Serum levels and renal excretion of digoxin during maintenance therapy in children.

Abstract

ABSTRACT. Iisalo, E. and Dahl, M. (Departments of Pharmacology and Paediatrics, University of Turku, Turku, Finland). Serum Levels and Renal Excretion of Digoxin during Maintenance Therapy in Children. Acta Paediatr Scand,63:699, 1974.—To exclude an increased excretion of digoxin as a possible reason for higher dose requirement in children a radioimmunoassay of digoxin in the serum and the 24 hr urine was carried out in 26 children, mainly infants, with congenital heart disease. This procedure was repeated on two consecutive days, in total 64 times during digoxin maintenance therapy.The daily digoxin dose per kilogram of body weight in these small children was twice as high as that used in adults. The steady state level of serum digoxin corresponded approximately to that of adults. A few fairly high digoxin levels were, however, measured in infants without any signs of digitalis toxicity.The daily excretion of digoxin in the urine during maintenance therapy was approximately the same in all age groups and on an average 47 per cent of the daily dose. This percentage is somewhat lower than that found in adults. The low renal excretion of digoxin in one newborn caused high serum digoxin levels.The higher dosage requirement of digoxin per kilogram of body weight in children as compared to adults cannot be explained with differences in the renal excretion of digoxin.