From the Guidelines
The recommended intravenous (IV) dosage of digoxin is 0.25-0.5-mg IV bolus, with a maximum loading dose of 1.0 mg over 24 hours, and a maintenance dose of 2.4-3.6 mcg/kg/d, as indicated in the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia 1. The dosage may need to be adjusted based on the patient's age, lean body weight, renal function, and concomitant drugs.
- Key considerations for dosing include:
- Initial dose: 0.25-0.5-mg IV bolus
- Maximum loading dose: 1.0 mg over 24 hours (approximately 8-12 mcg/kg)
- Maintenance dose: 2.4-3.6 mcg/kg/d
- Dosing intervals: 6-8 hours for loading doses
- It is crucial to monitor for potential adverse effects, such as anorexia, nausea, vomiting, visual changes, and cardiac arrhythmias, which may occur if digoxin toxicity develops (associated with levels >2 ng/mL) 1.
- The therapeutic effect of digoxin is achieved through its inhibition of the sodium-potassium ATPase pump, leading to increased intracellular calcium in cardiac cells, enhanced myocardial contractility, and slowed conduction through the AV node, making it effective for heart failure and certain arrhythmias.
From the FDA Drug Label
DOSAGE AND ADMINISTRATION Digoxin dose is based on patient-specific factors (age, lean body weight, renal function, etc.) See full prescribing information. Monitor for toxicity and therapeutic effect. (2) Intravenous administration is preferable to intramuscular. Avoid bolus administration. (2)
The FDA drug label does not provide a specific intravenous (IV) dosage of digoxin, as it states that the dose is based on patient-specific factors and refers to the full prescribing information for details.
From the Research
Intravenous Dosage of Digoxin
The intravenous (IV) dosage of digoxin is an important consideration in the management of certain cardiac conditions.
- The recommended IV loading dose of digoxin for rate control of atrial arrhythmias in critically ill patients is a median total dose of 750 mcg, with a target serum digoxin concentration (SDC) of 0.8-1.5 ng/mL 2.
- For a 155-pound (70.0-kg) patient, the 24-hour IV dose of digoxin should not exceed 1.0 mg, administered in divided doses every 4 to 8 hours 3.
- It is essential to monitor patients receiving IV digoxin for risk factors, such as impaired renal function, low body weight, and drug interactions, to minimize the risk of toxicity 4, 3.
- The therapeutic plasma concentration range for digoxin is generally considered to be between 0.5 and 2 ng/ml 5.
Key Considerations
- IV digoxin can be used for rapid digitalization, when oral digitalization is not feasible, or as augmentation therapy to other medication protocols 3.
- The serum half-life of IV digoxin is approximately 34 hours, similar to oral administration 3.
- Patients with elevated digoxin levels are at risk of toxicity, which can be exacerbated by factors such as hypokalemia, hypomagnesemia, and hypothyroidism 6, 4.