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Synera Patches

Generic name: lidocaine and tetracaine topicalLYE-doe-kane-and-TET-ra-kane-TOP-i-kal ]
Drug class: Topical anesthetics

Medically reviewed by Philip Thornton, DipPharm. Last updated on May 2, 2021.

What is Synera?

Synera patches contain a combination of lidocaine and tetracaine. Lidocaine and tetracaine are local anesthetics (numbing medicines). They work by blocking nerve signals in your body.

Synera patches are used to numb a small area of your skin. This can help prevent pain during certain medical procedures such as a skin biopsy, minor skin surgery, insertion of an intravenous (IV) needle, or other needle-stick procedures.

Synera patches are also used to numb a skin area during minor cosmetic procedures such as a Botox injection, laser treatment, or tattoo removal.


An overdose of numbing medicine can cause fatal side effects if too much of the medicine is absorbed through your skin. This can happen if you apply more than the recommended dose, or if you leave a Synera skin patch on too long.

Keep both used and unused Synera skin patches out of the reach of children or pets.

Before taking this medicine

You should not use Synera if you are allergic to:

  • any type of numbing medicine; or

  • sunscreen or other skin products that contain para-aminobenzoic acid (PABA).

Fatal overdoses have occurred when numbing medicines were used without the advice of a medical doctor (such as during a cosmetic procedure like laser hair removal). Be aware that many cosmetic procedures are performed without a medical doctor present.

Synera skin patches are not approved for use by anyone younger than 18 years old.

To make sure Synera is safe for you, tell your doctor if you have:

  • liver disease;

  • a blood cell disorder called methemoglobinemia (in you or a family member);

  • a genetic enzyme deficiency called glucose-6-phosphate dehydrogenase (G6PD) deficiency;

  • a condition for which you take a heart rhythm medicine; or

  • allergy to any other medicine used for anesthesia.

Older adults and people who are debilitated may be more sensitive to the effects of this medicine.

Tell your doctor if you are pregnant or breastfeeding.

If you apply lidocaine and tetracaine topical to your chest, avoid areas that may come into contact with the baby's mouth.

The Synera transdermal patch may burn your skin if you wear the patch during an MRI (magnetic resonance imaging). Remove the patch before undergoing such a test.

How should I use Synera?

Use Synera patches exactly as prescribed. Follow all directions on your prescription label and read all medication guides or instruction sheets. Never use this medicine in larger amounts, or for longer than prescribed.

This medicine is usually applied 20 to 30 minutes before your procedure (or 60 minutes before tattoo removal).

If you use Synera at home, read and carefully follow any Instructions for Use provided with your medicine. Ask your doctor or pharmacist if you do not understand these instructions.

Do not take by mouth. Topical medicine is for use only on the skin. If this medicine gets in your mouth, nose, rectum, or vagina, rinse with water.

For a cosmetic procedure, a healthcare professional or other care provider will apply this medicine to your skin.

Apply Synera patches only to clean, dry, healthy skin on the area to be numbed. Avoid skin that is raw or blistered. Press the patch firmly into place.

You may feel a warming sensation which is normal, but it should not feel unpleasantly hot.

Wash your hands after applying a Synera skin patch.

After your prescribed amount of numbing time, remove the skin patch, then clean and disinfect the skin as recommended by your doctor.

After removing a skin patch: fold it in half with the sticky side in, and throw it away in a place out of the reach of children or pets.

Store unused skin patches at room temperature away from moisture and heat.

Both used and unused Synera skin patches should be kept out of the reach of children or pets. The amount of medicine in the skin patches could be harmful to a child or pet who accidentally sucks on or swallows a patch. Seek emergency medical attention if this happens.

Dosing information

Usual Adult Dose for Local Anesthesia:

Apply one film topically to intact skin 20 to 30 minutes before procedure.

Usual Pediatric Dose for Local Anesthesia:

>= 3 yrs: Apply one film topically to intact skin 20 to 30 minutes before procedure.

What happens if I miss a dose?

Since Synera is used as a single dose, it does not have a daily dosing schedule.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of numbing medicine can cause fatal side effects if too much of the medicine is absorbed through your skin and into your blood.

Your body may absorb too much of this medicine if:

  • you apply more than the recommended dose;

  • you apply the medicine to skin that is cut or irritated; or

  • you leave a Synera skin patch on your skin for too long.

Overdose symptoms may include numbness or tingling in your face, ringing in your ears, drowsiness, nausea, and slurred speech. Serious complications of lidocaine or tetracaine overdose may include seizure (convulsions), slowed breathing, coma, heart failure, or respiratory failure (breathing stops).

What should I avoid while using Synera?

Do not allow this medicine to come into contact with your eyes. If it does, rinse with water.

Do not use a Synera skin patch if it has been cut or damaged.

Avoid touching the sticky side of a skin patch while applying it.

Do not receive a "live" vaccine while using lidocaine and tetracaine. The vaccine may not work as well and may not fully protect you from disease. Live vaccines include measles, mumps, rubella (MMR), polio, rotavirus, typhoid, yellow fever, varicella (chickenpox), and zoster (shingles).

Synera side effects

Get emergency medical help if you have signs of an allergic reaction to Synera: hives; wheezing, difficulty breathing; swelling of your face, lips, tongue, or throat.

Tell your caregivers or call your doctor right away if you have:

  • severe burning, stinging, or other irritation where the medicine was applied;

  • sudden dizziness or drowsiness after the medicine is applied;

  • pale, gray, or blue colored skin;

  • headache, fast heartbeats, shortness of breath;

  • tiredness, or feeling like you might pass out;

  • blurred vision, ringing in your ears; or

  • unusual sensations of hot or cold.

Common Synera side effects include:

  • skin redness;

  • skin swelling; or

  • changes in skin color where the medicine was applied.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Synera?

Medicine used on the skin is not likely to be affected by other drugs you use. However, some drugs can cause conditions that may make it harmful for you to use Synera. Tell each of your healthcare providers about all medicines you use, including prescription and over-the-counter medicines, vitamins, and herbal products.

More about Synera (lidocaine / tetracaine topical)

Patient resources

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Professional resources

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Further information

  • Your pharmacist has information about Synera.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Synera only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.