A False Positive Serum Digoxin Level in Elderly Patients.

Abstract

We investigated the serum digoxin concentration (SDC) by TDx Digoxin II assay in 113 elderly patients who were not receiving any cardiac glycosides. Most of the falsely elevated SDCs were regarded as negligible clinically, whereas some of the values were markedly high. It was of interest that all of four false positive SDCs exceeding 0.3 ng/ml were derived from patients undergoing continuous intravenous drip infusion with sodium containing solution at the time of sampling.In conclusion, TDx Digoxin II may be applicable to the elderly who are not receiv ing intravenous sodium infusion treatment. However, since false positive SDC can become elevated in aged patients undergoing this therapy, careful attention must be paid to such patients.