L06 - Neuromuscular Blocking Agents Flashcards
What is the classification of neuromuscular blocking agents
Depolarising
Non depolarising
Why do we need neuromuscular blocking agents
For delicate microscopic surgery
To decrease muscular tone - easier retraction of body wall
Among depolarising and non depolarising, which one is of greater clinical significance
Non depolarising
What is the most common neuromuscular blocking agent used nowadays
Atracurium
What is the mode of action of depolarising NMB
These agents act by depolarizing the plasma membrane of the skeletal muscle fiber. This persistent depolarization makes the muscle fiber resistant to further stimulation by ACh.
What is the mode of action of non depolarising NMB
These agents constitute the majority of the clinically relevant neuromuscular blockers. They act by competitively blocking the binding of ACh to its receptors, and in some cases, they also directly block the ionotropic activity of the ACh receptors.[9]
Give an example of depolarising NMB
what is its pharmacokinetics
Succinylcholine
Rapid onset, rapid offset
What are the side effects of succinylcholine
Bind to Ach -> autonomic effect Arrhythmia Sinus bradycardia Hyperkalemia Phase II neuromuscular block Increase in intracoculAr pressure
Give examples of non depolarising NMB
Short acting - Micacurium
Intermediate acting - Atracurium
Long acting - pancuroium
Why is Atracrium commonly used
It is not limited by renal and liver insufficienct
How do you check whether the patient has been paralysed
Stimulate impulse into nerve
Adductor pollicis muscle is monitored because it is far from the ulnar nerve
Give two categories of drugs which terminate NMB
Anticholinesterase
Chelating agent
Give two examples of anticholinesterase
Neostigmine
Pyridostigmine
