Cardiac glycosides

Definition

Cardiac glycosides are a class of organic compounds that increase the force of heart contractions and are used in the treatment of heart failure and certain arrhythmias. They function by inhibiting the sodium-potassium ATPase enzyme.

5 Must Know Facts For Your Next Test

1. Cardiac glycosides, such as digoxin, increase intracellular calcium levels, enhancing cardiac contractility.
2. They primarily inhibit the sodium-potassium ATPase pump, leading to an increase in intracellular sodium.
3. Cardiac glycosides have a narrow therapeutic index, making monitoring for toxicity essential.
4. Common signs of cardiac glycoside toxicity include nausea, vomiting, visual disturbances (e.g., seeing halos), and arrhythmias.
5. These medications are particularly useful in patients with atrial fibrillation due to their ability to control ventricular rate.

Review Questions

• What is the primary mechanism of action for cardiac glycosides?
• Why is it important to monitor levels of cardiac glycosides closely?
• List some common symptoms associated with cardiac glycoside toxicity.

Related terms

Digoxin:

A commonly used cardiac glycoside for treating heart failure and atrial fibrillation.

Sodium-Potassium ATPase Inhibitor: A type of drug that inhibits this enzyme, which is crucial for maintaining cellular ion balance.

Inotropic Agent: A category of drugs that modify the force or energy of muscular contractions, especially in the heart.