digoxin immune fab

Absorption: Administered IV only, resulting in complete bioavailability.

Distribution: Widely distributed throughout extracellular space.

Metabolism/Excretion: Excreted by the kidneys as the bound complex (digoxin immune Fab plus digoxin).

Half-Life: 14–20 hr.

Time/Action Profile ⬆ ⬇

(reversal of arrhythmias and hyperkalemia; reversal of inotropic effect may take several hr)

ROUTE	ONSET	PEAK	DURATION
IV	30 min (variable)	unknown	2–6 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

No known contraindications.

Use Cautiously in:

Known hypersensitivity to sheep proteins or products;
Children, pregnancy, or lactation (safety not established).

Adv. Reactions/Side Effects ⬆ ⬇

CV: re-emergence of HF, re-emergence of atrial fibrillation

F and E: HYPOKALEMIA

Interactions ⬆ ⬇

Drug-drug:

Prevents therapeutic response to digoxin.

Route/Dosage ⬆ ⬇

Digibind: 38 mg of digoxin immune Fab will bind 0.5 mg of digoxin. Each vial contains 38 mg of digoxin immune Fab; DigiFab: 40 mg of digoxin immune Fab will bind 0.5 mg of digoxin. Each vial contains 40 mg of digoxin immune Fab

Known Amount of Digoxin Ingested (Administered)

IV (Adults and Children ): For digitalis glycoside toxicity due to digoxin tablets, oral solution, or IM digoxin: dose of digoxin ingested (mg) × 0.8/1000 × 38. For digitalis glycoside toxicity due to digoxin capsules, IV digoxin: dose of digoxin ingested (mg)/0.5 × 38.

Known Serum Digoxin Concentrations (SDCs)

IV (Adults and Children ): Digibind: Dose (mg)=SDC (nanograms/mL) × body weight (kg)/100 × 38; DigiFab: SDC (nanograms/mL) × body weight (kg)/100 × 40.

Unknown Amount Ingested/SDCs Unavailable

IV (Adults and Children ): Digibind: 760 mg (20 vials); DigiFab: 800 mg (20 vials).

Toxicity during chronic digoxin therapy

IV (Adults and Children ): Digibind: 228 mg (6 vials); DigiFab: 240 mg (6 vials).

Availability ⬆ ⬇

Powder for injection, lyophilized (Digibind): 38 mg/vial
Powder for injection, lyophilized (DigiFab): 40 mg/vial

Assessment ⬆ ⬇

Monitor ECG, pulse, BP, and body temperature before and during treatment. Patients with atrial fibrillation may develop a rapid ventricular response as a result of decreased digoxin levels.
Assess patient for increase in signs of HF (peripheral edema, dyspnea, rales/crackles, weight gain).

Lab Test Considerations:

Monitor serum digoxin levels before administration.
- Monitor serum potassium levels frequently during treatment. Before treatment, hyperkalemia usually coexists with toxicity. Levels may decrease rapidly; hypokalemia should be treated promptly.
- Free serum digoxin levels fall rapidly after administration. Total serum concentrations rise suddenly after administration but are bound to the Fab molecule and are inactive. Total serum concentrations will decrease to undetectable levels within several days. Serum digoxin levels are not valid for 5–7 days after administration.

Implementation ⬆ ⬇

Cardiopulmonary resuscitation equipment and medications should be available during administration.
- Delay redigitalization for several days until the elimination of digoxin immune Fab from the body is complete.

IV Administration:

Intermittent Infusion: Diluent: Reconstitute each vial in 4 mL of sterile water for injection and mix gently. Solution will contain a concentration of 9.5 mg/mL (Digibind) or 10 mg/mL (DigiFab). May be further diluted with 0.9% NaCl to achieve the concentration below. Reconstituted solution should be used immediately but is stable for 4 hr if refrigerated. For small doses in infants and children, a reconstituted 38-mg vial can be diluted with 34 mL of 0.9% NaCl (Digibind) or 36 mL of 0.9% NaCl (DigiFab) for a concentration of 1 mg/mL. Concentration: 1 mg/mL.
Rate: Infuse over 30 min through a 0.22-micron membrane filter. If cardiac arrest is imminent, rapid IV push injection may be used. Do not use rapid direct injection in other patients because of increased risk of adverse reactions. Small doses in infants and children may be administered with a tuberculin syringe.
Incompatibility: Information unavailable. Do not mix with other drugs or solutions.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