CV Drugs Flashcards
What is the ultimate goal of the CV system?
Oxygen delivery to tissues
T/F: CO can be decreased when HR is too high and too low.
TRUE. If too high then the ventricle isn’t able to fully fill up to eject max amount of blood. If the HR is too low, then there isn’t enough blood reaching the ventricle to be pumped out.
What drug class alters contractility?
Inotropes
What is the MOA of anticholinergics?
Competitive antagonists of muscarinic Ach receptors
What effects do anticholinergic drugs have on the SA and AV node?
Increase firing rate of SA node (chronotropy) and conduction speed through AV node (dromotropy)
T/F: Glycopyyrolate is used for emergency use and doesn’t cross BBB.
FALSE. NOT used for emergency due to slower onset of action
What class of cardiac drug is lidocaine and what is the channel it acts on?
Na channel blocker-Class I. Used for VPC and Vtach
What class of cardiac drug are beta-blockers and what are the drugs used for?
Class II. USed for sinus tachy or supraventricular tachycardia.
What receptors do most pressors/inotropes act on?
Adrenergic receptor
What is the exception drug that doesn’t act on adrenergic receptors?
Vasopressin
What effects are seen at A1/A2 and B1/B2?
A1/A2: Vasoconstriction
B1: Increases inotropy and chronotropy
B2: vasodilation and bronchodilation
What is a dose dependent inotrope that at low dose is a B agonist and at high dose is a B and A agonist?
Dopamine
What is the firstline of treatment for hypotension in cats?
Dopamine
What receptors does ephedrine act on?
Mixed agonist: primarily A but also B1/B2
T/F: Ephedrine increases MAC.
True-CNS stimulation
What inotrope is used in CPR or for anaphylactic shock?
Epinephrine
What inotrope drug would you use if your patient was in refractory shock or non-responsive hypotension.
Norepinephrine
What receptors does phenylephrine act on?
Alpha-1 agonist
What effects will you see in your patient after phenylephrine is given?
Vasoconstriction and increased BP –> decreased CO and perfusion
How will phenylephrine be useful in a patient with a nephrosplenic entrapment?
Phenylephrine causes constriction which can allow the spleen to contract causing the spleen to shrink and the entrapped GI to escape
What receptors does Dobutamine act on?
B agonist-primarily B1–> increased inotropy, minimal chronotropy effects (mild B2 effects)
What inotrope drug can be used to tentatively treat 3rd degree AV block until a pacemaker can be placed?
Isoproterenol
What kind of drug is vasopressin?
Non-adrenergic sympathomimetic causing vasoconstriction via V1 receptors
How do you respond if your patient is hypotensive?
Turn down the vaporizer –> if patient gets too light administer a MAC sparing drug –> give crystalloid fluid bolus –> consider giving CV drug therapy and tx underlying cause
