Digoxin Flashcards

Digoxin Overview

• Digoxin, also known as Lanoxin, is a medication used primarily for heart conditions.

Classification

• Classified as an inotropic agent and cardiac glycoside, it influences heart contractility.

Mechanism of Action

• Functions as a rapid-acting cardiac glycoside.
• Enhances the force of myocardial contraction and increases the refractory period of the AV node.
• Elevates total peripheral resistance, impacting overall cardiovascular function.

Indications for Use

• Prescribed for congestive heart failure and re-entry supraventricular tachycardias (SVTs).
• Used for ventricular rate control in cases of atrial flutter and atrial fibrillation.

Contraindications

• Not suitable for patients with ventricular fibrillation or ventricular tachycardia.
• Avoid in cases of digitalis toxicity and hypersensitivity to digoxin.

Adverse Reactions and Side Effects

• Common side effects include fatigue, headache, and blurred vision, particularly yellow or green.
• Other serious effects may include seizures, confusion, bradycardia, dysrhythmias, nausea, vomiting, anorexia, and skin rash.

Drug Interactions

• Co-administration with amiodarone, verapamil, or quinidine can significantly increase serum digoxin levels (by 50%-70%).
• Concurrent use of digoxin and verapamil can lead to severe heart block.
• Diuretics can enhance cardiac toxicity.

Supply Information

• Available in vials at a concentration of 0.25 mg/mL.

Dosage and Administration

• Adult loading dose is 4-6 mcg/kg administered over 5 minutes; subsequent doses of 2-3 mcg/kg may follow at 4- to 8-hour intervals.
• Not recommended for pediatric use in a prehospital setting.

Duration of Action

• Onset of action occurs within 5-30 minutes, with peak effects seen in 30-120 minutes.
• Effects may last several days.

Special Considerations

• Pregnancy safety category C; monitor patients receiving IV digoxin.
• Patients with renal failure are at higher risk for digitalis toxicity.
• Conditions like hypokalemia, hypomagnesemia, and hypercalcemia can exacerbate toxicity.
• Use cautiously in patients with Wolff-Parkinson-White syndrome.