Cholinergics Flashcards
onset/duration of tropicamide?
fast, short duration
rate of hydrolysis of physotigmine and neostigmine?
slow (hours)
which NMJ blockers have CV effects?
atracurium (minimum)
pancuronium (increase heart rate & BP)
which AChase inhibitor can enter CNS?
physostigmine
does it enter the CNS?
succinylcholine
no
how is pancuronium degraded?
kidney
side effects of oxybutynin?
high incidence of anti-muscarinic side effects
- xerostomia
- blurred vision
- GI
- CNS (drowsiness, confusion)
choline esters
acetylcholine, bethanechol
side effects of neuromuscular blocking agents
prolonged apnea
cardiovascular collapse (rare - histamine release)
anaphylaxis (rare)
administration of edrophonium?
IV
use of neostigmine
- treats myasthenia gravis (oral)
- prevents and treats post-operative atony of gut and bladder (oral)
- reversal of paralysis by competitive NMJ blockers (IV)
what to use glycopyrrolate for?
block parasympathomimetic effects during reversal of NM blockade with anticholinesterase agents
which drug is used to treat anticholinesterase or muscarinic toxicity
atropine
administration of bethanechol?
oral, subcutaneous
administration of pilocarpine
orally, ophthalmic
therapeutic uses of physotigmine
glaucoma wide angle
toxicity by antimuscarinic drug poisoning
administration of physotigmine?
ophthalmic (glaucoma)
IV (antimuscarinic drug poisoning)
how is atracurium degraded?
Hofmann hydrolysis, spontaneously degrades in plasma to inactive metabolytes, and by plasma esterases
uses of atropine?
- ophthalmic (mydriasis, cycloplegia)
- anesthesia (block vagal reflexes)
- anticholinesterase toxicity
how to treat muscarinic receptor antagonist poisoning?
physostigmine
administration of scopoloamine
transdermal patch
which of the musc. agonists can enter the CNS?
pilocarpine (tertiary amine)
therpeutic use of bethanechol?
urinary retention in the absence of obstruction
side effects of muscarinic antagonists
- hot as a hare
- dry as a bone
- red as a beet
- blind as a bat
- drowsiness
no sweating, dry mouth, hot skin, mydriasis, cycloplegia, CNS action
with AChase inhibitors, what are the toxic side effects outside the SLUDGE?
- medullary respiratory center depression, muscle paralysis
- death due to respiratory failure
use of scopolamine?
motion sickness, vestibular disease
how is rocuronium degraded?
liver metabolism
which drug is commonly given to block responses to vagal reflexes induced by surgical manipulation of visceral organs?
atropine
onset/duration of edrophonium?
rapid, short
therapeutic use of pilocarpine?
- xerostomia
- ophthalmically for wide angle glaucoma
- emergency narrow angle glaucoma
which NMJ blockers release histamine?
atracurium
pancuronium
how does succinylcholine work?
agonist of nicotinic receptors at NMJ, cause opening of cation channel
adminstration of ipratropium?
inhalation
alkaloids
atropine, scopolamine
function of tropicamide?
ophthalmic solution to produce mydriasis and cyloplegia
which drugs should be avoiding in patients with hyperthyoidism?
bethanechol, pilocarpine (musc agonists)
which of the naturally occurring alkaloids has greater CNS penetration
scopolamine
(more CNS penetration and prominent effects than atropine)
use of oxybutynin?
treats overactive bladder and incontinence
musc agonists should be used with caution in which patients?
- asthma/COPD
- urinary, GI obstruction and peptic ulcer
- CV disease (bradycardia, hypotension, hyperthyroidism)
how do NMJs work?
compete fwith ACh for unoccupied end-plate nicotinic receptors without activating the channel
uses of edrophonium
- diagnosis of myasthenia gravis
- distinguish cholinergic crisis from myasthenic crisis
- reverse paralysis
how do you treat competitive NMJ toxicity?
nestogimine or edrophonium
combine with glycopyrrolate to reduce muscarinic actions (bradycardia, GI/GU secretions/motility)
toxic effects of muscarinic antagonists
mad as a hatter (ataxia, restlessness, excitement, hallucinations, delirium, coma)
does glycopyrrolate penetrate the CNS?
no
pralidoxime
reactivates AChase peripherally, treat quickly because no longer effective after enzyme has aged
administration of neostigmine?
oral, IV
therapeutic use of rocuronium?
faciliate endotracheal intubation
long acting NMJ blocker
pancuronium
therapeutic use of NMJ blockers?
adjusvant in surgical anesthesia to obtain relaxation of skel muscle (mainly abdominal wall)
allows for much lighter level of anesthesia
use of ipratropium
COPD
rhinorrhea associated with common cold or rhinitis
SLUDGE
salivation, lacrimation, urination, defecation, GI, emisis (vomiting)
therapeutic use of succinylcholine?
muscle paralysis
effects of muscarinic antagonists
- mydriasis and cycloplegia (paralysis of accommodation)
- relax non-vascular smooth muscle (airways, GI, urinary bladder)
- inhibit exocrin egland secretion (sweat, salivary, etc.)
- increase HR
- CNS effects (low - sedation, high - delirium)
how is vecuronium degraded?
liver
you should use muscarninic antagonists with caution in which patients?
- glaucoma
- prostatic hypertophy - difficulty voiding
- tachycardia
side effects of succinylcholine
- prolonged apnea
- hyperthermia
- muscle pain (fasciculation)
- hyperkalemia
why aren’t muscarinic agonists administered IV?
will cause hypotension due to activation of muscarinic receptors of vascular endothelium
does ipratropium cross into CNS?
no, quaternary amine
administration of tropicamide?
ophthalmic solution
aminosteroid
rocuronium
atracurium
vecuronium
pancuronium
