Pharm NMJ part I Flashcards Preview

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Flashcards in Pharm NMJ part I Deck (50)
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1
Q

What are the nondepolarizing NMJ blocking drugs

A
cisatracurium
tubocurarine
pancuronium
rocuronium
vecuronium
2
Q

which nondepolarizing blocking drugs are steroid derivatives

A

pancuronium
rocuronium
vecuronium

3
Q

what is the depolarizing NMJ blocking drug

A

succinylcholine

4
Q

what drugs do we have that are muscle relaxants aka spasmolytics

A

dantrolene

botulinum toxin

5
Q

What are the AChEI

A
echothiophate
edrophonium
neostigmine
physostigmine
pyridostigmine
6
Q

what are the antimuscarinic agents

A

atropine

7
Q

what are the cholinesterase reactivators

A

pralidoxime

8
Q

what are the 2 main therapeutic groups of drugs that affect skel mm function

A

NMJ blockers

spasmolytics

9
Q

how do nondepolarizing NMJ blockers work

A

antagonists of nAChR

10
Q

how do depolarizing NMJ blockers work

A

excess depolarizing agonist, so AchR taken up

11
Q

What makes NMJ blockers hard to enter CNS

A

one or 2 quaternary nitrogens,, poorly lipid soluble

12
Q

how are NMJ blockers administered

A

parenterally because highly polar and inactive orally

13
Q

what muscles are more R to NMJ blockades

A

trunk, paraspinals and diaphragm

14
Q

what is the last muscle to be paralyzed and quickest to recover from a NMJ blockade

A

diaphragm

15
Q

what is the least potent nondepolarizing NMJ blocker

A

rocuronium

16
Q

how do you reverse a NMJ blockade

A

Ach or succinylcholine

17
Q

what cholinesterase inhibitors can antagonize nondepolarizing blockers blockade

A

neostigmine and pyridostigmine because increase ACh availability and increase release of NT from motor nerve terminal

18
Q

why is edrophonium less effective in reversing the effects of nondepolarizing blockers

A

no effect on NT release

19
Q

what is given to minimize adverse effects of cholinesterase inhbitors

A

anticholinergic agents like atropine

20
Q

what are the adverse effects of cholinesterase inhibitors

A

bradycardia, bronchoconstriction, salivation, nausea, vomiting

21
Q

adverse effects nondepolarizing NMJ blockers

A

histamine release which can cause wheal reaction, bronchospasm, hypotension and bronchial and salicary secretion

22
Q

at large doses tubocurarine and metocurine can cause what

A

ACh blockade at autonomin ganglia in adrenal medulla causing a dec in BP and tachycardia

23
Q

why is d tubocurarine not used anymore

A

long duration and caused significant histamine release

24
Q

what drugs can potentiate the NMJ blockade from nondepolarizing afents

A

inhaled anesthetics

aminoglycosides

25
Q

be careful with NMJ blockers in what population subtype

A

elderly because longer duration from decreased hepatic and renal clearance

26
Q

what patients are resistant to nondepolarizing muscle relaxants

A

patients with severe burns and with UMN disease

27
Q

which nondepolarizing NMJ blocker has very little to no CV effects

A

cisatracurium

28
Q

which nodepolarizing relaxant has the shortest duration of action

A

mivacurium

29
Q

inermediate acting steroid muscle relaxants are excreted how

A

biliary excretion or hepatic metabolism

30
Q

what metabolizes steroid mm relaxants

A

3- 17- or 3,17 hydroxy derivatives

31
Q

which muscle relaxant is least likely to cause histamine release

A

steroidal NMJ blockers

32
Q

agent of choice for patients with normal renal and hepatic function requireing paralysis for more than one hour

A

pancuronium

33
Q

adverse effects pancuronium

A

tachy
HTN
increased CO from vagal blockade

34
Q

most rapid time onset steroidaly relaxant

A

rocuronium

35
Q

common use rocuronium

A

used to facilitate a difficult tracheal intubation because rapid acting
basically no CV effects

36
Q

alternative to rocuronium for intubation

A

vecoronium

37
Q

PK of succinylcholine

A

short duration because rapid hydrolysis and inactivation by butyrylcholinesterase

38
Q

What is the phase I block for succinylcholine

A

depolarizes motor end plate and spreads to adjacent membranes. remain depolarized (block)

39
Q

what augments the phase I depolarizing block ofd succinylcholine

A

cholinesterase inhibitors

40
Q

what is the phase II desensitizing block of succinylcholine

A

continued exposure causes intiial depolarization to decrease and membrane repolarized. R has to be desensitized until it can depolarize again

41
Q

what reverses the phase II block by succinylcholine

A

AChE inhibitors

42
Q

what occurs with standad dose IV succinylcholine

A

fasciculations within 30 sec then paralysis withing 90 sec

initiall arm and neck, leg muscles then respiratory muscles

43
Q

when is succinylcholine used

A

EM surgery when need to secure airway rapidly

44
Q

what degrades succinylcholine

A

plasma cholinesterases

45
Q

CV effects of succinylcholine

A

cardiac arrhythmias when administered with halothane anesthesia
negative inotropic and chronotropic effects
large doses cause positive inotropic and chronotropic effects

46
Q

What acid base status does succinylcholine cause

A

hyperkalemia

47
Q

adverse effects succinylcholine

A

increased intraocular P
increased intragastric P
muscle pain
slight histamine release

48
Q

CI to succinylcholine

A

personal or familial Hx of malignant hyperthermia
myopathies with elevated CPK values
acute phase injury following major burns
multiple trauma
extensive denervation of skel mm or UMN injury

49
Q

black block warning on succinylcholine

A

acute rhabdomyolysis with hyperkalemia followed by ventricular dysrhythmias, cardiac arrest, and death if administered to child with undiagnosed skel mm myopathy

50
Q

what drug if used with succinulcholine can induce malignant hypertermia

A

volatile anesthetics