Lidocaine (Topical)

Available in various formats, Lidocaine is primarily used as a topical solution or ointment to induce local anesthesia in certain parts of the body.

Overview

If patients are due to undergo medical tests or procedures, Lidocaine is often used to induce numbness or a loss of feeling. This enables the test or procedure to be carried out without the patient experiencing any pain or discomfort. When applied to the skin, Lidocaine can be used in the form of an ointment, jelly, foam, cream, aerosol spray or gel.

If Lidocaine is used to numb the mouth or throat, however, it is typically prescribed as an oral solution. When patients are undergoing dental work, x-rays or endoscopic procedures, this form of Lidocaine can be used to minimize discomfort and to prevent the patient from gagging.

In addition to this, Lidocaine can be prescribed in the form of a skin patch. Sometimes used to relieve pain caused by postherpetic neuralgia (shingles), a Lidocaine skin patch can release medication over an extended period of time and provide greater relief from symptoms.

When applied to a specific area, Lidocaine numbs the tissue and acts as a local anesthetic. Unlike general anesthetics, Lidocaine does not cause the patient to lose consciousness and not does have a sedative effect when it is used topically. Instead, it blocks pain signals from being sent to the brain and provides surface anesthesia.

As well as being used during medical procedures and tests, Lidocaine can be used to treat itching and pain caused by minor injuries, such as cuts, scratches, minor burns and sunburn. Furthermore, Lidocaine may be applied to relieve the discomfort and itching caused by insect bites, poison oak, poison ivy, insect stings, nettle stings and/or poison sumac.

Due to its range of uses, Lidocaine is a popular form of local anesthetic and is a much-used medication. As Lidocaine is fairly fast acting, the medication takes effect quickly and patients should notice the numbness caused by Lidocaine taking effect within minutes of application. Whilst Lidocaine can be combined with other medications to provide long-lasting anesthesia, when used in isolation, Lidocaine will provide short to intermedia numbness and anesthesia.

Conditions Treated

Used during medical and/or dental tests and procedures

  • Pain
  • Irritation
  • Minor stings, bites, cuts, scratches, burns and sunburn
  • Postherpetic neuralgia
  • Type Of Medicine

  • Topical local anesthetic

 

Side Effects

When patients use Lidocaine, they may experience some adverse effects. In many cases, the following side-effects are more common when patients first apply Lidocaine but decrease over time:

  • Unpleasant, unusual or bad (after) taste
  • Metallic taste
  • Unusual drowsiness or sleepiness
  • Change in taste
  • Loss or lack of strength
  • Cold or numbness
  • Heat sensation
  • Confusion about time, place and identity
  • Hearing loss
  • Continuing buzzing or ringing or other unexplained noise in the ears
  • Headache
  • Double vision

If the above side-effects are fairly mild, patients may not need to access medical assistance. However, if the patient's side-effects are severe or concerning, they should seek medical help.

In addition to this, patients will need to obtain medical assistance immediately if they experience the following side-effects when using Lidocaine or after the medication has been applied:

  • Reddening, itching, crusting, irritation or blistering of the skin
  • Lethargy
  • Cough
  • Scaly, dry or cracked skin
  • Nervousness or fear
  • Fast heartbeat
  • Pale, clammy or cold skin
  • Fever
  • Welts, hives, itching or rash on the skin
  • Hoarseness
  • Confusion
  • Irritation
  • Chest discomfort or pain
  • Joint swelling, stiffness or pain
  • Noisy breathing
  • Large, hive-like swelling on the eyelids, tongue, hands, face, lips, throat, feet, legs or sex organs
  • Swelling of the face, hands, feet, lips or eyelids
  • Blurred vision
  • Tightness in the chest
  • Dizziness or drowsiness
  • Troubled swallowing or breathing
  • Itching, blistering, redness, bruising, discoloration, swelling or burning at the application site
  • Unusual or false sense of well-being
  • Lightheadedness, faintness or dizziness when getting up suddenly from a sitting or lying position
  • Shallow, slow, fast or irregular breathing
  • No pulse or blood pressure
  • Seizures
  • Blue or pain skin, lips or fingernails
  • Swelling or puffiness around the face, tongue, lips, eyes or of the eyelids
  • Weakness
  • Shakiness in the arms, feet, hands or legs
  • Unusual weakness or tiredness
  • Slow heart rate
  • Irregular or slow heartbeat
  • Twitching
  • Stopping of heart
  • Unconsciousness
  • Shaking or trembling of the feet or hands

Whilst many of the above side-effects are fairly rare, they do warrant medical attention if they occur. Patients should also obtain medical advice if they experience any other side-effects whilst using Lidocaine.

Dosage

When patients are prescribed Lidocaine, their dose will depend on their condition, age and medical history, as well as the format of the medication they are given. If adult patients are prescribed Lidocaine as an ointment, they are normally instructed to apply the medication three to four times a day, if they are treating relatively minor skin conditions. Each application should not exceed 5g of Lidocaine. If patients are prescribed the ointment at a strength of 5%, each dose equates to approximately six inches of ointment.

