A serum digoxin level of 3.0 ng/mL indicates what?

• A. It is in the high (elevated) range.
• B. It is in the low (decreased) range.
• C. It is within the normal range.
• D. It is in the low average range.

Answer: (A)

Digoxin has a very narrow therapeutic window, so staying within a specific range is essential to treat without causing toxicity. The typical therapeutic range is about 0.5 to 2.0 ng/mL. A level of 3.0 ng/mL is above that range, which means it’s elevated and associated with a higher risk of digoxin toxicity. This would prompt clinicians to assess for toxicity symptoms (like GI upset, bradycardia, or CNS changes) and consider dose adjustment or holding the medication. It’s not within the therapeutic range, and it’s not a low or normal level.