Hoffman's elimination is feature of
Ans. d (Atracurium) (Ref KDT 6th !345; Anaesthesia by Ajay yadav, 2nd ed., p. 90)The unique feature of atracurium is inactivation in plasma by spontaneous nonenzymatic degradation (Hofmann elimination) in addition to that by cholinesterases. Consequently its duration of action is not altered in patients with hepatic/renal insufficiency or hypodynamic circulation. It is the preferred muscle relaxant for such patients as well as for neonates and the elderly. Hypotension may occur due to histamine release.Cisatracurium, R-Cis, R-Cis enantiomer of atracurium is nearly 4 times more potent, slower in onset, but similar in duration of action. Like atracurium it undergoes Hofmann elimination, but in contrast it is not hydrolysed by plasma cholinesterase. Most importantly, it does not provoke histamine release.ATRACURIUM BESYLATE# Long acting and non-depolarising muscle relaxant.# Muscle relaxant of choice in renal failure or anephric patients.# pH of solution is 3.5.; Stored at 4degC.; Duration of action doubled at 25degC.# Metabolism mainly by Hofmann elimination (chemical degradation) and hydrolysis in plasma and elsewhere in body.# Major metabolite is laudanosine, which is CNS stimulant.# Cisatracurium is one of the ten isomers of atracurium and its active metabolites contain less laudanosine which causeless hypotension, central nervous system excitement, and seizures than that of atracurium.# It is considered an intermediate-acting agent in terms of duration of action.Notable features of Few muscle relaxantsPropertyMuscle relaxant (MR)Rapid onset of ActionShortest ActingLongest ActingSch (overall); Rocuronium (non-depolarising)Sch (overall); Mivacurium (non-depolarising)DoxacuriumExcreted in LiverRocuronium; VecuroniumNo placenta crossingd -TCHistamine released-TC (maximum) Atracuronium Mivacuronium SchLeast Histamine releaseVecuroniumMost CardiostableVecuroniumM.R. used to decrease BPd -TCM.R. Used to maintain BPPancuroniumM.R. Safe in asthmaVecronium; CisatracuroniumM.R. Causing epilepsyAtracurium; secondary LaunodocinM.R. Causing epilepsyCisatracurium; Atracurium
Pancuronium
Thiopentone
Vecuronium
Atracurium
Muscle Relaxant