digoxin immune fab digifab logo DIGIFab

DIGIFab Rapidly Binds and Neutralizes Digoxin to Resolve Digoxin Toxicity

  • DIGIFab neutralizes free digoxin within minutes to resolve the cardiotoxic effects and other clinical manifestations of potentially life-threatening digoxin toxicity.1,2
digifab mechanism of action image
A

High concentrations of free digoxin can overwhelm Na+-K+ ATPase pumps, resulting in systemic toxic effects including cardiotoxicity.3-5

B

DIGIFab rapidly binds to free digoxin with high affinity.6,7 As DIGIFab binds more free digoxin, more digoxin dissociates from Na+-K+ ATPase pumps.6,8

C

DIGIFab neutralizes digoxin to undetectable concentrations.7*

*Fab-digoxin complexes are cleared by the kidney and reticuloendothelial system.6

See DIGIFab in Action

References

  1. DIGIFab Digoxin Immune Fab (ovine) [package insert]. BTG International Inc.; 2017.
  2. Ward SB, Sjostrom L, Ujhelyi MR. Comparison of the pharmacokinetics and in vivo bioaffinity of DigiTAb versus Digibind. Ther Drug Monit. 2000;22(5):599-607.
  3. Levine MD, O’Connor A. UpToDate. Updated January 2020. Accessed November 21, 2023. https://www.uptodate.com/contents/digitalis-cardiac-glycoside-poisoning
  4. Goldberger AL et al. UpToDate. Updated January 2020. Accessed November 21, 2023. https://www.uptodate.com/contents/cardiac-arrhythmias-due-to-digoxin-toxicity
  5. Kanji S, MacLean RD. Cardiac glycoside toxicity more than 200 years and counting. Crit Care Clin. 2012(4);28:527-535.
  6. DIGIFab Digoxin Immune Fab (ovine). Package insert. BTG International Inc.; 2017.
  7. Ward SB, Sjostrom L, Ujhelyi MR. Comparison of the pharmacokinetics and in vivo bioaffinity of DigiTAb versus Digibind. Ther Drug Monit. 2000;22(5):599-607.
  8. Schmidt TA, Kjeldsen K. Enhanced clearance of specifically bound digoxin from human myocardial and skeletal muscle samples by specific digoxin antibody fragments: subsequent complete digitalis glycoside receptor (Na,K-ATPase) quantification. J Cardiovasc Pharmacol. 1991;17(4):670-677.

INDICATIONS AND USAGE

DIGIFab is indicated for the treatment of patients with life-threatening or potentially life-threatening digoxin toxicity or overdose, including:

  • Known suicidal or accidental consumption of fatal doses of digoxin: 10 mg or more of digoxin in healthy adults, or 4 mg (or more than 0.1 mg/kg) in healthy children, or ingestion of an amount that can cause steady state serum concentrations of ≥10 ng/mL;
  • Chronic ingestions causing steady-state serum digoxin concentrations >6 ng/mL in adults or 4 ng/mL in children;
  • Manifestations of life-threatening toxicity of digoxin overdose such as severe ventricular arrhythmias, progressive bradycardia, and second or third degree heart block not responsive to atropine, serum potassium levels exceeding 5.5 mEq/L in adults or 6 mEq/L in children with rapidly progressive signs and symptoms of digoxin toxicity.

IMPORTANT SAFETY INFORMATION

Warnings and Precautions

General

Suicidal ingestion may result from more than one drug. Consider toxic effects of other drugs or poisons in cases where signs and symptoms of digitalis toxicity are not relieved by administration of DIGIFab.

Rapid drop in serum potassium concentration may occur after treatment. Monitor frequently.

Patients with poor cardiac function may deteriorate secondary to the withdrawal of the inotropic action of digoxin by DIGIFab. Monitor frequently and provide additional inotropic support if needed. Postpone re-digitalization, if possible, until the Fab fragments have been eliminated; this may require several days or a week or longer in patients with impaired renal function.

Hypersensitivity Reactions

Anaphylaxis and hypersensitivity reactions are possible. Carefully monitor patients for signs and symptoms of an acute allergic reaction and if one occurs, stop the infusion and treat immediately with appropriate emergency medical care.

Patients with known allergies to sheep protein or those who have previously received intact ovine antibodies or Fab are particularly at risk for an anaphylactic reaction.

Do not administer DIGIFab to patients with a known history of hypersensitivity to papaya or papain unless the benefits outweigh the risks and appropriate management for anaphylactic reactions is readily available.

Use of DIGIFab in Renal Failure

The elimination half-life of DIGIFab in renal failure has not been clearly defined. Monitor patients with severe renal failure who receive DIGIFab for a prolonged period for possible recurrence of toxicity. Monitoring of free (unbound) digoxin concentrations after the administration may be appropriate.

Laboratory Tests

DIGIFab may interfere with digitalis immunoassay measurements. Thus, standard serum digoxin concentration measurements may be clinically misleading until the Fab fragments are eliminated from the body. This may take several days or a week or more in patients with markedly impaired renal function. If possible, obtain serum digoxin samples before DIGIFab administration to establish the level of serum digoxin at the time of diagnosis.

The total serum digoxin concentration may rise precipitously following administration of DIGIFab, but this will be almost entirely bound to the Fab fragment and not able to react with receptors in the body.

Adverse Reactions

The most common adverse reactions (>7%) related to DIGIFab administration are worsening congestive heart failure (13%), hypokalemia (13%) and worsening atrial fibrillation (7%).

Please see full Prescribing Information.