Background: Indomethacin therapy for large patent ductus arterious would be more effective when it is prescribed for 5 or 6 days vs 2 or 3 days. Effects on renal function of such prolonged therapy is still debated.
Patients and methods: Seven preterm infants (gestational age: 28.6 +/- 0.9 weeks; birth-weight: 1,169 +/- 267 g) with symptomatic patent ductus arterious were given indomethacin, 0.1 mg/kg/day for 6 days (four patients) and 5 days (three patients). Urinary water excretion, water output/input ratio, creatinine clearance and body weight were measured before and every day during therapy.
Results: Urinary water excretion, water output/input ratio and creatinine clearance were significantly decreased after 5 days of treatment, -40 +/- 30%, -42 +/- 27% and -48 +/- 31%, respectively. Creatinemia and body weight were significantly increased, + 34 +/- 36% and + 9 +/- 7%, respectively. Mean sodium plasma level and fractional excretion of sodium, potassium and chloride remained stable.
Conclusion: Prolonged therapy with indomethacin does not avoid the renal side effects seen with shorter administration.