The effectiveness of digoxin-specific F(ab')2-antibody fragments in the treatment of digitoxin poisoning: experimental investigations in the cat.

In animal experiments heterologous digoxin-specific F(ab')2 antibody fragments have been found to be effective for the treatment of arrhythmias induced by toxic doses of digoxin. So far they have been successfully employed in three patients suffering from digoxin poisoning. The present study was undertaken to test whether these antibodies are also effective in the treatment of digitoxin poisoning. Ventricular tachycardia, induced in digitalized cats by intravenous injections of digitoxin, was fatal in four out of five controls. However, sinus rhythm was reinstated in all the animals treated with digoxin-specific F(ab')2 after onset of the arrhythmia. Cross-reactivity between the antibodies used and digitoxin, while slight in vitro, is, nevertheless, sufficient to justify their clinical use in cases of digitoxin poisoning.