Benzocaine

Benzocaine is a local anesthetic that works by numbing the nerve endings in the skin. It is used to reduce discomfort or pain caused by sore throats, skin irritations, teething pain, and other minor pains on the body’s surface.

Overview

Sold under the brand name Orajel, benzocaine is a local anesthetic typically used as a topical pain reliever or in cough drops. Benzocaine is the active ingredient in most over-the-counter anesthetic ointments such as products used for managing oral ulcers. It can also be combined with antipyrine to produce A/B otic drops that are used to remove earwax while relieving pain in the ear. Benzocaine relieves pain by blocking the nerve signals on the skin’s surface.

What you should discuss with your healthcare provider before using benzocaine topical

First, and most important, do not use benzocaine topical if you have a previous history of methemoglobinemia - a blood disorder in which the body produces abnormal amounts of methemoglobin.

An overdose of numbing medications has been linked to fatal side effects, especially when too much of the medication is absorbed into the blood stream via the skin. This occurs often when numbing medications are used without the direction of a professional healthcare provider (such as during cosmetic procedures like laser hair removal). It is important to be aware that most cosmetic procedures are done in the absence of qualified medical practitioners.

Ask your healthcare provider or pharmacist if it is safe to use benzocaine if you have:

  • Cardiovascular condition
  • Bronchitis, asthma, emphysema, or other breathing disorders
  • A family or personal history of methemoglobinemia, or any genetic enzyme deficiency condition
  • If you drink or smoke

It is not clear how benzocaine may affect unborn babies. Thus, it is important that you consult your doctor before using this medication if you are pregnant.

It is not known whether this medication can be passed through breast milk or if it can affect a nursing baby. It is therefore important to seek your doctor’s direction before using benzocaine if you are breastfeeding.

Benzocaine should never be administered to children younger than 2 years without the doctor’s consent.

Conditions treated

  • Anesthesia
  • Hemorrhoids
  • Pain on skin
  • Pruritus
  • External burns

Type of medicine

  • Topical local anesthetics

Side effects of benzocaine

Generally, benzocaine is well-tolerated and non-toxic if applied topically as directed. However, serious, and sometimes life-threatening, side effects have been linked to this medication. These include seizures, irregular heartbeats, coma, and respiratory complications. These side effects may occur as a result of over-application of the medicine or when applying topical products with high benzocaine concentrations to the skin.

Over-application of topical anesthetics like benzocaine have been linked to an increased risk of pulmonary aspiration. This is because the medication relaxes the gag-reflex and allows regurgitation of stomach contents or oral secretions to access the airway. Applying benzocaine and consuming beverages before going to bed can be specifically hazardous.

Topical use of high concentrations of benzocaine spray (14 -20%) in the mouth or mucous membranes have been attributed to methemoglobinemia, which may result in dangerously low oxygen levels in the body. This side effect is most common in toddlers under 2 years of age. As a result, the FDA has a directive that this medication should never be administered to children under the age of 2 years without close supervision from a qualified healthcare provider. Symptoms of methemoglobinemia usually show within minutes to hours of administering benzocaine, and can occur during first time use as well as during subsequent uses.

Benzocaine may cause allergic reactions. These include anaphylaxis (which is rare) as well as contact dermatitis.

Seek emergency medical help if you experience the following side effects after applying benzocaine:

  • Headache, general feeling of tiredness and confusion
  • Rapid heart rate
  • Lightheadedness and shortness of breath
  • Blue, pale, or grey appearance on the skin, lips, and fingernails

Also, seek emergency help if you notice the following allergic reaction signs: hives, swelling of the face, tongue, lips and throat, and breathing problems.

Stop using benzocaine and call your doctor immediately if you experience the following after using the medication:

  • Severe stinging, burning, or sensitivity on the spot where the medication was applied
  • Swelling, fever, or redness
  • Blistering, oozing, and any sign of infection

The following side effects are common and often go away as the body adjusts to benzocaine:

  • Mild burning, stinging, or itching on the spot where the medication has been applied
  • Tenderness or redness of the skin
  • Dry white flakes on the spot where the medication has been applied.

Some users may experience side effects that are not listed here. Contact your healthcare provider for advice about benzocaine side effects. You may also report benzocaine side effects to the FDA at 1800-FDA-1088.

Benzocaine dosage

Adult dosage for anesthesia

  • Awake intubation, bronchoscopy, oral airway: Apply 0.5 second burst to buccal folds. The patient should swallow several times and wait for about one minute before beginning the procedure.
  • Upper endoscopy: apply 0.5 second burst to each buccal fold and swallow several times. Wait for 30 seconds before inserting the scope.
  • Esophageal motility: Apply no more than 0.5 second burst to each naris. Wait for 30 to 60 seconds before inserting transducer
  • Indirect laryngoscopy, neck and head examinations: spray 0.5 second burst to each buccal fold and swallow several times. Wait for 30 to 60 seconds before starting the procedure.
  • Arch bar removal: spray the target spot for no longer than 0.5 seconds. Wait for 30 to 60 seconds before removing the arch bar
  • Mucositis, stomatitis, thrush, pharyngitis, and cancer of the throat: apply topically to the affected area as directed by your healthcare provider.

Benzocaine topical 20% mucus membrane gel

  • Awake intubation, bronchoscopy, oral airway: apply small amounts of benzocaine to naris prior to nasal intubation
  • Flexible sigmoidoscopy, proctoscopy: topically apply to rectal area. Wait for 30 to 60 seconds before initiating the procedure
  • Mucositis, stomatitis, thrush, pharyngitis, and cancer of the throat: topically apply to the affected area as directed by your healthcare provider.

