Prophylactic ibuprofen in premature infants: a multicentre, randomised, double-blind, placebo-controlled trial

The definition of a haemodynamic significant duct in randomized controlled trials: a systematic literature review

AIM

A patent ductus arteriosus (PDA) is associated with morbidity in preterm infants. Treatment is prescribed for a haemodynamically significant duct (HSDA), but its definition varies. We systematically reviewed the clinical and ultrasound criteria used for the definition of an HSDA.

METHODS

PubMed and the Cochrane library were searched for randomized trials evaluating ductal treatment. The included studies were explored, and we categorized clinical and ultrasound criteria used to define an HSDA.

RESULTS

Sixty-seven trials were included in our review. Forty-two were placebo-controlled trials, and 25 were comparative trials. The diagnosis of the PDA was made by clinical examination, followed by ultrasound in most trials. Most trials used clinical and ultrasound criteria to define an HSDA, but there was a wide variety in criteria and cut-offs used. Of the clinical criteria, a murmur or hyperdynamic circulation was most used, and of the ultrasound criteria, the left-atrium-to-aorta ratio (LA/Ao ratio) was most used.

CONCLUSION

We found a wide variety in the definition of an HSDA. This finding implies that comparison of studies is difficult. International consensus should be reached on the definition of an HSDA, which will make future studies more comparable.

Evidence-based use of indomethacin and ibuprofen in the neonatal intensive care unit

Indomethacin and ibuprofen are potent inhibitors of prostaglandin synthesis. Neonates have been exposed to these compounds for more than 3 decades. Indomethacin is commonly used to prevent intraventricular hemorrhage (IVH), and both drugs are prescribed for the treatment or prevention of patent ductus arteriosus (PDA). This review examines the basis for indomethacin and ibuprofen use in the neonatal intensive care population. Despite the call for restrained use of each drug, the most immature infants are likely to need pharmacologic approaches to reduce high-grade IVH, avoid the need for PDA ligation, and preserve the opportunity for an optimal outcome.

Ibuprofen for the prevention of patent ductus arteriosus in preterm and/or low birth weight infants

BACKGROUND

Patent ductus arteriosus (PDA) complicates the clinical course of preterm infants and increases the risk of adverse outcomes. Indomethacin has been the standard treatment to close a PDA but is associated with renal, gastrointestinal and cerebral side-effects. Ibuprofen has less effect on blood flow velocity to important organs.

OBJECTIVES

To determine the effectiveness and safety of prophylactic ibuprofen compared to placebo/no intervention in the prevention of PDA in preterm infants.

SEARCH STRATEGY

Randomized controlled trials of prophylactic ibuprofen were identified by searching in The Cochrane Library, MEDLINE, CINAHL, EMBASE and trials registries in December 2010.

SELECTION CRITERIA

Randomized or quasi-randomised controlled trials comparing ibuprofen with placebo/no intervention or other cyclo-oxygenase inhibitor drugs to prevent PDA in preterm and/or low birth weight infants.

DATA COLLECTION AND ANALYSIS

Outcomes data including presence of PDA on day three, need for surgical ligation or rescue treatment with cyclo-oxygenase inhibitors, mortality, intraventricular haemorrhage (IVH), renal, pulmonary and gastrointestinal complications were extracted. Meta-analyses were performed and treatment estimates are reported as typical weighted mean difference, relative risk (RR), risk difference (RD) and, if statistically significant, number needed to treat to benefit (NNT) or number needed to treat to harm (NNH) along with their 95% confidence intervals (CI).

MAIN RESULTS

In this update, seven studies (n = 931) comparing prophylactic ibuprofen with placebo/no intervention are included. Ibuprofen decreased the incidence of PDA on day three [typical RR 0.36 (95% CI 0.29 to 0.46); typical RD -0.27 (95% CI -0.32 to -0.21); NNT 4 (95% CI 3 to 5)], decreased the need for rescue treatment with cyclo-oxygenase inhibitors and decreased the need for surgical ligation. Results from two studies administering oral ibuprofen had similar results, but showed an increased risk of gastrointestinal bleeding (NNH 4, 95% CI 2 to 17). In the control group the spontaneous closure rate was 58% by day three. Ibuprofen negatively affects renal function. No significant differences in mortality, IVH, chronic lung disease were found.

AUTHORS' CONCLUSIONS

Prophylactic use of ibuprofen decreased the incidence of PDA, decreased the need for rescue treatment with cyclo-oxygenase inhibitors and decreased the need for surgical closure. In the control group, the PDA closed spontaneously by day three in 58% of the neonates. Prophylactic treatment exposes many infants to a drug that has concerning renal and gastrointestinal side effects without conferring any important short-term benefits and is not recommended. Until long-term follow-up results are published from the trials included in this updated review, no further trials of prophylactic ibuprofen are recommended.

Patent ductus arteriosus in the preterm infant: a survey of clinical practices in French neonatal intensive care units

Patent ductus arteriosus (PDA) is one of the most common problems in the care of premature infants, especially the extremely premature. There is no real consensus regarding the diagnostic criteria or treatment of a hemodynamically significant PDA. Its diagnosis, assessment, and treatment still remain challenges. Therefore, we investigated clinical practices in French tertiary neonatology centers regarding the management of PDA to compare their similarities and differences. We sent a questionnaire by email to the PDA specialist in every French tertiary neonatal intensive care unit. It contained 27 items regarding the unit's structure, method of diagnosing PDA, and treatment choices. The completed questionnaire were returned via email and analyzed blindly. The questionnaire response rate was 87.5%, which allowed us to draw some conclusions regarding French clinical practices in the care of neonates with PDA. Although the diagnostic criteria are quite similar, the therapeutic practices are rather different across neonatal care units. We highlight the great variability in French clinical practices when it comes to treating PDA and underscore the necessity for harmonization of these practices, which could be achieved using multicenter, randomized studies to identify the advantages of one approach compared with another.

Should we definitively abandon prophylaxis for patent ductus arteriosus in preterm new-borns?

