Sildenafilo oral como tratamiento de un neonato con hipertensión pulmonar persistente

Effect of early adjunctive use of oral sildenafil and inhaled nitric oxide on the outcome of pulmonary hypertension in newborn infants. A feasibility study

INTRODUCTION

Inhaled nitric oxide (iNO) is the standard therapy for infants with persistent pulmonary hypertension of the newborn (PPHN). Recently, sildenafil has been evaluated as an alternative or adjunctive pulmonary vasodilator.

OBJECTIVE

To assess the effectiveness of adding sildenafil as an early adjunctive therapy together with iNO when treating newborns with PPHN and/or hypoxemic respiratory failure.

METHODS

This is a randomized placebo trial on newborns with gestational age > 34 weeks, postnatal age < 48 hours, and diagnosed with PPHN (oxygen index (OI) ≥ 20). Newborns were randomized to two groups: Group A- received oral sildenafil and iNO, and group B- received placebo and iNO. Initial and follow up echocardiography were performed over 14 days period.

RESULTS

A total of 24 newborns were recruited; 13 of them received sildenafil in addition to iNO and 11 received iNO and placebo. The most common causes of PPHN were meconium aspiration syndrome, pneumonia, and RDS. At the starting point, OI was marginally higher in the intervention group without statistical significance (29 vs 28). There were no differences between the two groups regarding surfactant administration, incidence of pneumothoraces, and the underlying causes of PPHN. Sildenafil or placebo treatment started within 12 hours after starting iNO (8 vs 6 hours).

CONCLUSION

Early use of oral sildenafil next to iNO in cases of PPHN was tolerated well by newborns and it did not show significant adverse effects. Further studies with a larger sample size is needed to assess its effecacy.

Development and stability assessment of liquid paediatric formulations containing sildenafil citrate

The purpose of this study is to develop and improve oral liquids formulations of sildenafil citrate for paediatric use. Four different formulations were developed, which are as follows: two aqueous solutions of sildenafil citrate (2.5 mg/mL), with or without preservatives, and two other solutions of sildenafil in simple syrup (1.25 mg/mL), with or without preservatives. All of the formulations were physically, chemically and microbiologically stable for three months. The results of the stability studies allowed for the optimisation of formulations without preservatives due to their simplicity and their similar stable conditions when compared to the formulations containing antimicrobials. The shelf life of both formulations was three months; however, upon opening, aqueous solutions should be used within 10 days and kept refrigerated, and syrup solutions should be used within 14 days in a hospital setting.

Oral sildenafil in infants with persistent pulmonary hypertension of the newborn: a pilot randomized blinded study

BACKGROUND

Persistent pulmonary hypertension (PPHN) occurs in as many as 6.8 of 1000 live births. Mortality is approximately 10% to 20% with high-frequency ventilation, surfactant, inhaled nitric oxide, and extracorporeal membrane oxygenation but is much higher when these therapies are not available. Sildenafil is a phosphodiesterase inhibitor type 5 that selectively reduces pulmonary vascular resistance.

OBJECTIVE

Our goal was to evaluate the feasibility of using oral sildenafil and its effect on oxygenation in PPHN.

DESIGN

This study was a proof-of-concept, randomized, masked study in infants >35.5 weeks' gestation and <3 days old with severe PPHN and oxygenation index (OI) >25 admitted to the NICU (Hospital Niño Jesús, Barranquilla, Colombia). The sildenafil solution was prepared from a 50-mg tablet. The first dose (1 mg/kg) or placebo was given by orogastric tube <30 minutes after randomization and every 6 hours. Preductal saturation and blood pressure were monitored continuously. OI was calculated every 6 hours. The main outcome variable was the effect of oral sildenafil on oxygenation. Sildenafil or placebo was discontinued when OI was <20 or if there was no significant change in OI after 36 hours.

RESULTS

Six infants with an OI of >25 received placebo, and 7 received oral sildenafil at a median age of 25 hours. All infants were severely ill, on fraction of inspired oxygen 1.0, and with similar ventilatory parameters. Intragastric sildenafil and placebo were well tolerated. In the treatment group, OI improved in all infants within 6 to 30 hours, all showed a steady improvement in pulse oxygen saturation over time, and none had noticeable effect on blood pressure; 6 of 7 survived. In the placebo group, 1 of 6 infants survived.

CONCLUSIONS

Oral sildenafil was administered easily and tolerated as well as placebo and improved OI in infants with severe PPHN, which suggests that oral sildenafil may be effective in the treatment of PPHN and underscores the need for a large, controlled trial.