Local anesthesia in otolaryngology. A re-evaluation

Area of Science:

• Otolaryngology
• Anesthesiology
• Pharmacology

Background:

• Cocaine is still widely used for topical anesthesia in otolaryngology despite attempts to ban it.
• Synthetic substitutes have not entirely replaced cocaine due to its unique pharmacological profile.

Purpose of the Study:

• To analyze cocaine's pharmacological properties, adverse effects, and compare it with potential synthetic substitutes.
• To understand why cocaine remains a preferred agent in otolaryngology.

Main Methods:

• Review of cocaine's topical effectiveness, duration, toxicity, and vasoconstrictive properties.
• Comparison of cocaine with synthetic anesthetics like procaine, dibucaine, tetracaine, and lidocaine.
• Analysis of factors influencing cocaine's safety and efficacy in topical applications.

Main Results:

• Cocaine offers excellent topical anesthesia, vasoconstriction, and mucosal shrinkage, with a good safety margin when used topically and dosed appropriately (below 200 mg).
• Synthetic substitutes like tetracaine and dibucaine are more toxic, while lidocaine has a shorter duration of action.
• Cocaine's inherent vasoconstriction reduces absorption, and it sensitizes patients to exogenous epinephrine, making co-administration potentially harmful.

Conclusions:

• Cocaine remains a crucial tool in otolaryngology for topical anesthesia, offering a unique combination of efficacy, duration, and vasoconstriction.
• Controlled topical application of cocaine presents an acceptable safety profile compared to its synthetic alternatives.
• Understanding cocaine's pharmacology is key to optimizing its use and minimizing risks in otolaryngologic procedures.