Multiple-dose kinetics of digoxin in neonates

Area of Science:

• Neonatal Pharmacology
• Clinical Pharmacokinetics
• Pediatric Drug Metabolism

Background:

• Digoxin is commonly prescribed for neonatal heart conditions.
• Understanding digoxin's pharmacokinetic profile in neonates is crucial for safe and effective treatment.
• Limited data exists on the changes in digoxin kinetics during the first week of intravenous therapy in neonates.

Purpose of the Study:

• To investigate the multiple-dose pharmacokinetics of digoxin in neonates over a 7-day period.
• To determine if key kinetic parameters change significantly during the initial week of intravenous digoxin therapy.
• To assess the stability of digoxin's absorption, distribution, metabolism, and excretion in this population.

Main Methods:

• Five neonates receiving intravenous digoxin therapy were studied.
• Serum digoxin levels and urinary excretion were measured after the 1st and 7th doses.
• Creatinine clearance, renal digoxin clearance, total body digoxin clearance, volume of distribution, and half-life were calculated.

Main Results:

• Creatinine clearance averaged 12-13 ml/min/1.73 m2.
• Renal and total body digoxin clearance showed no significant changes from day 1 to day 7.
• Volume of distribution and half-life remained stable, with values of approximately 7 L/kg and 48 hours, respectively.

Conclusions:

• Neonatal digoxin pharmacokinetics, including clearance and half-life, are stable during the first week of intravenous therapy.
• These findings support consistent dosing regimens for digoxin in neonates.
• Further research may explore longer-term kinetics and effects of varying gestational and postnatal ages.