NMB: Part 2 - Reversal Flashcards by Anna Logan

What are the clinical uses of anticholinesterase drugs?

REversal of NMBD
Antagonism of CNS effects on other drugs
Treatmetn of MG or glaucoma

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What is the mechanism of action of anticholinesterase drugs?

NMJ effects due to inhibition of acetylcholinesterase

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What are the three classifications of anticholiesterase drugs?

Reversible inhibition
formation of carbamyl esters
Irriversible inactivation

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How is edrophonium classified?

reversible inhibition

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What is echothiophate and how is it classified?

It is an organophosphate used in pesticide. It is classified as irreversible inactivation

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Neostigmine, Physostigmine and pyridostigmine. How are they classified and which one is different?

Formation of carbonyl esters.
Physostigmine is the only one that crosses the blood brain barrier.
(the only one with an H goes to the Head)

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How do Pyridostigmine, Neostigmine and edrophonium compare in onset and duration of action?

Edrophonium is short, neo in the middle and Pyridostigmine is longest onset/duration.

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How are anticholinesterase drugs eliminated?

50-75% of elimination is via renal clearance

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Could you give anticholinesterase to a pt with renal failure?

Yes, it would have prolonged effect, but so would your relaxant, so its cool

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How does age affect neostigmine?

children and infants require less

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What effects do anticholinesterase drugs have on the cardiovascular system?

Bradycardia

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What effects do anticholinesterase drugs have on the GI/GU systems?

Increased secrtion and motility

Tx of paralytic ileus or atonic bladder

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What effects do anticholinesterase drugs have on the secretory glands/airways?

Increased secretions and bronchoconstrictions

Increased secrtions in bronchial, lacrimal, sweat, salivary, gastric and intestinal

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Which neurologic disorder do anticholinesterase drugs treat?

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What is the treatment for Anticholinesterase OD?

Atropine with pralodoxime (cholinesterase reactivator)

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What are the nicotinic and CNS symptoms of anticholinesterase OD?

Nicotinic
-from skeletal muscle weakness to paralysis resulting in apnea
CNS
-confusion
-ataxia
-siezure
-coma
-depression of ventilation

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What is the dose for Neostigmine?

0.04-0.07 mg/kg

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Is 5 mg the max dose for neostigmine?

NO!!! Above 5mg increases the chance PONV, but it is not a max

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What is the rule for when a pt may be reversed?

The absence of any palpable single twitches following 5 s of tetanic stimulation at 50Hz implies very intensive blockade that cannot be reversed

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What is onset, peak and duration of neostigmine?

ONset-5-10 minutes
Peak-10 minutes
duration-1 hour

How do anticholinergics work?

they prevent Ach binding at muscarinic receptors
reversible bond to Ach receptor
can be overcome with increased Ach

What are the effoects of anticholinergics?

Sedation (atropine and scopalamine)
Antisialagogue
Increase HR
Relax smooth muscle
Mydiasis
Prevent motion sickness
Decrease gastric ion secretion

Why do we use glyco instead of atropine when giving neostigmine?

closest onset and duration compared to neo

How are anticholinergics cleared?

Cleared unchanged in urine. but its not really a big deal for renal pts

How do you administer atropine, and glyco?

IM or IV. Po is unpredictable

What is the lipid solubility of atropine, glyco and scopalamine?

scopalamine and atropine are lipid soluble | glyco is not

What are clinical uses for anticholinergics?

``` Important -Pre op med -tx of bradycardia -NDNMB reversal Less common -Bronchodilation -Smooth muscle relaxant (biliary and uretal) -Antagonism of gastric acid secretion (Not used since the dose needed is very high and better drugs are available) -Prevents nausea and vomiting ```

HOw would anticholinergics affect glaucoma?

make it worse

Do anticholinergics cross the placenta?

Yes, but it's not a big deal for the baby

Which anticholinergic is the most potent sedative? Where does it work?

scopalamine works at reticular activating system 4 mg IV is a good dose. Will cause amnesia

Why would atropine be a bad choice for sedation?

causes memory deficit and delayed arousal

How much glycopyrolate do you give for sedation?

glyco has no sedation effects

Which anticholinergic is the most potent antisialogogue?

Scopalamine | 3x more potent than atropine with less HR changes

how does glyco compare to atropine as an antisialogogue?

2x more potent | Useful when sedative effects are not wanted

How do anticholinergic drugs work to treat bradycardia?

Blocks Ach @ SA node

How does glyco compare to atropine for treating bradycardia?

equal in effectiveness, but the onset of glyco is slower

What is the mechanism for anticholinergics causing bronchodilation?

block the muscarinic receptors of the smooth muscle of medium and large AW leading to decreased resistance and increased deadspace

What is the anticholinergic drug used for bronchodilatin? what is it called when its combined with albuterol?

``` ipratropium bromide (atrovent) combivent ```

Can anticholinergic drugs be used to treat narcotic induced biliary constriction?

What are symptoms of central anticholinergic syndrome?

restlessness hallucinations somnolence unconsciousness

What is the treatment for central anticholinergic syndrome?

Physostigmine-it crosses BBB

Which pts are susceptible to central anticholinergic syndrome?

Children and elderly

What dose of glyco causes central anticholinergic syndrome?

It does not cross into the central nervous system, so it wont cause CAS. It is most common with scopalamine, but can be caused by atropine

What are the symptoms of anticholinergic OD?

``` Dry mouth blurred vision tachycardia Increased temp flushing irritability ```

What are the effects of anticholinergic OD?

Seizures coma ventilatory paralysis

What is the treatment for anticholinergic OD?

physostigmine

What are criteria for a pt being reversed?

``` TOF ratio >0.7 tetanus with 100 Hz stimulation Grip strength Negative inspiratory pressure > 20 cm H2O Sustained head lift = 5 seconds ```

What nerves do we use to monitor TOF?

Ulnar nerve Posterior Tibial Peroneal Facial nerve

What's so special about Sugammedex?

Works independent of Ach level in NMJ-so a profound block with no twitches can be reversed Cleared renally but speed of reversal is independent of renal function No need for muscarinic antagonist Still awaiting approval-some evidence of anaphylactic reaction