Warning issued against benzocaine products

An alert has been issued on the use of benzocaine products due to its potentially fatal side effect by the Department of Health.

Two pharmaceutical products containing benzocaine are registered in Hong Kong for topical oral use. One of them is approved for children aged two and over, and the other is approved for children over three years of age.

The US Food & Drug Administration recently warned of methaemoglobinaemia associated with the use of benzocaine products, whether as sprays during medical procedures to numb the mucous membranes of the mouth and throat, or as gels and liquids to relieve pain in a variety of conditions, such as teething, canker sores and irritation of the mouth and gums.

Though rare, the condition is very serious and can be fatal due to the reduction in oxygen carried in the blood. It can occur with all strengths of benzocaine sprays, gels and liquids, and tends to affect mainly children aged two years or younger.

The US recommended such products should not be used on children less than two years of age, except on a doctor's advice. Adults using benzocaine gels or liquids should follow recommendations on the product labels.