Short- and long-term effects of inhaled iloprost therapy in children with pulmonary arterial hypertension.
OBJECTIVE
This study investigated the short- and long-term outcome of children with pulmonary arterial hypertension (PAH) treated with inhaled iloprost.


BACKGROUND
Inhaled iloprost has been approved for the treatment of adults with PAH, but little is known about the effects in children with PAH.


METHODS
We evaluated the acute effects of inhaled iloprost on hemodynamic status and lung function and the response to long-term therapy in 22 children (range 4.5 to 17.7 years) with PAH (idiopathic, n = 12; congenital heart disease, n = 10). Cardiac catheterization, standard lung function testing before and after iloprost inhalation, 6-min walk test, World Health Organization functional class, and hemodynamic parameters were monitored.


RESULTS
Acute administration of inhaled iloprost lowered mean pulmonary artery pressure equivalent to the response to inhaled nitric oxide with oxygen. Acute iloprost inhalation reduced forced expiratory volume in 1 s and mid-volume forced expiratory flow by 5% and 10%, respectively, consistent with acute bronchoconstriction. At 6 months, functional class improved in 35%, decreased in 15%, and remained unchanged in 50% of children. Sixty-four percent of patients continued receiving long-term iloprost therapy, 36% stopped iloprost, due to lower airway reactivity, clinical deterioration, or death. In 9 patients on chronic intravenous prostanoids, 8 transitioned from intravenous prostanoids to inhaled iloprost, which continued during follow-up.


CONCLUSIONS
Inhaled iloprost caused sustained functional improvement in some children with PAH, although inhaled iloprost occasionally induced bronchoconstriction. Most patients tolerated the transition from intravenous to inhaled prostanoid therapy. Clinical deterioration, side effects, and poor compliance, owing to the frequency of treatments, could limit chronic treatment in children.
Ivy
D Dunbar
DD
The Pulmonary Hypertension Program and Pediatric Heart Lung Center, Department of Pediatrics, The University of Colorado School of Medicine and The Children's Hospital, Denver, Colorado 80045, USA. ivy.dunbar@tchden.org
Doran
Aimee K
AK
Smith
Kelly J
KJ
Mallory
George B
GB
Beghetti
Maurice
M
Barst
Robyn J
RJ
Brady
Daniela
D
Law
Yuk
Y
Parker
Donna
D
Claussen
Lori
L
Abman
Steven H
SH
D000280:Administration, Inhalation; D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis* / Q000188:drug therapy*; D016285:Iloprost / Q000008:administration & dosage*; D008297:Male; D015999:Multivariate Analysis; D011336:Probability; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome; D014655:Vascular Resistance / Q000187:drug effects; D014665:Vasodilator Agents / Q000008:administration & dosage*
D014665:Vasodilator Agents; D016285:Iloprost