antidigoxine

Antidigoxine, commonly referred to as digoxin immune Fab or digoxin antibody fragments, is a biologic treatment used to reverse the toxic effects of digoxin, a cardiac glycoside prescribed for some heart conditions. It consists of antibody fragments that specifically bind digoxin and neutralize its activity. It is used mainly in cases of digoxin overdose or life-threatening toxicity.

Mechanism of action is based on high-affinity binding: the antibodies trap free digoxin in the bloodstream, forming inactive digoxin-Fab complexes. This prevents digoxin from inhibiting the sodium-potassium ATPase pump, allowing normal cellular function to resume. The resulting complexes are eliminated by the kidneys. Clinically, reversing the toxic effects can lead to rapid stabilization of cardiac rhythm and hemodynamics, with careful monitoring of electrolytes, particularly potassium.

Indications for use include life-threatening digoxin toxicity, significant hyperkalemia associated with acute overdose, and severe arrhythmias or hemodynamic instability attributable to digoxin. Dosing is individualized and guided by factors such as the estimated digoxin burden, serum concentration, renal function, and clinical response. Therapy is typically given intravenously and may require multiple vials to achieve clinical improvement. Monitoring includes vital signs, ECG, serum potassium, renal function, and digoxin levels as appropriate.

Adverse effects are uncommon but can include hypersensitivity or infusion reactions to the Fab fragment. Potential electrolyte shifts, particularly potassium, require careful monitoring because rapid changes can affect cardiac rhythm. Antidigoxine should be used with caution in patients with hypersensitivity to the product or its components, and in settings where monitoring and supportive care are readily available.