Changes in mean arterial blood pressure during sildenafil use in neonates with meconium aspiration syndrome or sepsis

Sildenafil Exposure in the Neonatal Intensive Care Unit

OBJECTIVE

Pulmonary hypertension causes substantial morbidity and mortality in infants. Although Food and Drug Administration approved to treat pulmonary arterial hypertension in adults, sildenafil is not approved for infants. We sought to describe sildenafil exposure and associated diagnoses and outcomes in infants.

STUDY DESIGN

Retrospective cohort of neonates discharged from more than 300 neonatal intensive care units from 2001 to 2016.

RESULTS

Sildenafil was administered to 1,336/1,161,808 infants (0.11%; 1.1 per 1,000 infants); 0/35,977 received sildenafil in 2001 versus 151/90,544 (0.17%; 1.7 per 1,000 infants) in 2016. Among infants <32 weeks' gestational age (GA) with enough data to determine respiratory outcome, 666/704 (95%) had bronchopulmonary dysplasia (BPD). Among infants ≥32 weeks GA, 248/455 (55%) had BPD and 76/552 (14%) were diagnosed with meconium aspiration. Overall, 209/921 (23%) died prior to discharge.

CONCLUSION

The use of sildenafil has increased since 2001. Exposed infants were commonly diagnosed with BPD. Further studies evaluating dosing, safety, and efficacy of sildenafil are needed.

Association between oral sildenafil dosing, predicted exposure, and systemic hypotension in hospitalised infants

BACKGROUND

The relationship between sildenafil dosing, exposure, and systemic hypotension in infants is incompletely understood.

OBJECTIVES

The aim of this study was to characterise the relationship between predicted sildenafil exposure and hypotension in hospitalised infants.

METHODS

We extracted information on sildenafil dosing and clinical characteristics from electronic health records of 348 neonatal ICUs from 1997 to 2013, and we predicted drug exposure using a population pharmacokinetic model.

RESULTS

We identified 232 infants receiving sildenafil at a median dose of 3.2 mg/kg/day (2.0, 6.0). The median steady-state area under the concentration-time curve over 24 hours (AUC24,SS) and maximum concentration of sildenafil (Cmax,SS,SIL) were 712 ng×hour/ml (401, 1561) and 129 ng/ml (69, 293), respectively. Systemic hypotension occurred in 9% of the cohort. In multivariable analysis, neither dosing nor exposure were associated with systemic hypotension: odds ratio=0.96 (95% confidence interval: 0.81, 1.14) for sildenafil dose; 0.87 (0.59, 1.28) for AUC24,SS; 1.19 (0.78, 1.82) for Cmax,SS,SIL.

CONCLUSIONS

We found no association between sildenafil dosing or exposure with systemic hypotension. Continued assessment of sildenafil's safety profile in infants is warranted.

Sildenafil for the Treatment of Pulmonary Arterial Hypertension in Infants with Bronchopulmonary Dysplasia

Sildenafil, a phosphodiesterase-5 inhibitor, is a controversial treatment option for pulmonary arterial hypertension (PAH), a significant complication of bronchopulmonary dysplasia (BPD). The objective of this study was to evaluate the use of sildenafil in infants with PAH secondary to BPD. This was a retrospective review of medical records of all premature infants with PAH associated with BPD treated with sildenafil between January 2009 and May 2013 in a level 3 neonatal intensive care unit. The primary outcomes were clinical response (20 % decreases in respiratory support score or oxygen requirements) and echocardiographic response (20 % decrease in tricuspid regurgitation gradient or change of at least 1° of septal flattening). Twenty-three infants were included in the study. Significant echocardiographic and clinical responses were, respectively, observed in 71 and 35 % of cases. Most clinical responses were observed in the first 48 h of treatment, and the median time to an echocardiographic response was of 19 days. The median dose of sildenafil used was 4.4 mg/kg/day, with a median time to reach the maximum dose of 9 days. Transient hypotension was the primary reported side effect, and it was observed in 44 % of our study population. Sildenafil treatment in patients with PAH secondary to BPD was associated with an echocardiographic improvement in the majority of patients, whereas clinical improvement was observed in a minority of patients. Many infants presented with transient hypotension during the course of the treatment. Further prospective studies are required to better assess safety and efficacy of this treatment in this population.

Safety of sildenafil in infants*

OBJECTIVE

In view of the recent U.S. Food and Drug Administration's warning against the use of sildenafil in pediatric patients, we aimed to provide an updated overview of the dosing and safety of sildenafil in infants and to explore the relevance of the present safety concerns to the infant population.

DATA SOURCE

The National Library of Medicine PubMed and Cochrane Database of Systematic Reviews were searched using the following terms: Sildenafil AND (infant OR infants OR newborn OR newborns OR child OR children OR childhood OR pediatric OR pediatrics OR paediatric OR paediatrics).

STUDY SELECTION

Studies presenting original clinical data regarding the dosing, use, or safety of sildenafil in infants with pulmonary hypertension would be included.

DATA EXTRACTION

Of the 49 included studies, case reports and case series were the most common type of publications (n = 25). The identified trials included 625 children, with more than 140 infants. Persistent pulmonary hypertension of the newborn and pulmonary hypertension associated with other conditions were the most common underlying diagnoses.

CONCLUSION

There is currently no evidence of serious adverse event in infants exposed to sildenafil. Present safety concerns regarding the use of sildenafil in pediatric patients should be further explored before being applied to infant population. Sildenafil remains a valuable option for the treatment of pulmonary hypertension in young infants. Prospective studies should be designed in such a way that they include a safety assessment to evaluate potential adverse outcomes of sildenafil therapy in this population.