Serum digoxin levels in neonates whose weights are less than 1,500 grams

Area of Science:

• Neonatal Cardiology
• Pediatric Pharmacology

Background:

• Congestive heart failure in premature infants often co-exists with patent ductus arteriosus.
• Respiratory distress syndrome is a common comorbidity in these neonates.
• Standard digoxin dosing may not be appropriate for very low birth weight infants.

Purpose of the Study:

• To evaluate the efficacy and safety of digoxin in premature infants (<1,500 gm) with congestive heart failure and isolated patent ductus arteriosus.
• To determine the relationship between digoxin dosage and serum levels in this specific population.
• To establish appropriate digoxin dosing guidelines for digitalization in small premature infants.

Main Methods:

• Twenty-nine infants weighing less than 1,500 gm with congestive heart failure and isolated patent ductus arteriosus were administered digoxin.
• Parenteral maintenance therapy was given twice daily for at least 4 days.
• Serum digoxin levels were measured and correlated with the administered dose.

Main Results:

• A significant correlation was found between digoxin dose and serum levels (P < .001).
• A total parenteral maintenance dose of 5 micrograms/kg resulted in a mean serum digoxin level of 2.4 ng/ml (+/- 1.2 ng).
• This effective serum level was achieved with a lower dose regimen than commonly recommended.

Conclusions:

• Digoxin can be safely and effectively administered to small premature infants with congestive heart failure and patent ductus arteriosus.
• The required digoxin dose for therapeutic serum levels is lower in this population, necessitating careful dose titration.
• These findings underscore the importance of individualized dosing and cautious digitalization in neonates to avoid toxicity.