Circulation, Vol 51, 713-717, Copyright © 1975 by American Heart Association
AC Giardina, KH Ehlers, JB Morrison and MA Engle
Serum digitoxin levels were measured in 18 infants (under two years) and in
23 children (aged 2-13 years) receiving maintenance therapy. Digitalization
was carried out because of heart failure in 17 infants and 13 children and
for control of dysrhythmia in one infant and 10 children. Mean maintenance
dosage for infants was 0.0042 plus or minus 0.0008 (sd) mg/kg/day and for
children was 0.0031 plus or minus 0.0012 mg/kg/day. The mean serum
digitoxin level was not significantly different in infants (30 plus or
minus 10 ng/ml, range 14-58) from that found for children (34 plus or minus
11 ng/ml, range 19-61). Both values were significantly different (P smaller
than 0.001) from those determined in this laboratory for adults (mean 24
plus or minus 7 ng/ml, range 5-39). In four infants with
electrocardiographic or other evidence of toxicity, the mean serum level
was 71 plus or minus 2 ng/ml (range 68-72), and in four children with
electrocardiographic or other evidence of toxicity, the mean serum level
for digitoxin was 72 plus or minus 14 ng/ml (range 53-84). The data suggest
that infants and children tolerate a higher serum digitoxin concentration
without any evidence of toxicity and may require more digitoxin (mg/kg) for
therapeutic effect than do adults. Serum digitoxin levels may serve as an
important guide in determining the adequacy of digitalization and in the
recognition and management of digitalis toxicity.
ARTICLES
Serum digitoxin concentrations in infants and children