Comparable effects of DIGIBIND and DigiFab in thirteen digoxin immunoassays

Digoxin is widely prescribed for the treatment of cardiac conditions (1). Because of its narrow therapeutic range, digoxin-related toxicity resulting from acute or chronic overdose is common. Metabolites of digoxin as well as related compounds, including digitoxin, tanshinones, bufandienolide, and oleander, can contribute to or independently produce digoxin toxicity (2,3). Digoxin toxicity can be rapidly and safely reversed by administration of anti-digoxin immune fragments (Fab) such as DIGIBIND ®, which has been available in the US since 1986. Therapeutic Fab products act by binding digoxin with high affinity (109-1010 L/mol), favoring movement of digoxin out of tissue and thus promoting elimination. Factors that impact dosing with Fab products include known or suspected digoxin load, patient weight and history, and renal function (4-7).