Oral Sildenafil in Persistent Pulmonary Hypertension of the Newborn

Use of off-label compounded oral sildenafil in the management of persistent pulmonary hypertension of the newborn: A case report

We report a case of a newborn with persistent pulmonary hypertension (PPHN) due to meconium aspiration syndrome with associated lung collapse. Echocardiogram revealed features of persistent pulmonary hypertension. He was treated with compounded oral sildenafil. Oral sildenafil has proven to be effective and safe in the management of PPHN in neonates with persistent pulmonary hypertension. Therefore, in situations where inhaled nitric oxide is not available it may be used as an alternative therapy in PPHN. Further randomized controlled studies are needed to determine its efficacy and pharmacokinetics.

Oral drugs used to treat persistent pulmonary hypertension of the newborn

Introduction:Persistent Pulmonary Hypertension of the Newborn (PPHN) is a life-threatening neonatal condition, mostly treated with inhaled nitric oxide (iNO), intravenous prostaglandins, oral bosentan, sildenafil and tadalafil. However, the utility of non-oral agents is limited in PPHN for their side effects and inconvenient deliveries. Therefore, oral agents such as bosentan, sildenafil and tadalafil are becoming appealing for their satisfactory efficacy, easy mode of administration and acceptable side effects. Areas covered: We conducted a comprehensive search on Pubmed, Scopus, Web of Sciences concerning the use of bosentan, sildenafil and tadalafil to treat PPHN and summarized their efficacy, safety and pharmacokinetics. Expert opinion: Current randomized controlled trials (RCTs) have demonstrated the favorable responses and tolerable side effects of bosentan and sildenafil. Nevertheless, those RCTs are small and only one study has described the pharmacokinetics of sildenafil in neonates. Accordingly, bosentan, sildenafil and tadalafil remain off-label in clinical use. More well-designed RCTs with large samples and long-term follow-up and pharmacometrics studies are needed to demonstrate the efficacy, safety and pharmacokinetics of bosentan, sildenafil and tadalafil in PPHN.

Outcome of oral sildenafil in neonatal persistent pulmonary hypertension of non-cardiac causes

BACKGROUND

Despite recent treatment modalities, mortality from persistent pulmonary hypertension (PPHN) remains significant. In instances where infants do not respond to inhaled nitric oxide (iNO), oral sildenafil could hold promise as a selective pulmonary vasodilator. Further studies are still needed to explore its efficacy and safety in newborns with PPHN.

OBJECTIVES

To validate the efficacy of oral sildenafil on oxygenation and its short-term safety in newborns with persistent pulmonary hypertension.

METHODS

A total of 27 newborns ≥36 weeks gestational age were admitted to NICU with oxygenation index (OI) ≥15 and confirmed diagnosis of PPHN with echocardiography. Oral sildenafil given at a dose of 1-2 mg/kg every 6 hours. We monitored improvement in oxygenation, safety and short-term outcomes.

RESULTS

Among 27 newborns, oral sildenafil was efficacious in 21 patients (78%) with reduction of OI from 34.9 ± 9.6 to 13 ± 3.2 (p <  0.001), increase of PaO2 from 42.4 ± 13.5 to 78 ± 11.5 mmHg (<0.001), and reduction of FiO2 from 1.0 ± 0 to 0.3 ± 0.06 (<0.001). OI decreased by 6.3 % from baseline after the first dose of sildenafil and continued to decrease with subsequent doses. In 6 patients (22%) sildenafil did not work; 5/6 patients (18%) transferred to another tertiary NICU and one patient (4%) died of sepsis. None of the patients had significant systemic hypotension.

CONCLUSION

Oral sildenafil is a promising pulmonary vasodilator in patients with PPHN, particularly in medical facilities with no available iNO and ECMO. It is well tolerated with no significant short term complications.