Although the prophylactic administration of indomethacin in extremely low-birth weight infants reduces the frequency of patent ductus arteriosus and severe intraventricular hemorrhage, it does not appear to provide any long-term benefit in terms of survival without neurosensory and cognitive outcomes. Considering the increased drug-induced reduction in renal, intestinal, and cerebral blood flow, the use of prophylaxis cannot be routinely recommended in preterm neonates. However, a better understanding of the genetic background of each infant may allow for individualized prophylaxis using NSAIDs and metabolomics.

Patent ductus arteriosus in the preterm infant: to treat or not to treat?

Pharmacological and/or surgical closure of a hemodynamically significant patent ductus arteriosus (PDA) in the very preterm infant has been the standard of care over the past few decades. However, the rationale for closure of PDA has recently been challenged. In this article, the factors that have fueled the controversy of the approach to the management of PDA and the gap in our knowledge are reviewed in detail. In addition, the pros and cons of the different treatment strategies applied in clinical care are evaluated with a focus on discussing the available evidence in the literature.

Therapeutic closure of the ductus arteriosus: benefits and limitations

Patency of the ductus arteriosus (PDA), a common complication of preterm birth, has been associated to increased risk for intraventricular cerebral hemorrhage, necrotizing enterocolitis, bronchopulmonary dysplasia and death. Consequently, prophylactic or curative treatment has been advocated before the critical left-to-right shunting occurs. A host of studies has shown that both pharmacological agents and surgical closure are effective in closing the ductus arteriosus in premature infants. Indomethacin has long been the drug of choice. However, renal and cerebral haemodynamic side effects have been frequently reported. Strategies to minimise adverse effects of indomethacin, such as the association with frusemide, dopamine or the use of low-dose prolonged treatment with indomethacin have failed or shown partial benefit. Other NSAIDs have been investigated. But either the profile of adverse effects was unfavourable, as in the case of mefenamic acid, or their efficacy was less than that of indomethacin for PDA closure. More recently, ibuprofen has been proposed for the treatment of PDA as it was shown to induce less adverse effects on cerebral blood flow, intestinal and renal hemodynamics, while retaining similar efficacy to indomethacin. However, since renal perfusion, GFR and diuresis in early neonatal life strongly depend on the vasodilator effects of PGs on the afferent glomerular arterioles, ibuprofen, as other COX-inhibitors may not be exempt of some renal undesirable effects. While numerous studies have shown that PDA is a risk factor associated with immaturity and with increased incidence of complications of preterm birth, including broncho-pulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis and death, there is little evidence that such association is causative. Moreover, still little evidence exists from even recent randomized controlled trials that the pharmacological closure of PDA benefits to premature infants in terms of clinically significant short-term or medium-term outcomes, beyond a positive effect on DA patency. The use of COX-inhibitors for the prophylaxis or closure of PDA during the first hours or days of life should thus be cautious and based on an individual evaluation of benefit and risk. There is need of a randomized, placebo-controlled trials designed to assess the benefits in terms of mortality and morbidity outcomes of an early, or even very early pharmacological closure of PDA in extremely low gestational age infants.

Treatment of persistent patent ductus arteriosus in preterm infants: time to accept the null hypothesis?

Medical and surgical interventions are widely used to close a persistently patent ductus arteriosus in preterm infants. Objective evidence to support these practices is lacking, causing some to question their usage. Emerging evidence suggests that treatments that close the patent ductus may be detrimental. This review examines the history of and evidence underlying these treatments. Neither individual trials, pooled data from groups of randomized-controlled trials, nor critical examination of the immediate consequences of treatment provide evidence that medical or surgical closure of the ductus is beneficial in preterm infants. These conclusions are supported by sufficient evidence. Neither continued routine use of these treatments nor additional clinical trials using similar designs seems to be justified. A definitive trial, comparing current standard management with novel strategies not primarily intended to achieve ductal closure, may be necessary to resolve doubts regarding the quality or conduct of prior studies.

Renal Side Effects of Non-Steroidal Anti-Inflammatory Drugs in Neonates

Non-steroidal anti-inflammatory drugs like ibuprofen or indomethacin are commonly prescribed drugs to induce pharmacologic closure of a patent ductus arteriosus in preterm neonates. Based on a recently published Cochrane meta-analysis, both drugs are equally effective to induce closure. Drug choice can therefore be based on differences in side effects or pharmaco-economic arguments. The current review quantifies the negative impact of either ibuprofen or indomethacin on renal function, including diuresis, glomerular filtration rate and renal tubular function. Both ibuprofen and indomethacin have a quantifiable impact on renal function. However, compared to ibuprofen, the negative impact of indomethacin is more pronounced.

Ibuprofen in very preterm infants impairs renal function for the first month of life

We carried out a study aiming to determine the renal effect of ibuprofen treatment for patent ductus arteriosus (PDA) in very preterm infants during the first month of life. Infants aged 27-31 weeks gestation were enrolled from October 2004 to August 2006. They were assigned to two different groups according to ibuprofen exposure during care of their PDA status assessed by echocardiography. Infants of both groups were matched based on gestational age, Clinical Risk Index for Babies score, birth weight and inclusion center. Renal function was evaluated at baseline and weekly for 1 month. One hundred and forty-eight infants were enrolled. Glomerular filtration rate (GFR) was significantly decreased in the ibuprofen group after treatment withdrawal (GFR on day 7, ibuprofen versus no ibuprofen: 12.8 +/- 6.2 vs. 18.1 +/- 12.1 ml/min/1.73 m(2); P < 0.001). Adjusted analysis proved this decrease to be sustained during the first month of life. Tubular function was also impaired during the first month in ibuprofen-treated infants. Ibuprofen administered for PDA is associated with a decreased GFR during the first month of life. Renal function of infants receiving ibuprofen should be carefully monitored and drugs that are eliminated by glomerular filtration handled cautiously during this period.

Accounting for multiple births in neonatal and perinatal trials: systematic review and case study

OBJECTIVES

To determine the prevalence in the neonatal literature of statistical approaches accounting for the unique clustering patterns of multiple births and to explore the sensitivity of an actual trial to several analytic approaches to multiples.

