FDA warns about a serious adverse effect associated with the use of benzocaine

FDA issued drug safety communications about a serious adverse effect associated with the use of over-the-counter (OTC) benzocaine gels, sprays, and liquids applied to the throat and gums to reduce pain.

In its communication to healthcare professionals, FDA is warning the public that the use of benzocaine is associated with methemoglobinemia, a rare but serious condition that results in the amount of oxygen carried through the blood stream being greatly reduced. In the most severe cases, methemoglobinemia can result in death.

Methemoglobinemia has been reported with all strengths of benzocaine gels and liquids, including concentrations as low as 7.5%. The cases occurred mainly in children aged 2 years or younger who were treated with benzocaine gel for teething.

FDA is particularly concerned about the use of OTC benzocaine products in children for relief of pain from teething because of the serious outcomes, including death, that may be associated with methemoglobinemia, as well as the difficulty parents or consumers may have in recognizing the signs and symptoms of methemoglobinemia when using these products at home.

Benzocaine gels and liquids are sold OTC under different brand names such as Anbesol, Hurricaine, Orajel, Baby Orajel, Orabase, and store brands.

Furthermore, symptoms of methemoglobinemia may not always be evident or attributed to the condition. Parents and caregivers should not use OTC benzocaine products on children under 2 years of age, except under the advice and supervision of a healthcare professional. If benzocaine products are used, it should be used sparingly and only when needed, but not more than 4 times a day.

In addition, FDA continues to receive reports of methemoglobinemia associated with benzocaine sprays. These sprays are used during medical procedures to numb the mucous membranes of the mouth and throat.

Benzocaine sprays are marketed under different brand names such as Hurricaine, Cetacaine, Exactacain, and Topex.

In 2006, FDA issued a public health advisory warning about methemoglobinemia with the use of benzocaine sprays during medical procedures. Since then, FDA reportedly has received notice of 72 new cases of methemoglobinemia, including 3 resulting in death, associated with the use of benzocaine sprays, bringing the total to 319 cases. A review of the cases indicates that the development of methemoglobinemia after treatment with benzocaine sprays may not be related to the amount applied. Symptoms of methemoglobinemia may appear within minutes to 1 or 2 hours after using benzocaine.

Benzocaine is also sold in a lozenge form.

People who develop methemoglobinemia may experience pale, gray- or blue-colored skin, lips, and nail beds; shortness of breath, fatigue, confusion, headache, lightheadedness, and rapid heart rate. The signs and symptoms usually appear within minutes to hours of applying benzocaine and may occur with the first application of benzocaine or after additional use.

“OTC gel and liquid medications containing benzocaine provide relief for children and adults who experience mouth pain. While FDA’s announcement notes very rare but serious instances of methemoglobinemia . . . these products are safe when used as directed for the large majority of consumers,” according to a statement prepared by the Consumer Healthcare Products Association, in Washington, D.C., for Drug Topics.

“Due to these rare instances, FDA has recommended that the products not be used in children under 2 years of age except under the advice of a healthcare professional. We will continue to study this issue and remain committed to working with the agency to ensure the safe and effective use of these products.”