Serum digoxin concentration and half-life in newborn

Area of Science:

• Neonatal Pharmacology
• Pediatric Cardiology

Background:

• Digoxin is used to treat heart conditions in newborns.
• Understanding digoxin pharmacokinetics in neonates is crucial for safe and effective dosing.

Purpose of the Study:

• To determine serum digoxin concentration and half-life in mature newborns.
• To investigate factors influencing digoxin levels in neonates with respiratory distress or congenital heart disease.

Main Methods:

• Radioimmunological determination of serum digoxin levels and half-life in 9 newborns.
• Administered intravenous and oral digoxin loading doses, followed by maintenance doses.
• Monitored serum digoxin levels 12 hours post-dose and calculated half-life.

Main Results:

• Mean serum digoxin level at 12 hours was 2.0 ng/ml (range 1.4-2.5 ng/ml).
• Mean serum digoxin half-life was 30.0 hours (range 21.7-42.4 h).
• Newborn digoxin half-life was comparable to adults without renal disease.

Conclusions:

• Elevated serum digoxin levels in newborns are primarily due to higher administered doses per unit body weight.
• Digoxin elimination in mature newborns is not significantly diminished compared to adults.
• This suggests careful dose adjustment is key for neonatal digoxin therapy.