What conditions is Digoxin (digitalis glycoside) prescribed for?

Digoxin Indications

Digoxin is prescribed for two primary conditions: (1) symptomatic heart failure with reduced ejection fraction (HFrEF) to reduce hospitalizations, and (2) ventricular rate control in chronic atrial fibrillation, particularly when combined with heart failure or in sedentary patients. 1

Heart Failure with Reduced Ejection Fraction

Digoxin should be added to guideline-directed medical therapy (diuretics, ACE inhibitors/ARBs, and beta-blockers) in patients with persistent NYHA class II-IV symptoms despite optimal treatment. 2

Key Clinical Benefits in Heart Failure:

• Reduces heart failure-related hospitalizations and emergency care visits 1, 3
• Improves symptoms, quality of life, and exercise capacity 2, 3
• Has no effect on mortality—neither beneficial nor harmful 2, 1
• Benefits occur regardless of underlying rhythm (sinus rhythm or atrial fibrillation), etiology (ischemic vs. nonischemic), or concomitant ACE inhibitor use 2

Positioning in Treatment Algorithm:

Multiple strategies are acceptable according to ACC/AHA guidelines 2:

1. Add digoxin after optimizing diuretics, ACE inhibitor/ARB, and beta-blocker in persistently symptomatic patients 2
2. Add digoxin early in severely symptomatic patients alongside initial therapy 2
3. Consider aldosterone antagonists first, reserving digoxin for non-responders or those intolerant to aldosterone antagonists 2

Critical caveat: Digoxin is NOT indicated for acute decompensated heart failure or stabilization of acutely ill patients—intravenous therapies should be used first, with digoxin initiated only after stabilization as part of long-term management. 2, 3

Atrial Fibrillation

Digoxin controls ventricular rate in chronic atrial fibrillation, but is most appropriate when combined with heart failure or in sedentary patients with low sympathetic tone. 1, 4

Important Limitations for Rate Control:

• Digoxin monotherapy is ineffective during exercise or high adrenergic states—it works primarily through vagotonic effects on the AV node 5, 4, 6
• Beta-blockers are superior for rate control, particularly during exertion 2
• Digoxin should be considered an adjunctive agent for rate control, not first-line monotherapy 2
• The combination of digoxin plus beta-blocker (or calcium channel blocker) effectively controls rate both at rest and during exercise 5, 4

What Digoxin Does NOT Do in Atrial Fibrillation:

• Does not restore sinus rhythm 6, 7
• Does not prevent recurrence of atrial fibrillation 6, 7
• Does not prevent excessive tachycardia at the onset of paroxysmal atrial fibrillation 6

Contraindications

Absolute contraindications include: 2, 8

• Significant sinus or second/third-degree AV block without a permanent pacemaker 2, 8
• Pre-excitation syndromes (e.g., Wolff-Parkinson-White with atrial fibrillation/flutter) 8, 9

Use with extreme caution in: 2, 9

• Patients taking other AV nodal blocking agents (amiodarone, beta-blockers, verapamil, diltiazem) 2
• Hypokalemia, hypomagnesemia, or hypothyroidism—these dramatically increase toxicity risk 9, 3
• Renal dysfunction or advanced age (>70 years)—reduced clearance increases toxicity risk 9, 4

Practical Dosing Considerations

Standard maintenance dose: 0.125-0.25 mg daily for most adults with normal renal function 2, 8

Reduced dosing (0.125 mg daily or every other day) required for: 2, 8

• Age >70 years 2, 8
• Impaired renal function 2, 8
• Low lean body mass 2, 8

Target serum concentration: 0.5-0.9 ng/mL for heart failure—levels above 1.0 ng/mL offer no additional benefit and may increase mortality risk. 2, 8, 10

Loading doses are NOT recommended for chronic heart failure management—maintenance dosing should be started directly. 2, 8, 3