Before administering digoxin, which vital sign is most important to check?

• A. Blood pressure
• B. Respiratory rate
• C. Apical heart rate
• D. Temperature

Answer: (C)

Digoxin affects the heart’s electrical conduction and can slow the heart rate. Because of this, the most important vital sign to check before giving the drug is the apical heart rate, measured for a full minute. The apical pulse gives an accurate read of the true heart rate and rhythm, helping you catch bradycardia or conduction issues that digoxin could worsen. If the apical rate is too slow (for adults, often below 60 bpm), the dose should be withheld and a clinician should be informed. While blood pressure, respiratory rate, and temperature are useful, they don’t directly indicate the risk of digoxin-induced bradycardia as clearly as the apical heart rate does. Remember, digoxin has a narrow therapeutic window, so monitoring the heart rate is essential.