Benzocaine (Orajel) - Dosage, Indications, Brands

Benzocaine blocks both the conduction and initiation of neuronal impulses by decreasing the neuronal membrane's permeability to sodium ions

Topical use:
- Dermal irritation:
  - It is used as ointment 5%, spray 5% and 20%
  - It has used in the temporary relief of pain and itching associated with minor skin irritations, cuts, sunburn, scrapes, minor burns, and insect bites
  - It is also used in the prevention of infection in minor cuts, scrapes, and burns
- Poison ivy/sumac:
  - Spray 5% (Ivy-Rid only):
    - It is used for temporary relief of pain and itching associated with poison ivy/oak/sumac
Topical oral use:
- Mouth and gum irritation:
  - Ointment 20%:
    - It is used for temporary relief of pain associated with fever blisters and cold sores.
  - Gel 10% and 20%, lozenge, spray 5%, liquid 10% and 20%:
    - It is used for temporary relief of pain associated with sore gums, sore throat, toothache, canker sores, braces, minor dental procedures, or minor injury of the mouth and gum caused by dentures or orthodontic appliances.
    - It is not recommended due to safety concerns related to increased methemoglobinemia risk in infants and children <2 years of age.
Sore throat/mouth, gag reflex suppression:
- Spray 20%:
  - It is used as a topical anesthetic for oral or mucosal areas
  - It is used for temporary relief of occasional minor irritation and pain with sore mouth and throat
  - It also used for temporary suppression of gag reflex.
Topical anesthetic:
- Gel or liquid 20% (Topex only):
  - It is used as a topical anesthetic for use on oral mucosa prior to local anesthetic injections, scaling and prophylaxis
  - It is used to relieve discomfort associated with taking impressions and intraoral radiographs.

Benzocaine Dose in Adults

Dosage in the treatment of Dermal irritation:

Topical (external):
- Spray 5% and 20%, ointment 5%:
  - Apply to the affected area or 1 spray after every 6 hours daily as needed.
  - In cases of bee stings, stinger should be removed before treatment.

Dosage in the treatment of Mouth and gum irritation:

Topical (oral):
- Gel 10% or 20%, liquid 10% or 20%, ointment 20%, spray 5%:
  - A thin layer is applied to the affected area or use 1 spray up to 4 times daily as required.

Use in the Poison ivy/sumac:

Topical (external):
- Spray 5% (Ivy-Rid only):
  - Spray on the affected area till it becomes wet.

Use in the treatment of Sore throat/mouth, gag reflex suppression:

Topical (oral):
- Lozenge:
  - Allow 1 lozenge to completely dissolve in the mouth
  - It can be repeated after every 2 hours as required.
- Spray 20%:
  - Benz-O-Sthetic:
  - It should be sprayed 2 - 3 times or as required.
  - Repeat if needed for larger areas.
- Hurricaine:
  - Spray on affected area or throat up to 4 times in 1 day.

Use in the treatment of Topical anesthetic:

Topical (oral):
- Gel or liquid 20% (Topex only):
  - Apply a small amount to mucosa to induce topical anesthesia.

Benzocaine Dose in Childrens

Due to risk of methemoglobinemia, AAP, FDA, and the American Academy of Pediatric Dentistry does NOT recommend use for teething and mouth pain in infants and children younger than 2 years

Use in the treatment of Dermal irritation (insect bites, minor cuts, scrapes, minor burns, sunburn):

Topical:
- 20% spray, 5% ointment:
  - Children ≥2 years and Adolescents:
    - It is applied to affected area 3 to 4 times daily as needed.

Use in the treatment of Mouth and gum irritation (including fever blisters and cold sores):

Topical:
- Oral 10% or 20% gel/liquid:
  - Children ≥2 years and Adolescents:
    - It is applied as a thin layer to affected area up to 4 times daily as needed.
  - Oral 5% spray:
    - Children ≥6 years and Adolescents:
      - Use 1 spray to affected area up to 4 times per day.

Use in the treatment of Sore throat, sore mouth, and gag reflex suppression:

Oral lozenge:
- Children ≥5 years and Adolescents:
  - Allow 1 lozenge to dissolve slowly in the mouth
  - It may be repeated every 2 hours as required.
Oral spray 5%:
- Children ≥6 years and Adolescents:
  - Apply 1 spray to affected area or throat up to 4 times daily.
Oral spray 20%:
- Children ≥2 years and Adolescents:
  - Spray on affected area or throat up to 4 times per day.

Benzocaine pregnancy risk category: C

Benzocaine can only be used for topical purposes. It is not recommended for use during pregnancy, as there is insufficient data.

Use during breastfeeding:

It can be used while you breastfeed.

Benzocaine Dose in Renal Disease:

No dose adjustments have been advised by manufacturer in patient with kidney disease.

