HF4

Question 1

what effect does hyperkalemia have on digoxin?

what effect does hypokalemia have

Answer 1

hyperkalemia = less benefits of digoxin
hypokalemia = digoxin toxicity

Question 2

what are the adverse effects of digoxin

Answer 2

muscle weakness
agitation
vision problems
fatigue
anorexia
nausea and vomiting

Question 3

what should be used for digoxin toxicity treatment

Answer 3

digoxin immune fab (digibind)

Question 4

what category is amiodarone’s interaction with digoxin?

what should be done if taken together

Answer 4

category D

decrease digoxin dose by 1/3 to 1/2

Question 5

what is the interaction category of verapamil and digoxin?

what should be done if taken together

Answer 5

category C
monitor closely (can increase digoxin conc.)

Question 6

what category interaction is spironolactone and digoxin?

what should be done if taken together

Answer 6

category C
monitor closely (can increase digoxin conc.)

Question 7

what category interaction is quinidine and digoxin?

what should be done if taken together

Answer 7

category D

decrease digoxin dose by 1/4 to 1/2

Question 8

what is the MOA of beta agonists in HF (3 steps)?

Answer 8

1. activates adenylyl cyclase which produces cAMP
2. cAMP activates protein kinase
3. phosphorylation of L type Ca channel increases Ca conc.

Question 9

what are two B agonists for HF

Answer 9

Dopamine

Dobutamine

Question 10

what is increased by B agonists

Answer 10

increases:
inotropic = FOC
chronotropic = HR
lusitropic = relaxation rate

Question 11

what beta adrenergic agonist is used for short term treatment of severe, refractory chronic HF

Answer 11

Dopamine

Question 12

why is dopamine only used short term?

Answer 12

increase in oxygen demand due to tachycardia

Question 13

what are the adverse effects of dopamine

Answer 13

tachycardia

arrhythmias

Question 14

what do low doses of dopamine do

Answer 14

cause vasodilation in periphery by binding to receptors on KIDNEYS
also causes diuresis

Question 15

what do intermediate doses of dopamine do?

Answer 15

cause vasodilation via B2 receptors and increase HR and FOC via B1 receptors

Question 16

what do high doses of dopamine do

Answer 16

cause vasoconstriction throughout body via alpha1 receptors

Question 17

what does high doses of dopamine do to hemodynamics

Answer 17

increase afterload and SVR

Question 18

what receptor is effected the most by both enantiomers of dobutamine

Answer 18

beta1 effected most

Question 19

what enantiomer of dobutamine is an alpha1 antagonist

Answer 19

+ enantiomer

Question 20

what enantiomer of dobutamine is an alpha1 agonist

Answer 20

• enantiomer

Question 21

what are the hemodynamic effects of dobutamine

Answer 21

increase SV and increase CO

Question 22

what are some adverse effects of dobutamine

Answer 22

angina

tachycardia

Question 23

why do b-agonists development create tolerance

Answer 23

receptor down regulation

Question 24

what is the MOA of phosphodiesterase inhibitors in HF?

Answer 24

inhibit breakdown of cAMP, causing phosphorylation of L-type Ca channel, increasing Ca conc

Question 25

what PDE inhitors are used for HF?

Answer 25

PDE-3s:
inamrinone
milrinone

Question 26

what is the hemodynamic effects of PDE inhibitors

Answer 26

increase FOC
decrease afterload
decrease preload

Question 27

why are PDE inhibitors used short term only

Answer 27

long term linked to increased mortality

Question 28

what are some adverse effects of PDE inhibitors

Answer 28

ventricular arrhythmias
thrombocytopenia
N and V
increased LFTs

Question 29

what PDE inhibitor is preferred?

why

Answer 29

milrinone

inamrinone has 10% incidence of thrombocytopenia

Question 30

increased preload leads to what type of symptoms

Answer 30

congestive symptoms