Anticholinergics Flashcards
What is the dose of atropine when used with edrophonium as a reversal
0.014 mg/mg edrophonium
Dose of atropine when used for bradycardia
0.2-0.4 mg
Indications for atropine
- Reversal with Enlon
- Brady Arrhythmias
- Vagal stimulation ( Ex. by occulocardia reflex or peritoneal stimulation).
In what patients should you cautiously use atropine
- Narrow-angle glaucoma –> (atropine = sympathetic stimulation which dilates pupils and decreases outflow of intraocular aqueous humor, which increases IOP)
- crosses the placenta to increase FHR and decrease beat-to-beat variability in baby
MOA of atropine
- Competitive acetylcholine antagonist @ central and peripheral receptors
- antimuscarinic
- naturally occurring alkaloid
- Tertiary amine
CV effects of atropine
Increased HR
Would glyco or atropine be a better choice to increase HR in eye surgery, pneumoperitoneum for lap cases, pull on peritoneum or cervix?
Atropine because it is better for increasing HR from vagal stimulation
Onset and DOA of atropine
Onset = < 1 min
DOA = 30 min (IV)
2-4 hours (IM)
Is atropine a tertiary or quarternary amine
Tertiary amine
Other name for glycopyrolate
Robinul
Dose of robinul when used as a reversal with neostigmine
0.2 mg/mg Neo
Indications for robinul
Reversal agent, antisialoguge, bradycardia
MOA & CV effects of glycopyrolate
MOA:
- competitive ACh antagonist
- synthetic antimuscarinic
CV:
- increase HR (not as extreme as atropine)
Why might you give robinul in preop
In situation you want pt “dry” and need to increase HR
Onset and DOA of Glycopyrollate
Onset:
- 1 min IV
- 15-30 min IM
DOA:
- vagal blocking = 2-3 hours
- antisialogous = up to 7 hours
T or F: glycopyrollate readily crosses BBB and placenta
F — quarternary ammonium does not cross easily
Indication for scopolamine
- decrease secretions
- PONV
- motion sickness/vertigo
- unstable trauma patient
- dilate pupils and cycloplegia
Contraindications for scopalamine
Can cause toxic psychosis in elderly
- effects from restlessness to agitation
MOA of scopalamine
Competitive antagonist of ACh at muscarinic receptors
Antagonizes histamine and serotonin
tertiary amine, naturally occurring Alkaloid
Clinical considerations for scopalamine
- causes a lot of amnesia — good for trauma pts, women who get N/V
- decrease secretions/motion sickness
- don’t touch eyes after handling this med (can dilate pupils for 12 hours).
- remove after 24 hours and wash hands!
T or F: scopolamine crosses BBB
T - tertiary compound, naturally occurring alkaloid
Glycopyrrolate uses/effects:
Used in combo with Neostigmine for reversal; antisialogogue (xerostomia); increases HR
Causes NO CNS symptoms or mydriasis: quartenary ammonium
Glycopyrrolate drug class and MOA:
Synthetic antimuscarinic; competitive ACh antagonist
Glycopyrrolate (___)
___ (Robinul)
Central Anticholinergic Syndrome treatment and dose:
Treat with Physostigmine: tertiary amine that crosses BBB
Dose: 1-2 mg IV and may need to be repeated every 1-2 hrs (physostigmine is metabolized rapidly)
Central Anticholinergic Syndrome signs:
- anxiety
- disoriented
- hyperactive
- sedation
- seizure
- mydriasis
- increased HR
- atropine flush
- dry/flushed skin
- atropine fever
Can be mistaken for delayed recovery from anesthesia
Scopolamine dose (conc.):
duration:
Dose:
- 0.3-0.5 mg IM or IV
- 1.5 mg transdermal patch
Concentration:
- 0.4 mg/cc
DOA: 24-48 hrs
Glycopyrrolate dose:
onset:
DOA:
0.2 mg per 1 mg Neostigmine
onset: about 1 min IV
15-30 min IM
DOA: 2-4 hrs
Scopolamine is a (tertiary amine/quaternary ammonium)
tertiary amine
Glycopyrrolate is a (tertiary amine/quaternary ammonium).
quaternary ammonium
Atropine is a (tertiary amine/quaternary ammonium).
tertiary amine
Atropine dose:
onset:
duration:
0.014 mg/mg of edrophonium
OR
0.2-0.4 mg for vagal stimulation
onset: 1 min
duration: up to 30 mins
Primary reason for giving muscarinic antagonist agents?
Used to antagonize the muscarinic effects of anticholinesterases used to reverse NDMBs
(anticholinesterases cause increase in ACh, which stimulates the parasympathetic pathway and causes SLUDGE)
General effects of all muscarinic antagonists:
Opposite of SLUDGE:
inhibits salivation, lacrimation
reduces gastric secretions and motility
causes bronchodilator
increases HR
Muscarinic antagonists’ MOA and primary effect:
Competitive inhibitors of ACh at parasympathetic muscarinic receptors –> primary effect is to increase HR
