Esters are metabolized by what process?

Esters are metabolized by what process?

• A. Liver microsomal enzymes
• B. Pseudocholinesterase in blood
• C. Renal excretion
• D. Nerve membrane hydrolysis

Answer: (B)

Esters are broken down mainly by hydrolysis in the bloodstream, carried out by the enzyme pseudocholinesterase (butyrylcholinesterase). This plasma-mediated cleavage destabilizes the ester bond, yielding inactive products and causing ester local anesthetics to have a relatively short duration. In contrast, amide local anesthetics are mainly metabolized in the liver by microsomal enzymes, which is why they often last longer. Renal excretion is a route of elimination rather than metabolism, and nerve membrane hydrolysis is not a recognized mechanism for metabolizing these drugs. So the best answer is that esters are metabolized by hydrolysis via pseudocholinesterase in blood.

Esters are broken down mainly by hydrolysis in the bloodstream, carried out by the enzyme pseudocholinesterase (butyrylcholinesterase). This plasma-mediated cleavage destabilizes the ester bond, yielding inactive products and causing ester local anesthetics to have a relatively short duration. In contrast, amide local anesthetics are mainly metabolized in the liver by microsomal enzymes, which is why they often last longer. Renal excretion is a route of elimination rather than metabolism, and nerve membrane hydrolysis is not a recognized mechanism for metabolizing these drugs. So the best answer is that esters are metabolized by hydrolysis via pseudocholinesterase in blood.