Serum digoxin concentration in a neonate with renal and hepatic impairment

This report demonstrates the questionable usefulness of monitoring digoxin concentrations using the available immunoassays in some clinical situations. The patient reported here showed three characteristics (being a neonate with hepatic and renal impairment) that are associated with the presence of digoxin-like immunoreactive substances. The patient's serum digoxin concentration continued to rise to a peak of 43.7 nmol/L (34.1 ng/mL), 19 days after administration of the drug was discontinued.