Why Oral Benzocaine Is Not Meant to Be Swallowed
Oral benzocaine, found in products like gels, sprays, and lozenges, is a topical analgesic designed to numb the surface of the mouth or throat temporarily. Its purpose is to provide short-term pain relief from issues like canker sores, cold sores, or sore throats. The key to its safe and effective use is that it remains on the surface where the pain is located and is not ingested. The medication label clearly instructs users to spit out liquid formulations and not to swallow whole lozenges.
When benzocaine is swallowed, it enters the bloodstream and can disrupt the body's normal processes, leading to systemic side effects that topical application avoids. The concentration and rapid absorption that occur upon ingestion are particularly dangerous, triggering a rare but serious adverse reaction known as methemoglobinemia.
The Primary Risk: Methemoglobinemia
Methemoglobinemia is a blood disorder where a large amount of a variant hemoglobin (methemoglobin) is produced, which is unable to release oxygen to the body's tissues. This causes a significant reduction in the amount of oxygen carried by the blood, potentially leading to brain damage, tissue damage, and in severe cases, death. This condition is not dose-dependent, meaning even a small amount of benzocaine can trigger a reaction.
Symptoms of methemoglobinemia can appear within minutes to hours after benzocaine use. Anyone experiencing these signs should stop using the product and seek emergency medical help immediately.
Symptoms of Methemoglobinemia
- Bluish-gray, pale, or blue-colored skin, lips, and nail beds
- Shortness of breath or difficulty breathing
- Fatigue or unusual tiredness and weakness
- Confusion
- Headache
- Lightheadedness or dizziness
- Rapid heart rate
Who Is Most at Risk from Swallowing Benzocaine?
While swallowing oral benzocaine is dangerous for anyone, certain populations face a significantly higher risk of developing complications. The FDA has issued strong warnings regarding its use, particularly for children.
Children Under Two Years Old
The FDA has explicitly warned against using oral benzocaine products for teething in infants and children younger than two. Studies have shown that most reported cases of methemoglobinemia occurred in children under two who were given benzocaine gels for teething pain. The potential benefits of using these products are far outweighed by the serious risks. Instead, health authorities recommend safer, non-medicated alternatives for teething pain, such as chilled teething rings or gently massaging the gums.
Elderly Patients and Those with Underlying Conditions
Older adults, as well as individuals with pre-existing health issues, are also at an increased risk. Those with breathing problems like asthma, bronchitis, or emphysema, heart disease, or certain inherited metabolic defects (such as G6PD deficiency) should use extreme caution and only under a doctor's supervision. For these individuals, the body may already have a reduced capacity to carry oxygen, and benzocaine exposure could exacerbate the problem.
Proper Use and First Aid for Oral Benzocaine
Safe use of oral benzocaine depends entirely on following the product instructions carefully. For gels and liquids, apply a small amount to the affected area and do not use more than four times a day. For lozenges, allow them to dissolve slowly in the mouth without chewing or swallowing them whole.
In case of accidental ingestion, take these immediate steps:
- Stay calm: Assess the person's condition and look for symptoms of methemoglobinemia.
- Contact Poison Control: Call the Poison Control center immediately at 1-800-222-1222 for guidance.
- Seek Emergency Care: If the person shows signs of severe distress, such as trouble breathing, bluish skin, or loss of consciousness, call 911 right away.
Oral Anesthetic Comparison Table
It is helpful to compare oral benzocaine with other options to understand its specific role and risks.
| Feature | Benzocaine (e.g., Orajel, Anbesol) | Lidocaine (Prescription Strength) | Non-Medicated Remedies |
|---|---|---|---|
| Application | Topical use in the mouth only; not to be swallowed. | Can be prescribed in topical form; safer for ingestion in controlled doses. | External pressure or cold applied to the gums. |
| Action | Temporarily blocks nerve signals at the surface. | More potent and longer-lasting anesthetic; also has cardiac effects. | Provides counter-irritation and soothing sensation. |
| Key Risks | High risk of methemoglobinemia if swallowed, especially in young children. | Lower risk of systemic issues if used correctly under supervision. | No systemic drug risks; choking hazard with small objects. |
| FDA Recommendations | Avoid for children under 2. Use sparingly in adults. | Prescription use only; safer profile for medical use. | Recommended for teething babies over benzocaine. |
Conclusion: Prioritizing Safety Over Convenience
While over-the-counter benzocaine products can offer temporary relief for mouth and throat pain, they are not a benign solution. The potential for serious harm, specifically methemoglobinemia, necessitates strict adherence to proper usage and a complete avoidance of swallowing the product. For adults, this means using it sparingly and only as directed. For children under two, the FDA's warning is clear: do not use benzocaine products for teething pain at all due to the significant and potentially fatal risk. By understanding the dangers and opting for safer alternatives when appropriate, consumers can prioritize health and safety for themselves and their families.
For more information on drug safety, visit the FDA's official website.
