Ingestion of false hellebore plants can cross-react with a digoxin clinical chemistry assay

We report a case of digoxin-like toxicity because of ingestion of foraged plants. This patient presented with nausea, vomiting, bradycardia, and hypotension after ingesting Veratrum viride (false hellebore). The patient's serum specimen demonstrated a positive digoxin level (0.38 ng/mL) measured by a clinical tubidimetric immunoassay. We hypothesize that steroidal alkaloid compounds contained in V. viride cross-react with the Multigent Digoxin immunoassay reagent antibodies.

Plant extracts from V. viride demonstrated cross-reactivity to Multigent reagent antibodies but did not bind therapeutic DigiFab antibodies. Gas chromatography/mass spectrometry analyses identified several steroidal alkaloid compounds present in the V. viride extracts: jervine, ribigirvine, solanidine, and veratraman.

This study indicates that compounds extracted from V. viride can cross-react with a clinical Digoxin immunoassay. Yet these extracts did not bind DigiFab antibody fragments used for therapeutic intervention. Providers should not unnecessarily administer DigiFab fragments as an antidote in symptomatic V. viride toxic patients.