From the FDA Drug Label
All patients should be aware that when topical anesthetics are used in the mouth or throat, the production of topical anesthesia may impair swallowing and thus enhance the danger of aspiration. Numbness of the tongue or buccal mucosa may increase the danger of biting trauma. For this reason food and/or chewing gum should not be used while the mouth or throat area is anesthetized.
The use of Oracorte (lidocaine) on the tongue is not entirely safe. While the drug label does not explicitly state that it is unsafe, it does highlight the potential risks associated with using topical anesthetics in the mouth or throat, including impaired swallowing, aspiration, and biting trauma. Therefore, it is recommended to exercise caution when using Oracorte on the tongue and to follow the recommended dosage and administration guidelines to minimize the risk of adverse effects 1.
From the Research
Lidocaine products like Orajel or Xylocaine can be used on the tongue for temporary pain relief, but should be used with caution, as excessive use can lead to systemic toxicity, as reported in a case study 2. When using lidocaine on the tongue, it is essential to follow the package instructions and use the minimum amount necessary to achieve pain relief.
- The risk of systemic toxicity is higher with excessive use, as seen in a case where a 22-year-old man developed toxic symptoms after using more than 240 ml of oral viscous lidocaine per day 2.
- A review of the literature on the risk of systemic toxicity with topical lidocaine/prilocaine found that possible factors contributing to systemic toxicity include excessive amount of application, large application area, prolonged application time, and diseased or inflamed skin 3.
- A study on the systemic absorption of lidocaine after topical application for the treatment of oral mucositis in bone marrow transplantation patients found that plasma lidocaine levels were lower than the therapeutic range, indicating minor systemic absorption 4.
- Another study compared the serum levels of lidocaine and its metabolite monoethylglycinexylidide (MEGX) after application of five commonly-available lidocaine-containing topical anesthetics and found significant interindividual differences in absorption levels 5. It is crucial to be aware of these potential risks and to use lidocaine products judiciously, especially in children under 2 years, who should not use these products, and adults, who should avoid eating or drinking for at least 60 minutes after application to prevent accidental biting of the numbed area. If tongue pain persists beyond a few days or is severe, it is essential to consult a healthcare provider rather than continuing to use topical anesthetics, as lidocaine can mask pain that might indicate a more serious condition requiring medical attention.