Cardiac Drugs Flashcards
inotropes
change contractility of the heart. sites: ventricles and atria. positive inotrope drugs: Digoxin, Dopamine, Dobutamine, Amrinone, Milronone, Pimobendan
chronotrope
changes heart rate. site SA node.
dromotropic
changes conduction velocity. site: AV node and atria/ventricles
Digoxin: class
cardiac glycoside
Digoxin: MOA
inhibit Na+/K+ ATPase: weak, positive inotrope (increases CO). acts on vagal nuclei to decrease HR: negative chronotrope
Dopamine: class
catecholamine
Dopamine: MOA
alpha (non-selective) and beta1 agonist. dopaminergic receptors. positive inotrope (increases CO)
Dobutamine: class
synthetic catecholamine
Dobutamine: MOA
Beta agonist (B1>B2). and mild alpha 1. positive inotrope (increases CO)
Amrinone and milronone: class
PDE3 inhibitor
Amrinone and milronone: MOA
inhibits PDE3. positive inotrope (increases CO). not used frequently.
Pimobendan: class
Ca2+ sensitizer
Pimobendan: MOA
INCREASE AFFINITY OF TROPONIN C FOR Ca2+, THIS SENSITIZES THE CONTRACTILE APPARATUS TO ENHANCE CONTRACTILITY. positive inotrope (increases CO)
Anti-arrhythmics classes: “NoBody Kills Cats” stands for?
Class 1: block Na+ channels
Class 2: Beta blockers
Class 3: K+ channel blockers
Class 4: Ca2+ channel blockers
drugs in class 1A
quinidine, procainamide
what does class 1A do to action potential?
prolongs action potential, makes cell less excitable
drugs in class 1B
lidocaine, mexiletine
what does class 1B do to action potential?
shortens action potential
drugs in class 1C
flecainide, propafenone
what does class 1C do to action potential?
no obvious change
drugs in class 2
atenolol, propranolol, esmolol, solatol
what do class 2 drugs do
decrease HR and contractility
drugs in class 3
solatol, amiodorone
what do class 3 drugs do
delay depolarization, leads to increase in AP, makes cell less excitable
drugs in class 4
verapamil, diltiazem, amlodipine
what do class 4 drugs do
decrease HR and contractility
atenolol: selectivity? half-life/dosing? BBB?
B1 selective, half life 5-6 hrs, dosed every 12. does NOT cross BBB.
propranolol: selectivity? half-life/dosing? BBB?
Beta NON selective. half-life <2 hrs, dosed every 8. Crosses BBB.
esmolol: selectivity? half-life/dosing? BBB?
Beta 1 selective. very short half life, dosed IV/CRI. does NOT cross BBB.
solatol: selectivity? half-life/dosing? BBB?
beta NON selective. half life 5-6 hrs. does NOT cross BBB
vasodilator drugs
nitroglycerin, nitroprusside sodium, verapamil, diltiazem, amlodipine, sildenafil, enalapril, benazpril
what do venodilators do?
relax vein smooth muscle and decrease preload
what do arteriodilators do?
relax vein smooth muscle or arterioles and decrease afterload
Nitroglycerin
venodilator, works via increasing NO
Nitroprusside sodium
venodilator AND arteriodilator. works via increasing NO
verapamil
arteriodilator. works via blocking Ca2+ channels (class 4)
diltiazem
WEAK ARTERIODILATOR! works via blocking Ca2+channels. (class 4)
amlodipine
areriodilator. works via blocking Ca2+ channels (class 4)
sildenafil
venodilator AND arteriodilator. works via PDE5 inhibition
enalipril
venodilator AND arteriodilator. works via ACE INHIBITION. (prevents angiotensin 2 formation)
benazpril
venodilator AND arteriodilator. works via ACE inhibition (prevents angiotensin 2 formation)
