In the event of a toxic reaction to local anesthesia, the recommended treatment is:

• A. Oxygen
• B. Epinephrine
• C. Benadryl
• D. Lidocaine

Answer: (A)

The main idea is that the first priority in a toxic reaction to local anesthesia is to support breathing and oxygen delivery. Giving 100% oxygen helps counteract any hypoxia from CNS or respiratory symptoms and reduces the risk of further cardiac and neurologic compromise while you assess and intervene.

Stopping the local anesthetic administration and securing the airway are essential next actions, but oxygenation is the immediate, foundational step because inadequate oxygen can quickly worsen CNS effects like dizziness or seizures and heart problems.

The other options aren’t the best initial choice: epinephrine can be used later if there is specific cardiovascular collapse or severe hypotension, but it isn’t the first-line treatment for LAST. Benadryl is aimed at allergic reactions and doesn’t address the toxic effects on the CNS and heart. Lidocaine would worsen the situation since it’s the agent causing toxicity, not a remedy. In severe cases, lipid emulsion therapy is added as a specific rescue treatment, along with seizure control and hemodynamic support, but oxygen remains the immediate starting measure.