Repeated courses of ibuprofen are effective in closure of a patent ductus arteriosus

Molecular Mechanisms Underlying Remodeling of Ductus Arteriosus: Looking beyond the Prostaglandin Pathway

The ductus arteriosus (DA) is a physiologic vessel crucial for fetal circulation. As a major regulating factor, the prostaglandin pathway has long been the target for DA patency maintenance or closure. However, the adverse effect of prostaglandins and their inhibitors has been a major unsolved clinical problem. Furthermore, a significant portion of patients with patent DA fail to respond to cyclooxygenase inhibitors that target the prostaglandin pathway. These unresponsive medical patients ultimately require surgical intervention and highlight the importance of exploring pathways independent from this well-recognized prostaglandin pathway. The clinical limitations of prostaglandin-targeting therapeutics prompted us to investigate molecules beyond the prostaglandin pathway. Thus, this article introduces molecules independent from the prostaglandin pathway based on their correlating mechanisms contributing to vascular remodeling. These molecules may serve as potential targets for future DA patency clinical management.

Cost-effectiveness of Oral Versus Intravenous Ibuprofen Therapy in Preterm Infants With Patent Ductus Arteriosus in the Neonatal Intensive Care Setting: A Cohort-based Study

PURPOSE

Use of ibuprofen for the patent ductus arteriosus (PDA) has become increasingly common. This study aimed to evaluate the clinical and economic impact of oral ibuprofen versus intravenous ibuprofen for PDA among preterm infants.

METHODS

This retrospective, cohort-based pilot study examined the clinical and economic associations of oral versus intravenous ibuprofen for PDA. A decision-analytic model was constructed, from the hospital perspective, to follow the oral versus intravenous administrations of ibuprofen for PDA and their clinical and economic consequences. The course regimen of either formulation was an initial 10 mg/kg followed by 5 mg/kg at 24- and 48-h intervals. Clinical and resource utilization data were extracted from Cerner medical database, from 2014 through 2018, at the tertiary neonatal intensive care unit setting in Qatar. The primary outcome measures were the rate of successful closure based on the ductal diameter measure after the first course of treatment and the overall direct medical cost of PDA management. A population of 118 neonates was required for results with 80% power and 0.05 significance. Sensitivity analyses involving unit costs and a subgroup analysis based on gestational age and birth weight, added to a second-order probabilistic analysis of all model inputs, were performed.

FINDINGS

Forty infants were available for inclusion in the oral ibuprofen study group, not achieving the desired sample size, with successful PDA closure reported in 64% of cases compared with a reduced success of 36% with intravenous ibuprofen (n = 59) (risk ratio = 0.56; 95% CI, 0.32-0.97; P = 0.04), which was associated with economic advantage to oral ibuprofen. The probabilistic analysis illustrated that oral ibuprofen costs less than intravenous ibuprofen in 72% of patient cases, with QAR 48,751 (US $13,356) (95% CI, QAR 47,500-50,000, US $13,014-$13,699) in mean savings. Sensitivity analyses confirmed the robustness of study conclusions and found that the rate of closure success versus failure was the most influential on results, followed by the occurrence of adverse drug events with both intravenous and oral ibuprofen. Although both ibuprofen formulations had similar safety profiles (P = 0.16), the intravenous formulation was associated with a larger number of adverse drug effects.

IMPLICATIONS

This is the first cost-effectiveness evaluation of oral versus intravenous formulations of ibuprofen among infants with PDA. The oral ibuprofen might be associated with an enhanced ductal closure at a considerably lower cost. The study results support recent trends in neonatal intensive care unit practices in favor of the oral administration of ibuprofen.

