Section 2e Neuromuscular Nicotinic Blockers Flashcards
Do Depolarizing blockers depolarize the cell?
only in the initial stage
Which blocker is competitive to the nicotinic receptor
Nondepolarizing blocker
Which blocker is resistant to AChE?
Depolarizing blockers
What is an example of a depolarizing blocker?
Succinylcholine
What is an example of Nondepolarizing blocker?
Tubocurarine
Which blocker acts as an agonist and which an antagonists between the two blockers
agonist = depolarizing antagonists = nondepolarizing
What does fasciculations mean?
twitching of the muscle (such as during the depolarizing phase of the depolarizing blockers)
What happens during phase 2 of depolarizing neuromuscular blocking drugs
Succinylcholine stays on the receptor and blocks the end-plate depolarization - desensitizing the effects of ACh
How long is the duration of action for Succinylcholine?
short muscle faciculations then a few minutes of paralysis (extremely short)
What can degrade Succinylcholine?
Butyrylcholinesterase (psuedocholinesterase)
What is dangerous adverse effect of succinylcholine in burn patients?
hyperkalemia
what are the major 4 adverse effects of succinylcholine?
hyperkalemia, bradycardia, malignant hyperthermia, apnea
What is probably reason behind the adverse effect apnea for succinylcholine?
patients with a deficiency in pseudocholinesterase = may need ventilation until drug is cleared from the body
What are the two groups of nondepolarizing blockers?
Benzylisoquinolinium (-acurium and tubocurarine) and Aminosteroid (-onium) compounds
What is the order/on set of action for neuromuscular blocking agents? (opposite for recovery)
smaller muscles –> larger muscles (on set of action)
How does the duration of action compare between Tubocurarine and Succinylcholine?
tubocurarine is much longer
What are the 2 major uses of Tubocurarine?
- adjuvant drug in anesthesia to relax muscles during surgery
- facilitate intubation during orthopedic surgery
What are side effects of Tubocurarine and the reasoning behind it?
hypotension and compensatory tachycardia due to marked histamine release
Is Tubocurarine used more or sythetic durgs?
sythetic drugs because they have lesser side effects
What is the duration of action for d-tubocuratine and pancuronium?
very long lasting
What is the duration of action for vecuronium, Atracurium, and rocuronium?
intermediate duration
What is the duration of action for mivacurium?
rapidly degraded (thus really short duration)
Which nondepolarizing agents cause histamine release?
Tubocurarine, atracurium and mivacurium
Which drug blocks muscarinic receptors in the heart, resulting in tachycardia?
Pancuronium
Which drugs have active metabolites that cause side effects?
Atracurium –> laudanosine
Pancuronium –> 3-hydroxy metabolite
Vecuronium –> 3-deacetylvecuronium
Which will have more side effects when messed with, nicotinic or muscarinic receptors?
nicotinic receptors
if it deals with heart rate what is it called?
chronotropy
if it deals with blood velocity what is it called?
dromotropy
if it deals with contractility (force) what is it called?
iontropy
if it deals with myocyte relaxation what is it called?
lusitropy
