Anesthesia Technologist Practice Exam

Which of the following is a depolarizing muscle relaxant?

1. Anectine

2. Rocuronium

3. Pancuronium

4. Cisatracurium

The correct answer is: Anectine

The correct answer is Anectine, which is the trade name for succinylcholine. Succinylcholine is classified as a depolarizing muscle relaxant because it works by mimicking the action of acetylcholine, binding to the nicotinic receptors at the neuromuscular junction. This binding causes an initial depolarization of the motor end plate, leading to muscle contraction. However, succinylcholine is not broken down by acetylcholinesterase but instead by plasma cholinesterase, resulting in prolonged depolarization and subsequent muscle paralysis. In contrast, the other substances listed are non-depolarizing muscle relaxants. Rocuronium, pancuronium, and cisatracurium act by competing with acetylcholine for the same receptors, thereby preventing depolarization and resultant muscle contraction. They do not cause initial muscle contractions and work differently to achieve muscle relaxation during surgical procedures or mechanical ventilation. This distinction in mechanism of action is what sets succinylcholine apart as a depolarizing agent.