Factors affecting the effectiveness of oral ibuprofen in the treatment of patent ductus arteriosus in preterm infants

Background Data on the effectiveness of oral ibuprofen treatment for patent ductus arteriosus are limited, and the factors affecting its effectiveness remain unclear. Objective The aim was to identify the potential factors affecting the clinical effectiveness of oral ibuprofen in preterm infants. Setting Neonatal intensive care unit in a prefecture-level maternal and child healthcare hospital in China. Method Over a 5-years period, the medical records of 327 preterm infants with patent ductus arteriosus who were admitted to the neonatal intensive care unit of our hospital to receive a single course of oral ibuprofen were retrospectively reviewed. Main outcome measures The prevalence of risk factors affecting the effectiveness of oral ibuprofen. Results In total, 201 (61.47%) preterm infants were considered to have undergone "effective therapy" and classified accordingly, whereas 11 (3.36%) showed certain adverse events. Factors affecting therapeutic effectiveness were postnatal age at the initiation of treatment and Day 1/Day 0 ratio of urine output/fluid intake during the treatment course, with odds ratios of 0.892 (95% CI: 0.835-0.953; P = 0.001) and 0.473 (95% CI 0.265-0.845; P = 0.011), respectively. Conclusion A single course of oral ibuprofen for patent ductus arteriosus closure among preterm infants is effective and safe. Preterm infants with postnatal age of ≤ 9 days at the initiation of treatment and Day 1/Day 0 ratio of ≤ 0.708 of the urine output/fluid intake during the treatment course can be considered predictors of effectiveness of patent ductus arteriosus.

Intravenous paracetamol in comparison with ibuprofen for the treatment of patent ductus arteriosus in preterm infants: a randomized controlled trial

Our aim was to assess the efficacy and safety of intravenous (i.v.) paracetamol vs. i.v. ibuprofen for the treatment of hemodynamically significant patent ductus arteriosus (hsPDA) in preterm infants. This is a multicenter randomized controlled study. Infants with a gestational age of 25⁺⁰-31⁺⁶ weeks were randomized to receive i.v. paracetamol (15 mg/kg/6 h for 3 days) or i.v. ibuprofen (10-5-5 mg/kg/day). The primary outcome was the closure rate of hsPDA after the first treatment course with paracetamol or ibuprofen. Secondary outcomes included the constriction rate of hsPDA, the re-opening rate, and the need for surgical closure. Fifty-two and 49 infants received paracetamol or ibuprofen, respectively. Paracetamol was less effective in closing hsPDA than ibuprofen (52 vs. 78%; P = 0.026), but the constriction rate of the ductus was similar (81 vs. 90%; P = 0.202), as confirmed by logistic regression analysis. The re-opening rate, the need for surgical closure, and the occurrence of adverse effects were also similar.Conclusions: Intravenous paracetamol was less effective in closing hsPDA than ibuprofen, but due to a similar constriction effect, its use was associated with the same hsPDA outcome. These results can support the use of i.v. paracetamol as a first-choice drug for the treatment of hsPDA.Trial registration: Clinicaltrials.gov : NCT02422966, Date of registration: 04/09/2015; EudraCT no: 2013-003883-30. What is Known: • The successful closure of patent ductus arteriosus with oral paracetamol has been recently reported in several preterm infants, but only one randomized controlled study investigated the efficacy of intravenous paracetamol. What is New: • Intravenous paracetamol is less effective in closing hsPDA than ibuprofen, but have a similar constriction effect. • These results can support the use of i.v. paracetamol as a first-choice drug for the treatment of hsPDA.

Molecular and Mechanical Mechanisms Regulating Ductus Arteriosus Closure in Preterm Infants

