Autonomic and Cardiac Review Flashcards
what is the main neurotransmitter of cholinergic NS
acetylcholine
what is the main neurotransmitters of the adrenergic NS
epinephrine, NE, DA
what is the main result of an alpha1 receptor agonist
vasoconstriction, increase BP
what is the main result of a beta1 receptor agonist
increase HR and contractility
what is the main result of a beta2 receptor agonist
dilation, bronchodilation
Does an M receptor agonist increase activity in PNS or SNS
PNS
what receptor does bethanecol target and agonist or antagonist
M receptor agonist
what is bethanecol indicated for
decreased bladder contractility, equine gastric ulcer syndrome (increase activity of PNS)
when are some examples of when bethanecol would be contraindicated
obstruction, gastric ulcers in small animals, hyperthyroidism (cause a-fib), hypotension, bradycardia, vagal nerve dysfunction, asthma (bronchoconstriction), hx recent GI sx
In myasthenia gravis, what does the drug want to inhibit
cholinesterase
what is the diagnostic drug of choice for myasthenia gravis
neostigmine
what is a potential adverse effect of neostigmine
cholinergic overdose-hypotensive, bradycardic, bronchoconstriction
what is the drug of choice in treating myasthenia gravis
pyridostigmine bromide
what are some adverse effects of pyridostigmine bromide
downregulate Mn receptors so constantly need to increase dose, can lead to intussception
is atracurium a cholinergic or adrenergic agonist or antagonist
cholinergic antagonist (decrease PNS activity)
what are the indications for atracurium
unblocking male cats and to paralyze animals
T or F: animals who received atracurium receive both an analgesic and pain relief effect
false! it just paralyzes them but they can feel everything
what is the order of muscles that become paralyzed with atracurium
- first small muscles become weak, flaccid, paralyzed
- small muscles
- large muscles
- abdominal and laryngeal muscles
- respiratory muscles
**recover in reverse order
what drug is used to reverse the effects of atracurium
acetylcholinesterase inhibitors like neostigmine
is atropine sulfate a cholinergic or adrenergic agonist or antagonist
cholinergic antagonist
what receptor does atropine sulfate act on
M receptor competitive antagonist
what are the labeled used of atropine sulfate
- decrease secretions pre-anesthesia
- bradycardia, sinoatrial arrest, incomplete AV blocks
- vagally mediated or primary bradycardia
- tx cholinergic toxicities
- pain secondary to uveal or corneal dz
- dilation
- synechia breakdown
what effect does atropine sulfate have on the eyes
dilation, blocks accommodation, dry eyes, and increase IOP
what is an adverse effect of atropine sulfate in horses
colic (decreasing PNS activity)
is glycopyrolate a cholinergic or adrenergic agonist or antagonist
cholinergic antagonist
what are some indications of glycopyrolate
- pre-med for dogs and cats (labeled)
- bradycardia (ELDU)
- counteract imidiocarb in horses (ELDU)
you are trying to choose between using glycopyrolate or atropine sulfate in pregnant dog who is bradycardia under anesthesia, which is better
glycopyrolate- quaternary amine so has a lower distribution so won’t cross placenta, milk or CNS like atropine sulfate will
is oxybutinin chloride a cholinergic or adrenergic agonist or antagonist
cholinergic antagonist
what is oxybutinin chloride indicated for
detrusor hyperreflexia in dogs
what are some potential side effects of oxybutinin chloride
tachycardia, bronchodilation, increase IOP (decrease PNS/increase SNS)
what are some contraindications for oxybutinin chloride
blocked patients, tachycardia, glaucoma
is isoproterenol a cholinergic or adrenergic agonist or antagonist
adrenergic agonist
what receptors does isoproterenol act on
direct acting B1 (increase HR and contractility) and B2 (bronchodilation) agonist
what are some indications for isoproterenol
- bradycardic-B1 receptor
- acute bronchoconstriction-B2 receptor
what are some adverse effects of isoproternol
hypotension, tachycardia
is epinephrine a cholinergic or adrenergic agonist or antagonist
agonist
what receptors does epinephrine act on
alpha1 (high dose), B1 (low dose)
what are some indications for epinephrine
- cardiac arrest, bradycardia (B1-low dose)
- anaphylaxis (alpha1-vasoconstriction)
is NE a cholinergic or adrenergic agonist or antagonist
adrenergic agonist
