Medication use in the neonatal intensive care unit

OBJECTIVE

The aim of the article is to provide an update on medication use in infants admitted to the neonatal intensive care unit (NICU) in the United States and examine how use has changed over time.

STUDY DESIGN

We performed a retrospective review (2005-2010) of a large prospectively collected administrative database.

RESULT

Medications most commonly administered during the study period were ampicillin, gentamicin, caffeine citrate, vancomycin, beractant, furosemide, fentanyl, dopamine, midazolam, and calfactant (56-681 exposures per 1,000 infants). Those with the greatest relative increase in use included azithromycin, sildenafil, and milrinone. Medications with the greatest relative decrease in use included theophylline, metoclopramide, and doxapram.

CONCLUSION

Medication use in the NICU has changed substantially over time, and only 35% of the most commonly prescribed medications are Food and Drug Administration -approved in infants.

Vancomycin cerebrospinal fluid pharmacokinetics in children with cerebral ventricular shunt infections

This study described the cerebrospinal fluid (CSF) exposure of vancomycin in 8 children prescribed intravenous vancomycin therapy for cerebral ventricular shunt infection. Vancomycin CSF concentrations ranged from 0.06 to 9.13 mg/L and the CSF: plasma ratio ranged from 0 to 0.66. Two of 3 children with a staphylococcal CSF infection had CSF concentrations greater than minimal inhibitory concentration at the end of the dosing interval.

Use of opportunistic clinical data and a population pharmacokinetic model to support dosing of clindamycin for premature infants to adolescents

Clindamycin is commonly prescribed to treat children with skin and skin-structure infections (including those caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA)), yet little is known about its pharmacokinetics (PK) across pediatric age groups. A population PK analysis was performed in NONMEM using samples collected in an opportunistic study from children receiving i.v. clindamycin per standard of care. The final model was used to optimize pediatric dosing to match adult exposure proven effective against CA-MRSA. A total of 194 plasma PK samples collected from 125 children were included in the analysis. A one-compartment model described the data well. The final model included body weight and a sigmoidal maturation relationship between postmenstrual age (PMA) and clearance (CL): CL (l/h) = 13.7 × (weight/70)(0.75) × (PMA(3.1)/(43.6(3.1) + PMA(3.1))); V (l) = 61.8 × (weight/70). Maturation reached 50% of adult CL values at ~44 weeks PMA. Our findings support age-based dosing.

Late-onset bloodstream infections in hospitalized term infants

BACKGROUND

The epidemiology and incidence of late-onset blood stream infections (BSIs) in premature infants have been described, but studies describing late-onset BSI in term infants are sparse. We sought to describe the pathogens, incidence, risk factors and mortality of late-onset BSI in hospitalized term infants.

METHODS

A cohort study was conducted of infants ≥37 weeks gestational age and ≤120 days of age discharged from Pediatrix Medical Group neonatal intensive care units from 1997 to 2010. We examined all cultures obtained from day of life 4-120 and used multivariable regression to assess risk factors for late-onset BSI.

RESULTS

We found a total of 206,019 infants cared for between day of life 4 and 120, and the incidence of late-onset BSI was 2.7/1000 admissions. We identified Gram-positive organisms in 64% of the cultures and Gram-negative organisms in 26%. We found a decreased risk of late-onset BSI in infants with the following characteristics: small for gestational age, delivery by Cesarean, antenatal antibiotic use and discharged in the later years of the study. Late-onset BSI increased the risk of death after controlling for confounders [odds ratio 8.43 (95% confidence interval 4.42-16.07)].

CONCLUSION

Our data highlight the importance of late-onset BSI in hospitalized term infants. We identified Gram-positive organisms as the most common pathogen, and late-onset BSI was an independent risk factor for death.

Advances in pediatric pharmacology, therapeutics, and toxicology

In the United States, passage of the FDASIA legislation made BPCA and PREA permanent, no longer requiring reauthorization every 5 years. This landmark legislation also stressed the importance of performing clinical trials in neonates when appropriate. In Europe the Pediatric Regulation, which went into effect in early 2007, also provides a framework for expanding pediatric clinical research. Although much work remains, as a result of greater regulatory guidance more pediatric data are reaching product labels.