STUDY DESIGN

A systematic review of recent perinatal trials assessed the prevalence of studies accounting for clustering of multiples. The Nitric Oxide to Prevent Chronic Lung Disease (NO CLD) trial served as a case study of the sensitivity of the outcome to several statistical strategies. We calculated odds ratios using nonclustered (logistic regression) and clustered (generalized estimating equations, multiple outputation) analyses.

RESULTS

In the systematic review, most studies did not describe the random assignment of twins and did not account for clustering. Of those studies that did, exclusion of multiples and generalized estimating equations were the most common strategies. The NO CLD study included 84 infants with a sibling enrolled in the study. Multiples were more likely than singletons to be white and were born to older mothers (P < .01). Analyses that accounted for clustering were statistically significant; analyses assuming independence were not.

CONCLUSIONS

The statistical approach to multiples can influence the odds ratio and width of confidence intervals, thereby affecting the interpretation of a study outcome. A minority of perinatal studies address this issue.

Coagulopathy screening and early plasma treatment for the prevention of intraventricular hemorrhage in preterm infants

BACKGROUND

Despite the improvement in the assistance and treatment of preterm infants, intraventricular hemorrhage (IVH) remains a frequent complication in these patients. Our aim was to demonstrate the hypothesis that a coagulopathy screening and the early treatment with fresh-frozen plasma (FFP) of proven coagulopathy may contribute to decrease the occurrence of IVH in infants with gestational age of less than 29 weeks.

STUDY DESIGN AND METHODS

This study compared two cohorts of infants who received FFP (10 mL/kg) after the evidence of pathologic coagulation tests performed within 2 hours after birth (screening group, n = 127) or after the development of bleedings and evidence of pathologic coagulation tests (no-screening group, n = 91).

RESULTS

The screening strategy decreased the relative risk (RR) of developing IVH (RR = 0.65; 95% confidence interval, 0.44-0.98) compared to no-screening strategy, but the effect was limited to infants born at 23 to 26 weeks of gestation in whom screening strategy lowered IVH occurrence (34.5% vs. 61.1%, p = 0.008).

CONCLUSIONS

A coagulopathy screening strategy decreases the risk of developing IVH in preterm infants but this effect is limited to infants born at 23 to 26 weeks of gestation.

Renal effects of ibuprofen for the treatment of patent ductus arteriosus in premature infants

In recent years ibuprofen has been proposed for the treatment of patent ductus arteriosus (PDA) as it has been proved to be equally as effective as indomethacin and shows fewer cerebral blood flow, intestinal and renal hemodynamic effects. A number of studies and several meta-analyses comparing both drugs are now available that debate whether indomethacin or ibuprofen should be used for PDA prophylaxis or closure. This review examines the available knowledge on the specific issue of the effects of ibuprofen on kidney function, as improved renal tolerance is a major argument in favor of its use in the routine treatment of PDA. There is sufficient evidence to consider that ibuprofen, at the currently proposed dosing regimen, has a similar efficacy to indomethacin but is better tolerated by the neonatal kidney when employed for the treatment of established PDA. However, adverse effects of ibuprofen have been evidenced both in trials on the use of ibuprofen for the prevention of PDA and of intraventricular hemorrhage-periventricular hemorrhage (IVH-PVH), and in experimental studies on a neonatal, anesthetized animal model. Thus ibuprofen, as with other cyclooxygenase (COX) inhibitors, may not be exempt from causing renal adverse effects, especially in circumstances when renal prostaglandin activation is maximal (i.e., when administrated early after birth, in more immature patients and in certain situations such as in the anesthetized rabbit). However, although the issue has been addressed extensively in the last decades, there is insufficient evidence that therapeutic intervention in PDA is beneficial in terms of mortality or clinically significant morbidity outcomes. Studies aimed at resolving this key issue are still needed.

Therapeutic management of patent ductus arteriosus

Management of patent ductus arteriosus (PDA) in premature neonates has always been a challenge to the neonatologist and continues to be a controversial topic. Indications for treatment are not clear. Approximately 40% of ductus arteriosus close spontaneously even in extremely-low-birth-weight neonates. Prophylactic or early pre-symptomatic treatment may unnecessarily expose these babies, in whom the ductus might close spontaneously, to pharmacologic agents and their adverse effects. On the other hand, with advancing postnatal age, delaying treatment could potentially decrease successful medical closure thereby increasing the rate of surgical ligation and the complications associated with surgery. We tried to develop some clinical guidelines for management of PDA in premature neonates based on evidence, or lack thereof, and experience.

Randomized pilot study comparing oral ibuprofen with intravenous ibuprofen in very low birth weight infants with patent ductus arteriosus

BACKGROUND

We conducted a prospective, randomized, single-masked pilot study with the principal aim of comparing efficacy and tolerance between oral and intravenous ibuprofen in early closure of patent ductus arteriosus in very low birth weight infants. The possibility of ductal closure with only 1 or 2 doses of treatment was a secondary objective.

MATERIAL AND METHODS

Sixty-four very low birth weight patients with echocardiographically confirmed patent ductus arteriosus and respiratory distress were studied. The patients were randomly assigned to receive either oral (group O, n=32) or intravenous (group I, n=32) ibuprofen starting on the third day of life. After the first dose of treatment in both groups, echocardiographic evaluation was performed to determine the need for a second or third dose. The rate of ductal closure, adverse effects, complications, and the patient's clinical course were recorded.

RESULTS

In each group, 24 (75%) patients were born after 28 weeks' gestation. The rate of ductal closure tended to increase in group O (84.3% vs 62.5%). Closure of the ductus was obtained after 1 or 2 doses of treatment in 19 (70.3%) of 27 patients in group O and 14 (70%) of 20 patients in group I. The adverse effects were increased in group I (31.2% vs 9.3%). There were no significant differences with respect to complications during the stay. Adverse effects were significantly fewer when closure was achieved after an incomplete course of treatment (23.1% vs 76.9%).