What are the indications of NE
Hypotension in dogs, cats and foals
What are some adverse effects of NE
Hypertension, arrhythmias, seizures
Is dopamine HCl a cholinergic or adrenergic agonist or antagonist
Adrenergic agonist
What are some indications for dopamine HCl
Hypotension in dogs and cats
What does low dose dopamine target/cause
DA receptors in renal and mesenteric vasculature causing dilation
What does high dose dopamine target/cause
Target alpha1 receptors resulting in vasoconstriction
Is phenylephrine a cholinergic or adrenergic agonist or antagonist
Adrenergic agonist
What receptor does phenylephrine HCl act on
Direct acting alpha1 agonist
What are some indications for phenylephrine HCl
- Hypotension in cats and dogs
- Ascending colon displacement in horses
- Ophthalmic solution- induce myriadsis without loss of accommodation
When can phenylephrine be used in emergency situations
To increase BP if fluid blouses and atropine already on board or to increase CO without contractility or HR
What are some adverse affects of phenylephrine
Reflex bradycardia, hypertension, colic, hemorrhage, necrosis
What are some contraindications with phenylephrine
Arrhythmia or bradycardia, hypertension, renal or hepatic insufficiency, elderly, hyperthyroidism
Is dobutamine a cholinergic or adrenergic agonist or antagonist
Adrenergic agonist
What receptor does dobutamine act on
Direct acting B1 agonist
What are some indications for dobutamine HCl
Tx acute heart failure
What are some adverse affects of dobutamine
Tachycardia, arrhythmias, seizures
What are some contraindications for dobutamine
Subaortic stenosis, hypovolemia, myocardial infarction, arrhythmias, hypersensitivity
Which receptors does albuterol, clenbuterol, and terbutaline act on and what are they indicated for
Direct acting b2 agonists- indicated for bronchoconstriction
Is phenylpropanolamine a cholinergic or adrenergic agonist or antagonist
Adrenergic agonist
What are some indications for phenylpropanolamine
Urinary incontinence
What receptor does phenylpropanolamine act on
Mixed acting adrenergic agonist
What are some adverse effects of phenylpropanolamine
Urine retention, tachycardia, hypertension
What are some contraindications for phenylpropanolamine
Glaucoma, prostatic hypertrophy, hyperthyroidism, DM, CVD, kidney insufficiency, hypertension
Is ephedrine sulfate a cholinergic or adrenergic agonist or antagonist
Adrenergic agonist
What are some indications for ephedrine sulfate
- Hypotension associated with anesthesia in dogs, cats and horses
- Urinary incontinence but rarely used
What receptor does ephedrine sulfate act on
Mixed acting adrenergic agonist
Is prazosin a cholinergic or adrenergic agonist or antagonist
Adrenergic antagonist
What receptor does prazosin act on
Competitive Alpha1 antagonist
What are some indications for prazosin
- Functional urethrospasm in dogs
- Hypertension in dogs and cats
- Adjunctive in CHF management with digoxin
Is phenoxybenzamine HCl a cholinergic or adrenergic agonist or antagonist
Adrenergic antagonist
What receptor does phenoxybenzamine HCl act on
Non competitive alpha1 antagonist
What are some indications for phenoxybenzamine
- Functional urethrospasm in dogs, cats and horses
- Pheochromocytoma
How does phenoxybenzamine treat a pheocrhomocytoma
Tumor releases NE and Epi cause severe hypertension, tachycardia, and arrhythmia. Phenoxybenzamine is a non-competitive alpha1 antagonist so will block alpha1 therefore avoiding vasoconstriction
What are some adverse effects of alpha1 antagonists
Hypotension, reflex tachycardia, nasal congestion, lethargy, GI effects, miosis, increased IOP, inhibit ejaculation
What are some contraindications for alpha1 antagonists
CHF, hypotensive, renal failure, colic, glaucoma
Are the following B1 or B1/2 antagonists: atenolol, esmolol, metoprolol. And what is their function
B1 antagonists- decreased HR and contractility
Are the following B1 or B1/2 antagonists: propranolol, sotalol, timolol. And what is their function
B1/2 antagonist: decrease HR and contractility (B1) and vasodilation (B2)
When are B-antagonists used
Tachycardic, hypertension
Which B-antagonists have a mild local anesthetic activity and what is mechanism
Propranolol and metoprolol via Na+ blockade
Which B-antagonists caused a marked decrease in HR in healthy cats and is contraindicated in cats with cardiac disease
Timolol