Cumulative radiation exposure and cancer risk estimation in children with heart disease

BACKGROUND

Children with heart disease are frequently exposed to imaging examinations that use ionizing radiation. Although radiation exposure is potentially carcinogenic, there are limited data on cumulative exposure and the associated cancer risk. We evaluated the cumulative effective dose of radiation from all radiation examinations to estimate the lifetime attributable risk of cancer in children with heart disease.

METHODS AND RESULTS

Children ≤6 years of age who had previously undergone 1 of 7 primary surgical procedures for heart disease at a single institution between 2005 and 2010 were eligible for the study. Exposure to radiation-producing examinations was tabulated, and cumulative effective dose was calculated in millisieverts. These data were used to estimate lifetime attributable risk of cancer above baseline using the approach of the Committee on Biological Effects of Ionizing Radiation VII. The cohort included 337 children exposed to 13 932 radiation examinations. Conventional radiographs represented 92% of examinations, whereas cardiac catheterization and computed tomography accounted for 81% of cumulative exposure. Overall median cumulative effective dose was 2.7 mSv (range, 0.1-76.9 mSv), and the associated lifetime attributable risk of cancer was 0.07% (range, 0.001%-6.5%). Median lifetime attributable risk of cancer ranged widely depending on surgical complexity (0.006%-1.6% for the 7 surgical cohorts) and was twice as high in females per unit exposure (0.04% versus 0.02% per 1-mSv effective dose for females versus males, respectively; P<0.001).

CONCLUSIONS

Overall radiation exposures in children with heart disease are relatively low; however, select cohorts receive significant exposure. Cancer risk estimation highlights the need to limit radiation dose, particularly for high-exposure modalities.

Pharmacokinetics and pharmacodynamics of antifungals in children: clinical implications

Invasive fungal disease (IFD) remains life threatening in premature infants and immunocompromised children despite the recent development of new antifungal agents. Optimal dosing of antifungals is one of the few factors clinicians can control to improve outcomes of IFD. However, dosing in children cannot be extrapolated from adult data because IFD pathophysiology, immune response, and drug disposition differ from adults. We critically examined the literature on pharmacokinetics (PK) and pharmacodynamics (PD) of antifungal agents and highlight recent developments in treating pediatric IFD. To match adult exposure in pediatric patients, dosing adjustment is necessary for almost all antifungals. In young infants, the maturation of renal and metabolic functions occurs rapidly and can significantly influence drug exposure. Fluconazole clearance doubles from birth to 28 days of life and, beyond the neonatal period, agents such as fluconazole, voriconazole, and micafungin require higher dosing than in adults because of faster clearance in children. As a result, dosing recommendations are specific to bracketed ranges of age. PD principles of antifungals mostly rely on in vitro and in vivo models but very few PD studies specifically address IFD in children. The exposure-response relationship may differ in younger children compared with adults, especially in infants with invasive candidiasis who are at higher risk of disseminated disease and meningoencephalitis, and by extension severe neurodevelopmental impairment. Micafungin is the only antifungal agent for which a specific target of exposure was proposed based on a neonatal hematogenous Candida meningoencephalitis animal model. In this review, we found that pediatric data on drug disposition of newer triazoles and echinocandins are lacking, dosing of older antifungals such as fluconazole and amphotericin B products still need optimization in young infants, and that target PK/PD indices need to be clinically validated for almost all antifungals in children. A better understanding of age-specific PK and PD of new antifungals in infants and children will help improve clinical outcomes of IFD by informing dosing and identifying future research areas.

