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25 Cards in this Set
- Front
- Back
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What are the 2 receptors targeted by anticholinergis?
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Muscarinic - atropine, scopolaine, glyco
Nicotinic - non-depolarizers |
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What is the mechanism of action of anticholinergics (antimuscarinics)?
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they competitively block binding by acetylcholine and prevents receptors activation.
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How do anticholinergics cause tachy?
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Muscarinic blockade in heart produces tachy
facilitates conduction through AV node and shortens P-R interval |
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What effect do anticholinergics have on ventricular function and peripheral vascualture?
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almost no effect - b/c there is little cholinergic innervation in therese areas even though there are choliniergic receptors
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How do anticholinergics effect sympathetic activity?
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There are pre-synaptic muscarinic receptors that inhibit norepi release. So muscarinic blockade could increase sympathetic activity.
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What is atropine flush?
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large doses of atropine can cause dilation of cutaneous blood vessels
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What are the effects of anticholinergic drugs on the respiratory system?
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1) decreases secretion from nose to bronchi
2) relaxation of bronchial smooth musculature * decreases airway resistance and increases anatomic dead space |
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What are the cerebral effects of anticholinergic drugs?
What can reverse these effects? |
can cause both excitation and depression
physostigmine can reverse the effects b/c it is an anticholinesterase inhibitor but crosses the BBB. |
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What is the effect of anticholinergics on the GI system?
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Gastric secretions decreased
decreased motility lower esophageal sphincter pressure - no evidence that they prevent asparation pneumonia |
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What are the opthalmic effects of anticholinergics
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mydryiasis (pupil dialation)
cycloplegia (inability to accommodate to near vision) |
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What are the effects of anticholinergics on the GU system?
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may decrease ureter and bladder tone and urinary retention
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What are the effects of anticholinergics on thermoregulation?
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Atropine fever - inhibits sweat glands
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What is the physical structure
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it is a tertiary amine - sold as a racemic mixture - crosses BBB
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What is the most effective anticholinergic for treating bradycardia?
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atropine
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what is ipatropium bromide a derivative of?
What is it used for? |
atropine
used in a metered dose inhaler for asthma --> bronchodilation |
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What conditions should you be cautious about giving atropine to?
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pt's with narrow-angle glaucoma, prostatic hypertrophy or bladder-neck obstruction
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What is the structure of scopolamine?
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it is a tertiary amine - same as atropine - except it has an oxide added
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Which anticholinergics have the best antisialagogue effects?
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scopaolamine and glyco
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which anticholinergic has the most sedative efects?
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scopolamine
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what condition should scopaolamine be avoided in?
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closed angle glaucoma
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which anticholinergic can be used for PONV
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scopolamine - as a transdermal patch
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What is the phyisical structure of glyco?
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it is a quaternary amine with both a cyclopentane and pyridine moieties
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Which anticholinergics cross the BBB?
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atropine and scopolamine
glyco has a quaternary structure and cannot |
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does glyco increase HR when given IM?
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no
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Compare glycos duration of action vs atropine
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glyco is longer (2-4hrs) vs 30mins for atropine after IV administration
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