PURPOSE: Inhaled iloprost is approved for the treatment of adults with pulmonary arterial hypertension (PAH); however, data in children are limited.
METHODS: Eleven children with PAH (age, 6.9-16.5 years; median, 12.4) were treated with inhaled iloprost (2.5 or 5.0 mcg/dose, 5-9 times daily) for 3-11 months (median, 7.8). Four had IPAH and 7 had APAH due to congenital heart disease. Pre-treatment response to iloprost vs. inhaled NO (20 ppm) during cardiac catheterization was compared. Iloprost was added to existing medications, including iv prostanoids (n = 4), bosentan (n = 8), and sildenafil (n = 11).
RESULTS: At cardiac catheterization, acute iloprost lowered mean PAP from 59 + 19 mmHg to 51 + 22 mmHg (p<0.05), which was identical to the response to inhaled NO. PFTs performed before and after acute iloprost treatment showed no change in FEV1 and FEF25-75% as a group; however, 3 children had a ≥ than 20% decrease in airflow, and iloprost was not continued in 2 due to airways reactivity. Of 7 patients studied at 6 months, WHO functional class improved in 4 and remained stable in 3. In 5 patients evaluated at 6 months, 6-MWD (baseline mean 481m, range, 278-583m) increased by ≥ 10% in 2 patients, changed minimally in 2, and fell by > 10% in 1. Side effects were minimal during chronic therapy. Four patients who were receiving iv prostanoids were transitioned to iloprost without adverse effects. Two patients required transition to iv prostanoid therapy after 5 and 10 months. Three patients with a > 20% fall in mPAP to acute iloprost had a favorable long term response.
CONCLUSION: Inhaled iloprost was safe and well-tolerated in children with PAH, but therapy was precluded by bronchospasm in some children. Iloprost acutely lowered mPAP as effectively as inhaled NO, and acute response to iloprost was predictive of clinical response to chronic therapy.
CLINICAL IMPLICATIONS: Inhaled iloprost may be a useful therapy in children with PAH; however, larger clinical investigations are necessary.
DISCLOSURE: D Ivy, Consultant fee, speaker bureau, advisory committee, etc. Encysive, CoTherix, United Therapeutics; Product/procedure/technique that is considered research and is NOT yet approved for any purpose, Iloprost is not approved for use in children.