Lower serum digoxin concentrations in heart failure and reassessment of laboratory report forms.

Serum digoxin concentrations (SDC) have been used clinically since the early 1970s. Whereas the therapeutic range for SDC is frequently cited as either 0.8 to 2.0 ng/mL or 0.5 to 2.0 ng/mL, studies over the past decade suggest an upper limit of 1.0 ng/mL for treating heart failure. The same upper limit for SDC is suggested for patients with heart failure and atrial fibrillation with rapid ventricular response. Reducing the upper limit of the therapeutic range to 1.0 ng/mL on computerized and paper laboratory report forms may guide clinicians to avoid unnecessarily high SDC, thus minimizing risk of digoxin toxicity without sacrificing therapeutic benefit for heart failure.