Characterization of the population pharmacokinetics of ampicillin in neonates using an opportunistic study design

Although ampicillin is the most commonly used drug in neonates, developmental pharmacokinetic (PK) data to guide dosing are lacking. Ampicillin is primarily renally eliminated, and developmental changes are expected to influence PK. We conducted an open-label, multicenter, opportunistic, prospective PK study of ampicillin in neonates stratified by gestational age (GA) (≤ 34 or >34 weeks) and postnatal age (PNA) (≤ 7 or >7 days). Drug concentrations were measured by tandem mass spectrometry. PK data were analyzed using population nonlinear mixed-effects modeling in NONMEM 7.2. Monte Carlo simulations were conducted to determine the probability of target attainment for the time in which the total steady-state ampicillin concentrations remained above the MIC (T>MIC) for 50%, 75%, and 100% of the dosing interval. A total of 142 PK samples from 73 neonates were analyzed (median [range] GA, 36 [24 to 41] weeks; PNA, 5 [0 to 25] days). The median ampicillin dose was 200 (100 to 350) mg/kg/day. Postmenstrual age and serum creatinine were covariates for ampicillin clearance (CL). A simplified dosing regimen of 50 mg/kg every 12 h for GA of ≤ 34 weeks and PNA of ≤ 7 days, 75 mg/kg every 12 h for GA of ≤ 34 weeks and PNA of ≥ 8 and ≤ 28 days, and 50 mg/kg every 8 h for GA of >34 weeks and PNA of ≤ 28 days achieved the prespecified surrogate efficacy target in 90% of simulated subjects. Ampicillin CL was associated with neonatal development. A simplified dosing regimen stratified by GA and PNA achieves the desired surrogate therapeutic target in the vast majority of neonates.

Effect of fluconazole prophylaxis on candidiasis and mortality in premature infants: a randomized clinical trial

IMPORTANCE

Invasive candidiasis in premature infants causes death and neurodevelopmental impairment. Fluconazole prophylaxis reduces candidiasis, but its effect on mortality and the safety of fluconazole are unknown.

OBJECTIVE

To evaluate the efficacy and safety of fluconazole in preventing death or invasive candidiasis in extremely low-birth-weight infants.

DESIGN, SETTING, AND PATIENTS

This study was a randomized, blinded, placebo-controlled trial of fluconazole in premature infants. Infants weighing less than 750 g at birth (N = 361) from 32 neonatal intensive care units (NICUs) in the United States were randomly assigned to receive either fluconazole or placebo twice weekly for 42 days. Surviving infants were evaluated at 18 to 22 months corrected age for neurodevelopmental outcomes. The study was conducted between November 2008 and February 2013.

INTERVENTIONS

Fluconazole (6 mg/kg of body weight) or placebo.

MAIN OUTCOMES AND MEASURES

The primary end point was a composite of death or definite or probable invasive candidiasis prior to study day 49 (1 week after completion of study drug). Secondary and safety outcomes included invasive candidiasis, liver function, bacterial infection, length of stay, intracranial hemorrhage, periventricular leukomalacia, chronic lung disease, patent ductus arteriosus requiring surgery, retinopathy of prematurity requiring surgery, necrotizing enterocolitis, spontaneous intestinal perforation, and neurodevelopmental outcomes-defined as a Bayley-III cognition composite score of less than 70, blindness, deafness, or cerebral palsy at 18 to 22 months corrected age.

RESULTS

Among infants receiving fluconazole, the composite primary end point of death or invasive candidiasis was 16% (95% CI, 11%-22%) vs 21% in the placebo group (95% CI, 15%-28%; odds ratio, 0.73 [95% CI, 0.43-1.23]; P = .24; treatment difference, -5% [95% CI, -13% to 3%]). Invasive candidiasis occurred less frequently in the fluconazole group (3% [95% CI, 1%-6%]) vs the placebo group (9% [95% CI, 5%-14%]; P = .02; treatment difference, -6% [95% CI, -11% to -1%]). The cumulative incidences of other secondary outcomes were not statistically different between groups. Neurodevelopmental impairment did not differ between the groups (fluconazole, 31% [95% CI, 21%-41%] vs placebo, 27% [95% CI, 18%-37%]; P = .60; treatment difference, 4% [95% CI, -10% to 17%]).

