ANS - Jensen Flashcards
3 Parasympathomimetic muscarinic agonists
Acetylcholine, Bethanechol, Pilocarpine
unique features of Acetylcholine
rapidly hydrolyzed by esterases
quaternary ammonium
actions/uses of Acetylcholine
cardiac, smooth and skeletal muscle action, miotic (open angle glaucoma), limited therapeutic use, limited distribution (short half life)
unique features of Bethanechol
not metabolized by esterase enzymes (longer half life), quaternary ammonium compound
affinity for gut and bladder SM
uses of Bethanechol (urecholine)
gastroparesis (post operative)
urinary retention
xerostomia
ocular diagnostics
unique features of Pilocarpine
tertiary ammonium compound
resistant to esterases
made from plant Pilocarpus jaborundi
actions/uses of Pilocarpine
miosis and accommodation
CNS effects
diaphoresis side effects
long duration
which of the parasympathomimetic muscarinic agonists have quaternary ammonium compounds
Acetylcholine
Bethanechol
which of the parasympathomimetic muscarinic agonists are resistant to esterases
Pilocarpine
Bethanechol
What are the 2 parasympathomimetic cholinesterase inhibitors
Neostigmine
Malathione
unique features of Neostigmine
quaternary ammonium compound
contains ester group (slowly hydrolyzed)
poorly absorbed
actions/uses of Neostigmine
miosis
narrow angle glaucoma
myesthenia gravis
unique features Malathione
tertiary ammonium compound
not hydrolyzed by esterase enzymes
insectaside
highly toxic
which parasympathomimetic cholinesterase inhibitor is reversible
Neostigmine
which parasympathomimetic cholinesterase inhibitor is irreversible
Malathione
what are the three parasympatholytic muscarinic receptor antagonists
atropine
ipratropium
scopolamine
what is the only therapeutically useful alternative to inhibit the PNS?
antagonize muscarinic receptors
if you want to mimic the PNS what are the two therapeutically useful ways to do so?
stimulate muscarinic receptors
prevent breakdown of ACh
benchmark parasympathetic response of iris of eye
miosis
benchmark parasympathetic response in arterioles
vasodilation
benchmark parasympathetic response in heart
negative chronotropic and neg. inotropic responses
benchmark parasympathetic response in bronchial SM
bronchoconstriction
benchmark parasympathetic response in GI and urinary tract
SLUD
Beta 1 stimulation of heart causes
positive inotropic and pos. chronotropic responses
Beta 2 stimulation of bronchus causes
bronchodilation
Beta 2 stimulation of myometrium causes
relaxation of myometrium
Beta 2 stimulation of pancreas caues
insulin release
Alpha 1 stimulation of arterioles causes
vasoconstriction
Alpha 1 stimulation of radial muscle of iris causes
mydriasis
Alpha 2 stimulation reduces what?
norepinephrine release
unique features atropine
from atropa belladona
tertiary ammonium compound
metabolized in liver
actions/uses of Atropine
inhibit SLUD
mydriasis and cycloplegia
antidote to AchE inhibitors
Rx diarrhea
unique features Ipratropium (Atrovent)
quaternary ammonium compound
actions/uses of Ipratropium
bronchodilation
unique features Scopolamine
from Hyocyaus niger
uses/actions of Scopolamine
greater CNS disturbance than atropine
used less frequently than atropine
motion sickness
what are the three therapeutically useful methods of mimicking the sympathetic nervous system?
stimulate adrenergic receptors
promote release of norepi
prevent elimination of norepi
unique features of epinephrine
stimulate alpha and beta receptors (more beta, less alpha than norepi)
metabolized in gut, blood and tissues
uses/actions of epinephrine
ineffective orally (bc metabolized in gut)
used in cardiac emergencies
bronchospasm
adjunct to local anesthesia
unique features of Phenylephrine (Neosynephrine)
alpha 1 agonist (–> constriction of arteriole)
effective orally
limited CNS access
OTC
uses/actions of Phenylephrine
nasal decongestant
mydriatic (good for conjunctivitis)
side effects of Phenylephrine
rebound congestion
increased peripheral resistance
reflex bradycardia
unique features of Clonidine
alpha 2 agonist (stimulates adrenergic receptors and reduces norepi release) effective orally crosses BBB CNS alpha preference long half life
uses/actions of Clonidine
centrally acting antihypertensive
side effects of Clonidine
dry mouth
sedation
sexual dysfunction
unique features of Isoproterenol (Isuprel)
beta receptor agonist (1 &2)
metabolized by COMT
short duration of action
uses/actions of Isoproterenol
cardiac arrest tachycardia bronchodilator selective vasodilation limited cardiac effect
unique features of Albuterol (Ventolin)
beta 2 agonist
limited cardiovascular effects
lasts several hours
uses/actions of Albuterol
bronchodilator
unique features of Amphetamine
stimulate release of norepi and dopamine
enteres CNS
inhibits MAO
actions/uses of Amphetamine
alpa and beta stimulation by norepi
vasoconstriction, cardiac stimulation, increased BP, mydriasis
CNS stimulation: euphoria, insomnia, anxiety, loss of appetite, hyperthermia
used to treat narcolepsy, obesity and ADHD
unique features of Phenelzine (Nardil)
monoamine oxidase inhibitor readily absorbed crosses BBB increases synaptic catecholamine levels interacts with sympathomimetics
uses of Phenelzine
antidepressant
what are the four sympatholytic drugs?
Prazocin (alpha antagonist)
Propranolol (Beta 1 and 2 antagonist)
Metoprolol (Beta 1 antagonist)
Reserpine (Adrenergic depletor)
if you wanted to inhibit the SNS would could you do?
block adrenergic receptors
deplete stores of norepi
