Chapter 44 - Cardiotonic Agents

Question 1

What is Digoxin?

Answer 1

Cardioglycoside for the treatment of…

1. HF
2. Atrial Fibrillation

Question 2

What are the actions of Digoxin?

Answer 2

Increases intracellular Ca+ and allows more Ca to enter the myocardial cell during depolarization causing a positive inotropic effect.

Increased Renal perfusion with a diuretic effect and decreased renin release, a negative chronotropic effect (slower HR), slowed conduction through the AV node.

Question 3

What are the adverse effects of Digoxin?

Answer 3

Visual Disturbances
Arrhythmias
GI upset
Drowsiness

DONT TAKE WITH POTASSIUM LOSING DIURETICS

Question 4

Contraindications of Digoxin?

Answer 4

1. Ventricular Tachy or V fib. (should be treated with something else)
2. Heart block or sick sinus syndrome
3. Idiopathic hypertrophic subaortic stenosis (IHSS)
4. Acute MI
5. Electrolyte Imbalances

DIGIFAB USED TO TREAT DIGOXIN TOXICITY

Question 5

What is Milrinone?

Answer 5

Phosphodiesterase Inhibitor that is for the treatment of…

1. HF for PT who have not responded to digitalis, diuretics, or vasodilators.

Question 6

Actions of Milrinone?

Answer 6

Blocks the enzyme phosphodiesterase, which leads to increase in myocardial cell cAMP, which increases Ca+ levels in the cell, causing a stronger contraction and prolonged response to sympathetic stimulation; directly relaxes vascular smooth muscle.

Question 7

Adverse effects of Milrinone?

Answer 7

Arrhythmias 
HypoTN
Thrombocytopenia
Pericarditis
Pleuritis

Question 8

Contraindications of Milrinone?

Answer 8

Severe Aortic or Pulmonic valvular disease
acute MI
fluid volume deficit 
Ventricular arrhythmias 
Elderly