What is the appropriate digoxin (Digitalis glycoside) loading dose and schedule for a patient with Impaired renal function (eGFR 43, Creatinine clearance 23mL/min), weighing 40.3kg, and 147cm tall, who is to be initiated on digoxin and diltiazem (Calcium channel blocker) 120mg as per cardiology Senior Medical Officer (SMO)?

From the Research

For this patient with a creatinine clearance of 23 mL/min, I recommend a reduced digoxin loading dose of 6-10 μg/kg, as suggested by the study published in 2013 1, to minimize the risk of digoxin toxicity. Given the patient's low body weight (40.3 kg) and reduced renal function, a lower loading dose is appropriate.

• The total digitalizing dose (TDD) would be approximately 241-403 micrograms, which is lower than the traditional loading dose.
• The loading dose can be administered in divided doses, such as 125 micrograms PO every 6 hours, to achieve the total loading dose over 12-24 hours.
• After loading, transition to a maintenance dose of 125 micrograms PO once daily, which is a lower maintenance dose considering the patient's reduced renal function.
• Monitor digoxin serum levels 12-24 hours after the last loading dose, aiming for a therapeutic range of 0.8-2.0 ng/mL, as suggested by the study published in 1997 2.
• Regular monitoring of serum potassium, magnesium, and calcium is essential, as electrolyte abnormalities can increase digoxin toxicity risk, and monitor heart rate and rhythm, and watch for signs of digoxin toxicity including nausea, visual disturbances, and arrhythmias. The study published in 2013 1 provides the most recent and relevant guidance on digoxin loading doses in patients with renal dysfunction, and its recommendations should be prioritized to minimize the risk of digoxin toxicity and ensure optimal patient outcomes.