Sildenafil as Bridge Therapy for Inhaled Nitric Oxide in Preterm Neonates

Inhaled nitric oxide (iNO) is a mainstay of treatment for infants with persistent pulmonary -hypertension. However, abrupt discontinuation of inhaled nitric oxide can result in rebound pulmonary -hypertension. The objective of this analysis is to describe the use of sildenafil to facilitate the weaning from iNO in preterm neonates.

This retrospective chart review identified all infants who were receiving iNO and subsequently received sildenafil between 2017 and 2021. Neonates were included if they met the following criteria: gestational age at birth less than 34 weeks, receiving iNO, and started on sildenafil with the indication to facilitate weaning or discontinuation of iNO. Patients were excluded if they had major congenital anomalies, including congenital heart disease or congenital diaphragmatic hernia.

We identified 7 neonates with a gestational age range of 22 5/7 weeks to 31 0/7 weeks and birth weight range of 545 to 910 g with previously failed attempts at iNO weaning. The most common starting dose for sildenafil was 0.125 mg/kg intravenously every 8 hours or 0.25 mg/kg enterally every 8 hours. Four infants were able to discontinue iNO within 48 hours of sildenafil initiation, 1 patient discontinued iNO within 5 days, and 1 patient within 10 days of sildenafil initiation. One patient experienced weaning failure from iNO despite initiation of sildenafil. No adverse events, such as hypotension or deaths, were reported in any of the 7 infants.

Sildenafil facilitated weaning off iNO in most preterm neonates evaluated without adverse side effects.