Serum Concentration and Serum Half-Life of Digoxin in Premature and Mature Newborns

Abstract

[The risk of digoxin intoxication is highest in premature infants.] Serum concentrations and half-life times of digoxin were determined in 10 mature and 9 premature newborns. Median serum digoxin concentration was 2.3 ng/ml (1.2-3.5 ng/ml) in mature newborns and 2.4 ng/ml (1.5-4.5 ng/ml) in premature newborns. Median serum digoxin half-life was 35 h (17-52 h) in mature newborns and 57 h (38-88 h) in premature newborns. The difference in serum digoxin half-life between the 2 groups is statistically significant. The relatively long serum digoxin half-life in premature newborns is probably due to immature renal function in this group. The data emphasize the need for cautious digoxin administration, especially in premature infants.