A double blind controlled trial in Children's Hospital Damascus between 5/2023 and 9/2024 on newborns up to 4 d old diagnosed with PPHN, patients were allocated randomly into one of the 2 arms of the study, group Sildenafil and group Vardenafil, both medicines administered orally, management of the patients was the same in both groups except for the investigated drug, pulmonary hypertension and resistance were measured by echo at diagnosis time and every 24 hours later on till normalization of pulmonary pressure, at the end of recruitment data was collected and analyzed to confirm the safety of Vardenafil and compare the efficacy of Vardenafil to Sildenafil
