The iDigoxin Assay is More Sensitive than LOCI Digoxin Assay for Rapid Detection of Convallatoxin, the Active Cardiac Glycoside of Lily of The Valley.

OBJECTIVE Lily of the valley is a poisonous plant due to the presence of the cardiac glycoside convallatoxin. We compared two immunoassays (LOCI digoxin assay and iDigoxin assay) for rapid detection of convallatoxin if present in human serum. MATERIALS AND METHODS Aliquots of a drug free serum pool and a digoxin serum pool were supplemented with microliter amounts of lily of the valley extract or nanogram to microgram quantities of convallatoxin, followed by measurement of apparent digoxin concentrations using the LOCI and iDigxoin assays. RESULTS Apparent digoxin concentrations were observed when aliquots of a drug free serum pool were supplemented with convallatoxin or lily of the valley extract using both assays but apparent digoxin concentrations were significantly higher using the iDigoxin assay. In addition, the interference of convallatoxin in serum digoxin measurement was also significantly higher using iDigxoin assay compared to the LOCI digoxin assay. CONCLUSIONS The iDigxoin assay is more sensitive in detecting convallatoxin in human serum.