True or False: Benzocaine is absorbed systemically.

True or False: Benzocaine is absorbed systemically.

• A. True
• B. False
• C. Not at all
• D. Unknown

Answer: (A)

Systemic absorption can occur with topical benzocaine. Although it’s applied to numb the surface, the mucous membranes of the mouth are highly vascular, so some of the drug passes into the bloodstream, especially when large areas are treated, contact is prolonged, or higher concentrations are used. This systemic exposure means there’s a real risk of effects beyond the local numbness, notably methemoglobinemia, which reduces the blood’s oxygen-carrying capacity, and potential CNS or cardiovascular symptoms at higher levels. The risk is greater in infants and young children, with broken or inflamed mucosa, or when high-concentration preparations are used over large areas or for extended times. In practice, use the minimum effective amount, avoid widespread or prolonged application, monitor for signs of methemoglobinemia, and avoid benzocaine in patients with known risk factors.

Systemic absorption can occur with topical benzocaine. Although it’s applied to numb the surface, the mucous membranes of the mouth are highly vascular, so some of the drug passes into the bloodstream, especially when large areas are treated, contact is prolonged, or higher concentrations are used. This systemic exposure means there’s a real risk of effects beyond the local numbness, notably methemoglobinemia, which reduces the blood’s oxygen-carrying capacity, and potential CNS or cardiovascular symptoms at higher levels. The risk is greater in infants and young children, with broken or inflamed mucosa, or when high-concentration preparations are used over large areas or for extended times. In practice, use the minimum effective amount, avoid widespread or prolonged application, monitor for signs of methemoglobinemia, and avoid benzocaine in patients with known risk factors.