Cardioactive steroids are among the many treatments used for CHF, and for the control of ventricular response rate in atrial tachydysrhythmias. There are many sources of cardioactive steroids:
Pharmaceutial: Digoxin, Digitoxin
Plants: Oleander, Yellow Oleander, Foxglove, Lily of the Valley, Dogbane, Red Squill
Animal: Bufo marinus toad
It is a potent Na+-K+-ATPase inhibitor and can lead to hyperkalemia in acute ingestion with associated signs and symptoms of N/V, abdominal pain, bradycardia and possibly, hypotension.
Toxicity should be suspected with bidirectional ventricular tachycardia or atrial tachycardia with high-degree AV block
Therapeutic range of digoxin of 0.5 - 2.0 ng/mL is helpful but not a sole indicator of toxicity
Indication for antidote (Digoxin-specific Antibody Fragments) include:
1) Digoxin-related life-threatening dysrhythma
2) Serum K+ > 5.0 mEq/L in acute ingestion
3) Serum digoxin concentration >15ng/mL at any time, or >10 ng/mL 6 hours postingestion
