Digoxin Immune Fab (Ovine) and Potassium imbalance

• Generic Name: digoxin immune fab
• Dosage Forms: n.a.
• Other Brand Names: DigiFab, Digibind

Treatment of life-threatening or potentially life-threatening digoxin toxicity or overdosage.

Has been used for treatment of life-threatening overdosage of digitoxin (no longer commercially available in US) or lanatoside C (not commercially available in US) intoxication; designated an orphan drug by FDA for treatment of potentially life-threatening cardiac glycoside (digitalis) intoxication refractory to conventional management.

Not indicated for treatment of non-life-threatening cardiac glycoside intoxication; limited experience and consequences of repeated exposure to the immune Fab not known.

Indicated in acute ingestions (e.g., known suicidal or accidental consumption) of ≥10 mg of digoxin in previously healthy adults or 4 mg (or >0.1 mg/kg) of digoxin in previously healthy children.

Minimum toxic or lethal acute doses of digoxin not well established; acute digoxin ingestions of >10 mg in previously healthy adults or >4 mg in previously healthy children often result in cardiac arrest.

Indicated in acute ingestions resulting in steady-state serum digoxin concentrations >10 ng/mL or chronic ingestions resulting in steady-state serum digoxin concentrations >6 ng/mL in adults or >4 ng/mL in children; ingestions resulting in steady-state serum digoxin concentrations >10 ng/mL often result in cardiac arrest.

Indicated when there are manifestations of life-threatening digoxin toxicity, including severe ventricular arrhythmias (e.g., ventricular tachycardia or fibrillation), progressive bradycardia (e.g., second- or third-degree heart block not responsive to atropine), or serum potassium concentrations >5–5.5 mEq/L in adults or >6 mEq/L in children with rapidly progressive signs and symptoms of digoxin toxicity.

Progressive hyperkalemia treated by conventional supportive and symptomatic measures without digoxin immune Fab (ovine) has poor prognosis. Also consider other potential causes of hyperkalemia, especially if digoxin immune Fab (ovine) does not appear to substantially decrease serum potassium concentrations.

Has been used for treatment of poisonings involving ingestion of certain cardiotoxic plants, including common or pink oleander (Nerium oleander), yellow oleander (Thevetia peruviana), and Indian hemp (Apocynum cannabinum). Has reversed or improved cardiotoxicity in some individuals; additional study needed.

Has not been effective in poisonings involving ingestion of foxglove extract or yew berry.

Reversed or improved cardiotoxicity associated with ingestion of toad venom. Toad venom has been identified in illicit street drugs marketed as aphrodisiacs; contains several cardioactive steroids (bufadienolides), including bufalin, cinobufagin, cinobufotalin, and resibufogenin.

Has been used with some success for management of severe preeclampsia or eclampsia; designated an orphan drug by FDA for treatment of severe preeclampsia and eclampsia.

Severe preeclampsia and eclampsia are major causes of maternal and fetal morbidity and mortality. There is some evidence that increased concentrations of endogenous cardiotonic steroids, including endogenous digitalis-like factors (EDLFs), in maternal and/or cord blood may contribute to pathogenesis of preeclampsia, particularly elevated BP; additional study needed to evaluate use of digoxin immune Fab (ovine).