CV pharm PPT Flashcards
Step 1: draw a picture Step 2: game on Step 3: own it Step 4: repeat steps 2 + 3 until completion
What is the result of beta-1 agonism?
increased inotropy
increased chronotropy
increased cardiac output
What is the result of beta-2 agonism?
peripheral vasodilation (decreasing afterload)
bronchodilation
What is the result of alpha-1 agonism?
skin, mesenteric, hepatorenal constriction
leading to an increase in afterload
Epinephrine infusion starting dose?
0.01 - 0.02 mcg/kg/min
(to a max of 0.3 mcg/kg/min)
(4 mg in 250 mL D5W or NS = 16 mcg/mL)
Epinephrine pings on what adrenergic receptors?
beta-1 and beta-2 (with low doses of 0.01 - 0.04 mcg/kg/min)
alpha-1 (with higher doses, up to 0.3 mcg/kg/min)
Why can an epinephrine infusion cause mild hypokalemia?
d/t the increased activity of the Na/K pump, silly muppet…
Norepinephrine infusion starting dose?
0.01 - 0.02 mcg/kg/min
(to a max of 0.3 mcg/kg/min)
(4 mg in 250 mL D5W or NS = 16 mcg/mL)
Norepinephrine pings on what adrenergic receptors?
beta-1 and beta-2 (beta-1 > beta-2)
alpha-1 (potent effect!)
Is norepinephrine a good first line drug for low cardiac output in cardiopulmonary bypass?
hell yeah it is. use that shit!
Milrinone is what class of drug?
a phosphodiesterase inhibitor
What do phosphodiesterase inhibitors do?
phosphodiesterase breaks down cyclic-AMP within the cell.
with inhibition, you have the cAMP building up.
in cardiac muscle this leads to increased inotropy.
in vascular smooth muscle this causes vasodilation.
(may selectively dilate pulmonary greater than the systemic system)
good times…
Will milrinone work in the presence of a beta-blocker?
yes.
phosphodiesterase inhibitors are considered “back-door” drugs.
they work within the cell, not at the receptor site outside the cell.
Milrinone loading dose?
50 - 75 mcg/kg over 10 minutes
Milrinone infusion starting dose?
0.375 - 0.75 mcg/kg/min
20 mg in 100mL = 200mcg/mL
Is milrinone recommended with MI patients?
not at all
Nipride infusion starting dose?
0.25 - 0.5 mcg/kg/min
(max dose 10 mcg/kg/min)
(50 mg in 250 mL D5W or NS = 200 mcg/mL)
How does nipride work?
it is a direct nonselective arterial and venous smooth muscle dilator (arterial > venous). because of this, it decreases both preload and afterload.
(direct NO donor, activates guanylyl cyclase, increases cGMP, inhibits Ca++, vascular smooth muscle relaxation)
Can nipride inhibit hypoxic pulmonary vasoconstriction?
yes, yes it can
How does cyanide toxicity occur with nipride? (quick and dirty)
nipride interacts with oxyhemoglobin, releasing cyanide and NO, and turns the oxyhemoglobin into methemoglobin
Cyanide toxicity causes what?
tissue hypoxemia and anearobic metabolism
cyanide toxicity can occur at rates > 2 mcg/kg/min
What does amiodarone do?
inhibits K+ channels, prolonging action potentials and repolarization
(per the PPT, it also blocks alpha receptors, beta receptors, K+ channels, and Ca++ channels)
(d/t K+ and Ca++ blockade, there are some minor negative inotropic and potent vasodilating effects)
Amiodarone is used to treat what?
SVT, VT, and A-fib
by depressing AV node and accessory tracts
Two side effects of amiodarone. (per the PPT)
pulmonary alveolitis
prolonged QT interval
What is lidocaine used to treat?
PVCs and V-tach
