Digoxin IV Infusion Time for Loading Dose
A loading dose of digoxin 0.5mg/ml diluted in 4ml of saline should be administered over 10 minutes. 1
Rationale for Infusion Time
- According to ACC/AHA/ESC guidelines, when administering digoxin IV for heart rate control in patients with heart failure and without accessory pathway, the loading dose should be 0.25 mg IV each 2 hours, up to a total of 1.5 mg 1
- For amiodarone, which is also used for heart rate control, the guidelines specifically recommend infusion over 10 minutes 1
- The FDA label for IV digoxin indicates that rapid digitalization can be achieved with IV administration, with onset of action occurring within 5-30 minutes depending on the rate of infusion 2
Pharmacokinetic Considerations
- The time to onset of pharmacologic effect for IV digoxin is 5-30 minutes, depending on the rate of infusion 2
- The time to peak effect for IV digoxin is 1-4 hours 2
- Administering too rapidly increases the risk of digoxin toxicity, while administering too slowly may delay the therapeutic effect 3
Safety Considerations
- Digoxin toxicity is commonly associated with serum levels greater than 2 ng/mL, but may occur at lower levels if hypokalemia, hypomagnesemia, or hypothyroidism coexist 3
- Cardiac manifestations of digoxin toxicity include bradycardia, enhanced atrial, junctional, or ventricular automaticity, atrioventricular block, and ventricular tachycardia 4
- Too rapid administration of IV digoxin increases the risk of arrhythmias and hypotension 3
Monitoring During and After Infusion
- Regular monitoring of heart rate and rhythm is essential during and after digoxin administration 4
- Withhold digoxin if the pulse rate is less than 60 beats per minute or if there is significant sinus or atrioventricular block 4
- Monitor serum electrolytes (potassium, magnesium) as electrolyte abnormalities can increase the risk of digoxin toxicity 4
Special Patient Considerations
- Lower doses and potentially slower infusion rates should be considered for patients over 70 years of age, those with impaired renal function, or low lean body mass 5
- Use caution in patients taking other drugs that can depress sinus or atrioventricular nodal function (e.g., amiodarone or beta-blockers) 4
- Digoxin should not be administered to patients with significant sinus or atrioventricular block without a permanent pacemaker 4