew worse. Questioning revealed that the severe symptoms had appeared shortly after they put Vicks VapoRub under her nose.

The researchers at the time were using ferrets — whose airway anatomy and cell lining are similar to those of humans — to study infant respiratory problems. To look at the effect of VapoRub, they applied the ointment directly to cultured ferret tracheal cells as well as under the noses of healthy ferrets and ferrets with tracheal inflammation similar to that of humans with a cold.

In the cultured cells, the ointment increased mucus secretion by 59 percent. It increased secretion by 14 percent in the airways of healthy animals and by 8 percent in those with inflamed airways.

Because the airways of infants are much narrower than those of adults, “any increase in mucus or inflammation can narrow them more severely,” Rubin said.

The ointment also slowed the action of the hair-like cilia in the throat that carry mucus away.

The team has since identified three more infants brought to emergency rooms with breathing problems after being treated with Vicks VapoRub. All four recovered quickly once application of the ointment was stopped.

David Bernens, a spokesman for Vicks VapoRub manufacturer Procter &Gamble Co., said, “The safety and efficacy of the product has been determined by multiple clinical trials with over 1,000 children tested. … Our results are inconsistent with the claims of this study.”

Bernens added that the company’s post-marketing surveillance showed only three adverse incidents per 100 million units sold, with no mention of respiratory distress among them.

Conscientious pediatricians would not recommend that parents use Vicks VapoRub, “because it hasn’t been shown to be effective,” said Dr. Daniel Craven, a pediatric pulmonologist at Rainbow Babies &Children’s Hospital in Cleveland who was not involved in the study. However, he added, “we were never concerned that it would cause a problem.”

Craven said the new study was too small to confirm a risk from the ointment. He said he hoped more studies would be undertaken to further support or refute the possibility.