What is the IV dose of digoxin (digitalis glycoside) used for acute decompensated heart failure?

IV Dosing of Digoxin for Acute Decompensated Heart Failure

For acute decompensated heart failure, the recommended IV loading dose of digoxin is 0.25-0.5 mg IV bolus, which can be repeated up to a maximum loading dose of 1.0 mg over 24 hours, administered at 6-8 hour intervals. 1

Dosing Algorithm

Initial Loading Dose

• Standard adult loading dose: 0.25-0.5 mg IV bolus over 2 minutes 1
• Administer over at least 5 minutes to prevent systemic and coronary vasoconstriction 2
• Can repeat 0.25 mg IV bolus up to maximum loading dose of 1.0 mg over 24 hours 1

Dose Adjustments Based on Patient Factors

• Age >70 years: Use lower dose (0.125 mg) 1, 3
• Impaired renal function: Use lower dose (0.125 mg) 1, 3
• Low lean body mass: Use lower dose (0.125 mg) 1, 3
• Concomitant medications that affect digoxin levels (amiodarone, verapamil, diltiazem): Reduce dose by 30-50% 1, 3

Administration Guidelines

• Avoid bolus administration to prevent systemic and coronary vasoconstriction 2
• Can be administered undiluted or diluted with a 4-fold or greater volume of sterile water, normal saline, or 5% dextrose 2
• Do not mix with other drugs in the same container or IV line 2

Clinical Considerations

Indications

• Acute decompensated heart failure, particularly with atrial fibrillation and rapid ventricular rate 1, 3
• Useful for initial control of ventricular rate in patients with rapid atrial fibrillation and heart failure 1, 3

Contraindications

• Second or third-degree heart block without a pacemaker 1, 3
• Pre-excitation syndromes 1, 3
• Previous evidence of digoxin intolerance 1, 3

Monitoring

• Monitor serum electrolytes (potassium, magnesium, calcium) 3
• Target serum digoxin concentration: 0.5-1.0 ng/mL 1, 3
• Higher levels (>2 ng/mL) are associated with toxicity 1

Potential Adverse Effects

• Cardiac arrhythmias: Ectopic and re-entrant rhythms, heart block 1
• Gastrointestinal symptoms: Anorexia, nausea, vomiting 1
• Neurological complaints: Visual disturbances, disorientation, confusion 1

Important Caveats

• Loading doses are not necessary for chronic heart failure management but may be needed in acute settings 1, 4
• Digoxin is not indicated as primary treatment for stabilization of acutely decompensated heart failure but can be initiated after emergency treatment 4
• Risk of toxicity increases with hypokalemia, hypomagnesemia, or hypothyroidism 1
• Recent evidence suggests that digoxin initiation after acute heart failure may help reduce 30-day readmission rates in patients with reduced ejection fraction 5

Maintenance Therapy Transition

• After initial IV loading, transition to oral maintenance therapy with 0.125-0.25 mg daily based on renal function, age, and other clinical factors 1, 3
• Maintenance dose should be adjusted to achieve serum levels of 0.5-1.0 ng/mL 1, 3

By following this evidence-based dosing algorithm for IV digoxin in acute decompensated heart failure, clinicians can optimize treatment while minimizing the risk of adverse effects.