Lidocaine Side Effects and Interactions You Need to Know About

  • Lidocaine is a local anesthetic that can be administered through injection or applied directly to a targeted area. It comes in the form of creams, gels, and ointments.

  • This medication works by blocking nerve signals in the body to temporarily numb a particular area.

  • Injected lidocaine is typically used before administering epidurals, or prior to dental work and certain surgical procedures.

  • Common side effects of lidocaine include headaches, injection site reactions, nausea, and vomiting.

  • More serious side effects include an allergic reaction, excessive pain and discomfort, and even cardiac arrest.

If you’ve ever received a numbing injection before a procedure in a medical setting, there’s a good chance that you have encountered lidocaine.

Often referred to as local anesthetic, lidocaine is used to temporarily numb a particular area of the body.

While lidocaine is largely considered safe when administered by a healthcare professional, you may experience some side effects.

In this article, we will discuss the possible side effects you may experience with lidocaine, as well as some more serious reactions associated with the drug.

What is Lidocaine?

Lidocaine belongs to a class of medications called local anesthetics. It works by blocking nerve signals in the body, resulting in a temporary loss of feeling in the area.

This drug is most commonly used to numb an area before a procedure, but it can also be used to relieve pain and other unpleasant side effects associated with certain medical conditions.

It is available in various forms, including:

  • Creams
  • Gels
  • Ointments
  • Patches
  • Oral lidocaine such as throat sprays
  • Solutions for injection

What is Lidocaine Used For?

Aside from surgical procedures and dental work, lidocaine can also be used for:

  • Topical pain relief: Creams, gels, and ointments can be applied to the skin to provide relief from things like sunburn, insect bites, and minor burns. It can also be used to soothe itching associated with certain skin conditions like eczema. A lidocaine spray may be used to treat throat problems.

  • Management of chronic pain conditions: Lidocaine infusions and patches are sometimes used for the management of chronic conditions that result in nerve or neuropathic pain.

  • Epidurals: Lidocaine injections are administered to women in labor or individuals having surgical procedures to provide pain relief.

  • Cardiac arrhythmias: In a medical setting, intravenous (IV) lidocaine can be used to treat certain types of arrhythmias — which are irregular heart rhythms — such as ventricular tachycardia and ventricular fibrillation.

The form of lidocaine you use will depend on what you need it for. You should always follow your doctor’s directions when using lidocaine, as this medication can lead to some adverse reactions.

A woman in pain

Lidocaine Side Effects

There are certain common side effects of lidocaine that many people experience when using the drug. These side effects may improve as your body adjusts to lidocaine.

The following side effects occur most frequently, and it’s possible you may experience some of them when using lidocaine.

Local reactions

When lidocaine is applied or injected locally, you may experience some side effects in the targeted area or at the injection site. These may include:

  • Redness
  • Swelling
  • Itching
  • A burning sensation

As lidocaine blocks nerve signals in a specific area, it can result in changes in blood flow and tissue response in the region. This could lead to irritation and inflammation in the targeted area.


The main purpose of lidocaine is to numb a specific area of the body. So, you can expect to experience numbness when using this medication.

However, excessive numbness may occur, making it difficult to use or move the affected body part.

A tingling sensation

You may experience a pins and needles sensation (paresthesia) in the area where the lidocaine has been used. This typically occurs as the medication is wearing off.

The tingling feeling results from the nerves ‘waking up’ and the gradual return of sensation in the area.

An unusual sense of well-being

Although very rare, having unusual feelings of well-being may be a side effect of lidocaine.

There isn’t much scientific study into this side effect, but it may be a result of the relief that is felt once the pain begins to subside in some individuals.

An unpleasant taste

Some people may experience a bitter or metallic taste in their mouths once lidocaine has been injected or applied to the throat or mouth area.

This is because lidocaine can affect the taste buds and sensory perception in the mouth and throat. It usually occurs when lidocaine is used for dental work.

An unexplained noise in the ears

You may hear a ringing, buzzing, or other unexplained noise in your ears. It’s unclear why lidocaine causes this, but it may be due to its influence on nerve activity.

Bowel control loss

While this is more serious than other side effects, it is possible that you may lose control of your bowels if lidocaine is used as an epidural.

Vomiting and nausea

There’s the possibility that lidocaine can affect the digestive system and certain areas of the brain. This can result in nausea and vomiting.

When it comes to these symptoms, they are more likely to be caused by IV lidocaine use.

Lightheadedness, dizziness, or faintness

Lidocaine can affect the central nervous system, especially when administered via an IV. This may lead to dizziness or lightheadedness as it circulates throughout the bloodstream.


Although the exact connection between lidocaine and headaches is not fully understood, this medication is believed to change the blood flow in the body, leading to headaches.

Changes in heart rate

This local anesthetic can affect the activity of the heart, which can lead to changes in heart rate. Your heart may beat faster or slower than usual.

