Digoxin Toxicity in Renal Failure: Resolution With Plasma Exchange After Fab Therapy Failure

Digoxin toxicity is a serious clinical concern, particularly in patients with chronic kidney disease (CKD), due to impaired renal clearance and the potential for both chronic tissue accumulation and acute overdose. Standard therapy with digoxin-specific antibody fragments (Fab) may be insufficient in cases with large tissue digoxin burdens and in patients with acute renal failure, as the delayed clearance of digoxin-Fab complexes can result in complex dissociation and rebound toxicity. We present a unique case of a 73-year-old woman with acute-on-chronic digoxin toxicity in the setting of acute renal failure who exhibited persistent toxicity symptoms despite Fab therapy. The patient underwent plasma exchange (PLEX) to remove lingering digoxin-Fab complexes and remaining free digoxin, resulting in successful clinical resolution and no disease recurrence. This case highlights the use of PLEX as a potential salvage therapy for patients with chronic digoxin toxicity and renal impairment who exhibit persistent toxicity symptoms despite treatment with Fab therapy.