Which short-acting depolarizing neuromuscular blocking agent is used as an adjunct to anesthesia to produce skeletal muscle relaxation?

• A. Vecuronium
• B. Rocuronium
• C. Succinylcholine
• D. Atracurium

Answer: (C)

Depolarizing neuromuscular blockers act as acetylcholine receptor agonists at the motor endplate, causing an initial stimulation (fasciculations) followed by a prolonged depolarized, inactivated state that prevents further muscle contraction. The shortest-acting member of this class is succinylcholine, which is broken down rapidly by plasma cholinesterase, giving a very brief duration—often only a few minutes. This makes it ideal as an adjunct to anesthesia for rapid skeletal muscle relaxation and quick airway control, such as during rapid sequence intubation.

In contrast, the other agents listed are nondepolarizing, competitive antagonists at the same receptor. They block acetylcholine without causing initial depolarization and typically have longer durations, requiring reversal for longer procedures. Hence succinylcholine best fits the description of a short-acting depolarizing option used to produce skeletal muscle relaxation during anesthesia.