4 Non Depolarizing Muscle Relaxants (NDMR)

Non Depolarizing Muscle Relaxants (NDMR) :
  • No Muscle fassiculation.
  • Slow onset and slow dissociation.
  • Reversed by Neostigmine.
  • Muscle remains responsive to other stimulus (Therefore Neuromuscular monitor used).
  • Fade & Post tetanic stimulation.
  • Mild hypothermia antagonizes block.

Atracurium :

  • Metabolism - 75% by Hoffman degradation, 25 % by  ester hydrolysis.
  • Metabolite - Laudanosine (pro convulsant)
  • Does not require any reversal agent
  • DOC in :
  1. Renal and Hepatic failure cases.
  2. Myesthenia Gravis - Use 1/10 th of normal dose

CisAtracurium :
  • 3 times more potent
  • No histamine release
  • Non cumulative
  • Only Hoffman degradation
  • Laudanosine levels are lower.

Mivacurium :
  • Ultra Short
  • Metabolism - Plasma Cholinesterase (=Pseudo)
  • Ideal Muscle relaxant for Continuous infusion , day care surgery.

Doxacurium :
  • Most Potent
  • Long acting
  • Metabolism - Kidney

D Tubocurarine :
  • Long acting 
  • Cause hypotension by ganglionic block

Vecuronium Bromide :
  • Most Haemodynamically stable
  • Minimum Vagolytic
  • Metabolism - Liver

Pancuronium :
  • Causes Hypertension and tachycardia (therefore good in Shock)
  • Long acting
  • Vagolytic
  • Causes Nor-epinephrine release

Rocuronium bromide :
  • Rapid onset (therefore can be used in full stomach)
  • Slightly vagolytic
  • Largely excreted unchanged in bile

Pipecuronium :
  • Longest acting
  • No vagolytic activuty

Rapacuronium :
  • Fastest Onset (among NDMR) ( Note: Overall Fastest Onset Muscle relaxant is Sch )
  • Increases incidence of bronchospasm.

  • Maximum propensity for vagal blockade
  • Cross Placenta (therefore contraindicated in Pregnancy)
  • Also Contraindicated in Renal disease.

Alcuronium :

  • Anaphylaxis is common
  • Deterioration on exposure to sunlight.

Fastest onset agents are used in full stomach : (preference order as mentioned below)
  1. Succinylcholine
  2. Rapacuronium
  3. Rocuronium


  1. nicely compiled, good job

    1. Thanks for the compliment. We will try our best to make medical study easy for all our readers.

  2. u guys r doin an awesome job...thanq is un underword..still...my gratitude and thanqq!!!

  3. Thanks Dr.Anuja. It feels gr8 when we see people getting some benefit out of our work. Keeps us going and improving :)


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