CONCLUSIONS

In very low birth weight infants, the rate of early ductal closure with oral ibuprofen is at least as good as with the intravenous route. Ductal closure may be obtained with an incomplete course of ibuprofen. Oral ibuprofen is associated with fewer adverse effects. However, a larger sample is needed for more definitive conclusions.

The fate of ductus arteriosus in infants at 23-27 weeks of gestation: from spontaneous closure to ibuprofen resistance

BACKGROUND

Some extremely preterm infants experience spontaneous closure of the ductus arteriosus. On the other side, a high percentage (22-30%) of preterm infants born at the lower gestational age fail to respond to a single course of ibuprofen.

AIM

To assess if there are clinical characteristics effective as predictive factors for spontaneous closure of the ductus arteriosus, development of patent ductus arteriosus (PDA) and ibuprofen-resistant PDA.

METHODS

A cohort of inborn infants less than 28 weeks of gestation were prospectively studied. We distinguished infants who had spontaneous closure of ductus arteriosus, who developed PDA and who developed ibuprofen-resistant PDA.

RESULTS

We studied 34 infants. Eight infants (24%) had spontaneous closure of PDA, 17 infants (50%) had a closure of PDA following the first ibuprofen course, while 9 infants (26%) failed to respond to the first ibuprofen course. Infants born at 23-25 weeks of gestation were found to have lower likelihood of PDA spontaneous closure, and higher risk of developing PDA refractory to ibuprofen therapy. Sepsis was found to increase significantly the risk of ibuprofen failure in closing PDA.

CONCLUSION

An important percentage of extremely preterm infants exhibited spontaneous closure of PDA. Among clinical characteristics lowest gestational ages predict PDA and ibuprofen-resistant PDA, while sepsis predicts only ibuprofen-resistant PDA.

Treatment of patent ductus arteriosus: indomethacin or ibuprofen?

Persistent patent ductus arteriosus (PDA) in preterm infants can result in serious hemodynamic changes causing respiratory, gastrointestinal and renal morbidities if not treated within the first week of life. The treatment options available are a conservative approach, pharmacological treatment with cyclo-oxygenase (COX) inhibitors and surgical ligation. The COX inhibitors approved for use in the United States are indomethacin and ibuprofen lysine. Both of these drugs are equally effective in closing the PDA. Subtle differences exist between these two preparations. Indomethacin has a protective effect on the incidence of intraventricular hemorrhage (IVH) but reduces the blood flow to the kidneys and the brain. Ibuprofen is less toxic but has no effect on IVH. Efficacy of pharmacological treatment is influenced by timing of initiation of therapy. Surgical treatment is the only option when pharmacological treatment fails to close the PDA in symptomatic infants. Long-term neurological and respiratory morbidities are associated with surgical ligation. This paper reviews these medical considerations in the treatment options for PDA in premature infants.

Patent ductus arteriosus: lack of evidence for common treatments

Patent ductus arteriosus (PDA) is a common diagnosis among extremely premature infants, especially in those with lung disease. Treatments are often used to close the PDA. Despite nearly three decades of research, the question of whether the benefits of treatments to prevent ductal patency or promote closure outweigh the risks of these treatments remains unanswered. The authors rarely use treatments designed to close the PDA. This article reviews three considerations in support of this restrained approach: rates of spontaneous closure of the ductus arteriosus; adverse effect of persistent ductal patency; and benefits and risks of treatments for closure.

Renal drug clearance in preterm neonates: relation to prenatal growth

Aminoglycosides and glycopeptides are almost exclusively eliminated by renal excretion. Postmenstrual age (PMA) is the best predictor of their clearance, presumably because it predicts the time course of development of the glomerular filtration rate (GFR). Intrauterine growth restriction has an impact on the normalized weight of the kidney, on the number of nephrons, on GFR, and on tubular function in human perinatal life. We investigated whether prenatal growth also affects clearance of drugs such as aminoglycosides or glycopeptides that are eliminated through the kidney. Observations collected in two population pharmacokinetic studies involving preterm neonates and investigating amikacin and vancomycin in the first month of postnatal life were used to estimate the impact of prenatal growth (as judged by birth weight for gestational age) on the clearance of these drugs. Data from 1212 drug measurements (vancomycin, 648; amikacin, 564) in 531 subjects (vancomycin, 249; amikacin, 282) were available for study. Neonates born small for gestational age (SGA) were found to have a 16.2% (coefficient of variation, 12.2%) reduction in drug clearance. This effect was present from birth up to the postnatal age of 4 weeks. The covariate size (weight 0.75) explained 47.3% of drug clearance; PMA, 25.2%; coadministration of a nonselective cyclo-oxygenase inhibitor, 3.5%; renal function, 7.6%; and SGA, 1.7%. Renal drug clearance is significantly lower in preterm neonates born SGA than in appropriate-for-gestational-age (AGA) controls. This reduced clearance was observed not only at birth but also up to the postnatal age of 4 weeks.

Conservative treatment for patent ductus arteriosus in the preterm

BACKGROUND

A patent ductus arteriosus (PDA) is common among preterms, and prophylactic medical treatment has been advocated as the first-line approach. Conservative treatment may result in similar outcome, but without exposure to the harmful side effects of medication. A retrospective analysis revealed a ductal closure rate of 94% after conservative treatment with adjustment of ventilation (lowering the inspiratory time and increasing positive end expiratory pressure) and fluid restriction.

OBJECTIVE

To study prospectively over one year the rate of PDA closure, and morbidity and mortality following conservative treatment.

METHOD

Prospective study (1 January 2005 - 31 December 2005) including 30 newborns <or=30 weeks' gestation, all of whom were being ventilated and required surfactant. Echocardiography was performed 48-72 h after birth. Clinically important PDA was conservatively treated as described above. The percentage of children with PDA, ductal ligation and major complications was determined.

RESULTS

Ten neonates (33%) developed a clinical important PDA. Following conservative treatment the duct closed in all neonates (100%), and none required ductal ligation or medical treatment. The rates of major complications were no higher than those reported by the Vermont Oxford Network and in the literature.

