Digoxin Immune Fab

Digoxin immune fab (ovine) is the generic name for an antidote for overdose of digitalis. It is made from immunoglobulin fragments from sheep that have already been immunized with a digoxin derivative, digoxindicarboxymethoxylamine. Its brand names include Digibind ( GlaxoSmithKline) and DigiFab (BTG plc).

Pharmacology
It works by binding to the digoxin, rendering it unable to bind to its action sites on target cells. The complexes accumulate in the blood and are expelled by the kidney.

Contraindications
Although no contraindications have been noted, the patient must be closely monitored for anaphylactic shock, and anyone allergic to sheep protein, papain, bromelain, or papaya extracts (papain is used to cleave the antibody into Fab and Fc fragments) should not use ovine digoxin immune fab. Because it is relatively new, no drug interaction studies have been performed yet.