CONCLUSIONS AND RELEVANCE

Among infants with a birth weight of less than 750 g, 42 days of fluconazole prophylaxis compared with placebo did not result in a lower incidence of the composite of death or invasive candidiasis. These findings do not support the universal use of prophylactic fluconazole in extremely low-birth-weight infants.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00734539.

Developmental pharmacokinetics of piperacillin and tazobactam using plasma and dried blood spots from infants

Piperacillin-tazobactam is often given to infants with severe infection in spite of limited pharmacokinetics (PK) data. We evaluated piperacillin-tazobactam PK in premature and term infants of ages <61 days with suspected systemic infection. Infants received intravenous piperacillin-tazobactam (80 to 100 mg/kg of body weight every 8 h [q 8 h]) based on gestational and postnatal age. Sparse plasma samples were obtained after first and multiple doses. Drug concentrations were measured by tandem mass spectrometry. PK data were analyzed using population nonlinear mixed-effect modeling. Target attainment rates for the time unbound piperacillin concentrations remained above the MIC for 50% and 75% of the dosing interval at steady state were evaluated. Bias in population PK parameter estimates was assessed for dried blood spot (DBS) samples, and a comparability analysis was performed for DBS and plasma drug concentrations using linear regression. We obtained 128 plasma samples from 32 infants, median gestational age of 30 weeks (range, 23 to 40 weeks) and postnatal age of 8 days (range, 1 to 60). Piperacillin and tazobactam PK models included body weight (WT) and postmenstrual age (PMA) as covariates for clearance and WT for volume of distribution and were used to optimize dosing in infants. DBS drug concentrations were 50 to 60% lower than those in plasma, but when combined with plasma concentrations and a matrix effect, the data generated PK model parameters similar to those for plasma alone. With PMA-based dosing (100 mg/kg q 8 h, 80 mg/kg q 6 h, and 80 mg/kg q 4 h for PMA of ≤30, 30 to 35, and 35 to 49 weeks, respectively), 90% of simulated infants achieved the surrogate therapeutic target of time above the MIC (≤32 mg/liter) for 75% of the dosing interval.

Fluconazole prophylaxis for prevention of invasive candidiasis in infants

PURPOSE OF REVIEW

Invasive candidiasis is a serious infection in hospitalized infants that results in significant mortality and morbidity. Fluconazole is approved by the US Food and Drug Administration for prophylaxis of invasive candidiasis in patients undergoing bone marrow transplantation but is not approved for use in infants. This review will describe the history of fluconazole use for prophylaxis in infants.

RECENT FINDINGS

Limiting fluconazole prophylaxis to infants with risk factors, in addition to low birth weight and early gestational age, reduces the number of infants treated with fluconazole and the duration of fluconazole therapy for each infant.

SUMMARY

Fluconazole prophylaxis appears to be well tolerated for use in premature infants. Reduction in the incidence of invasive candidiasis is observed even when prophylaxis is limited to infants with multiple risk factors. Centers with a low incidence of invasive candidiasis may not benefit from fluconazole prophylaxis. Significant short-term and long-term toxicity and increases in fluconazole-resistant organisms have not been observed with fluconazole use in the intensive care nursery.

Predictors of positive cerebrospinal fluid cultures in infants with bacteremia

BACKGROUND

Meningitis causes substantial morbidity and mortality in hospitalized infants. There is no consensus on the ability of blood cultures to predict results from cerebrospinal fluid (CSF) cultures in hospitalized infants.

METHODS

We used the Pediatrix Medical Group database of infants discharged from 333 neonatal intensive care units between 1997 and 2011. We identified all infants with a positive blood culture and a CSF culture obtained within 3 days. We evaluated the odds of a concordant blood-CSF culture pair, controlling for severity of illness, organism type, gestational age, day of blood culture and blood-CSF culture pairing, exposure to CSF-penetrating antibiotics and the presence of a ventriculo-peritoneal shunt.

