Amino esters are a class of local anesthetics. They are named for their ester bond (and are unlike amide local anaesthetics). Structure Structurally, local anesthetics consist of three molecular components: a lipophilic part an intermediate aliphatic chain a hydrophilic (amine) part The chemical linkage between the lipophilic part and the intermediate chain can be of the amide-type or the ester-type, and is the general basis for the current classification of local anesthetics. Amino esters, in reference to anesthetic agents, are rapidly metabolized in the plasma by butyrylcholinesterase to para-aminobenzoic acid derivatives, then excreted in the urine. This suggests their very short half lives. Allergy is more likely to occur with ester-type agents, as opposed to amide-type. Examples Amino ester-type include: Cocaine Procaine (Novocain) Tetracaine (Pontocaine) Benzocaine Chloroprocaine References University of Texas Med School, Pharmacology Syllabus. Katzung. 10th edition. Chapter 26. Local anesthetics