Indications for Digoxin
Digoxin is primarily indicated for the treatment of mild to moderate heart failure and for the control of ventricular response rate in patients with chronic atrial fibrillation. 1
Heart Failure Indications
Primary Indications
- In patients with symptomatic heart failure and reduced ejection fraction (LVEF <40%), digoxin (in addition to an ACEI) improves ventricular function, patient well-being, and reduces hospital admission for worsening heart failure, but has no effect on survival 2
- Recommended for patients with mild to severe symptoms (NYHA functional class II-IV) who remain symptomatic despite optimal therapy with ACEIs/ARBs, beta-blockers, and aldosterone antagonists 2
- Most beneficial for patients with persistent symptoms despite guideline-directed medical therapy 3
Clinical Benefits in Heart Failure
- Reduces risk of hospitalization for worsening heart failure by 28% (absolute risk reduction of 7.9%) 2
- Improves symptoms, quality of life, and exercise tolerance in patients with mild to moderate heart failure 4
- No effect on all-cause mortality 2
Atrial Fibrillation Indications
Primary Indications
- Control of ventricular response rate in patients with chronic atrial fibrillation 1
- Particularly indicated when ventricular rate at rest is >80 bpm or >110-120 bpm during exercise 2
- Useful for initial control of ventricular rate in patients with rapid atrial fibrillation, especially in decompensated heart failure patients prior to beta-blocker initiation 2
Optimal Use in Atrial Fibrillation
- In patients with AF and reduced ejection fraction (LVEF <40%), digoxin should be used to control heart rate in addition to, or prior to, a beta-blocker 2
- For long-term management, a beta-blocker alone or in combination with digoxin is preferred for rate control 2
- Most appropriate for patients with atrial fibrillation and concomitant heart failure 3, 5
- Less effective than beta-blockers or calcium channel blockers for rate control during exercise or high adrenergic states 6
Contraindications
- Second or third-degree heart block without a permanent pacemaker 2
- Pre-excitation syndromes 2
- Previous evidence of digoxin intolerance 2
- Use with caution in patients with suspected sick sinus syndrome 2
Dosing Recommendations
Initial Dosing
- Starting dose: 0.125-0.25 mg daily for most adults with normal renal function 3, 2
- Lower doses (0.125 mg or 0.0625 mg daily) for elderly patients, those with impaired renal function, or low lean body mass 2, 3
- Loading doses are generally not required in stable patients 2
Monitoring and Target Levels
- Therapeutic serum concentration should be between 0.6 and 1.2 ng/mL 2, 3
- Regular monitoring of serum electrolytes and renal function is mandatory 2
- Dose adjustment needed when used with medications that increase digoxin levels (amiodarone, diltiazem, verapamil, certain antibiotics, quinidine) 2, 3
Potential Adverse Effects
- Sinoatrial and AV block 2, 3
- Atrial and ventricular arrhythmias, especially with hypokalemia 2
- Signs of toxicity: confusion, nausea, anorexia, and disturbance of color vision 2, 3
- Digoxin toxicity risk increases with serum levels >2 ng/mL and with hypokalemia, hypomagnesemia, or hypothyroidism 4, 5
Clinical Pearls and Pitfalls
- Digoxin is not indicated as primary therapy for acute stabilization of decompensated heart failure 2, 4
- Higher doses of digoxin (>0.375 mg daily) are rarely needed or beneficial 2, 3
- For atrial fibrillation without heart failure, digoxin may be less effective and potentially associated with increased mortality 7, 8
- When using digoxin for rate control in atrial fibrillation, combining with a beta-blocker is often necessary for adequate rate control, especially during exercise 5, 6