Which of the following drug undergoes Hoffman’s elimination?
**Core Concept**
Hoffmann's elimination is a type of chemical reaction that involves the conversion of a tertiary amine into a secondary amine, typically resulting in the formation of a quaternary ammonium compound. This process is mediated by the enzyme pseudocholinesterase (also known as butyrylcholinesterase) and is an important mechanism for the elimination of certain drugs.
**Why the Correct Answer is Right**
Drugs that undergo Hoffman's elimination are typically tertiary amines that contain an ester or amide group. These compounds are converted into their corresponding quaternary ammonium salts by the action of pseudocholinesterase, which hydrolyzes the ester or amide linkage. This process is an important mechanism for the inactivation of certain anesthetics, muscle relaxants, and anticholinesterase agents. For example, succinylcholine, a common muscle relaxant, is rapidly hydrolyzed by pseudocholinesterase to form a quaternary ammonium compound that is inactive.
**Why Each Wrong Option is Incorrect**
**Option A:** Atropine is a tertiary amine that does not undergo Hoffman's elimination. Instead, it is primarily excreted unchanged in the urine.
**Option B:** Vecuronium is a non-depolarizing neuromuscular blocker that is metabolized by the liver, but it does not undergo Hoffman's elimination.
**Option C:** Mivacurium is a short-acting non-depolarizing neuromuscular blocker that undergoes Hoffman's elimination, but it is not the correct answer in this case.
**Clinical Pearl / High-Yield Fact**
It is essential to note that pseudocholinesterase deficiency can lead to prolonged apnea following the administration of succinylcholine, highlighting the importance of considering this enzyme deficiency in patients who receive this medication.
**Correct Answer: C. Mivacurium**