Missed dose

Since benzocaine is only used when needed, you may not require a dosing schedule. If you are on a schedule, however, use the missed dose as soon as you can. You may skip the missed dose if your next schedule is just hours away. Do not make up for a missed dose by using extra medicine.

Benzocaine overdose

Benzocaine topical overdose applied to the skin can cause life threatening side effects such as seizures, irregular heartbeats, breathing problems, or respiratory failures. Seek emergency help as soon as you suffer from benzocaine overdose or contact the Drugs and Poison help line at 1800-222-1222.

Proper use of benzocaine topical

Use benzocaine exactly as directed by your healthcare provider or as indicated on the label. Never use the medication in larger or smaller amounts, or for longer than recommended.

Use the smallest amount of benzocaine needed to relieve the pain or numb the skin. Do not use large amounts or cover treated areas with a wrap or bandage unless advised by your doctor.

What to avoid while using benzocaine topical

Do not eat for at least 1 hour after using benzocaine topical inside your mouth or on your gums.

Benzocaine topical is for use only on your skin’s surface, or just inside the rectum, mouth or vagina. Do not let this medication get into contact with your eyes. Do not swallow the liquid, gel, or ointment while applying it inside your mouth or to your gums. Oral lozenge or throat sprays may be swallowed gradually during use.

Benzocaine interactions

It is unlikely that other drugs you take orally or via injection will interact with topically applied benzocaine. However, many drugs can interact with each other. Inform your healthcare providers about all medications you are using, including prescriptions, over-the-counter medications, vitamins, and herbal products.

Benzocaine warnings

  • Check with your doctor if your condition does not improve, or if it worsens, within 7 days of using benzocaine topical.
  • After applying benzocaine to the skin of your child, carefully watch the child to make sure that they do not ingest the medicine or get it into contact with their eyes. Benzocaine can cause serious side effects, especially in children, if it is ingested.
  • Stop the medicine right away and consult your healthcare provider if you develop skin rashes, severe stinging, burning, swelling or irritation of the skin.
  • Avoid applying cosmetics and other skin care products on the treated spot
  • Benzocaine, as already mentioned, may cause a rare but serious blood condition called methemoglobinemia. The risk is higher in children under 2 years. Be sure to keep this medication out of reach of children. Also, contact your healthcare provider right away if you or your child develops the following symptoms after benzocaine topical treatment: grey, pale, or blue-colored lips, skin, or nails; lightheadedness, rapid heartbeat, breathing difficulty, unusual fatigue and general weakness, and headache.
  • Inform your healthcare provider if you are taking medicines that contain nitrates or nitrites. These include nitroglycerine (brand names Nitro-Bid, Isordil, Imdur, or Transderm-Nitro).
  • Your body may absorb more of benzocaine if you use too much, if you apply heat, a plastic wrap or bandage to the treated area, or if you apply it over a large spot. An open wound may also absorb this medication into your system.
  • Do not use benzocaine topical to treat deep puncture wounds or large skin areas. Also, do not apply the medication on a raw or blistered spot, such as areas with severe burns or abrasions.
  • Carefully read patient information, instructions, and the medication guide before using benzocaine topical. Ask your pharmacist or doctor if you have any questions
  • When treating minor skin conditions, apply a thin layer of benzocaine topical to the affected spot. If using the spray, hold the container 5 to 10 inches away from your skin. Do not spray your face with this medication. Instead, spray it on your hands and rub it into your face, avoiding contact with your eyes.
  • Apply benzocaine 6 times per day when treating hemorrhoids
  • Clean the area of skin to be treated with water and soap before applying the medication. Clean your hands before and after inserting a rectal suppository.
  • Never take the rectal suppository by mouth. It is only meant for rectal use.
  • Empty your bladder and bowel before using benzocaine suppository.
  • If you are using benzocaine to treat a sore throat, call your healthcare provider if the pain lasts longer than 2 days, especially if you develop a skin rash, headache, fever, swelling, coughing, nausea and vomiting, and breathing difficulty.

Benzocaine storage

Store benzocaine in a closed container at room temperature, away from direct sunlight, moisture and heat. Do not freeze. Do not store benzocaine inside a car where it could be exposed to extreme cold or heat. Do not poke holes into the canister or throw it into a fire even if there is no medicine in it. Keep the medicine out of the reach of children. Do not keep expired or unused medicine. Ask your healthcare provider how to dispose of medications that you no longer use.

Summary

Benzocaine is a local anesthetic or numbing medication. It works by blocking the nerve signals on the skin. It is administered to reduce discomfort or pain that is caused by sore throat, minor skin irritations, sunburns, rectal or vaginal irritation, teething pain, hemorrhoids, ingrown toenail, and other sources of pain on the body’s surface. It can also be used to numb the surface of the mouth, nose, vagina, throat, and rectum.

It is important that you use this medication as directed by your healthcare provider or pharmacist. The use of this medication is not recommended for children under the age of 2 years because of increased chance of methemoglobinemia, a rare but fatal condition.

Benzocaine overdose may result in life threatening side effects. Consult your doctor as soon as you experience benzocaine side effects like lightheadedness, breathing difficulty, and headache. Finally, avoid ingesting this medication or getting it into contact with your eyes. Benzocaine is meant for use only on the surface of the body. As such, do not ingest it. Since the body absorbs benzocaine, do not apply it over a large surface or use it for an extended period. Contact your healthcare provider if the pain persists for more than 7 days while on benzocaine treatment. Also, do not apply it on open wounds or cover the treated area with a wrap or bandage.

Resources
Last Reviewed:
December 25, 2017
Last Updated:
December 22, 2017