Treatment of 63 severely digitalis-toxic patients with digoxin-specific antibody fragments.

Sixty-three patients with life-threatening digitalis intoxication were treated with purified fragments of digoxin-specific antibodies (Fab) obtained from sheep. Twenty-eight patients developed toxicity as the result of digitalis ingestion in a suicide attempt, 5 ingested a large amount of digoxin accidentally and 30 developed toxicity in the course of treatment for underlying heart disease. The dosage of digoxin-specific Fab was calculated to be equimolar to the amount of cardiac glycoside in the patient's body. Digitalis toxicity was completely reversed in most cases, with onset of effect usually within 30 minutes of administration of Fab fragments. Unbound and, therefore, active digoxin serum concentrations decreased to undetectable levels within minutes after administration of the fragments. In all patients who had elevated serum potassium concentrations caused by massive digitalis toxicity, treatment with the Fab fragments reversed the hyperkalemia. There were no obvious adverse reactions to treatment. Potentially life-threatening digitalis intoxication can be rapidly and safely reversed by treatment with purified digoxin-specific Fab fragments.