Pharm NMJ part II Flashcards Preview

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Flashcards in Pharm NMJ part II Deck (55)
1

what are the clinical uses of NMJ blocking drugs

surgical relaxation
endotracheal intubation
control of ventilation

2

how do NMJ blockers help control ventilation

reduce chest wall R and improve thoracic compliance
permit adequate gas exchange and prevents atelectasis in patients who have ventilatory failure
pancuronium and vecuronium most common if >24 hours

3

MOA dantrolene

inhibition of RYR Ca Ch blocking release of Ca from SR and so no muscle contraction

4

side effects dantrolene

generalized muscle weakness, sedation, and occasionally hepatitis

5

what is dantrolene used for

Tx for spascitiy associated with UMN disorders and management of malignant hyperthermia

6

what patients are at risk for malignant hyperthermia

hereditary mutations in RyR gene
permits excessive Ca release from SR under certain triggering agents
increase Ca, increase lactic acid, increase temperature

7

what do we use to reduce Ca in malignant hyperthermia

IV dantrolene

8

MOA botulinum toxin

cleaves SNARE and blcoks release of ACh by preventing vesicle exocytosis

9

what is botulinum used for

generalized spastic disorders, cervical dystonia and blepharospasm

10

what are direct acting cholinomimetics

bind and activate mAChR and nAChR

11

what are indirect acting cholinesterase inhibitors

inhibit AChE increasing ACh in the celft

12

where is butyrylcholinesterase made

liver and found inliver and plasma

13

AChE is found where

highly [ ] postsynaptic end plate and prevents lateral diffusion from adjacent nAChRs

14

primary target for cholinesterase inhibiting drugs

AChE but also block BuChE

15

3 chemical groups of cholinesterase inhibitors

Alcohols
Carbamic acid esters
Organophosphates

16

how does alcohol work as AChE inhibitor

+ charged quaternary ammonium that binds to AChE noncovalently

17

how do carbamic acid esters work like AChEI

quaternary and tertiary ammonium groups that bind to AChE noncovalently

18

which AChEI are carbacmic acid esters

neostigmine, pyridostigmine, physostigmine, carbaryl

19

what AChEI are alcohols

edrophonium

20

what AChEI are organophosphates

echothiophate, parathion and malathion, sarin, soman, tabun

21

what is a precaution with organophosphates

CNS toxicity since neutrally charged and lipid soluble

22

bond between organophosphates and AChE

covalent and irreversible

23

what is preferred administration for the AChE I with quaternary ammoniums

parenteral
no CNS distribution

24

What are the tertiary uncharged AChE I and distribution?

physostigmine, donepezil, tacrin, rivastigmine, glantamine
CNS distrivution

25

what organophosphate is safe for use as insetidiced

malation

26

what is "aging" or organophosphates

phosphorylated enzyme will break one of the O-PO4 bonds of inhibitor and strenghten the bond

27

high [ ] effects of AChEI on CNS

generalized convulsions d/t neuronal hyperstimulation

28

effects of AChE I on eyes

contraction of iris
contraction of ciliary muscle

29

AChE I effects on hearat

Sympathetic and Parasympathetic
parasympathetic dominates and CO decreases
bradycardia

30

Tx myasthenia gravis

pyridostigmine, neostigmine and ambenonium
do not cross bbb
repeated dose every 2-8 hours

31

what is favored test for myasthenia gravis

ice pack test

32

Myasthenic crisis

life threatening condision defined as weakness from acquired myasthenia gravis that is severe enough to necessitate intubation

33

excessive AChE I use can lead to what

cholinergic crisis

34

Sx cholinergic crisis

muscle weakness

35

how to differentiate cholinergic crisis from myasthenic crisis

edrophonium test
myasthenic crisis Sx will get better
cholinergic crisis will remain unchanged

36

what AChE I are pregerred to reverse paralysis induced by NMJ blockers

neostigmine and edrophonium

37

Tx paralytic ileus, atony urinary bladder and congenital megacolon

AChE I

38

What is glaucoma

increased intraocular P

39

how do AChE I help with glaucoma

reduce intraocular P by stimulating mACHRs of ciliary body and cause contraction which facilitates outflow of aqueous humor

40

what is preferred Tx for glaucoma

topical beta blockers and PG derivatives

41

What is used to Tx dementia

donepezil, rivastigmine, glantamine and physostigmine

42

intoxication from anticholinergic Sx

cutaneous vasodilation, anhidrosis, anhydrotic hyperthermia, nonreactive mydirasis, delerium, hallucinations, reduction or elimination of desire to urinate

43

reversal of antimuscarinc toxicity

physostigmine because crosses bbb

44

what occurs if combine succinylcholine with AChE I

enhance phase I block and antagonize phase 2 block

45

effects of beta blocker with AChE I

bradycardia

46

Sx AChE intoxication

miosis, salivation, sweating, bronchial constriction, vomiting, diarrhea

47

what are the CNS involvements of AChE intoxication

confusion, ataxia, generalized convulsions, coma and respiratory paralysis

48

what causes death in AChE intoxication

respiratory failure

49

Dx AChE intoxication

measure AChE activity in RBCs and plasma

50

antidote for AChE intoxication

atropine
except is ineffective in peripheral NMJ, need cholinesterase regenerators

51

pralidoxime

cholinesterase regenerator

52

what is window frame for effective use of pralidoxime against organophosphate toxicity

before aging has occured

53

does pralidoxime cross bbb

no

54

pyridostigmine is used in military for what

prophylaxis AChE inhibitor posioning
(nerve gas)

55

side effects of pyridostigmine

stomach cramps, diarrhea,nausea, urination, HA, dizziness, SOB, worsening peptic ulcer, blurred vision, watery eyes