Benzocaine Dose in liver Disease:

No dose adjustments have been advised by manufacturer in patient with liver disease.

Side effects of Benzocaine:

Central nervous system:
- Localized burning
- Stinging sensation
Dermatologic:
- Contact dermatitis
- Localized erythema
- Localized rash
- Urticaria
Hematologic & oncologic:
- Methemoglobinemia
Hypersensitivity:
- Hypersensitivity
Local:
- Local pruritus
- Localized edema
- Localized tenderness

Contraindication to Benzocaine include:

Allergy reactions to para-aminobenzoic (PABA) or any other part of the formulation
Self-medication should be avoided if you are allergic to any local anesthetics such as procaine, benzocaine and butacaine.
It shouldn't be used on lacerations, puncture wounds or deep wounds.

Warnings and precautions

Methemoglobinemia:
- It was reported to be effective when applied topically to the mucous membranes or mouth, in a concentration of 14% to 20%.
- It is not recommended to spray multiple times or for a longer duration than the indicated time.
- Be careful in the following situations:
  - Coexisting breathing issues (emphysema and bronchitis in smokers)
  - Mucosa damaged or inflamed
  - Heart disease
  - Children under 6 months old
  - Hemoglobin or enzyme abnormalities (glucose-6-phosphate dehydrogenase deficiency, hemoglobin-M disease, NADH-methemoglobin reductase deficiency, pyruvate-kinase deficiency).
  - Patients at greater risk should consider alternative treatments to benzocaine sprays such as topical lidocaine.

Benzocaine: Drug Interaction

Note: Drug Interaction Categories:

Risk Factor C: Monitor When Using Combination
Risk Factor D: Consider Treatment Modification
Risk Factor X: Avoid Concomitant Use

Risk Factor C (Monitor therapy).
Dapsone (Topical)	May increase the toxic/adverse effects of Methemoglobinemia Associated Agents.
Local Anesthesia	Methemoglobinemia Associated agents may increase the harmful/toxic effects of Local Anesthestics. Methemoglobinemia risk may increase.
Methemoglobinemia associative Agents	Local anesthetics may have a greater adverse/toxic impact. Methemoglobinemia risk may increase.
Nitric Oxide	May increase the toxic/adverse effect of Methemoglobinemia Associated Agents. Combinations of these agents can increase the risk of methemoglobinemia. When nitric dioxide is combined with other agents that can cause methemoglobinemia, it is important to monitor patients for signs such as hypoxia and cyanosis. Avoid lidocaine/prilocaine.
Prilocaine	Methemoglobinemia Associated Agents can increase the toxic/adverse effects of Prilocaine. Combinations with these agents can increase the risk of methemoglobinemia. When prilocaine is combined with other agents that can cause methemoglobinemia, monitor patients for signs such as hypoxia and cyanosis. Lidocaine/prilocaine should not be given to infants who are receiving these agents.
Sodium Nitrite	Methemoglobinemia Associated Agents can increase the toxic/adverse effect of Sodium Nitrite. Combinations of these agents could increase the chance of significant methemoglobinemia.

Monitor:

Evaluate patients for signs and symptoms of methemoglobinemia such as nausea, pallor, fatigue, cyanosis, muscle weakness, dizziness, confusion, agitation, dyspnea, and tachycardia.
The major clinical finding of methemoglobinemia is chocolate brown-colored arterial blood.
Suspected cases should be confirmed by performing co-oximetry, which yields a direct and accurate measure of methemoglobin levels.
Standard pulse oximetry readings or arterial blood gas values are not usually reliable.
Clinically significant methemoglobinemia requires immediate management.

How to administer Benzocaine?

Contact should be avoided with eyes and other mucous membranes.
Some spray products could contain flammable ingredients, do not use near fire, flame or heat.
Some products can stain certain fabrics; avoid contact with clothing or furniture.

Topical, external:

The ointment should be applied evenly.

Spray:

It should be shaken well before using.
Hold 6 to 12 inches from the affected area.
When applying to face, first spray into palm of the hand, then touch hand to face.
It should not be applied to broken, blistered, or abraded skin.

Topical, oral: Gel/liquid:

It should be applied with a cotton applicator or fingertip to the affected area.
For dental irritation, do not reinsert dentures till irritation or pain is relieved
rinse mouth well before reinserting.

Lozenge:

It should be allowed to dissolve slowly in the mouth.

Ointment:

It should be applied evenly.

Spray:

It should be shaken well prior to use
some products might be used with an extension tube for finer direct application.

Mechanism of action of Benzocaine:

It reduces the neuronal membrane's permeability to sodium ions, which blocks both conduction and initiation neuronal impulses.
It causes depolarization inhibition and conduction blockade.

Onset: