Digoxin immune fab or digoxin-specific antibody is an antidote for overdose of digoxin. It is made from immunoglobulin fragments from sheep that have already been immunized with a digoxin derivative, digoxindicarboxymethoxylamine (DDMA). Its brand names include Digibind (GlaxoSmithKline) and DigiFab (BTG plc). Medical uses
It is used for digoxin toxicity. Digoxin toxicity can emerge during long-term therapy as well as after an overdose. It can occur even when the serum digoxin concentration is within the therapeutic range when one of the following is present:
Hemodynamically unstable arrhythmia
End organ damage
digoxin level > 4 ng/ml if chronic ingestion
digoxin level > 10 ng/ml if acute ingestion
potassium > 5 mEq/L and symptomaticSide effects of digoxin immune fab may occur:

hives
difficult breathing
swelling of the lips, tongue, face, or throat
itching
skin redness
wheezing
cough
lightheadedness

Contraindications
Avoid use in hypokalemia as this drug, while reversing the effects of digitalis, will further reduce serum potassium levels and could precipitate dangerous and even fatal cardiac arrhythmias. 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. 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.
A patent to use digoxin immunoglobulins C07k16/44 as a regulator of the preeclamptic/eclamptic patients sodium/potassium ATPase activity was approved in 2003 to Charles David Adair under application number WO2004011028A1. Commercial aspects
Price increase was reported to range from US $380 to US $750 during 2013 for digoxin-Fab. However, these price increases are not reflective of the United States average AWP for digoxin-Fab as it represents Australian costs converted to US. Prior to 2011, Digibind and DigiFab pricing was US $797 per 38 mg vial and US $786 per 40 mg vial respectively. After GSK discontinued Digibind sale in USA in 2011, the AWP of DigiFab increases by 15% to US $903 per 40 mg vial. AWP of DigiFab has continued to increase as much as 54% occurring in March 2014 to US $2,370 per 40 mg vial. However, the cost may vary depending on wholesaler contractor manufacturer rebates. References
External links
Drug information online
Digibind description