Reason for preferring cis-Atracurium over Atracurium is:-
Cis-atracurium and Atracurium both are NMJ blocking agent. Cis atracurium has same pharmacokinetic propeies as atracurium. Atracurium release histamine and is metabolized to Laudonasine, which can provoke seizures. Both undergo Hoffman elimination.
Faster acting than Atracurium
Lesser provocation of histamine release
Shoer action than atracurium
Does not undergo Hoffman elimination
NEET 2019