Cardiac Glycosides & Phosphodiesterase Inhibitors

Cardiac glycosides

Medications used in patients with heart failure, atrial fibrillation, and atrial flutter.

Heart Failure (HF)

The heart is incapable of pumping adequately to supply oxygen to the body.

Cardiac glycosides

Medications used in patients with heart failure, atrial fibrillation, and atrial flutter.

Heart Failure (HF)

The heart is incapable of pumping adequately to supply oxygen to the body.

Atrial Fibrillation (A-Fib)

Cardiac dysrhythmias with rapid, uncoordinated contractions of the atrial myocardium.

Atrial Flutter

Cardiac dysrhythmias with rapid contractions of 200-300 BPM.

Positive inotropic response

Increases myocardial contractions by increasing intracellular calcium.

Negative chronotropic response

Decreases heart rate.

Negative dromotropic response

Slows the speed of electrical conduction through the AV node.

Digoxin

A secondary drug used for heart failure, given intravenously or orally.

Half-life of Digoxin

30-40 hours.

Digitalis toxicity

An adverse reaction to digoxin that can result in ventricular dysrhythmias.

Symptoms of Digitalis Toxicity

Include rhythm changes like PVC and bradycardia, GI issues like nausea and vomiting, and neurological changes like blurred vision.

Potassium-wasting diuretics and Digoxin

Increase the effects of digoxin, leading to a higher risk for toxicity.

Cortisone drugs and Digoxin

Increase the effects of digoxin by promoting sodium reabsorption and potassium excretion.

Antacids and Digoxin

Decrease the effects of digoxin by increasing gastric pH and decreasing absorption.

Phosphodiesterase inhibitors (PDE) inhibitors

Act as vasodilators and produce an inotropic response, similar to cardiac glycosides.

Risk of IV PDE inhibitors

Using for more than 48-72 hours can cause severe cardiac dysrhythmias.