May 2015

Digoxin has been used in clinical practice for many decades to treat patients with atrial fibrillation. However, clinical trial data about the use of digoxin for atrial fibrillation has been very limited, and its safety and effectiveness in these patients remains controversial.

Researchers analyzed 19 previously published studies that looked at the connection between digoxin use and death from atrial fibrillation and heart failure. The studies were published between 1993 and 2014, and included more than 325,000 patients.

In this review of published studies on the subject, patients treated with digoxin had a 21 percent increased risk of early death overall from any cause, compared with patients not taking the drug. Among patients with atrial fibrillation, researchers found a 29 percent greater risk of premature death, while the increased risk was 14 percent among heart failure patients. These findings are hypothesis-generating rather than definitive, as combining multiple studies together does not reduce the potential of being misleading.

Detrimental digoxin effects, particularly in AF, include digoxin-mediated increase in vagal tone, reduced AV-node conduction, and shortening of atrial refractory periods; all of these effects may render the atrium more susceptible to AF. Digoxin has been found to be associated with doubling of relapses of AF following cardioversion.Finally, digoxin may provoke paroxysmal atrial tachycardias, ventricular tachyarrhythmias including fascicular or bi-directional ventricular tachycardia or torsade de pointes tachycardia, and serious bradyarrhythmias including high-degree AV block, particularly when electrolyte disorders are present. These proarrhythmic effects of glycosides may be caused or further accentuated by significant drug–drug interactions, for instance with antiarrhythmic drugs such as amiodarone or quinidine.

Beta blockers and calcium channel blockers are considered better nowadays. If digoxin is used, careful monitoring of patients for digoxin blood levels is mandatory.

Reference

Vamos M, Erath JW, Hohnloser SH. Digoxin-associated mortality: a systematic review and meta-analysis of the literature. Eur Heart J. 2015 May 4.