Lidocaine and Prilocaine (Topical)

Sold under the brand name EMLA, lidocaine and prilocaine is meant for external use only and must never be ingested or applied to an open wound.


Lidocaine and prilocaine is an emulsion used to numb the skin in preparation for minor surgical or medical procedures like skin laser surgery or vaccination. The two active ingredients, lidocaine and prilocaine, belong to a group of medicines called local anesthetics. Sold under the brand name EMLA, this medication works by temporarily blocking the pathway of pain signals along the nerves by preventing the sodium entering the nerve ending at the location of pain. This, in turn, prevents a build-up of electrical signals from passing along the nerve fibers to the brain. This makes it possible for otherwise painful procedures to be performed without the patient feeling pain. This medicine is only available with the healthcare provider's prescription and comes in the following packaging:

  • Cream
  • Film
  • Kit

Conditions Treated

  • Normal intact skin for local analgesia.

Type Of Medicine

  • Local anesthetic cream

Side Effects

Alongside the desired effects, lidocaine and prilocaine topical may cause some undesirable effects. Some side effects are mild and tend to go away as the body adjusts to the medication. However, other lidocaine and prilocaine side effects tend to be severe and may require medical attention.

Consult your healthcare provider if you experience any of the following lidocaine and prilocaine side effects:

  • Persistent cough
  • Difficulty swallowing
  • Severe dizziness and faint feeling
  • Large hives on the eyelids, face, lips, tongue and throat
  • Breathing with difficulty
  • Stuffy nose
  • Skin hives, rashes and itching
  • Wheezing
  • Tightness of the chest
  • Blisters on the application area
  • Blurred vision
  • Blue or blue-purple color of fingernails, lips, skin and face
  • Convulsions
  • Dizziness and drowsiness
  • Dark urine
  • Persistent headache
  • Fainting or shortening of breath
  • Irregular or rapid heartbeat
  • Nausea and vomiting
  • Muscle twitching and trembling
  • Buzzing or ringing in the ears
  • Unusual excitement, restlessness or nervousness
  • General fatigue and weakness

Some lidocaine and prilocaine topical side effects may not require medical attention. These side effects often go away during medication as the body adjusts to the drug. Additionally, your healthcare provider may be able to advise you on how to manage or reduce some of these side effects. Check with your healthcare provider if any of the following lidocaine and prilocaine symptoms persist or become bothersome:

  • Burning, swelling, rashes or itching at the treatment site
  • Red or white skin at the drug application site

You may also report these side effects to the FDA at 1-800-FDA-1088.

Lidocaine and prilocaine dosage

Lidocaine and prilocaine topical come with a Patient Information Leaflet. It is important that you carefully read and understand the instructions on how to use this medication. Ask your healthcare provider, pharmacist or nurse any questions that you may have concerning this medication.

Lidocaine and prilocaine topical should be applied only to the normal skin and the genital area. Do not apply it to an open wound or a broken/irritated skin unless by approval of your healthcare provider.

How to apply lidocaine and prilocaine topical

  • Thoroughly wash your hands with soap and water before and after applying the medication
  • Apply a thick layer of the ointment to the location where numbness is needed. Do not spread the medication on your skin.
  • Use a special bandage called occlusive dressing to cover the medicine. This will keep the ointment in place.
  • Keep the medicine from leaking by sealing the edges of the bandage. Do not disturb the bandage. Keep the medicine tightly covered so it can work properly.
  • For toddlers and younger patients, you may need to apply a second covering to prevent them from touching the ointment.
  • Carefully watch your child while the ointment is in place. Do not let them remove or loosen the bandage, touch the ointment, or put it in the eyes, mouth, ears or nose.
  • Keep the bandage and ointment in place until you or the child arrives at the medical facility
  • Your healthcare provider will remove the bandage and wipe off the ointment before performing the intended medical procedure.

Dosing information

The dosage and length of application period depend on the patient's age, medical condition and the intended procedure for which numbness is required. In children, the dosage may also vary with the patient's body weight.

Adult patients'Intact skin

Minor dermal procedures
For minor procedures such as venipuncture and intravenous cannulation, apply the ointment over 20 to 25 cm2 of skin surface for at least one hour before the procedure.

Major dermal procedures
For more painful dermatological procedures that involve a larger skin area, such as skin graft harvesting or split thickness, apply the ointment and allow it to remain in contact with the skin for at least two hours before the procedure.

Adult male genital skin dosage
Using lidocaine and prilocaine topical as an adjunct prior to local anesthetic infiltration: Apply the ointment to the treatment area and leave for 15 minutes. Local anesthetic infiltration should be performed as soon as the ointment is cleaned away.

Adult female patients' Genital mucous membranes

For minor procedures on the female genitalia, such as pre-treatment for anesthetic infiltration or removal of condylomata acuminate, apply the ointment and leave it in position for five to 10 minutes.

Occlusion is not necessary; however, it may be helpful to keep the ointment in place. The patient should lie down during lidocaine and prilocaine topical application, especially if occlusion has not been used.

Important precautions

  • Do not apply lidocaine and prilocaine near your eyes, in the ears, nose or on open wounds
  • Keep the medication out of reach of children
  • If the child becomes excessively sleepy, very dizzy or develops duskiness of the lips or face after applying lidocaine and prilocaine topical, remove the medication and contact the emergency room right away.

Lidocaine and prilocaine interactions

Although certain medications should not be used in combination, in other cases two or more medications may be combined even if an interaction might occur. In such cases, your healthcare provider may recommend a change of dosage for one of the medications, or recommend appropriate precautions. Tell your healthcare provider about the medications you are currently taking, including over-the-counter medications, supplements and herbal drugs, before using lidocaine and prilocaine topical so they can check if the combination is safe.

There may be an increased risk of a blood disorder called methemoglobinemia if lidocaine and prilocaine are combined with any of the following medications:

  • Acetanilid
  • Aniline dyes
  • Benzocaine
  • Chloroquine
  • Dapsone
  • Metoclopramide
  • Naphthalene
  • Nitrates and nitrites
  • Nitrofurantoin
  • Nitroglycerin
  • Nitroprusside
  • Pamaquine
  • Para-aminosalicylic acid
  • Phenacetin
  • Phenobarbital
  • Phenytoin
  • Primaquine
  • Quinine
  • Sulphonamide antibiotics

Lidocaine and prilocaine topical should not be administered to toddlers under one year old who are being treated with any of the drugs listed above.

There may be an increased risk of side effects if large quantities of lidocaine and prilocaine topical are used by patients who are already using other local anesthetics, or structurally related-medications such as mexiletine or tocainide.

Lidocaine and prilocaine topical should be used with caution by patients who are taking drugs that treat irregular heartbeat such as amiodarone, because the risk of side effects on the heart may increase if sufficient quantities of this medication are absorbed into the body.

Other Medical Problems

The presence of other underlying medical conditions may affect the use and efficiency of lidocaine and prilocaine topical. Make sure you inform your healthcare provider if you suffer from any of the following medical conditions.

  • A history of heart disease
  • A history of Glucose-6-phosphate dehydrogenase (G6PD) deficiency
  • Heart rhythm problems
  • A history of methemoglobinemia
  • Large sores, severe injury or broken skin in the area of application
  • A history of liver disease

Lidocaine and prilocaine warnings

Before you begin using lidocaine and prilocaine, be sure to inform your healthcare provider of any underlying medical condition or allergies you may have, including drug, food, and pet allergies. In addition, disclose any medications you are currently taking, whether you are expectant or breastfeeding, and any other significant fact about your health. These factors may affect how you use this drug.


It is possible to suffer from severe allergic reactions while using this medication. Thus, before using lidocaine and prilocaine topical, be sure to inform your healthcare provider about any previous adverse reactions to medicine, especially drugs used to numb the skin. Contact your healthcare provider immediately if you experience signs of allergic reaction such as itching, skin rash, breathing problems or swelling of the face, lips and throat.


Do not get lidocaine and prilocaine into contact with your eyes. If this happens, wash your eyes thoroughly with flowing water or rinse with sodium chloride solution.

Liver function

Lidocaine and prilocaine is broken down by the liver. A history of liver disease or reduced liver function may result in a build-up of this medicine in the body, causing severe side effects. If you have a history of liver problems, consider discussing how this medication may affect your health condition with your healthcare providing before using it. Also, discuss how your medical condition will affect the dosing as well as the effectiveness of lidocaine and prilocaine, and whether you need any special monitoring while on this medication.


