Which laboratory value is used to monitor the effectiveness of digoxin therapy?

Which laboratory value is used to monitor the effectiveness of digoxin therapy?

• A. Digoxin levels
• B. ALT
• C. Bilirubin
• D. A1C

Answer: (A)

Digoxin has a narrow therapeutic window, so keeping its serum concentration within a specific range ensures the drug is effective without causing toxicity. The lab value used to monitor therapy is the serum digoxin level. By checking this level, clinicians can confirm the patient stays in the therapeutic range (commonly around 0.5–2.0 ng/mL, though exact targets vary by condition) and adjust the dose as needed. Levels above the range raise toxicity risk, with symptoms like bradycardia, vision changes, or nausea; levels below may not adequately control heart failure or atrial fibrillation. The other values—ALT and bilirubin—reflect liver function, not digoxin activity or toxicity, and A1C reflects long-term glucose control. So measuring digoxin levels is the best way to monitor its effectiveness.

Digoxin has a narrow therapeutic window, so keeping its serum concentration within a specific range ensures the drug is effective without causing toxicity. The lab value used to monitor therapy is the serum digoxin level. By checking this level, clinicians can confirm the patient stays in the therapeutic range (commonly around 0.5–2.0 ng/mL, though exact targets vary by condition) and adjust the dose as needed. Levels above the range raise toxicity risk, with symptoms like bradycardia, vision changes, or nausea; levels below may not adequately control heart failure or atrial fibrillation. The other values—ALT and bilirubin—reflect liver function, not digoxin activity or toxicity, and A1C reflects long-term glucose control. So measuring digoxin levels is the best way to monitor its effectiveness.