A new warning from the U.S. Food and Drug Administration says that teething infants can be seriously harmed or even die from certain "gum numbing" medications. 

The FDA said Wednesday that local anesthetics such as viscous lidocaine and benzocaine-containing teething products should never be used on teething children, unless used under the supervision of a doctor or health care professional.

Viscous lidocaine is a local anesthetic and is typically used to treat mouth ulcers that can occur in patients undergoing chemotherapy. The medication is available by prescription only. Parents should not use the medication to help teething babies. There have been reports of babies overdosing on the medication and even dying in children as old as 3 years old. 

Symptoms of overdosing include confusion, jitteriness, shaking, seizures, falling asleep too easily, vision problems and vomiting, according to the FDA. Viscous lidocaine can also make swallowing difficult and increase the risk of choking. 

The FDA also said that over-the-counter benzocaine products should not be used on children 2 years old or younger. These products include Anbesol, Hurricaine, Orajel, Baby Orajel and Orabase.

Benzocaine products for mouth and gum pain can cause a rare but serious and potentially fatal condition called methemoglobinemia, a disorder in which the amount of oxygen carried through the blood stream is greatly reduced.

Parents may simply have to accept teething as an uncomfortable part of infancy, experts say. If your child has swollen or tender gums, you can gently massage them with your finger and give your child a cool teething ring or cool, wet washcloth to teeth on, the FDA said.