Failure of ductus arteriosus closure after preterm birth is associated with significant morbidities. Ductal closure requires and is regulated by a complex interplay of molecular and mechanical mechanisms with underlying genetic factors. In utero patency of the ductus is maintained by low oxygen tension, high levels of prostaglandins, nitric oxide and carbon monoxide. After birth, ductal closure occurs first by functional closure, followed by anatomical remodeling. High oxygen tension and decreased prostaglandin levels mediated by numerous factors including potassium channels, endothelin-1, isoprostanes lead to the contraction of the ductus. Bradykinin and corticosteroids also induce ductal constriction by attenuating the sensitivity of the ductus to PGE2. Smooth muscle cells of the ductus can sense oxygen through a mitochondrial network by the role of Rho-kinase pathway which ends up with increased intracellular calcium levels and contraction of myosin light chains. Anatomical closure of the ductus is also complex with various mechanisms such as migration and proliferation of smooth muscle cells, extracellular matrix production, endothelial cell proliferation which mediate cushion formation with the interaction of blood cells. Regulation of vessel walls is affected by retinoic acid, TGF-β1, notch signaling, hyaluronan, fibronectin, chondroitin sulfate, elastin, and vascular endothelial cell growth factor (VEGF). Formation of the platelet plug facilitates luminal remodeling by the obstruction of the constricted ductal lumen. Vasa vasorum are more pronounced in the term ductus but are less active in the preterm ductus. More than 100 genes are effective in the prostaglandin pathway or in vascular smooth muscle development and structure may affect the patency of ductus. Hemodynamic changes after birth including fluid load and flow characteristics as well as shear forces within the ductus also stimulate closure. Current pharmacological treatment for the closure of a patent ductus is based on the blockage of the prostaglandin pathway mainly through COX or POX inhibition, albeit with some limitations and side effects. Further research for new agents aiming ductal closure should focus on a clear understanding of vascular biology of the ductus.

Plasma B-type natriuretic peptide cannot predict treatment response to ibuprofen in preterm infants with patent ductus arteriosus

Plasma B-type natriuretic peptide (BNP) is a useful marker for diagnosis of hemodynamically significant PDA (hsPDA) and serial BNP measurement is also valuable for monitoring treatment response. This retrospective study was performed to evaluate whether plasma BNP level can predict treatment response to ibuprofen in preterm infants born at <30 weeks of gestation with hsPDA. Plasma BNP was measured before (baseline) and 12 to 24 h after (post-treatment) completion of the first (IBU1) and second (IBU2) course of ibuprofen. We compared the BNP levels of responders (closed or insignificant PDA) with those of non-responders (hsPDA requiring further pharmacologic or surgical closure) to each course of ibuprofen. The treatment response rates for IBU1 (n = 92) and IBU2 (n = 19) were 74% and 26%, respectively. In IBU1, non-responders had lower gestational age and birth weight than responders (both, P = 0.004), while in IBU2, non-responders had lower birth weight (P = 0.014) and platelet counts (P = 0.005) than responders; however, baseline BNP levels did not differ significantly between responders and non-responders in either IBU1 (median 1,434 vs. 1,750 pg/mL) or IBU2 (415 vs. 596 pg/mL). Post-treatment BNP was a useful marker for monitoring treatment efficacy of IBU1 and IBU2 for hsPDA with a cut-off value of 331 pg/mL (P < 0.001) and 423 pg/mL(P < 0.010), respectively. We did not identify a cut-off baseline BNP level that could predict treatment response to ibuprofen in preterm infants with hsPDA.

Patent ductus arteriosus in preterm infants born at 23-24 weeks' gestation: Should we pay more attention?

BACKGROUND

Infants born at 23-24 weeks' gestation have the highest risk of developing a hemodynamically significant patent ductus arteriosus (hsPDA), that is refractory to pharmacological closure requiring surgical ligation. Thus, these patients might have the greatest benefits from hsPDA closure, although previous studies on PDA closure were not focused on this population.

AIM

To compare the occurrence of hsPDA, failure rate of the first course of ibuprofen in closing hsPDA, and need of surgical closure in infants born at 23⁺⁰-24⁺⁶ weeks' gestation to those in infants born at 25⁺⁰-28⁺⁶ weeks' gestation.

STUDY DESIGN

This is a retrospective multicenter study including infants born at 23⁺⁰-28⁺⁶ weeks of gestation admitted to the neonatal care units from January 2013 to December 2017. All infants underwent echocardiographical assessment for hsPDA diagnosis and eventually pharmacological treatment, and surgical closure.

