June 26, 2014 -- Prescription oral viscous lidocaine 2% solution should not be used to treat infants and children with teething pain because of a serious risk, the FDA says.

"Oral viscous lidocaine solution is not approved to treat teething pain, and use in infants and young children can cause serious harm, including death," the agency says.

This year, the FDA has reviewed 22 case reports of serious reactions, including deaths, in infants and young children who were given the solution to treat mouth pain (including teething and stomatitis) or who accidentally ingested it.

“When too much viscous lidocaine is given to infants and young children or they accidentally swallow too much, it can result in seizures, severe brain injury, and problems with the heart. Cases of overdose due to wrong dosing or accidental ingestion have resulted in infants and children being hospitalized or dying," the FDA says.

The agency is requiring that a warning be added to the prescribing information, and is asking doctors not to prescribe or recommend the solution for teething pain.

Topical medications and pain-relievers rubbed on the gums "are not necessary or even useful, because they wash out of the baby's mouth within minutes,” the FDA says.

Parents and caregivers should follow the American Academy of Pediatrics' recommendations for treating teething pain, the agency says: Use a teething ring chilled in the refrigerator (not frozen), or gently rub or massage the child's gums with your finger.