• Digitalis purpurea (purple foxglove) contains several potent and highly cardiotoxic cardenolide glycosides and their metabolites, including latanoside C, digitoxin, gitoxin, digitoxigenin, digitoxigenin monodigitoxoside, and digitoxigenin bisdigitoxoside.
• Because of the cross-sensitivity of digoxin immunoassays and the serum concentrations reached by the glycosides and their metabolites, the digoxin immunoassay can become positive after intoxication with foxglove extracts.
• The exact glycosides and metabolites circulating in the patient’s serum can be identified and quantified using liquid chromatography–electrospray mass spectrometry.
• Symptoms of digitalis intoxication include gastrointestinal distress (e.g., nausea, vomiting, abdominal pain, and anorexia) and cardiovascular dysfunction (e.g., hypotension, bradycardia, heart block, ventricular arrhythmias). Other known side effects include neurosensorial symptoms (e.g., headache, dizziness, blurred vision) and altered mental status (e.g., confusion, delirium).
• Ingesting only a few grams of D. purpurea leaves can be lethal.
• Cardenolides are a type of steroid found in plants many of which are found in a form of cardiac glycosides. Digitalis lanata and Nerium oleander are two other plants that contain cardenolide glycosides.
