Intermittent intravenous sildenafil for pulmonary hypertension management in neonates and infants

Abstract

The use of intermittent i.v. sildenafil dosing in three patients with pulmonary hypertension (PH) and limited venous access is reported. One preterm infant with PH in addition to bronchopulmonary dysplasia and two full-term neonates with PH after congenital diaphragmatic hernia repairs were successfully treated for PH with adjunctive intermittent i.v. sildenafil. sildenafil dosages ranged from 0.4 to 2 mg/kg every six hours. Infusion periods ranged from one to three hours. The longer infusion periods were used to minimize the risk of hypotension during infusion, with continued efficacy assessment between dosing intervals by monitoring ongoing oxygenation saturation trends and oxygen requirements when the drug was not infusing. Treatment duration ranged from 5 to 50 days. Decreases or fluctuations in systemic blood pressure were noted at the beginning of treatment, but minimal interventions were required to maintain blood pressure, which generally increased during extended treatment. Fraction of inspired oxygen requirements were decreased or remained stable during each patient's first dose, and the need for respiratory support decreased over time, with improvements in oxygenation and prevention of continual life-threatening desaturation episodes. PH eventually resolved in each patient, based on improvements in serial echocardiographic studies with decreased requirements for inhaled nitric oxide, oxygen, and mechanical ventilation. All three patients required weaning from sildenafil treatment, suggesting a potential for rebound respiratory insufficiency with abrupt discontinuation of sildenafil. Intermittent i.v. sildenafil dosing provided a well-tolerated, practical, and potentially effective treatment for PH in three patients when enteral intake was undesirable and when there was a need to conserve available venous access.