RESULTS

We studied a total of 842 infants of which 562 (67%) developed a PDA. Among those with PDA, 511 (91%) received a pharmacological treatment for a hsPDA. We found that a hsPDA occurred in 70% (106/151) of infants born at 23-24 weeks and in 59% (405/691) of infants born at 25-28 weeks of gestation (P < 0.001). Failure of closure with the first-treatment cycle (69 vs. 40%; P < 0.001) and need of surgical closure (19 vs 10%) were more frequent (P < 0.011) in infants born at 23-24 than 25-28 gestational weeks. Paracetamol vs. ibuprofen treatment and gestational age of 23-24 versus 25-28 weeks increased closure failure, while less severe RDS and maternal clinical chorioamnionitis decreased it.

CONCLUSIONS

Among extremely preterm infants, infants born at 23-24 weeks of gestation have the highest risk of developing a hsPDA refractory to pharmacological treatment requiring surgical closure. Our findings support the need of individualized more careful strategies for hsPDA management in this special population.

Patent ductus arteriosus in preterm infants born before 30 weeks' gestation: high rate of spontaneous closure after hospital discharge

AimThe aim of this study was to determine the spontaneous closure rate of patent ductus arteriosus at a 2-year follow-up, following failed medical therapy and beyond initial hospital discharge, and to evaluate in-hospital spontaneous or pharmacological closure rates.Materials and methodsA retrospective evaluation was conducted in a cohort of preterm infants admitted to the Neonatal ICU of Ancona between January, 2004 and June, 2013. Inclusion criteria were gestational age between 24+0 and 29+6 weeks or birth weight 1.5 mm, a left atrium-to-aorta ratio >1.4, and/or reversal of end-diastolic flow in the aorta >30% of the anterograde. First-line treatment was intravenous ibuprofen. Intravenous indomethacin was used if ibuprofen failed. Surgical ligation was considered in haemodynamically significant patent ductus arteriosus after medical treatment.

RESULTS

A total of 593 infants met the inclusion criteria, and patent ductus arteriosus was diagnosed in 317 (53.4%). Among them, 283 (89.3%) infants had haemodynamically significant patent ductus arteriosus, with pharmacological closure achieved in 228 (80.6%) infants and surgical ligation performed in 20 (7.1%). Follow-up at 24 months was available for 39 (81.3%) of 48 infants with patent ductus arteriosus at the hospital discharge: 36 (92.3%) underwent spontaneous closure, two (5.1%) underwent surgical ligation, and one (2.6%) had a patent ductus arteriosus.DiscussionA significant number of patent ductus arteriosus that fail pharmacological closure undergo spontaneous closure by the age of 2 years. This information should be taken into account when considering surgery or additional attempts of pharmacological closure.

Simulation-based suggestions to improve ibuprofen dosing for patent ductus arteriosus in preterm newborns

Purpose

Ibuprofen is the drug of choice for treatment of patent ductus arteriosus (PDA). There is accumulating evidence that current ibuprofen-dosing regimens for PDA treatment are inadequate. We aimed to propose an improved dosing regimen, based on all current knowledge.

Methods

We performed a literature search on the clinical pharmacology and effectiveness of ibuprofen. (R)- and (S)-ibuprofen plasma concentration-time profiles of different dosing regimens were simulated using a population pharmacokinetic model and evaluated to obtain a safe, yet likely more efficacious ibuprofen exposure.

Results

The most effective intravenous ibuprofen dosing in previous clinical trials included a first dose of 20 mg kg⁻¹ followed by 10 mg kg⁻¹ every 24 h. Simulations of this dosing regimen show an (S)-ibuprofen trough concentration of 43 mg L⁻¹ is reached at 48 h, which we assumed the target through concentration. We show that this target can be reached with a first dose of 18 mg kg⁻¹, followed by 4 mg kg⁻¹ every 12 h. After 96 h postnatal age, the dose should be increased to 5 mg kg⁻¹ every 12 h due to maturation of clearance. This twice-daily dosing has the advantage over once-daily dosing that an effective trough level may be maintained, while peak concentrations are substantially (22%) lower.

