Most medications on the market for pulmonary hypertension are not made in appropriate strengths or forms for use in children. Medications can be compounded to make them child appropriate including new therapies emerging like sildenafil. The use of Sildenafil in the Treatment of Persistent Pulmonary Hypertension of the Newborn: A Review of the Literature.
https://www.ncbi.nlm.nih.gov/pubmed?term=22564297
Beneficial effect of oral sildenafil therapy on childhood pulmonary arterial hypertension: twelve-month clinical trial of a single-drug, open-label, pilot study.
https://www.ncbi.nlm.nih.gov/pubmed?term=15956137
Phosphodiesterase type 5 inhibitors in pulmonary arterial hypertension.
https://www.ncbi.nlm.nih.gov/pubmed?term=19768639