CONCLUSION

The managed care plan resulted in an overall ductal closure rate of 100%. These results suggest that conservative treatment of PDA is a worthy alternative to prophylactic medical treatment.

Pharmacologic, pharmacodynamic, and pharmacokinetic considerations with intravenous Ibuprofen lysine

Patent ductus arteriosus (PDA) is a common complication in preterm infants. An intravenous (IV) cyclooxygenase (COX) inhibitor is the pharmacotherapy of choice. Concerns over adverse effects associated with the traditional treatment, IV indomethacin, have led to the investigation of other COX inhibitors to assist closure of PDA. IV ibuprofen lysine is a COX inhibitor that demonstrates similar efficacy to indomethacin with few adverse effects. In addition, IV ibuprofen lysine does not cause reductions in cerebral, renal, and mesenteric blood flow that can be seen with indomethacin, and thus ibuprofen therapy is not associated with reduced renal function. Ibuprofen is primarily metabolized by cytochrome P450 (CYP) 2C9. The immaturity of neonatal biotransformation pathways has a pronounced effect on the pharmacokinetic parameters of ibuprofen, particularly because CYP2C9 enzyme activity is known to be very low at birth and to increase rapidly over the first several days of life. Ibuprofen is highly bound to albumin, raising concern that ibuprofen may displace bilirubin and subsequently increase free bilirubin concentrations. However, the ibuprofen concentrations achieved with approved dosing with IV ibuprofen lysine are lower than those expected to result in displacement of bilirubin and related adverse effects. Factors such as gestational age and CYP2C9 polymorphism may affect ibuprofen metabolism and therefore optimal dosing, but further clinical investigation is needed in these areas. Other areas for future investigation include prolonged dosing regimens, prophylactic administration, and alternate indications. At the approved dose, IV ibuprofen lysine is a safe, effective pharmacologic agent to promote closure of PDAs in preterm infants.

Clinical considerations for the pharmacologic management of patent ductus arteriosus with cyclooxygenase inhibitors in premature infants

When medical management is warranted for closure of a persistent patent ductus arteriosus (PDA) in premature infants, treatment with a cyclooxygenase (COX) inhibitor is indicated. Indomethacin, available since 1976, has been the conventional pharmacologic treatment for PDA, but its use is associated with vasoconstrictive effects that impair renal, mesenteric and cerebral blood flow. Intravenous (IV) ibuprofen lysine, approved in the United States in 2006, has less severe vasoconstrictive effects on these vital organs than IV indomethacin. Clinical trials have shown both of these COX inhibitors to be equally effective in closing the PDA in approximately 70%-80% of treated infants, with less vasoconstrictive and adverse renal effects occurring with IV ibuprofen lysine.1,2 Several clinical considerations are important in the process of medical decision-making when faced with the need for PDA treatment with one of these pharmacologic agents in the premature infant. This paper focuses on these clinical considerations, including cerebral, renal and mesenteric blood flow, renal function, pulmonary effects, protein-binding capacity as it relates to hyperbilirubinemia, and platelet aggregation. No differences in chronic lung disease, pulmonary hypertension, hyperbilirubinemia and coagulopathy were observed in clinical trials when comparing these 2 COX inhibitors; however, significant differences have been observed in arterial blood flow to the cerebral, renal and mesenteric organs, suggesting that IV ibuprofen lysine may be the more favorable agent.

Clinical experience with intravenous Ibuprofen lysine in the pharmacologic closure of patent ductus arteriosus

Patent ductus arteriosus (PDA) is the failure of the ductus that arises from the distal dorsal aortic arch to close during the first few days of life. The treatment options for PDA include "watchful waiting," pharmacologic therapy with cyclooxygenase (COX) inhibitors (COX-1 and COX-2), such as indomethacin or intravenous (IV) ibuprofen lysine, and surgery when medical interventions have proved ineffective. The clinical trials evaluating the utilization of IV ibuprofen lysine focus on either preventing the persistence of a PDA or treating the PDA in premature infants in whom the ductus does not close within 48 hours of birth. Although the role of COX inhibitors in prophylaxis of PDA has been studied, it has not been clearly delineated. Treatment of PDA in preterm low birth weight infants from the second day of life on with IV ibuprofen lysine has been studied in 4 major and 3 smaller clinical trials. Overall, in 7 studies with 492 patients, the closure rate of PDA was 75.1% with IV ibuprofen lysine compared to 73.5% with indomethacin. In addition, neonates treated with IV ibuprofen lysine had significantly better creatinine clearance, urine output, serum creatinine, and blood urea nitrogen (BUN) profiles than indomethacin-treated patients. Overall, IV ibuprofen lysine is as effective as indomethacin for closure of PDA, yet is associated with a better safety profile with fewer negative side effects when compared to indomethacin.

Common clinical and practical questions on the use of intravenous Ibuprofen lysine for the treatment of patent ductus arteriosus

Cyclooxygenase inhibitors have proven efficacy in the treatment of patent ductus arteriosus (PDA). Intravenous indomethacin has been the only approved treatment for PDA available in the United States for the past 20 years. The armamentarium has recently been expanded with the approval of intravenous ibuprofen lysine in 2006. Ibuprofen lysine has been used for years in Europe, and the author reviews the extensive published literature. This review addresses common questions about ibuprofen lysine, summarizes the available literature, and discusses the data submitted to the Food and Drug Administration (FDA) in support of its approval. Three major trials served as the approval basis for the safety and efficacy of ibuprofen lysine. The author has summarized these studies and, where appropriate, presents pooled results from additional analyses that have not been previously published. Many practical questions regarding the drug, including dosing, administration, and storage are addressed. The results of recently completed but unpublished tests on stability and compatibility with commonly used drugs in the neonatal setting are also reviewed. Ibuprofen lysine now represents an alternative pharmacological option to surgery for the treatment of PDA.

