Poison Prevention for Toddler | Medicines

Effects of Lidocaine

The Bottom Line

Lidocaine, a local anesthetic, works by causing a temporary numbing effect. When used sparingly and as directed, topical lidocaine is generally safe. Misuse or overuse can cause serious problems and even death.

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What is lidocaine?

Lidocaine is an anesthetic. Anesthetics have a numbing effect and are used to block pain. Topical anesthetics (intended to be used on body surfaces such as the skin) like lidocaine are available as gels, creams, liquids, sprays, eye drops, and patches. Because of their numbing effect, topical anesthetics are useful for treating pain such as sunburns, cuts or scrapes, insect bites, cold sores, rashes, hemorrhoids, injuries of the eye, or a sore throat.

How does it work?

Local anesthetics like lidocaine work by blocking nerves from sending pain signals to the brain. The result is numbness of the area on which they are applied. This effect is temporary and does not damage the nerve cells involved.

Lidocaine on the skin

When used sparingly and as directed, topical lidocaine is generally safe. However, misuse or overuse can lead to serious health problems and even death. Covering a large area of the body with lidocaine or leaving it on the skin for a long time can lead to absorption of the drug into the bloodstream. Absorption can also occur when it is applied to skin that is not intact, such as open wounds, blisters, or burns. Wrapping the treated area increases absorption.

Lidocaine and teething

Tooth eruption (known as teething) is a normal event in the development of a child and often causes gum irritation, drooling, and fussiness. Topical lidocaine applied to the area around an erupting tooth has been used in attempts to ease the discomfort. Application of a lidocaine product within the mouth of an unhappy child is not an easy task, and the lidocaine quickly becomes diluted with saliva. Some lidocaine is always swallowed. For this reason, most child health organizations, including the American Academy of Pediatrics, discourage the use of lidocaine for teething. Instead, they recommend using chilled teething rings or pacifiers, washcloths soaked with cold water, or even massaging the gums with a clean finger.

Is lidocaine safe to ingest?

Ingestion of lidocaine can cause numbness of the mouth and throat, which can lead to trouble swallowing and even choking. If a substantial amount is ingested, enough can be absorbed into the bloodstream to affect vital organs, primarily the brain and heart. Symptoms can range from mild drowsiness and headaches to confusion, seizures, coma, and cardiac arrest.

Lidocaine and methemoglobinemia

Lidocaine can impair the ability of hemoglobin in red blood cells to carry oxygen to the tissues. Methemoglobinemia is the condition of having blood that has this altered kind of hemoglobin. Methemoglobinemia can result even from normal use of lidocaine, especially in children.
Because their blood is not able to carry enough oxygen to the tissues, people with methemoglobinemia appear very pale or even blue, feel very tired, and experience shortness of breath. Methemoglobinemia can be life-threatening.

Have more questions?

If you have more questions about a lidocaine exposure, check the webPOISONCONTROL online tool or call Poison Control at 1-800-222-1222 for help.

Serkalem Mekonnen, RN, BSN, MPH
Certified Specialist in Poison Information

Revised William G. Troutman, PharmD
Professor of Pharmacy Emeritus

For More Information

FDA drug safety communication: FDA recommends not using lidocaine to treat teething pain and requires new Boxed Warning. US Food and Drug Administration. Updated January 16, 2016. Accessed May 12, 2025.

Skin numbing creams may cause death. NBC Washington. August28, 2008. Accessed May 12, 2025.

References

Amitai Y, Whitesell L, Lovejoy FH Jr. Death following accidental lidocaine overdose in a child. N Engl J Med. 1986;314(3):182-183.

Balit CR, Lynch AM, Gilmore SP, Murray L, Isbister GK. Lignocaine and chlorhexidine toxicity in children resulting from mouth paint ingestion: a bottling problem. J Paediatr Child Health. 2006;42(6):350-353.

Catterall WA, Mackie K. Local anesthetics. In: Bronton LL, Knollmann BE, eds. Goodman & Gilman’s the Pharmacological Basis of Therapeutics. 14^th ed. McGraw-Hill Education; 2022.

Curtis LA, Dolan TS, Seibert HE. Are one or two dangerous? Lidocaine and topical anesthetic exposures in children. J Emerg Med. 2009;37(1):32-39.

Hoda S, O'Brien J, Gamble J. Intractable seizures in a toddler after application of an over-the-counter local anesthetic cream. CMAJ. 2016;188(14):1030-1032.

Jonville AP, Barbier P, Blond MH, Boscq M, Autret E, Breteau M. Accidental lidocaine overdosage in an infant. J Toxicol Clin Toxicol. 1990;28(1):101-106.

Kargl S, Hornath F, Rossegg U, et al. Status epilepticus, cardiac resuscitation, and posterior reversible encephalopathy syndrome after ingestion of viscous lidocaine: a plea for more childproof packaging of pharmaceuticals. Pediatr Emerg Care. 2014;30(3):185-187.

Teoh L, Moses GM. Are teething gels safe or even necessary for our children? A review of the safety, efficacy and use of topical lidocaine teething gels. J Paediatr Child Health. 2020;56(4):502-505.