Less invasive alternative for treating severe pulmonary hypertension in infants
By Will Boggs MD
NEW YORK (Reuters Health) - Subcutaneous treprostinil improves outcomes in selected infants with severe pulmonary hypertension and chronic lung disease (CLD) of infancy that have not responded adequately to conservative therapies, researchers say.
"Subcutaneous (SQ) treprostinil is another medication available for use by physicians trained in managing children with pulmonary hypertension, and is well tolerated and efficacious in a select group of infants with pulmonary hypertension, who are candidates for parenteral prostanoids," Dr. Usha Krishnan from Columbia University Medical Center in New York told Reuters Health by email. "SQ use overcomes the disadvantages of having an indwelling catheter for intravenous prostanoids in these infants and parents can be trained in continuing use at home."
Continuous intravenous epoprostenol is required for treating severe and refractory pulmonary arterial hypertension, but this is complicated in infants and small children because of the need for central venous access and associated catheter-related complications (infections, catheter breakage, and the like).
Treprostinil is an alternative prostanoid formulation that can be delivered intravenously or subcutaneously, but significant infusion site pain has been described in older patients.
Dr. Krishnan and colleagues report on their use of subcutaneous treprostinil in five infants who had already required the addition of targeted pulmonary arterial hypertension treatment to conservative management for PAH-CLD.
The investigators initiated treatment at 1.25 ng/kg/min and increased the dose as tolerated by 1.25 ng every 12 to 48 hours. Once they reached the target dose of 20 ng/kg/min, the increase was slowed to 1.25 ng/kg once weekly until discharge or side effects. They changed the infusion sites every two to four weeks to prevent local reactions.
All five patients experienced improvements in respiratory and inotropic support and echocardiogram parameters after initiating subcutaneous treprostinil treatment, according to the June 30 Pediatrics online report.
Moreover, none of the infants had worsening of respiratory status acutely or throughout treatment initiation.
Patients 1 and 2 were ventilator-dependent before treatment, but were breathing room air at home at the end of the study. Patient 3, who had ongoing necrotizing enterocolitis and sepsis, improved hemodynamically but ultimately died of septic shock three weeks into treatment. Patient 4 was discharged to a chronic care facility on 35% inspired oxygen (by tracheostomy) after four months of subcutaneous treprostinil. Patient 5 was ultimately weaned from 1/2 L oxygen to room air after transitioning from intravenous epoprostenol to subcutaneous treprostinil.
Subcutaneous treprostinil "is of benefit in selected infants who have severe pulmonary hypertension despite being on oral or inhaled therapy and need parenteral prostanoids," Dr. Krishnan concluded. "This is a medication that should be used in highly selected patients with pulmonary hypertension and also only by physicians and teams trained in treating and following up pediatric patients with pulmonary hypertension."
Pediatrics 2014;134:e274-e278. (c) Copyright Thomson Reuters 2014. Click For Restrictions - http://about.reuters.com/fulllegal.asp