Health Canada released important safety information about health risks associated with the use of topical benzocaine products, including a rare but potentially serious blood condition known as methemoglobinemia (MetHb).
As per communication Health Canada said they are continuesly receiving reports of benzocaine-related adverse reactions, including MetHb. The risk is higher in children under two years of age.
Topical benzocaine products are available over-the-counter in various concentrations and formulations, including sprays, gels, liquids and creams, and are used to relieve pain from a variety of conditions such as sore throats, teething, toothache, canker sores, irritation of the mouth and gums, burns, insect bites, itching, and hemorrhoids. They are also used by healthcare practitioners during surgical, dental and other medical procedures to numb the mouth and throat.
MetHb reduces the ability of red blood cells to deliver oxygen throughout the body. Signs and symptoms of MetHb include pale, grey or blue-coloured skin, lips, or nail beds; shortness of breath; fatigue; confusion; headache; lightheadedness; nausea; and change in heart rate. These symptoms can appear within minutes or one to two hours after benzocaine use, and can occur after the first or several uses. In rare severe cases, MetHb can progress to stupor, coma and possibly death.
Other reported side effects associated with topical benzocaine products include breathing or swallowing difficulties, a swollen tongue or mouth, irregular heartbeat, malaise, body twitching, hypersensitivity, burning, redness, itching, rash, and irritation at the site of administration. These effects can occur with any topical benzocaine product, regardless of product type or benzocaine concentration, in sensitive individuals.
