Poison Control Center Management of Benzocaine Exposures

Benzocaine is a topical anesthetic frequently used in healthcare facilities and in over-the-counter medications in concentrations up to 20%. Benzocaine may induce methemoglobinemia, a condition that impairs the blood’s ability to carry oxygen. The optimal management of exposure to benzocaine remains unclear because serious toxicity is uncommon and may not be dose-related. In 2000, it was estimated that more than one million exposures to benzocaine, both therapeutic and unintentional, occur yearly in the US; yet fewer than 100 cases of benzocaine-induced methemoglobinemia have been reported in the medical literature over the last 50 years. Considerable under-reporting of cases probably exists, as patients with mild methemoglobinemia may have minimal symptoms or remain asymptomatic. Severe cases requiring treatment are evidently quite unusual.