Longest acting muscle relaxant?
Ans. a. Doxacurium (Ref: Tripathi 6th edition, 345; Lee 12th edition, p. 180-190).Doxacurium is a bisquaternary muscle relaxant having the least rapid onset and the longest action: suitable for longer duration surgeries. It is primarily eliminated by kidney, although hepatic metabolism also occurs. Cardio- vascular chnages are minimal.PROPERTY*MUSCLE RELAXANT (M.R.)Rapid onset of Action*Sch (overall); Rocuronium (non depolarising)Shortest Acting*Sch (overall); Mivacuronium (non depolarising)Longest Acting*DoxacuriumExcreted in Liver*Rocuronium; VencuroniumNo placenta crossing*d-TCHisatminerelease*d- TC (maximum): Atracuroniuin; Mivacuronium; SchLeast Histamine release* VlcoroniumMost CArdiostable*VicoroniumM.R. used to decrease BP*d-TCM.R. Used to maintain BP*PancuroniumM.R.Safein asthma* Vecronium: CisatracuroniumM.R. Causing epilepsv* Atrocuronium; secondary Launodo rubinM.R. Metabolised by Hoffmann's elimination* Cisatracuronium: AtracuroniumComparative properties of neuromuscular blocking drugsDrugDose (mg/kg)Onset (min)Duration (min)Hist. releaseGang blockVagal blockLONG ACTING1.d- Tubocurarilng0.2-0.44-630-60++++++-2.Pancuronium0.04- 0.14-660-120+-+-+3.Doxacurium0.03-0.084-860-120+--4.Pipecuronium0.05-0.082-850-100+---INTERMEDIATE NACTING5.Vecuronium0.08-0.12-430-60+--+6.Atracurium0.3-0.62-420-35+--7.Clsatracurium0.15-0.23-620-40---8.Rocuronium0.6-0.91-225-40--+-SHORT ACTING9.Mivacurium0.07-0.152-412- 20+--10.SUCCILNYLCHOLNE0.5-0.81-1.53-6++StSt.
Doxacurium
Atracurium
Scoline
Vecuronium
Muscle Relaxant