Do I hold digoxin (digitalis glycoside) in a patient with a heart rate of 70 beats per minute (bpm)?

Management of Digoxin in a Patient with Heart Rate of 70 BPM

You should not hold digoxin in a patient with a heart rate of 70 beats per minute, as this is within the normal range and not considered bradycardia according to current guidelines. 1, 2

Heart Rate Considerations with Digoxin

Heart rate monitoring is an important aspect of digoxin therapy management:

• The target heart rate at rest for patients on digoxin is typically <80 bpm 1
• A heart rate of 70 bpm is within normal range and does not indicate toxicity
• Bradycardia warranting concern would typically be <60 bpm, especially if symptomatic
• The FDA-approved digoxin labeling does not specify holding the medication at a heart rate of 70 bpm 2

Clinical Decision Algorithm for Digoxin Management

1. Assess heart rate in context:

   • Heart rate 70 bpm → Continue digoxin
   • Heart rate <60 bpm → Consider holding dose and evaluate for toxicity
   • Heart rate <50 bpm → Hold dose and evaluate for toxicity

2. Evaluate for signs of digoxin toxicity:

   • Cardiac: Bradyarrhythmias, heart blocks, ventricular arrhythmias
   • Non-cardiac: Visual disturbances, confusion, nausea, anorexia
   • If present with HR of 70 bpm → Hold dose and check serum level

3. Check serum digoxin concentration if concerned:

   • Optimal therapeutic range: 0.5-0.9 ng/mL 3
   • Higher concentrations (>1.0 ng/mL) may increase mortality risk 1
   • Sampling should be done just before next scheduled dose or at least 6-8 hours after last dose 2

Special Considerations

• Elderly patients: More susceptible to digoxin toxicity even at therapeutic levels; however, a heart rate of 70 bpm alone is not an indication to hold therapy 4

• Renal function: Impaired renal function increases risk of digoxin toxicity; monitor closely but don't hold based on heart rate of 70 bpm alone 2

• Electrolytes: Hypokalemia increases risk of digoxin toxicity; ensure potassium levels >4.0 mEq/L 3

• Concomitant medications: Check for drug interactions that might increase digoxin levels

Clinical Context for Digoxin Use

• In heart failure: Used to reduce hospitalizations, not mortality 1
• In atrial fibrillation: Used for rate control, target resting heart rate <80 bpm 1
• For both indications, a heart rate of 70 bpm is appropriate and within target range

Common Pitfalls to Avoid

• Don't hold digoxin based solely on a heart rate of 70 bpm - this is within normal range
• Don't increase digoxin dose to achieve lower heart rates, as this may increase toxicity risk
• Don't overlook other signs of potential toxicity even with normal heart rate
• Don't forget to consider the clinical context (heart failure vs. atrial fibrillation)

In summary, a heart rate of 70 bpm in a patient on digoxin is within the normal range and target parameters. Continue the medication while monitoring for any signs of toxicity through clinical assessment and appropriate laboratory monitoring.