Key Point: What to Do About Unwanted Side Effects

If the side effects you experience continue or affect your daily routine, contact your doctor or pharmacist.

There may be alternative medications that you can use that won't cause uncomfortable side effects.

Side Effects to Report to Your Health Care Professional Right Away

Lidocaine can cause more serious side effects than the ones listed above.

Be sure to call your doctor immediately if you experience any of these adverse effects as they could be life-threatening:

  • An allergic reaction which may include swelling, shallow breathing, loss of consciousness, double vision, chest pain, or low blood pressure
  • Unusual bleeding or bruising
  • Unusual tiredness
  • Cardiac arrest
  • Excessive pain or discomfort
  • Cold, clammy, or pale skin

Drug Interactions with Lidocaine

There are some possible interactions between lidocaine and other drugs.

Interactions happen when one drug affects the way another one works, either by making it stronger, weaker, or causing unpleasant side effects.

The most common medications that interact with lidocaine include:

  • Monoamine oxidase inhibitors (MAOIs) such as Parnate, Nardil, Marplan, and Eldepryl
  • Medicines used for blood pressure and heart disease
  • Medications for mood problems such as depression, anxiety, and psychosis
  • Other anesthetics
  • Phenytoin
  • Procarbazine

It’s also possible that certain nonprescription drugs, alcohol, and illicit drugs may interact with lidocaine.

For this reason, it’s vital that you tell your doctor about any medications you are taking or substances that you use, including herbal products and recreational drugs.

What to Tell Your Health Care Provider Before Taking Lidocaine

Typically, healthcare providers who prescribe or administer lidocaine will get your full medical history. This is because some underlying conditions make lidocaine more risky to use.

Whether you’re having dental surgery, an epidural, or using topical lidocaine, tell your doctor if you:

  • Have other medical conditions
  • Are breastfeeding
  • Currently have any infections
  • Have ever had an unusual reaction to lidocaine or similar anesthetics
  • Are pregnant or trying to conceive

How Should I Use Lidocaine?

If you are going to be receiving lidocaine injections, they will usually be administered by a doctor or nurse in a hospital or clinical setting.

Health care providers typically prescribe topical lidocaine, and you should use this medication exactly as they have directed.

Here is some guidance on using lidocaine:

Don’t share your topical lidocaine

This medicine is only for you and should not be shared with anyone else.

What to do if you overdose

If you think you have overdosed on this medication, you must contact Poison Control or visit an emergency room immediately.

Use in children

Children taking lidocaine may need special considerations, so be sure to speak to your pediatrician about this.

Take caution to protect the area

As you will not be aware of pain in the affected area, take caution against accidentally injuring yourself.

Skin preparation

Before applying topical lidocaine, ensure that the area is completely clean and dry. You can use an alcohol swab to sanitize the site.

This helps to maximize the effectiveness of the topical product and reduces the risk of contamination.

Don’t apply too much

Avoid applying excessive amounts of lidocaine to any area of the body, as this can lead to adverse effects. Only apply the medication as your doctor has directed.

Avoid sensitive areas

Don’t apply topical lidocaine to any broken or damaged skin unless your health care provider has instructed otherwise.

Keep topical lidocaine away from the eyes, mucous membranes, or open wounds.

Report serious side effects

Contact your doctor right away if you feel any unusual or severe side effects.

Use it only as prescribed

Don’t use lidocaine for any purposes other than what it was prescribed for. Never ingest topical lidocaine.

Don’t cover the affected area

It’s typically advised that you don’t cover the area when you apply lidocaine unless your doctor has instructed otherwise.

Using airtight dressings, plastic wraps, or bandages after applying this medication topically can increase absorption, which may lead to overdose.

Proper disposal

If you have any unused topical lidocaine left over, safely dispose of it. You can speak to your pharmacist about local guidelines for disposal.

Applying cream on knee
Key Point: What to Do if You Have Concerns About Lidocaine

If you have any concerns or questions about using lidocaine properly, speak to your doctor. They can provide personalized guidance on how to use the product and ensure that you’re using the right amount based on your medical condition and needs.

Where Can I Learn More About Lidocaine?

LifeMD can connect you to a licensed medical professional who can answer your questions and prescribe topical lidocaine if necessary.

Book your appointment today, to learn more about lidocaine and how to properly use it.

LifeMD makes it easy to stay on top of your health because talking to a doctor, filling your prescriptions, getting your labs done—and more—are all easy and cost-effective. Come discover a healthcare solution built around you and your life.

Connect with a doctor now!

This article is intended for informational purposes only and should not be considered medical advice. Consult a healthcare professional or call a doctor in the case of a medical emergency.

Feel better with LifeMD.

Your doctor is online and ready to see you.

Join LifeMD today and experience amazing healthcare, discounted labs and prescription medications... plus around-the-clock access to medical guidance.