Paediatrics: Sildenafil in the treatment of pulmonary hypertension in the neonate

Pulmonary hypertension refers to a group of diseases that is characterised by high pressure in the pulmonary artery, and pulmonary vascular resistance. Persistent pulmonary hypertension in the newborn is a condition in which the pulmonary artery pressure does not decrease after birth. It may occur in as many as 6.8 in 1 000 live births. Phosphodiesterase type 5 (PDE5) is the predominant phosphodiesterase isoform that metabolises cyclic guanosine monophosphate (cGMP) in the lung. It is upregulated in conditions that are associated with pulmonary hypertension. Thus, by selectively inhibiting PDE5, the accumulation of intracellular cGMP is promoted by sildenafil citrate. The nitric oxide-mediated vasodilatation is also enhanced. It is recommended that more large-scale randomised, controlled clinical trials should be carried out to confirm the efficacy, safety and optimal dosage of sildenafil in the treatment of pulmonary hypertension in neonates and paediatric patients.