Question

Which among the following is the most probable reason for preference of cisatracurium over atracurium?

• A. Decreased histamine release
• B. Increased histamine release
• C. Due to elimination by Hofmann elimination
• D. Increased CNS toxicity

Hint:

Both share Hofmann elimination; the real edge is no histamine release.

Answer 1

The Correct Option is A

Step 1: Both cisatracurium and atracurium are non-depolarizing neuromuscular blockers cleared by Hofmann elimination, so spontaneous degradation alone does not distinguish them.
Step 2: The clinically important advantage of cisatracurium is that it does NOT provoke histamine release, whereas atracurium can. Less histamine release means more cardiovascular stability (no flushing, hypotension or bronchospasm).
Step 3: Option c is true of both drugs, so it cannot be the reason for preference. Option b (increased histamine) and option d (increased CNS toxicity) are the opposite of cisatracurium's actual profile - cisatracurium produces LESS laudanosine, hence LESS CNS toxicity.
Step 4: The best single reason for preferring cisatracurium is its decreased histamine release.