Structurally, amino esters consist of three molecular components: • a
lipophilic part (ester) • an intermediate
aliphatic chain • a
hydrophilic part (
amine) 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==