A medication in the form of sprays, gels and liquids used during medical procedures to numb the mucous membranes of the mouth and throat. Benzocaine is also sold over-the-counter and used to relieve pain from a variety of conditions, such as teething, canker sores, and irritation of the mouth and gums. The FDA issued a notice in early April 2011 to healthcare professionals and patients that agency continues to receive reports of methemoglobinemia, a serious and potentially fatal adverse effect, associated with benzocaine products.