Safety and efficacy of ibuprofen versus indomethacin for the treatment of patent ductus arteriosus in the preterm infant: reviewing the evidence

THE DUCTUS ARTERIOSUS IS a vascular shunt that exists before birth to enable blood flow to bypass the lungs, which are not yet functional, and direct it instead to the systemic circulation and to vital organs such as the kidney and the gastrointestinal (GI) tract. In the term infant, this shunt should start to close within the first few hours after birth; it should close functionally within 72 hours and anatomically within 2 weeks after birth.1 In the preterm infant, functional and subsequent anatomic closure frequently does not take place. Failure of ductal closure occurs in as many as 60 percent of all infants who are less than 28 weeks gestation at birth.1 Causes for patency of the ductus arteriosus in preterm infants include decreased smooth muscle fibers in the duct and continued responsiveness of the ductus arteriosus to prostaglandins produced within it.

Pharmacoeconomics of Surgical Interventions vs. Cyclooxygenase Inhibitors for the Treatment of Patent Ductus Arteriosus

Management of neonatal patent ductus arteriosus (PDA) often is resource-intensive and costly. Therefore, it is in hospitals' best interests to ensure the most cost-efficient use of associated resources. Clinical status, comorbidities, and response to prior therapy are considered in selecting the most appropriate intervention for PDA management. Currently, supportive measures (e.g., fluid restriction), surgical ligation, and pharmacologically based medical therapy are the primary treatment modalities for correcting PDA. Medical therapy, which comprises a small percentage (2.0%–5.0%)1 of overall PDA treatment expenses in the United States, consists of either of the 2 intravenous (IV) cyclooxygenase (COX) inhibitors: IV indomethacin and the newly available IV ibuprofen lysine. Although IV COX inhibitors represent a small portion of medical expenses, their benefits appear to be considerable. Pharmacoeconomic studies have evaluated indomethacin's beneficial impact on cost-effectiveness per quality-adjusted life year in PDA prophylaxis; however, no analysis to date prospectively assesses the effect of COX inhibitors on resource use or expenses in treating PDA. Such analysis is desirable and should consider efficacy and safety outcomes, impact on health care resource use and length of stay (LOS), and any differential effects of the agents' safety profiles; notably, IV indomethacin adversely affects renal and mesenteric blood flow and increases serum creatinine and oliguria significantly more than IV ibuprofen. These observations lay the foundation to conduct studies assessing the influence of these differences on resource use, LOS and expenses associated with PDA management.

Pulmonary hypertension following L-lysine ibuprofen therapy in a preterm infant with patent ductus arteriosus

Patent ductus arteriosus is one of the most common congenital abnormalities found in premature infants. Ibuprofen, a nonsteroidal drug that is commonly used as an antipyretic, analgesic and anti-inflammatory agent, is also used to induce closure of symptomatic patent ductus arteriosus in preterm infants. Recently, we gave L-lysine ibuprofen to a preterm infant with respiratory distress to induce closure of a patent ductus arteriosus, and the infant experienced pulmonary hypertension. Only 3 cases of pulmonary hypertension following early administration of an ibuprofen solution buffered with tromethamine have previously been reported. However, this severe side effect has never been observed in multicentre, randomized, double-blind controlled trials, nor in recent reviews or meta-analyses of L-lysine ibuprofen use.

Limited predictability of amikacin clearance in extreme premature neonates at birth

AIM

Identify and quantify factors describing variability of amikacin clearance in preterm neonates at birth.

METHODS

Population pharmacokinetics of amikacin were estimated in a cohort of 205 extreme preterm neonates [post conception age (PCA) 27.8, SD 1.8, range 24-30 weeks; weight 1.07, SD 0.34, range 0.45-1.98 kg, postnatal age < 72 h]. Covariate analysis included weight, PCA, Apgar score, prophylactic administration of a nonsteroidal anti-inflammatory drug (NSAID) to the neonate, maternal indomethacin and betamethasone administration, and chorioamnionitis.

RESULTS

A one-compartment linear disposition model with zero order input (0.3 h i.v. infusion) and first-order elimination was used. The population parameter estimate for volume of distribution (V) was 40.2 l per 70 kg. Clearance (CL) increased from 0.486 l h(-1) per 70 kg at 24 weeks PCA to 0.940 l h(-1) per 70 kg by 30 weeks PCA. The population parameter variability (PPV) for CL and V was 0.336 and 0.451. The use of a NSAID (either aspirin or ibuprofen) in the first day of life reduced amikacin clearance by 22%. Overall 65% of the variability of CL was predictable. Weight explained 48%, PCA 15% and NSAIDs 2%.

CONCLUSIONS

Size and post-conception age are the major contributors to clearance variability in extreme premature neonates (<31 weeks PCA). The large (35% of total) unexplained variability in clearance reinforces the need for target concentration intervention to reduce variability in exposure to a safe and effective range.

Systematic review: intravenous Ibuprofen in preterm newborns

Ibuprofen, a nonsteroidal antiinflammatory drug, widely used as antipyretic, antiinflammatory, and analgesic agent and for therapy of arthritis, exerts a dose-dependent constriction of the ductus arteriosus in newborn lambs. Two intravenous preparations, namely ibuprofen lysine and ibuprofen-THAM, have been studied in preterm newborns with patent ductus arteriosus. Clinical trials have compared IV ibuprofen to placebo, or to indomethacin. Pharmacodynamic effects of this drug before and after its administration have also been evaluated. Compared with placebo, IV ibuprofen effectively closed PDA with minimal effect on renal function. One study using intravenous ibuprofen-THAM showed decreased renal function and increased risk of NEC and PPHN. Compared with indomethacin, IV ibuprofen lysine exerted similar efficacy (75% to 93% closure). However, indomethacin increased abnormal renal function and decreased mesenteric and cerebral blood flow and bio-energetics. Two clinical trials showed that ibuprofen did not reduce the incidence of intraventricular hemorrhage compared with placebo. The drug has prolonged elimination (plasma half-life = ca 23 hours), suggesting that once daily dosing is appropriate. Dose finding studies indicate that a starting dose of 10 mg/kg followed by 5 mg/kg/d for 2 more days provides optimal efficacy with the least adverse effects. Neonatal data on ibuprofen and indomethacin indicate that, on the first day of life when IVH prevention is desired, indomethacin and not ibuprofen should be used since ibuprofen has no effect on IVH risk. On or after the second day of postnatal life, when early or therapeutic PDA closure is needed, ibuprofen and not indomethacin is probably the first choice due to its better adverse event profile.

