How are local anesthetics categorized?

Local anesthetics are categorized primarily by their chemical structure, which plays a crucial role in determining their pharmacological properties, efficacy, and safety profiles. The two main classes of local anesthetics based on chemical structure are esters and amides. Esters are typically hydrolyzed in the plasma by pseudocholinesterase and can have a higher potential for allergic reactions due to the presence of the para-aminobenzoic acid metabolite. In contrast, amides are metabolized in the liver, leading to a different risk profile regarding allergy and metabolism. Understanding these categories helps clinicians choose the appropriate agent based on individual patient factors and procedural requirements.

The other options do not effectively categorize local anesthetics in a clinically relevant manner. Cost and flavor have no bearing on the intrinsic properties or mechanism of action of local anesthetics, while application is more related to the specific use in clinical practice rather than a categorization based on chemical structure.