Digoxin Immune Fab Dosage

Medically reviewed by Drugs.com. Last updated on Sep 14, 2022.

Applies to the following strengths: 38 mg; 40 mg

Usual Adult Dose for Digitalis Glycoside Toxicity

Acute ingestion and digoxin toxicity, serum digitalis concentration and amount ingested unknown:
Initial dose: 10 vials intravenously
Follow with an additional 10 vials, if needed, to avoid a febrile reaction

Acute ingestion, amount of digoxin ingested is known: Dose (in # of vials) = (amount of digoxin ingested in mg) / (0.5 mg/vial).

Chronic digoxin toxicity, serum digitalis concentration unknown: 6 vials intravenously

Chronic digoxin toxicity, serum digitalis concentration is known: Dose (in # of vials) = (serum digoxin ng/mL)x(weight in kg) / 100

Comments:

A lack of response to treatment may indicate the problem is not caused by digitalis toxicity.
Each vial contains 40 mg of digoxin-specific Fab, which binds approximately 0.5 mg of digoxin.
Many patients require higher doses for complete neutralization.
Doses should be rounded up to the nearest whole vial.
If toxicity is not adequately reversed in several hours, or recurs, use clinical judgement regarding additional dosing; measure free (unbound) serum digitalis concentration for dosing as Fab may still be present.

Use(s): Treatment of life-threatening or potentially life-threatening digoxin toxicity or overdose

Usual Pediatric Dose for Digitalis Glycoside Toxicity

Monitor for volume overload in small (under 20 kg) children

Acute ingestion, amount of digoxin ingested is known: Dose (in # of vials) = (amount of digoxin ingested in mg) / (0.5 mg/vial).

Chronic digoxin toxicity, serum digitalis concentration unknown:
Children 20 kg and over: 6 vials intravenously
Children under 20 kg and infants: 1 vial intravenously

Chronic digoxin toxicity, serum digitalis concentration is known: Dose (in # of vials) = (serum digoxin ng/mL)x(weight in kg) / 100

Comments:

A lack of response to treatment may indicate the problem is not caused by digitalis toxicity.
Each vial contains 40 mg of digoxin-specific Fab, which binds approximately 0.5 mg of digoxin.
Many patients require higher doses for complete neutralization.
Doses should be rounded up to the nearest whole vial.
If toxicity is not adequately reversed in several hours, or recurs, use clinical judgement regarding additional dosing; measure free (unbound) serum digitalis concentration for dosing as Fab may still be present.

Use(s): Treatment of life-threatening or potentially life-threatening digoxin toxicity or overdose

Renal Dose Adjustments

Data not available

The elimination half life in renal failure has not been clearly identified.
Monitor severe renal failure patients for digitalis toxicity for a prolonged period because of possible recurrence of toxicity.
Monitoring free (unbound) digoxin concentrations may be appropriate to establish recrudescent toxicity in renal failure patients.

Liver Dose Adjustments

Data not available

Dose Adjustments

Alternate dosing formulas:

Dose (in number of vials) = total digitalis body load in mg / (0.5 mg of digitalis bound/vial)

Dose (in number of vials) = (serum digoxin concentration in ng/mL x weight in kg) / 100

Pediatric:
Dose (in mg) = (dose in number of vials) x (40 mg/vial)

Dose (in number of vials) = (serum digoxin concentration in ng/mL x weight in kg) / 1000

Precautions

CONTRAINDICATIONS: None

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:

Administer as a slow IV infusion over at least 30 minutes.
Stop administration for infusion rate-related anaphylactoid reactions (e.g. hypotension, wheezing, urticaria); may restart at a lower rate.
May give as a bolus injection if cardiac arrest is imminent.
Infants and small children needing very small doses may be given this product undiluted using a tuberculin syringe.
Very small doses can be diluted with 36 mL of isotonic saline to achieve a concentration of 1 mg/mL.

Storage requirements:

Refrigerate; do not freeze

Reconstitution/preparation techniques:

Reconstitute each vial with 4 mL of sterile water for injection, mix gently.
Use reconstituted product promptly; if not used immediately, refrigerate (36 to 46F) for up to 4 hours.
Add reconstituted product to an appropriate volume of 0.9% sodium chloride for injection.