Esters are hydrolyzed in plasma by the cholinesterase enzymes, whereas the amide compounds undergo enzymatic degradation in the liver. Cocaine is an exception to this as it is metabolized predominantly by the liver.

Are esters metabolized in liver?

Most ester LAs are metabolized by pseudocholinesterase, while amide LAs are metabolized in the liver.

Where are amides and esters metabolized?

Amino esters are metabolized in the plasma via pseudocholinesterases, whereas amino amides are metabolized in the liver. Amino esters are unstable in solution, but amino amides are very stable in solution. Amino esters are much more likely than amino amides to cause allergic hypersensitivity reactions.