Benzocaine is the main ingredient in many OTC teething products. One of the safety concerns of using benzocaine products is that it can cause a serious and sometimes fatal condition called methemoglobinemia. This is a disorder in which the amount of oxygen carried through the blood stream is greatly reduced. This can occur within minutes after exposure, even after the first time it is used. It doesn’t happen very often overall, but children under 2 years old appear to be at particular risk. The Food and Drug Administration (FDA) warned consumers against using benzocaine for teething babies in April 2011 and May 2012.
Another problem with using oral topical anesthetics is that babies will swallow the medicine. If this happens the throat may become numb, and the baby could have difficulty sensing liquids during swallowing. This can increase the risk of choking or put the baby at risk for aspiration (food or liquids entering the airway).
Some of these products don’t stick to the gums for long. They often wash out pretty quickly and only work for a short time. Then well-meaning parents may use the product more often that recommended by the doctor or the product label. Parents have also been known to put liquid gel forms of a topical anesthetic into a baby’s formula or even soak a pacifier or a cloth in it then put that in their baby’s mouth. How much the baby gets is not measured, so it may be too much.
Recently we were contacted about a tragedy where a pair of twin babies overdosed with a prescribed product called viscous lidocaine. This is a gel like prescription liquid that’s supposed to be used for inflamed or irritated membranes in the mouth and throat. FDA has not approved this for use in babies who are teething but some doctors prescribe it that way. It’s unclear how the babies got too much, but both of them suffered a seizure and then a cardiac arrest. They were taken to an ER by an emergency medical service. Sadly, only one could be resuscitated at the hospital. Lidocaine levels in the babies were found to be in the toxic range.
Our organization believes that viscous lidocaine should not be prescribed for infants and children who are teething. The directions for use and potential for toxicity are often not clear to parents and sometimes not even their doctors, thus increasing the danger.
As mentioned above, there are alternatives that can be effective. The American Academy of Pediatrics also discourages topical anesthetic use and instead suggests using a rubber teething ring that’s been chilled in the refrigerator (not the freezer). You can also gently rub or massage the child’s gums with your finger. Pain medicines like acetaminophen and ibuprofen can also be useful. But only with advice from your pharmacist or baby’s doctor.