Dopamine is not an independent risk factor for reduced amikacin clearance in extremely low-birth-weight infants

INTRODUCTION

Important inter-individual variability in amikacin clearance was observed in preterm infants, only in part explained by gestational age (GA), birth weight, or coadministration of nonselective cyclo-oxygenase (COX) inhibitor. We therefore evaluated whether dopamine had an additional effect on amikacin clearance.

METHODS

Clinical characteristics (GA, weight, COX inhibitor, dopamine, prenatal betamethasone) and amikacin pharmacokinetics were retrospectively collected in a cohort of preterm infants (GA of <31 wks, early neonatal life on respiratory support, between January 1, 1999 and January 6, 2005). Pharmacokinetics were calculated by assuming a one-compartment model with instantaneous input and first-order output based on paired samples collected for therapeutic drug monitoring before and following second administration. Monovariate analysis (Spearman, Mann-Whitney U test) was used to study the impact of clinical characteristics on amikacin clearance, and logistic regression was used to assess their potential independent effect.

RESULTS

Paired amikacin samples were available for 240 neonates (mean GA, 28 wks; birth weight, 1042 g). Amikacin clearance was 0.46 (range, 0.09-2.33) mL/kg/min and distribution volume was 0.54 (range, 0.17-2.31) L/kg. GA, birth weight, COX inhibitor, and dopamine had a significant effect on amikacin clearance. In a logistic regression model, dopamine was no longer a significant variable when GA, birth weight, or cotreatment of a nonselective COX inhibitor was entered as second variable.

CONCLUSIONS

Dopamine is an indicator but not an independent marker of reduced amikacin clearance in early neonatal life in extremely low-birth-weight infants. Therefore, neither dose nor interval should be adapted when dopamine is prescribed, if GA and coadministration of nonselective COX inhibitors already have been taken into account.

Ibuprofen for the prevention of patent ductus arteriosus in preterm and/or low birth weight infants

BACKGROUND

A patent ductus arteriosus (PDA) often complicates the clinical course of preterm infants and increases the risk of intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC), chronic lung disease (CLD) and death. The standard treatment to close a PDA is indomethacin. Its use is associated with renal, gastrointestinal and cerebral side-effects. Ibuprofen has been shown to be effective in closing a PDA without reducing blood flow velocity to the brain, gut or kidneys.

OBJECTIVES

To determine the effectiveness and safety of prophylactic ibuprofen compared to placebo/no intervention or other cyclo-oxygenase inhibitor drugs (indomethacin, mefenamic acid, etc) in the prevention of PDA in preterm infants.

SEARCH STRATEGY

Randomized controlled trials comparing prophylactic ibuprofen use with placebo/no intervention/indomethacin were identified by searching the Cochrane Central Register of Controlled Trial (CENTRAL, The Cochrane Library, Issue 3, 2005), MEDLINE (1966-July 2005), CINAHL (1982-July 2005), EMBASE (1980-July 2005), reference lists of published trials and abstracts published in Pediatric Research (1990-July 2005). No language restrictions were applied.

SELECTION CRITERIA

Randomized or quasi-randomized controlled trials comparing use of ibuprofen with placebo/no intervention or other cyclo-oxygenase inhibitor drugs (indomethacin, mefenamic acid, etc) for the prevention of PDA in preterm and/or low birth weight infants.

DATA COLLECTION AND ANALYSIS

Data regarding the clinical outcomes including presence of PDA on day three and day seven, need for surgical ligation, need for rescue treatment with cyclo-oxygenase inhibitors, IVH, mortality, renal and gastrointestinal complications were extracted. Meta-analyses were performed using RevMan 4.2 and treatment estimates were reported as weighted mean difference (WMD), typical relative risk (RR), typical risk difference (RD) and, if statistically significant, number needed to treat (NNT) or number needed to harm (NNH), along with their 95% confidence intervals (CI).

MAIN RESULTS

Four trials (n = 672) were included in the review. There was a statistically significant decrease in the incidence of PDA on day three in the ibuprofen group [typical RR 0.37 (95% CI 0.29, 0.49); typical RD -0.29 (95% CI -0.35, -0.22); NNT 3 (95% CI 3, 5); 4 trials, n = 672], in the need for rescue treatment with cyclo-oxygenase inhibitors [typical RR 0.17 (95% CI 0.11, 0.27), typical RD -0.27 (95% CI -0.35, -0.22); NNT 4 (95%CI 3, 5), and in the need for surgical ligation [typical RR 0.34 (95% CI 0.14, 0.81), typical RD -0.04 (95% CI -0.07, -0.01); NNT 25 (95% CI 14, 100). The PDA had closed spontaneously by day three in 60% of the neonates in the control group. There was a significant increase in the serum creatinine levels in the ibuprofen group [WMD 0.13 mg/dl (95% CI 0.08, 0.17); 2 trials, n = 495]. Ibuprofen reduces urine output. There were no statistically significant differences in mortality, grade 3/4 intraventricular hemorrhage, chronic lung disease at 28 days or 36 weeks, necrotizing enterocolitis , gastrointestinal hemorrhage, intestinal perforation or time to reach full feeds. One trial (Gournay 2002) (n = 135) reported on three infants in the ibuprofen group who developed pulmonary hypertension responsive to nitric oxide treatment.

