Cis atracurium is prefferd over atracurium due to advantage of aEUR'

No histamine release Cisatracurium is a stereoisomer of Atracurium Unlike atracurium cisatracurium does not produce a consistent dose dependent increase in plasma histamine -Atracurium triggers dose dependent histamine release that becomes significant at dose above 5mg/kg. - The release is dose dependent such that with increasing dose administered at the same rate there is greater propensity for eliciting histamine release. The histamine release resulted in:- - Flushing - Hypotension - Reflex tachycardia These effects are transient and the extent of hypotensive effect and reflex tachycardia were rarely of clinical significance. - Cisatracurium does not cause increase in histamine secretion, does not affect hea rate or blood pressure nor does it produce autonomic effects. Cisatracurium does not cause bronchospasmQ Atracurium use has been associated with bronchospasm and it should be avoided in patients with Asthma. To date cisatracurium has not been repoed to elicit bronchospasm at doses that are clinically prescribed Cisatracurium produces less laudanosineQ Laudanosine results from Hoffman elimination of Atracurium and cisatracurium Laudanosine may cause C.N.S. toxicity Cisatracurium produces less laudanosine Cisatracurium is 4 times as potent as Atracurium and produces less Laudanosine and has longer duration of intubation dose