Sildenafil (Paediatric — PPHN / PAH)

How it works

By inhibiting PDE5 it prevents breakdown of cyclic GMP in pulmonary vascular smooth muscle, enhancing nitric-oxide-mediated vasodilatation and lowering pulmonary arterial pressure.

Prescribing in practice

• It must not be combined with nitrates or nitric-oxide donors and is used with caution in PPHN because of the risk of profound systemic hypotension, requiring initiation and monitoring in a specialist/critical-care setting.
• Abrupt withdrawal can cause rebound pulmonary hypertension, so treatment should be tapered and not stopped suddenly.
• Doses are weight-based and specialist-directed; confirm against a children's formulary and the relevant specialist protocol.

Monitoring

Monitor systemic and where available pulmonary blood pressure, oxygenation and clinical status closely, particularly during initiation, titration and any dose changes.

Counselling the patient

• This is a specialist heart-lung medicine that must be taken exactly as prescribed.
• Do not stop it suddenly, as symptoms can worsen sharply.
• Tell any healthcare professional about it before any other medicines, especially heart medicines, are given.

Evidence & guidelines

Sildenafil is an established oral therapy for paediatric pulmonary arterial hypertension; its use in PPHN is specialist and informed by neonatal critical-care evidence and the SPC.