Digoxin Dosing For Adults  
Marshall Pierce, Pharm.D.

Use the tab key to navigate the form. Required data entry fields are teal in color. Other fields are output only.
Enter Age (years)
Enter Height in
Enter Actual Weight in
Select Sex  
Enter Most Recent Serum Creatinine (mg/dl)
Enter Previous Serum Creatinine (mg/dl)
Use the same value twice if renal function is stable.

Enter time between serum creatinines (hours). Use 24 if renal function is stable. Creatinines should be > 1 T1/2 apart to accurately determine creatinine clearance when renal function is changing.
The factors below are known to clinically impact the kinetics of digoxin. When more than one factor is present the values are multiplied to obtain a final result. If you wish to be conservative when multiple drug interactions are present select the drug with the greatest impact.
Other significant drug interactions:
Give digoxin 1 or more hours before or two or more hours after: antacids (absorption decreased 30%), cholestyramine/colestipol (absorption decreased 30%), and kaolin-pectin (absorption decreased 60%).
Erythromycin and tetracycline therapy increase absorption by altering bowel flora, requires increased monitoring.
Congestive Heart Failure?
Clearance reduced 60%
Concurrent Quinidine?
Clearance reduced 50%, Vd reduced 30%
Concurrent Amiodarone?
Clearance reduced 50%
Concurrent Verapamil?
Clearance reduced 25%
Clinically Hyperthyroid?
Clearance and Vd increased 30%
Clinically Hypothyroid?
Clearance and Vd reduced 30%
Select Dosage Form
Select Drug
   
Calculated Lean Body Weight (kg)
Calculated Drug Dosing Weight (kg)
Calculated Creatinine Clearance (ml/min)
Calculated T1/2 for CREATININE (hours)
Calculated Drug K (hours-1)
Calculated Drug T1/2 (hours)
Calculated Drug Vd (liters)
Calculated Drug Clearance (liter/hour)
Calculated Loading Dose (mg)
For 1 ng/ml (mcg/liter) based on Dosing Weight
Administer in three divided doses of 50%, 25% and 25% of total calculated dose with 6 hours between each dose. Assumes no drug on board.
Calculated Daily Dose (mg)
For average level of 1 ng/ml (mcg/liter)  based on Dosing Weight
Enter Rounded Dose (mg)
Select Dosage Interval
Calculated Peak (ng/ml, mcg/liter) 
Atrial Fibrillation  
   Digoxin < 2.5 ng/ml (mcg/liter) 
Congestive Heart Failure :
  Digoxin < 1.5 ng/ml (mcg/liter)
  

Calculated Trough (ng/ml, mcg/liter)
Usual Goal for Atrial Fibrillation 
  Digoxin  1.5-2 ng/ml (mcg/liter)
Usual Goal for Congestive Heart Failure :
  Digoxin 0.8-1.2 ng/ml (mcg/liter)
  

Serum level analysis: Please complete the input boxes below if you have an actual level and the time is was drawn. These values along with the entered dosage history will be used to calculated the patient's elimination rate constant (K).
Enter Actual Measured Steady State Level ng/ml or mcg/l 
True troughs are suggested as dosage predictions will be more accurate.   Levels should be drawn at least 6 hours after an IV dose and 8 hours after an oral dose. Serum levels are recommended after 2 and 5 half-lives.

Enter Time Level Drawn FROM START OF PREVIOUS DOSE (hours)
K (hours-1) Fit (Fit from level, time of level,  and entered dosage history.)
Thanks for using the program. If you have any comments, suggestions or questions please contact the author.

Copyright Marshall A. Pierce, all rights reserved, no warranties expressed or implied.