Study To Evaluate Safety And Efficacy Of IV Sildenafil In The Treatment Of Neonates With Persistent Pulmonary Hypertension Of The Newborn

Official Title: Multi-centre, Randomized, Placebo-controlled, Double-blind, Two-armed, Parallel Group Study To Evaluate Efficacy And Safety Of Iv Sildenafil In The Treatment Of Neonates With Persistent Pulmonary Hypertension Of The Newborn (Pphn) Or Hypoxic Respiratory Failure And At Risk For Pphn, With A Long Term Follow-up Investigation Of Developmental Progress 12 And 24 Months After Completion Of Study Treatment.