Conclusions

We propose to improve intermittent ibuprofen-dosing regimens by starting with a high first dose followed by a twice-daily maintenance dosing regimen that requires increase over time and should be continued until sufficient effect has been achieved.

Electronic supplementary material

The online version of this article (10.1007/s00228-018-2529-y) contains supplementary material, which is available to authorized users.

Repeated Courses of Oral Ibuprofen in Premature Infants with Patent Ductus Arteriosus: Efficacy and Safety

BACKGROUND

There are limited data about the results of repeated oral ibuprofen (OIBU) treatment. This study aimed to describe patent ductus arteriosus (PDA) closure rates and adverse events after repeated courses of OIBU in premature infants with PDA.

METHODS

Preterm infants with hemodynamically significant (hs)PDA were enrolled in the study. If the first course of OIBU treatment failed, a second and, if required, third course was administered.

RESULTS

A total of 100 patients received OIBU. In six patients, treatment could not be completed due to death (n=3) and side effects (n=3). In three patients, adverse effects related to OIBU (thrombocytopenia and impairment of renal function) developed during the first course. During the second and third courses, no new adverse event occurred. After all courses, the PDA closure rate was determined as 88%. The rate was 71% after the first course, 40% after the second course, and 35% after the third course. Although the second course resulted in a significant increase in the closure rate (p<0.05), the rate did not increase significantly with the third course (p>0.05). The mean postnatal age at the start of the first dose of OIBU was not significantly different among the responders and non-responders to the first course (p>0.05). Clinical characteristics did not affect the closure rate significantly. The number of courses did not have a significant effect on death, when gestational age and birth weight were used as covariates [p=0.867, Exp(B)=0.901, 95% confidence interval=0.264-3.1].

CONCLUSION

A second course of OIBU seems effective and safe for use in preterm infants with hsPDA. Although a third course of OIBU results in PDA closure in some additional patients, the difference is not significant. Thus, surgical ligation should be considered after the second course, especially in patients with signs of severe heart failure.

Comparative effectiveness and safety of indomethacin versus ibuprofen for the treatment of patent ductus arteriosus

BACKGROUND

Patent ductus arteriosus (PDA) is common in extremely premature infants and associated with increased morbidity and mortality. Medical management of PDA uses either indomethacin or ibuprofen. Despite numerous studies, uncertainty exists as to which drug is safer or more effective; we sought to fill this knowledge gap.

METHODS

We identified infants <28weeks gestational age discharged from neonatal intensive care units included in the Pediatrix Medical Group Clinical Data Warehouse between 2006 and 2012 who were treated with indomethacin or ibuprofen between postnatal days 2 and 14. Infants treated with both drugs or infants with a congenital malformation were excluded. We used multivariable logistic regression to determine the association of indomethacin versus ibuprofen on clinical outcomes.

RESULTS

Of 6349 patients who met study criteria, 1177 (19%) received ibuprofen and 5172 (81%) received indomethacin. The median gestational age was 25weeks (interquartile range 24-26), and 2894 (46%) infants were <750g at birth. On unadjusted analysis, infants who received ibuprofen had significantly higher incidences of death prior to discharge, surgical ligation of the PDA prior to discharge, death or spontaneous intestinal perforation within 7days of therapy, death or surgical ligation of the PDA prior to discharge, and an elevated creatinine within 7days of treatment. However, on multivariable analysis, no significant differences in outcomes were observed (odds ratio for death/PDA ligation for ibuprofen vs. indomethacin=1.12 [95% CI 0.91-1.39]).

CONCLUSIONS

We observed similar effectiveness and safety profiles for indomethacin and ibuprofen in the medical management of PDA in premature infants.

