ester local anesthetic
An older class of local anesthetic agents metabolised by plasma cholinesterase, including procaine, benzocaine, and tetracaine; associated with a higher incidence of true allergic reactions than amide agents.
Full Definition
Ester local anesthetics contain an ester linkage (–COO–) between the aromatic ring and the intermediate chain and are hydrolysed in the plasma by pseudocholinesterase, yielding para-aminobenzoic acid (PABA) metabolites. PABA is a known allergen, which accounts for the higher allergenicity of ester agents compared with amide agents. In contemporary dental practice, ester agents are primarily encountered as topical anesthetics (e.g., benzocaine gels) rather than injectable solutions. Editors should note that a documented allergy to benzocaine (an ester) does not imply cross-reactivity with amide agents—a common source of clinical documentation error. Procaine (Novocain) is historically significant but rarely used today.
Usage
Usage note: Avoid writing 'ester-type' or 'ester-based'; the preferred editorial form is 'ester local anesthetic' or 'ester agent'.
In Context
- "The adverse-event report specified benzocaine, an ester local anesthetic, as the causative agent in the allergic contact dermatitis case." — Adverse event report in a dental journal
- "The editor inserted a parenthetical clarifying that procaine is an ester local anesthetic, anticipating reader confusion with the widely used amide lidocaine." — Copy-editing a historical pharmacology article