Is it safe to administer 2mg of digoxin (digitalis glycoside) as an intravenous (IV) push?

Administering Digoxin 2mg IV Push is Unsafe and Potentially Fatal

A 2mg IV push dose of digoxin is unsafe and exceeds the maximum recommended dose, posing significant risk of severe toxicity and death. 1

Correct Digoxin Dosing

• The recommended initial IV bolus dose of digoxin is 0.25-0.5mg, which can be repeated at 6-8 hour intervals up to a maximum total dose of 1.0mg over 24 hours 1
• The maximum loading dose should not exceed 8-12 mcg/kg total over 24 hours 1
• For maintenance therapy, dosing should be based on the patient's age, lean body weight, renal function, and concomitant medications 1

Risks of Excessive Digoxin Dosing

• A 2mg IV push dose (4 times the recommended initial bolus) can cause severe digoxin toxicity, including:
  • Life-threatening cardiac arrhythmias 1
  • Visual disturbances 1
  • Severe gastrointestinal symptoms (anorexia, nausea, vomiting) 2
  • Neurological symptoms 2
• Digoxin has a narrow therapeutic window with serum levels >2 ng/mL associated with toxicity 1, 3
• Toxicity can occur even at therapeutic levels in susceptible patients 4

Management of Digoxin Toxicity

• For severe digoxin toxicity, digoxin-specific antibody fragments (Fab) are the first-line treatment 1, 5
• Dosage of Fab is dependent on the amount ingested or known digoxin concentration 1
• One vial of Fab binds approximately 0.5mg of digoxin 1
• For known ingested amounts, administer 2 vials of Fab for every milligram of digoxin ingested 1
• Hemodialysis is NOT effective for digoxin toxicity due to its large volume of distribution 5

Risk Factors for Increased Toxicity

• Renal dysfunction (digoxin is primarily eliminated by the kidneys) 1, 2, 6
• Drug interactions with P-glycoprotein inhibitors (amiodarone, verapamil, clarithromycin, etc.) 1, 2
• Pre-existing AV block or SA node dysfunction 1
• Electrolyte abnormalities, particularly hypokalemia 1, 5
• Wolff-Parkinson-White (WPW) syndrome with atrial fibrillation/flutter 1

Clinical Pearls and Pitfalls

• Unlike many other cardiovascular medications, hypotension is not a common adverse effect of digoxin 2
• The apparent volume of distribution of digoxin is reduced by about one-third in patients with advanced renal failure 6
• Response to digoxin-Fab typically occurs within 30-45 minutes of administration 5
• Monitoring should continue after Fab treatment due to the small risk of rebound toxicity 4
• Serum digoxin levels may be unreliable after Fab administration 5

Correct Administration When Indicated

• When digoxin is indicated, administer initial IV bolus of 0.25-0.5mg over several minutes 1
• Allow 6-8 hours between doses to assess effect before administering additional doses 1
• Monitor for signs of toxicity including cardiac arrhythmias, gastrointestinal symptoms, and visual disturbances 1, 2
• Maintain therapeutic serum concentration between 0.6-1.2 ng/mL 5