However, if adult patients are prescribed Lidocaine in the form of a skin patch for the treatment of postherpetic neuralgia pain, they are usually advised to apply one to three patches, for up to twelve hours each day. The patch should be placed in the affected area so that the patient's pain is relieved by the localized numbness instigated by the patch.

Alternatively, patients may be prescribed Lidocaine as an oral solution for the treatment of a sore throat or mouth. Generally, the patient's dose will depend on their weight when Lidocaine is used in this way. For adults, a typical dose is 15 milliliters every three hours, but patients should not take more than eight doses each day. If children or infants are prescribed Lidocaine as an oral solution, their dose must be calculated by their physician. However, the dose for infants under the age of three years does not usually exceed 1.2 milliliters, with at least three hours between each dose.

Whilst this is a standard form of treatment with Lidocaine, patients should only use this medication as directed by their physician. Patients should not attempt to use more Lidocaine than they have been prescribed or to use the medication more often than is advised. Doing so could increase their risk of side-effects and additional medical complications.

Lidocaine is not used to treat certain skin conditions, such as infections or serious burns, and patients should obtain medical advice before using this medication on any skin complaint.

If patients are prescribed Lidocaine as an ointment or jelly, they should wash their hands thoroughly and gently apply the medication to the affected area. However, Lidocaine ointment or jelly should not be applied to broken skin, open wounds or inflamed skin. If the medication comes into contact with the eyes, it can cause irritation. Patients should rinse their eyes with water for approximately fifteen minutes and contact their physician for further advice. After the ointment or jelly has been applied, patients should wash their hands again to ensure that the medication is not inadvertently transferred elsewhere.

When patients are using Lidocaine skin patches, they should keep the patches in the protective packaging until they are ready for use. Skin patches should only be applied to dry, clean skin and should not be placed on irritated, broken or inflamed skin. In order for the patch to adhere to the skin, patients should select a location which has little or no hair and is free of cuts or scars. In addition to this, patients should not place the patch in area where it can be rubbed off easily by clothing. If the skin patch falls off and cannot be re-used, patients may apply another skin patch. If necessary, the skin patch can be cut into smaller pieces and used in different areas, providing the patient's doctor has authorized this.

Lidocaine patches should only be used on the skin and should not be allowed to come into contact with the patient's eyes, mouth or nose. Patients should ensure that the patch remains dry at all times and should not wear a Lidocaine skin patch when showering, swimming or bathing.

If patients are instructed to use Lidocaine oral solution, they should measure the appropriate dose with a medicine cup, measuring spoon or oral syringe. If patients are using Lidocaine solution to relieve mouth pain, they should swish the medicine around their mouth before spitting it out. Similarly, if patients are using this medicine to relieve throat pain or irritation, they should gargle with the solution before spitting it out.

If patients are using Lidocaine as a solution, gel, foam, jelly or ointment and they forget to administer a dose of medication, they should do so as soon as they remember. However, if the patient's next dose is due soon, they should simply skip the missed dose and continue using the medication as normal. Similarly, if patients forget to apply a Lidocaine skin patch or change an existing patch, they should do so when they remember. If their next skin patch is due to be applied soon, patients should simply continue with their regular dosing schedule. Patients should not attempt to use extra patches or apply double doses of Lidocaine, even if a previous dose has been missed.

When using Lidocaine, patients should follow their doctor's instructions. If patients are unsure when or how to use this medication, they should seek advice from their physician or pharmacist.

Potential Drug Interactions

As some medications can interact with one another, patients should tell their physician if they are taking or using any other medicines before they are prescribed Lidocaine. This includes prescribed medicines, over-the-counter medications, vitamins and/or supplements.

The use of Lidocaine alongside the following medication is not typically recommended:

  • Amiodarone

However, if patients are prescribed Lidocaine in conjunction with the above medication, their dose may be altered to try and prevent an interaction occurring. Alternatively, patients may be advised to use Lidocaine at a specific time so that the two medicines do not interact.

Once patients have started using Lidocaine, they should obtain medical advice before using any new medicines, supplements or vitamins.

Warnings

Before patients begin treatment with Lidocaine, they should discuss any existing medical problems with their physician. Similarly, patients should disclose their medical history to their doctor before they start using this medicine. There are some conditions which can affect the use of Lidocaine and these may include:

  • Liver disease
  • Sores at the site of use
  • Irritated or broken skin at the site of use
  • Severe injury or open wounds at the site of use
  • Heart block
  • Shock
  • Infection at or near the intended site of use

Although Lidocaine can be prescribed to pediatric patient in some forms, extreme caution must be shown. Generally, Lidocaine is only used to treat pediatric patients if other treatments have been deemed ineffective, particularly if the patient is under the age of three years. If pediatric patients are prescribed Lidocaine, parents, guardians and caregivers must monitor the child carefully during treatment.

