A patient on atracurium develops seizures due to accumulation of -

Ans. is 'b' i.e., Laudanosine o Atracurium is metabolised to laudanosine that is responsible for seizures.o Atracurium is inactivated by - (1) Hoffman's elimination, (2) Alkaline ester hydrolysis,o Cisatracurium is inactivated by Hoffman's elimination.Atracuriumo The unique feature ofatracurium is inactivation in plasma by spontaneous nonenzymatic degradation (Hofmann elimination) in addition to that by alkaline ester hydrolysis.o Consequently its duration of action is not altered in patients with hepatic / renal insufficiency or hypodvnamic circulation - Preferred muscle relaxant for such patients as well as for neonates and the elderly.o Atracurium is metabolised to laudanosine that is responsible for seizures.o It can cause histamine release - Hypotension & bronchoconstriction.Cisatracuriumo This is R-Cis, R-Cis enantiomer of atracurium is nearly 4 times more potent, slower in onset but similar in duration of action.o Like atracurium it undergoes Hofmann elimination, but in contrast it is not hydrolysed by plasma cholinesterase.o Most importantly it does not provoke histamine release.