Autonomic Nervous System Drugs Flashcards
Cholinergic and Adrenergic Drugs
PNS Effects: SLUDGE
S - salivation
L - lacrimation
U - uresis (urination)
D - diaphoresis/ diarrhea
G - GI motility/ secretions
E - emesis
SLUDGE and the Killer Bs (+)
S - salivation
L - lacrimation
U - urination
D - diaphoresis/ diarrhea
G - GI motility/ secretions
E - Emesis
B - brady cardia
B - Bronchospasm (constriction)
B - Bronchorrhea - bronchi sec
Alpha Methyl Tyrosine
Adrenergic Synthesis Inhibitor
= dec sympathetic effects
Risperidone
Inhibition of adrenergic storage
= dec sympathetic effects
Amphetamines
Adrenergic displacement
= increased sympathetic action
Use: stimulation of CNS (improved mood, concentration)
Adverse Effects: insomnia, irritability, psychosis, anorexia, tachycardia, dependence, tolerance
Treatment of toxicity: acidification of urine
Guanethidine
Inhibits adrenergic release
= decreased sympathetic action
Dobutamine
Beta-1 adrenergic agonist
= increased sympathetic action
Metroprolol
Beta-1 adrenergic antagonist
= blocks sympathetic action (decreased)
Cocaine, Tricyclic Antidepressants
Adrenergic reuptake inhibitors
= increased sympathetic effects
Pargyline
Adrenergic MAO inhibitor –> sympathomimetic
= increased sympathetic effects
Muscarine
Muscarinic Receptor Agonist
(found in mushrooms - Amanita muscaria, Inocybe, Clitocybe)
effects: SLUDGE+
a. heart = bradycardia
b. exocrine glands = inc sweating, salivation, bronchial sec, sec of gastric acid
c. smooth muscle = contraction of bronchi, motility of GI smooth muscle, contraction (= defecation) of detrusor muscle of bladder + relaxation of trigone and sphincter (= urination), vasodilation (= dec BP)
–> overstimulation of muscles with ACh paralyzes them
d. eyes = miosis and accommodation
Treatment Atropine (Muscarinic receptor antagonist)
Treatment for Muscarine
Atropine
(antagonist blocks the agonist’s effects)
Neostigmine, Physotigmine, Edrophonium
AChE Inhibitors - temporarily inactivates AChE resulting in increased ACh levels in synapse
–> indirect cholinergic agonists (cause ACh levels to remain high = agonist-like effects)
Effects: SLUDGE +
–> overstimulation of muscles with ACh paralyzes them
Edrophonium
short-acting, reversible inhibitor of AChE
–> can be used to differentiate between a
cholinergic crisis and severe symptoms
of myasthenia gravis
If Edrophonium is administered and muscle paralysis/ weakness symptoms intensify, the crisis is _____
cholinergic (dose of Edrophonium is too high)
if Edrophonium is administered and the muscle paralysis/ weakness symptoms decrease, the crisis is _____
myasthenic (dose of Edrophonium is too low to have a therapeutic effect)
Echothiopate, insecticides, nerve gasses
long-acting, irreversible inhibitor of AChE –> permanently bound to the enzyme
Treatment: Pralidoxime
Pralidoxime
Treatment for long-acting, irreversible inhibitors of AChE
***can treat source of the AChE inhibitor, effectively inducing AChE breakdown and resolving associated SLUDGE symptoms, but CANNOT reverse paralysis of muscles resulting from receptor overstimulation
- oxygen used for diaphragm paralysis
- diazepam used for seizures
Clinical use of Edrophonium
Myasthenia Gravis - chronic autoimmune disease linked to Nm receptors
- muscles do not contract in response to normal levels of ACh release (muscle weakness)
- by inactivating AChE, more ACh is available to stimulate the receptors and encourage muscle contraction (inc muscle strength)
Paralysis induced by non-depolarizing neuromuscular blocks
Contraindications for Muscarinic Agonists/ AChE inhibitors
GI/ Urinary Obstructions - SLUDGE effects result in increase secretion and excretion (bad if there’s no route to exit)
Asthma - SLUDGE+ effect is bronchospasm (dangerous if bronchi are already constricted)
Cholinergic Crisis
characterized by excessive muscarinic stimulation and depolarizing neuromuscular blockage –> resulting in muscle weakness or frank paralysis
- SLUDGE+ symptoms - inc salivation, lacrimation, urination, diaphoresis, diarrhea, GI motility/ secretions, emesis, bronchospasm, bradycardia, bronchorrhea
- Nm overstimulation - muscle weakness, paralysis, twitching (risk of paralysis via apnea)
Risk of Myasthenia Gravis treatment with AChE inhibitors
–> overstimulation of muscular receptors can result in same muscle weakness/ paralysis effects (need to differentiate)
Atropine
Muscarinic Antagonist
(derived from the plant Atropa belladonna)
Effects: OPPOSITE of SLUDGE+ (more SNS)
- increased HR and force of contraction = tachycardia
- decreased GI secretions and motility
- dilation of the bronchi
- mydriasis (pupil dilation
- cycloplegia (loss of accomodation)
Muscarinic Antagonist Uses
purposes OPPOSITE of SLUDGE+
a. reduce urinary incontinence (relax bladder, contract sphincter
b. dec hypermobility of GI tract
c. pre-op/palliative care (reduce secretions)
d. eye exam/ surgery (dec lacrimation, mydriasis)
e. treatment of muscarinic poisoning (AChE inhibitors/ muscarinic agonists)
f. treatment of asthma (bronchodilator)
Muscarinic Antagonist Adverse Effects
related to effects OPPOSITE of SLUDGE+
a. xerostomia (dry mouth d/t dec salivation)
b. Anhidrosis (lack of sweat)
c. urinary retention, constipation (bladder relaxation, sphincter contraction, dec GI mobility/ secretions)
d. burry vision, photophobia (mydriasis, cycloplegia)
e. psychosis, delirium (high doses excite CNS)