Digitoxin poisoning from an herbal cleansing preparation

Background: Cardioactive steroid poisoning is rarely associated with the use of herbal preparations. Identification of the specific compound is difficult due to the large number of potential agents and limitations of the analytic technique. We describe such a case and the subsequent analytic investigation. Case Report: A 36-year-old woman with no medical history and taking no conventional medication ingested an herbal preparation marketed for 'internal cleansing.' Its ingredients were neither known to the patient nor listed on the accompanying literature. The next morning she developed nausea, vomiting and weakness. In the ED, her pulse was 30/min and BP 110/60 mmHg. Her ECG revealed a junctional rhythm at a rate of 30/min with 'digitalis effect.' After empiric therapy with 10 vials of digoxin-specific Fab, her symptoms resolved and she reverted to a sinus rhythm at a rate of 68/min. Her serum digoxin concentration measured by fluorescence polarization immunoassay (FPIA; Abbott TDx[R]) was 1.7 ng/mL. Further serum analysis by the Tina Quant (Roche[R]) digoxin assay, a more digoxin-specific turbidimetric immunoassay, found a concentration of 0.34 ng/mL and an enzyme immunoassay for digitoxin revealed a concentration of 20 ng/mL (therapeutic 1030 ng/mL). Serum HPLC analysis revealed the presence of active digitoxin metabolites; the parent compound was not present. Conclusion: An empiric dose of 10 vials of digoxin-specific Fab should be given initially in patients poisoned by an unknown cardioactive steroid and then re-evaluate to determine if further administration is needed. Though the diagnosis should be suspected clinically, laboratory analysis involving immunoassays of varying specificity can confirm the presence of cardioactive steroids and perhaps assist with identification.
Barrueto F Jr., Jortani SA, Valdes R Jr., Hoffman RS, Nelson LS. New York City Poison Control Center, New York, [...]