AUTHORS' CONCLUSIONS

Prophylactic use of ibuprofen reduces the incidence of PDA, the need for rescue treatment with cyclo-oxygenase inhibitors and surgical closure. However, in the control group, the PDA had closed spontaneously by day three in 60% of the neonates. Prophylactic treatment therefore exposes a large proportion of infants unnecessarily to a drug that has important side effects (mainly involving the kidneys) without conferring any important short term benefits. Prophylactic treatment with ibuprofen is not recommended. Until long-term follow-up results are published from the trials included in this review, no further trials of prophylactic ibuprofen are recommended.

Efecto de la administración concomitante de indometacina o ibuprofeno en la farmacocinética de amikacina en neonatos prematuros

OBJECTIVE

To evaluate whether the concomitant administration of ibuprofen or indomethacin plus amikacin may alter the latter drug s pharmacokinetic parameters, and hence amikacin plasma levels.

METHOD

Retrospective cohort study performed by reviewing the medical records of premature children with persistent ductus arteriosus receiving amikacin and ibuprofen, or amikacin and indomethacin. They were divided up into three groups: group 1: treatment with amikacin went before indomethacin or ibuprofen; group 2: simultaneously treated with amikacin and indomethacin; group 3: simultaneously treated with amikacin and ibuprofen. Pharmacokinetic parameters, distribution volume, and amikacin clearance were measured using the PKS program (a non-linear regression method). Half life was determined from previous parameters.

RESULTS

Twenty-eight patients were included. No statistically significant differences were found among pharmacokinetic parameters corresponding to each study group.

CONCLUSIONS

Further studies are needed with a greater number of patients and currently recommended doses to assess the influence of indomethacin and ibuprofen in the pharmacokinetics of amikacin in premature children with persistent ductus arteriosus.

Nonselective cyclo-oxygenase inhibitors and glomerular filtration rate in preterm neonates

The adverse effects of nonselective cyclo-oxygenase (COX) inhibitors on the immature kidney have been described in newborn rabbits, but it is much more laborious and difficult to study its relative impact on renal function in human neonates. Amikacin clearance was therefore used as surrogate marker to study the impact of nonselective COX-inhibitors on glomerular filtration rate. Clinical characteristics and amikacin clearance of infants on respiratory support were retrospectively collected. Results in neonates in whom either ibuprofen-lysine or acetylsalicylic acid was administered prophylactically to induce closure of a patent asymptomatic ductus arteriosus were compared to infants not cotreated with any COX-inhibitor (Mann-Whitney U-, chi-square tests). Amikacin clearance was calculated in 142 infants, of whom 50 were cotreated with ibuprofen and 33 with acetylsalicylic acid. There were no significant differences in clinical characteristics between the three groups. Compared to controls (0.52, range 0.09-2.33 ml/kg/min), a significant similar decrease in amikacin clearance in infants cotreated with ibuprofen (0.38, range 0.13-0.80 ml/kg/min, p<0.01) or acetylsalicylic acid (0.38, range 0.13-0.78 ml/kg/min, p<0.01) was demonstrated. Using amikacin clearance as marker, a significant and similar reduction in glomerular filtration rate was documented in preterm infants cotreated with ibuprofen or acetylsalicylic acid.

Ibuprofeno frente a indometacina en el tratamiento del conducto arterioso persistente del prematuro

INTRODUCTION

Persistent patent ductus arteriosus (PDA) is a common entity in preterm infants. The most commonly used pharmacological treatment to close the ductus is indomethacin but it can affect cerebral, renal and mesenteric blood flow. Ibuprofen has recently been shown to be effective in closing PDA with fewer hemodynamic effects. In this study we compared the safety and efficacy of ibuprofen and indomethacin in the treatment of PDA in preterm infants.

MATERIAL AND METHODS

A randomized trial was performed. Premature infants with symptomatic PDA confirmed by echocardiography in the first week of life and who required respiratory support were included. The patients were randomly assigned to receive either intravenous indomethacin or ibuprofen. The rate of ductal closure, need for additional treatment, complications, and clinical course were evaluated.

RESULTS

Twenty-four patients were treated with indomethacin and 23 with ibuprofen. The clinical characteristics before treatment were similar in both groups. Both treatments were effective in closing PDA (87.5% in the indomethacin group and 82.6% in the ibuprofen group). The two cohorts did not differ in the rate of reopening, need for a second pharmacologic treatment, or surgical ductal ligation. No patient in the ibuprofen group developed gastrointestinal adverse effects, but two infants in the indomethacin group had isolated bowel perforation and one had necrotizing enterocolitis. Transient renal dysfunction developed in seven patients (29%) in the indomethacin group versus two (9%) in the ibuprofen group. Transient renal insufficiency was found in one patient in the indomethacin group and in none in the ibuprofen group. The rate of other complications was similar in both groups.

CONCLUSIONS

In our trial ibuprofen was as effective as indomethacin in closing PDA. No significant differences were found in the incidence of complications but fewer renal complications and no gastrointestinal complications were found in the ibuprofen group.

The impact of ibuprofen on renal clearance in preterm infants is independent of the gestational age

The aim of this investigation was to evaluate whether the relative change in renal clearance due to ibuprofen administration depends on the gestational age (GA). Clearance of amikacin was used as a surrogate marker for renal clearance in preterm infants (GA 24-34 weeks, day 1) on respiratory support. Clearance in infants co-treated with ibuprofen was compared to that of infants not co-treated with ibuprofen. Absolute change of clearance in four consecutive cohorts of increasing (<27, 27-28, 29-31, 32-34 weeks) GA and linear correlations of clearance on GA were calculated in both groups. Data were collected from 204 infants, of whom 93 were co-treated with ibuprofen. Mean amikacin clearance was lower (0.48 to 0.59 ml/kg/min, P <0.001) in infants co-treated with ibuprofen. Absolute decrease in mean amikacin clearance (0.10 to 0.14 ml/kg/min) was similar in all four cohorts. Linear correlations of clearance with GA were documented in infants co-treated (y =0.21+0.011x) or not co-treated (y =0.44+0.009x) with ibuprofen. Renal clearance, reflected by amikacin clearance, is decreased by ibuprofen in preterm infants of 24 to 34 weeks GA on respiratory support on the 1st day of life, independent of the GA.