<prompt> Maximum histamine is released by ?dTubocurarineSuccinylcholinePancroniumGallamine  <response>: Ans. is a i.e., d Tubocurarine Impoant facts about muscle relaxants from Goodman Gilman Longest acting Neuromuscular blocker Pancuronium duration of action 120-180 minutes. Note - KDT has mentioned doxacurium as longest acting. Shoest and fastest acting neuromuscular blocker Succinylcholine suxamethonium - duration of action 5-8 minutes. Shoest acting competitive nondepolarizing neuromuscular blocker Mivacurium duration of action 12-18 minutes. Fastest acting nondepolarizing blocker Rocuronium can be used for endotracheal intubation as an alternative to Sch. Histamine release is caused by -- D-TC maximum tendency, succinylcholine, mivacurium, doxacurium, atracurium, tubocurarine can cause bronchoconstriction. Viually no histamine release.--- Pancuronium Maximal vagal block and tachycardia is caused by -9 Pancuronium Previously it was gallamine, but it is not used now. Vagal stimulation is caused by -- succinylcholine. Maximum ganglion blockade is caused by d-TC Ganglion stimulation is caused by Succinylcholine Most commonly used muscle relaxant for routine surgery -9 vecuronium. Most potent skeletal muscle relaxant -- Doxacurium. oelaxa Least potent skeletal muscle relaxant Succinylcholine Gallamine was least potent but it is not used now. Least potent nondepolarizing muscle rnt -- Rocuronium. 