During the past 15 years, digoxin has been routinely measured in serum by various immunoassays. Unfortunately, all of the currently available immunoassays exhibit various cross reactivities with drugs, digoxin metabolites, and endogenous digoxin-like immunoreactive substances (1, 2). We recently encountered several patients for whom we were unable to obtain a reportable digoxin concentration wi...

BACKGROUND The impact of digoxin on outcomes of patients with advanced heart failure (HF) remains uncertain and its effect may be different for patients in atrial fibrillation (AF) or sinus rhythm (SR). OBJECTIVES To determine the impact of digoxin on outcomes of advanced HF patients and to assess whether prognosis differs in patients in AF and SR. METHODS A total of 268 consecutive patient...

OBJECTIVES To explore the luminescent oxygen channeling technology-based digoxin immunoassay (LOCI digoxin assay) for rapid detection of lily of the valley extract and convallatoxin. The potential in vitro binding of convallatoxin with Digibind was also evaluated. METHODS Aliquots of a drug-free serum pool and a digoxin serum pool were supplemented with lily of the valley extract or convallat...

INTRODUCTION The purpose of this study was to determine digoxin serum concentrations in patients with Chagas' cardiomyopathy with chronic heart failure, because little is known concerning this laboratory test in patients with this condition. METHODS This study focuses on 29 (29%) out of 101 patients with chronic heart failure secondary to Chagas' cardiomyopathy receiving digoxin therapy. Digo...

Six normal human volunteers as renal transplant donors were given 33H-digoxin before and again after unilateral nephrectomy. The serum digoxin concentration was modestly increased following nephrectomy, the serum digoxin half-time was slightly prolonged, and total digoxin excretion for the group was reduced by only 6.4% during a 7-day study. Four of the six patients studied before and after uni...

A single intravenous dose of tritiated digoxin was given to five obese patients before and after a mean loss of 102 pounds in weight. There were no significant differences in the blood concentrations of digoxin before and after the weight reduction. Likewise, there were no significant differences in the blood concentrations of digoxin when these data were corrected for fat-free body weight. The...

CONTEXT We hypothesized that in chronic digoxin toxicity, anti-digoxin antibodies (Fab) would be efficacious in binding digoxin, but this may not translate into improved clinical outcomes. OBJECTIVE This study aims to investigate changes in free digoxin concentrations and clinical effects on heart rate and potassium concentrations in chronic digoxin poisoning when anti-digoxin Fab are given. ...

BACKGROUND The ABC transporter P-glycoprotein (P-gp) is recognized as a site for drug-drug interactions and provides a mechanistic explanation for clinically relevant pharmacokinetic interactions with digoxin. The question of whether several P-gp inhibitors may have additive effects has not yet been addressed. METHODS We evaluated the effects on serum concentrations of digoxin (S-digoxin) in ...

INTRODUCTION The potential for ezogabine/retigabine (EZG/RTG) and its N-acetyl metabolite (NAMR) to inhibit the transporter protein P-glycoprotein-(P-gp)-mediated digoxin transport was tested in vitro. EZG/RTG did not inhibit P-gp. However, NAMR inhibited P-gp in a concentration-dependent manner. Based on these in vitro results, NAMR had the potential to inhibit P-gp at therapeutic doses of EZG...