BENZOCAINE

BENZOCAINE (ben'zoe-caine) Americaine, Americaine Anesthetic Lubricant, Americaine-Otic, Anbesol Cold Sore Therapy, Chigger-Tox, Dermoplast, Foille, Hurricaine, Orabase with Benzocaine, Orajel, Solarcaine, T-Caine Classifications: local anesthetic (ester type); antipruritic; Therapeutic:local anesthetic; antipruritic Prototype: Procaine Pregnancy Category: C

Availability

5% spray, cream, ointment; 6% cream; 8% lotion, 20% spray, ointment, gel, liquid; 20% otic solution

Action

Produces surface anesthesia by inhibiting conduction of nerve impulses from sensory nerve endings. Almost identical to procaine in chemical structure, but has prolonged duration of anesthetic action.

Therapeutic Effect

Temporary relief of pain and discomfort.

Uses

Temporary relief of pain and discomfort in pruritic skin problems, minor burns and sunburn, minor wounds, and insect bites. Otic preparations are used to relieve pain and itching in acute congestive and serous otitis media, swimmer's ear, and otitis externa. Preparations are also available for toothache, minor sore throat pain, canker sores, hemorrhoids, rectal fissures, pruritus ani or vulvae, as male genital desensitizer to slow onset of ejaculation, and for use as anesthetic-lubricant for passage of catheters and endoscopic tubes.

Contraindications

Hypersensitivity to benzocaine or other PABA derivatives (e.g., sunscreen preparations), or to any of the components in the formulation; use of ear preparation in patients with perforated eardrum or ear discharge; applications to large areas; use in children <2 y; pregnancy (category C).

Cautious Use

History of drug sensitivity; denuded skin or severely traumatized mucosa; children <6 y.

Route & Dosage

Anesthetic Adult: Topical Lowest effective dose Child: Topical Lower strengths

Administration

Topical

• Avoid contact of all preparations with eyes and be careful not to inhale mist when spray form is used.
• Do not use spray near open flame or cautery and do not expose to high temperatures. Hold can at least 12 inches (30 cm) away from affected area when spraying.
• Wash and neutralize chemical burns before benzocaine is applied.
• Clean and dry rectal area before administration of hemorrhoidal preparation. Usually administered morning and evening and after each bowel movement.
• Store at 15°–30° C (59°–86° F) in tight, light-resistant containers unless otherwise specified.

Adverse Effects (≥1%)

Body as a Whole: Low toxicity; sensitization in susceptible individuals; allergic reactions, anaphylaxis. Hematologic: Methemoglobinemia reported in infants.

Interactions

Drug: Benzocaine may antagonize antibacterial activity of sulfonamides.

Pharmacokinetics

Absorption: Poorly absorbed through intact skin; readily absorbed from mucous membranes. Peak: 1 min. Duration: 15–30 min. Metabolism: By plasma cholinesterases and to a lesser extent by hepatic cholinesterases. Elimination: In urine.

Nursing Implications

Assessment & Drug Effects

• Assess swallowing when used on oral mucosa, as benzocaine may interfere with second (pharyngeal) stage of swallowing; hold food and liquids accordingly.
• Assess for sensitivity. Local anesthetics are potentially sensitizing to susceptible individuals when applied repeatedly or over extensive areas.

Patient & Family Education

• Use specific benzocaine preparation ONLY as prescribed or recommended by manufacturer.
• Discontinue medication if the condition persists, worsens, or if signs of sensitivity, irritation, or infection occur.

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Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug