Benzocaine + Butamben + Tetracaine Hydrochloride

• Approved Indications:
• Topical anesthesia for mucous membranes during minor surgical procedures or diagnostic interventions in dentistry and otolaryngology.
• Relief of pain and itching associated with minor burns, insect bites, hemorrhoids, and other localized skin irritations.
• Temporary local anesthesia prior to venipuncture or intravenous catheter insertion.
• Used in gels, sprays, ointments, or solutions for topical anesthesia of oral, pharyngeal, nasal, and genitourinary mucosa.
• Off-label Uses:
• Adjunctive analgesia for minor dermatological procedures such as tattooing or laser therapy.
• Anesthetic for minor ophthalmic or ear procedures (with caution).

• Route: Topical application (gel, cream, spray, or solution).
• Adults and Children (typically >2 years):
• Apply a thin layer to the affected area as needed, usually 1 to 3 times daily.
• For mucosal anesthesia, apply shortly before the procedure; duration of anesthesia generally lasts 15 to 30 minutes.
• Avoid excessive dosing and prolonged use to minimize systemic absorption and toxicity risk.
• Pediatrics:
• Use cautiously in children under 2 years; dosing should be minimal and supervised by a healthcare professional due to increased sensitivity and risk of methemoglobinemia.
• Special Populations:
• Use with caution in elderly and patients with cardiovascular or hepatic impairment.
• Avoid application on large skin areas, broken skin, or mucosa to reduce systemic exposure.

Benzocaine, butamben, and tetracaine hydrochloride are local anesthetics that block nerve impulse conduction by inhibiting voltage-gated sodium channels on neuronal cell membranes. This inhibition prevents the initiation and propagation of action potentials in sensory nerve fibers, resulting in a reversible loss of sensation, including pain and itching, in the localized area of application. The combination provides rapid onset and prolonged anesthetic effect due to the differing lipophilic properties and durations of each agent.

• Absorption:
  Minimal systemic absorption when applied topically on intact skin or mucous membranes. Absorption increases with application over large areas, damaged skin, or mucosa.
• Distribution:
  Locally retained at the application site; any absorbed drug distributes in plasma bound to plasma proteins.
• Metabolism:
  Benzocaine and butamben undergo hydrolysis by plasma esterases.
  Tetracaine is metabolized primarily by hydrolysis via plasma cholinesterases.
• Elimination:
  Metabolites are excreted primarily via the kidneys.
• Onset & Duration:
  Rapid onset within 30 seconds to 2 minutes; duration typically 15 to 30 minutes, with tetracaine providing the longest anesthetic effect.

• Pregnancy:
  No adequate controlled studies in pregnant women; topical use in recommended doses considered low risk. Use only if clearly needed.
• Lactation:
  Limited data on excretion into breast milk; minimal systemic absorption suggests low risk, but caution is advised.

• Primary Therapeutic Class: Local Anesthetic
• Subclass: Ester-type local anesthetics combination

• Known hypersensitivity to benzocaine, butamben, tetracaine, or other ester-type anesthetics.
• History of methemoglobinemia or other blood dyscrasias.
• Application to large areas of damaged or inflamed skin or mucosa.
• Severe hepatic or cardiac impairment (relative contraindication).

• Risk of methemoglobinemia, a rare but potentially life-threatening condition, especially in infants, young children, and individuals with G6PD deficiency or other blood disorders. Monitor for cyanosis, headache, fatigue, or shortness of breath.
• Avoid excessive dosing and prolonged application.
• Use with caution in patients with known cardiac conduction abnormalities or arrhythmias.
• Discontinue immediately if signs of allergic reaction, severe irritation, or systemic toxicity occur.
• Not for injection; for topical use only.

Common:

• Local irritation, burning, stinging, or redness at the application site.
• Temporary numbness or tingling.

Serious but Rare:

• Methemoglobinemia (manifesting as cyanosis, headache, dizziness).
• Allergic reactions including rash, urticaria, angioedema, or anaphylaxis.
• Systemic toxicity symptoms (rare) such as CNS excitation or depression, seizures, cardiac arrhythmias with overdose.

• Caution with concurrent use of other drugs that can induce methemoglobinemia (e.g., dapsone, sulfonamides, nitrates).
• Concomitant use with other local anesthetics or systemic drugs affecting cardiac conduction requires monitoring.
• No significant CYP450 metabolism involvement.

• Increased awareness and monitoring for methemoglobinemia risk have been emphasized by regulatory authorities, especially in pediatric use.
• Recommendations highlight limiting dose and duration to reduce adverse effects.
• Combination products remain preferred for rapid and effective topical anesthesia in minor procedures.

• Store at 20°C to 25°C (68°F to 77°F).
• Protect from light and moisture.
• Keep container tightly closed.
• Do not freeze.
• Keep out of reach of children.