This is a condition where the blood cannot transport adequate amounts of oxygen through the body because the Ĺ“wrong form of haemoglobin called methemoglobin is produced in large quantities. Prilocaine stimulates the body to produce methemoglobin. When prilocaine accumulates in the body, or you have a preexisting condition that causes excess production of methemoglobin, the extra production of methemoglobin may be noticed. This is always symptomized by the development of greyish or brownish skin color or discoloration of the nails and lips. Seek medical attention as soon as you observe these symptoms.


The body absorbs lidocaine and prilocaine. As such, it is important that you only apply this medication on the spot that you are treating and leave it only for the duration recommended by your healthcare provider. Applying this ointment to larger areas of the skin may cause dangerous levels of the medicine to accumulate in your body. Contact with the medication remaining on the dressing or patch can also cause this to happen, especially to children. Symptoms of lidocaine and prilocaine accumulation in the body may include dizziness, confusion, seizures and very slow heartbeats that may result in slow breathing. Call the emergency room immediately if you or your child experience any of these symptoms.

Skin problems

If you have a pre-existing skin condition, such as allergic dermatitis, you may have to use this ointment for a short period of time to achieve the same numbing effect. Inform your healthcare provider if you have any skin conditions. The spot where you apply the medication will remain numb for several hours. Exercise caution to avoid accidental injuries or exposure to extreme cold or hot temperatures until your skin returns to complete sensation.

Pregnancy and breastfeeding

Lidocaine and prilocaine should never be used during pregnancy unless the benefits far outweigh the risks involved. If you conceive while taking this medication, contact your healthcare provider right away. Additionally, lidocaine is known to pass through breast milk. Talk to your doctor about whether you can use this medication while breastfeeding.

Children require close observation while on this medication since they are more vulnerable to the side effects. The use of this ointment in children who are less than 3 months old or weigh 20 kg should be as limited as possible. Do not use lidocaine and prilocaine in children who are younger than 3 months of age.

Finally, do not use lidocaine and prilocaine if you need large amounts of the medication and are not in or near the hospital.

Lidocaine and prilocaine storage

Lidocaine and prilocaine should be stored at room temperature (20 degrees C to 25 degrees C). The medication should be stored in a dry place. Do not store in the bathroom. Like with other drugs, keep this contraceptive away from pets and children. Check with your pharmacist about how to get rid of unused medication.


This combination product comes with two medicines: lidocaine and prilocaine. Both medicines belong to the group of medicines called topical anesthetics. The medicine is used to reduce pain or discomfort experienced during minor procedures such as laser treatment skin surgeries, administration of certain vaccinations, or when you are having your blood taken. The medicine may also be administered to provide relief from pain when removing debris from leg skin ulcers or when performing minor procedures on the genitalia.

Lidocaine and prilocaine work by numbing the skin surface as well as the lower layers of the skin to prevent pain messages from being relayed by the nerves under the skin. This numbing effect starts minutes after applying the medication and may continue for up to two hours after removing the medication.

Do not share this medication with ointment with anyone else even if they exhibit the same symptoms as you do. It can be harmful to take this medication without the doctor's prescription. Additionally, an overdose of lidocaine and prilocaine, like with other numbing medications, can cause severe or even fatal side effects if too much medication is accumulated in the body. This is more likely to occur if you are using the medicine without the doctor's advice. Lidocaine and prilocaine overdose symptoms may include irregular heartbeats, convulsions, slowed breathing, coma or complete respiratory failure.

Your body may accumulate this medication if you apply too much of it, if you apply it over a large skin area, if you subject the treated area to high temperature, or if you cover the treated area with bandages and plastic wraps. Do not apply this medication on a bruised skin or on an open wound.

Do not use lidocaine and prilocaine topical if you are allergic to any of its ingredients or other numbing medications. Additionally, inform your healthcare provider if you have suffered from, or are suffering from, liver disease, methemoglobinemia, or any genetic enzyme deficiency.

Lidocaine and prilocaine topical is for external use only. Do not ingest or apply it to an open wound. Avoid getting this ointment into contact with your eyes or any other bodily opening.