What are the dangers of using lidocaine patches?

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

Lidocaine is an anesthetic; anesthetics have a numbing effect and are used to block pain. Topical (intended to be used on body surfaces such as the skin) lidocaine is a common medicine cabinet item. Topical anesthetics like lidocaine are available as gels, creams, liquids, sprays, eye drops, and patches. They work by blocking nerves from sending pain signals to the brain. The result is temporary numbness of the area on which they are applied (a "local" anesthetic).

Because of their numbing effect, topical anesthetics are effective in treating pain such as sunburns, cuts or scrapes, insect bites, cold sores, rashes, hemorrhoids, injuries of the eye, or a sore throat. However, they should not be used to relieve teething discomfort in children.

When used sparingly and as directed, topical lidocaine is generally safe. However, misuse, overuse, or overdose can lead to a number of serious health problems and even death.

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 headache to confusion, seizures, coma, and cardiac arrest. It is important to note that these effects can result from excessive topical use or misuse of lidocaine as well. For example, 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. This can also occur when it’s applied to skin that is not intact such as open wounds, blisters, or burns. Wrapping the treated area also increases absorption.

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

It's easy to make dosing errors when using lidocaine. Such errors can be potentially toxic, especially in children. Use it carefully.

If someone has been exposed to lidocaine, 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

FDA drug safety communication: FDA recommends not using lidocaine to treat teething pain and requires new boxed warning [internet]. Silver Spring MD: US Food and Drug Administration; January, 2016 [accessed Jun 3, 2017].

Skin numbing creams may cause death [internet]. NBC Washington; August 2008 [accessed Nov 2, 2020].

Boyes RN, Scott DB, Jebson PJ, Godman MJ, Julian DG. Pharmacokinetics of lidocaine in man. Clin Pharmacol Ther 1971;12:105-16.

Jonville AP, Barbier P, Blond MH, Boscq M, Autret E, Breteau M. Accidental lidocaine overdosage in an infant. J Toxicol Clin Toxicol 1990;28:101-6.

Poison Statistics
Jingles
Spike Program

Lidoderm (lidocaine) is an amide-type, local anesthetic medication available in a patch form prescribed for relief of pain associated with postherpetic neuralgia. Lidocaine, like other local anesthetics causes a loss of sensation by reducing the flow of sodium in and out nerves to decrease the initiation and transfer of nerve signals.

Common side effects of Lidoderm include

application site reactions (local burning, bruising, blisters, itching, irritation),
lightheadedness,
dizziness,
nausea,
nervousness,
blurred vision, and
low blood pressure.

Serious side effects of Lidoderm include

severe application site reactions (burning, stinging, irritation, swelling, or redness),
sudden dizziness or drowsiness after medicine is applied,
confusion,
blurred vision,
ringing in your ears, and
unusual sensations of temperature.

Drug interactions of Lidoderm include anti-arrhythmia medications like amiodarone, propafenone, sotalol, tocainide, and mexiletine because such combinations can affect heart rate and rhythm and cause other additive side effects.

There are no adequate studies done on Lidoderm patches to determine safe and effective use in pregnant women.

Lidocaine may enter breast milk in trace amounts; therefore, it is best to be cautious before using it in breastfeeding mothers.

Common side effects of lidocaine patches include:

local burning,
bruising,
blisters,
itching,
irritation,
lightheadedness,
dizziness,
nausea,
nervousness,
blurred vision, and
low blood pressure.

Application Site Reactions

During or immediately after treatment with Lidoderm (lidocaine patch 5%), the skin at the site of application may develop blisters, bruising, burning sensation, depigmentation, dermatitis, discoloration, edema, erythema, exfoliation, irritation, papules, petechia, pruritus, vesicles, or may be the locus of abnormal sensation.
These reactions are generally mild and transient, resolving spontaneously within a few minutes to hours.

Allergic Reactions

Allergic and anaphylactoid reactions associated with lidocaine, although rare, can occur.
They are characterized by angioedema, bronchospasm, dermatitis, dyspnea, hypersensitivity, laryngospasm, pruritus, shock, and urticaria.
If they occur, they should be managed by conventional means. The detection of sensitivity by skin testing is of doubtful value.

Other Adverse Events

Due to the nature and limitation of spontaneous reports in postmarketing surveillance, causality has not been established for additional reported adverse events including:
Asthenia, confusion, disorientation, dizziness, headache, hyperesthesia, hypoesthesia, lightheadedness, metallic taste, nausea, nervousness, pain exacerbated, paresthesia, somnolence, taste alteration, vomiting, visual disturbances such as blurred vision, flushing, tinnitus, and tremor.

Systemic (Dose-Related) Reactions

Systemic adverse reactions following appropriate use of Lidoderm are unlikely, due to the small dose absorbed. Systemic adverse effects of lidocaine are similar in nature to those observed with other amide local anesthetic agents, including CNS excitation and/or depression (light-headedness, nervousness, apprehension, euphoria, confusion, dizziness, drowsiness, tinnitus, blurred or double vision, vomiting, sensations of heat, cold or numbness, twitching, tremors, convulsions, unconsciousness, respiratory depression and arrest).
Excitatory CNS reactions may be brief or not occur at all, in which case the first manifestation may be drowsiness merging into unconsciousness. Cardiovascular manifestations may include bradycardia, hypotension and cardiovascular collapse leading to arrest.

Antiarrhythmic Drugs

Lidoderm should be used with caution in patients receiving Class I antiarrhythmic drugs (such as tocainide and mexiletine) since the toxic effects are additive and potentially synergistic.

Local Anesthetics

When Lidoderm is used concomitantly with other products containing local anesthetic agents, the amount absorbed from all formulations must be considered.

Procedures & Tests Symptoms & Signs FAQs & Doctor's Views

Medications FDA Drug Labels on RxList.com