For example, the child must be watched to ensure that they do not get any of the medication in their eyes, mouth or nose. Even after the medicine has been applied to another area of skin, the child may attempt to lick the medication which could cause serious harm. Due to this, young patients must be monitored at all times when Lidocaine has been applied. If topical medication is swallowed, it can cause extremely serious side-effects, particularly in children.

If parents, guardians or caregivers suspect that a child has ingested Lidocaine, they must obtain emergency medical treatment straight away.

Whilst some forms of Lidocaine can be used to treat children and infants, Lidocaine skin patches have not been specifically tested on pediatric patients. Due to this, Lidocaine skin patches are only usually prescribed to adults and may not be used to treat children or infants.

Similarly, Lidocaine should be used in caution in geriatric patients and is normally only prescribed if other medications have been ineffective. Due to the toxicity of Lidocaine, patients should be monitored throughout their treatment.

When patients use Lidocaine, they should notice an improvement in their symptoms fairly quickly. However, if symptoms do not improve or worsen, patients should contact their physician.

Similarly, patients should inform their physician straight away if they develop the following symptoms when using Lidocaine:

  • Irritation
  • Swelling
  • Burning
  • Stinging
  • Rash

Patients should be aware of the signs of Lidocaine toxicity, particularly if they are using the medicine as an oral solution. If patients exhibit any of the following symptoms after using Lidocaine, they should stop using the medication and obtain immediate medical assistance:

  • Shallow breathing
  • Lethargy
  • Seizures

If Lidocaine is used to treat pain or irritation in the mouth or throat, patients should eat or drink for at least one hour after using the medicine. Similarly, patients should not chew gum during this time. As Lidocaine has a numbing effect, patients may choke if they attempt to eat or drink whilst the medication is taking effect. During this time, patients should also be careful not to accidentally bite their tongue, lips or the inside of their cheeks.

When using Lidocaine skin patches, heat can cause the medication to be absorbed into the skin more quickly than usual. This could increase the risks of overdose, toxicity and serious side-effects. If patients are using a Lidocaine skin patch, they should not use heat or tanning lamps, electric blankets, heat pads, sunlamps, saunas or heated beds. Patients should not sunbathe when using Lidocaine skin patches either.

Patients should not use cosmetics, moisturizers or other lotions or skin care products on the affected areas of skin.

Lidocaine is classified as a category B drug in terms of pregnancy and may, therefore, be suitable for pregnant patients in some situations. However, the medication may still present a risk to an unborn fetus and should only be used if other, safer treatments have failed to be effective. Patients who are pregnant should only use Lidocaine under their doctor's supervision.

If patients become pregnant when using Lidocaine, they should inform their physician straight away.

Although Lidocaine can be excreted in breast milk, it is not known whether it presents a risk to the infant if transferred via breastfeeding. Due to this, patients may be advised not to use Lidocaine whilst breastfeeding and should obtain medical advice before doing so.

If patients have any existing allergies, they should notify their physician before they start using Lidocaine. In rare cases, patients may develop an allergic reaction when using Lidocaine and, if so, they will require emergency medical treatment. The symptoms of an allergy may include:

  • Difficulty swallowing
  • Shortness of breath
  • Wheezing
  • Itching
  • Hoarseness
  • Hives
  • Rash on the skin
  • Difficulty breathing
  • Swelling of the face, hands, lips, mouth, tongue or throat

Storage

When storing Lidocaine, patients should follow the medication guidelines and manufacturer's instructions. Whilst most forms of Lidocaine can be stored at room temperature, they should be kept in a closed container and should be protected from light, heat and moisture.

Patients should store Lidocaine in a safe location and ensure that children and/or pets cannot gain access to it. When discarded a used Lidocaine skin patch, patients should fold the patch so that the medication cannot be accessed and dispose of it safely so that animals and/or children cannot access it.

If the medicines reaches its expiration date or if patients are advised to stop using Lidocaine, they should dispose of it responsibly. Medication should not be thrown out with regular household waste as it may cause harm to other people. Patients should contact their physician's office or pharmacist and use a specialist medicine disposal service.

Summary

Although Lidocaine can be used to treat the pain and irritation caused by minor injuries, such as insect bites and cuts, it is a powerful medication and must be used with caution. As Lidocaine has a numbing effect, patients must ensure that the do not inadvertently inflict any other injuries on the affected area whilst it's numb.

As Lidocaine toxicity is a serious problem, patients must be sure to adhere to their doctor's instructions when using this medication. If too much medication is applied or if Lidocaine is used too often, patients could suffer serious side-effects and/or an overdose. Due to this, Lidocaine should be used with caution and only under medical supervision.

Providing Lidocaine is used appropriately, it is an extremely effective form of local anesthesia. Appropriate for use on most areas of the body, patients can minimize pain or discomfort during medical procedures by using Lidocaine and can also obtain relief from the irritation and pain caused by minor skin injuries.