Indomethacin vs ibuprofen: comparison of efficacy in the setting of conservative therapeutic approach

Indomethacin has been the mainstay for medical closure of patent ductus arteriosus. With its discontinuation, many units shifted to the use ibuprofen. We compared the therapeutic efficacy (successful closure, a priori defined as complete closure or >50% reduction in size) and the impact of the two drugs on neonatal morbidities. Two time epochs were analysed (IV indomethacin, January 2008 to November 2010, and IV ibuprofen lysine, November 2010 to September 2013). Demographic, clinical and echocardiographic data was compared. A total of 101 infants formed the study population, 58 (57.4%, indomethacin epoch) and 43 (42.6%, ibuprofen epoch). The gestational age, birth weight and postnatal age at initial treatment respectively were comparable [26 ± 1.8 vs 26.5 ± 1.9 weeks, 806 ± 183 vs 862 ± 234 g and median 12 (6, 17) vs 11 days (8, 18)]. Successful closure was significantly higher in the indomethacin group [26 (45%) vs 6 (14%), p < 0.01]. The incidence of bronchopulmonary dysplasia (BPD) and discharge in oxygen was comparable. Four infants (all in the ibuprofen group) developed pulmonary hypertension; one required pulmonary vasodilator therapy. Posttreatment serum creatinine was significantly lower in the ibuprofen group. Mortality was higher during the indomethacin epoch. On univariate analysis, the choice of the drug and higher gestational age were associated with successful closure.

CONCLUSION

Indomethacin was more efficacious for ductal closure although did not impact outcomes. Use of staging schema may help understand 'need to treat' and refine therapy.

Intestinal muscularis propria increases in thickness with corrected gestational age and is focally attenuated in patients with isolated intestinal perforations

PURPOSE

Intestinal perforations are common in premature infants, leading to a diagnostic dilemma between necrotizing enterocolitis and isolated intestinal perforation (IIP). IIP is thought to result from a congenital or acquired absence of the muscularis propria. However, developmental events leading to IIP are not well understood. This study examines the relationship between corrected gestational age (CGA) and intestinal muscle development in controls and patients with IIP.

METHODS

Specimens from stillbirths and infants undergoing intestinal surgery from 8 to 48weeks' CGA were collected from 2005 to 2012. Twelve patients with IIP were identified. Control specimens were collected during 25 fetal autopsies and 39 bowel resections. In each case, three sections of intestine were examined histologically for muscularis mucosa, circular and longitudinal muscle thickness. Comparisons of control and perforated specimens were performed via linear regression and ANOVA.

RESULTS

Controls and adjacent normal segments in IIP showed a linear relationship between thickness of circular and longitudinal muscles with CGA. Circular and longitudinal muscles were thinner in perforated segments than in adjacent normals and CGA-matched controls (p<0.05).

CONCLUSION

Intestinal muscularis propria increases in thickness with CGA. Muscle thickness is focally attenuated in patients with isolated intestinal perforations, while the remaining intestine is normal, suggesting that primary repair is an appropriate treatment.

Patent ductus arteriosus in preterm infants: do we have the right answers?

Patent ductus arteriosus (PDA) is a common clinical condition in preterm infants. Preterm newborns with PDA are at greater risk for several morbidities, including higher rates of bronchopulmonary dysplasia (BPD), decreased perfusion of vital organs, and mortality. Therefore, cyclooxygenase (COX) inhibitors and surgical interventions for ligation of PDA are widely used. However, these interventions were reported to be associated with side effects. In the absence of clear restricted rules for application of these interventions, different strategies are adopted by neonatologists. Three different approaches have been investigated including prophylactic treatment shortly after birth irrespective of the state of PDA, presymptomatic treatment using echocardiography at variable postnatal ages to select infants for treatment prior to the duct becoming clinically significant, and symptomatic treatment once PDA becomes clinically apparent or hemodynamically significant. Future appropriately designed randomized controlled trials (RCTs) to refine selection of patients for medical and surgical treatments should be conducted. Waiting for new evidence, it seems wise to employ available clinical and echocardiographic parameters of a hemodynamically significant (HS) PDA to select patients who are candidates for medical treatment. Surgical ligation of PDA could be used as a back-up tool for those patients who failed medical treatment and continued to have hemodynamic compromise.