The clinical usefulness of the measurement of serum digoxin (DIG) is due to its low therapeutic ratio- a very small difference exists between therapeutic and toxic tissue levels. In addition, individuals may vary in their response to digoxin with an apparent increase in susceptibility to toxicity with age. The action of digoxin is to increase the force and velocity of the myocardial contraction. This is necessary in the treatment of congestive heart failure and arrhythmias such as atrial fibrillation and atrial flutter.

The Biorex Diagnostics Digoxin kit is intended for the quantitative determination of digoxin concentration in human serum or plasma by a microplate enzyme immunoassay.