RESULTS

We identified 8839 infants with 9408 blood-CSF culture pairs. Serratia marcescens (24/227, 11%) and Streptococcus pneumoniae (7/64, 11%) had the highest proportion of concordant blood-CSF culture pairs. The presence of a ventriculo-peritoneal shunt, as well as timing of the CSF culture on the same day as the blood culture, were associated with increased odds of blood-CSF culture pair concordance-odds ratio = 3.87 (95% confidence interval; 2.59-5.78) and 6.11 (2.81-13.24), respectively.

CONCLUSION

The frequency of blood-CSF culture pair concordance is related to organism type and to the timing of the CSF culture in relation to the blood culture.

Risk of necrotizing enterocolitis in very-low-birth-weight infants with isolated atrial and ventricular septal defects

OBJECTIVE

Necrotizing enterocolitis (NEC) is associated with a significant morbidity and mortality in premature infants. We sought to identify the frequency of NEC in very-low-birth-weight infants with isolated ventricular septal defects (VSDs) or atrial septal defects (ASDs) using a large multicenter database.

STUDY DESIGN

We identified a cohort of infants with birth weight <1500 g cared for in 312 neonatal intensive care units (NICUs) managed by the Pediatrix Medical Group between 1997 and 2010. We examined the association between the presence of an ASD or a VSD with development of NEC using logistic regression to control for small-for-gestational age status, antenatal steroid use, antenatal antibiotic use, gestational age, sex, race, Apgar score at 5 min and method of delivery.

RESULT

Of the 98 523 infants who met inclusion criteria, 1904 (1.9%) had an ASD, 1943 (2.0%) had a VSD and 146 (0.1%) had both. The incidence of NEC was 6.2% in infants without septal defects, 9.3% in those with an ASD, 7.8% in those with a VSD, and 10.3% in infants with both an ASD and a VSD. Compared with infants without septal defects, the adjusted odds ratios for developing NEC for each group-ASD alone, VSD alone and ASD with VSD-were 1.26 (95% confidence interval 1.07 to 1.49), 1.27 (1.07 to 1.51) and 1.79 (1.03 to 3.12), respectively.

CONCLUSION

The presence of an ASD or a VSD was associated with NEC in this cohort of premature infants.

Changes in the incidence of candidiasis in neonatal intensive care units

OBJECTIVE

Neonatal invasive candidiasis is associated with significant morbidity and mortality. We describe the association between invasive candidiasis and changes in use of antifungal prophylaxis, empirical antifungal therapy, and broad-spectrum antibacterial antibiotics over time.

METHODS

We examined data from 709,325 infants at 322 NICUs managed by the Pediatrix Medical Group from 1997 to 2010. We determined the cumulative incidence of invasive candidiasis and use of antifungal prophylaxis, broad-spectrum antibacterial antibiotics, and empirical antifungal therapy by year.

RESULTS

We identified 2063 (0.3%) infants with 2101 episodes of invasive candidiasis. Over the study period, the annual incidence of invasive candidiasis decreased from 3.6 episodes per 1000 patients to 1.4 episodes per 1000 patients among all infants, from 24.2 to 11.6 episodes per 1000 patients among infants with a birth weight of 750-999 g, and from 82.7 to 23.8 episodes per 1000 patients among infants with a birth weight <750 g. Fluconazole prophylaxis use increased among all infants with a birth weight <1000 g (or <1500 g), with the largest effect on birth weights <750 g, increasing from 3.8 per 1000 patients in 1997 to 110.6 per 1000 patients in 2010. The use of broad-spectrum antibacterial antibiotics decreased among all infants from 275.7 per 1000 patients in 1997 to 48.5 per 1000 patients in 2010. The use of empirical antifungal therapy increased over time from 4.0 per 1000 patients in 1997 to 11.5 per 1000 patients in 2010.

CONCLUSIONS

The incidence of invasive candidiasis in the NICU decreased over the 14-year study period. Increased use of fluconazole prophylaxis and empirical antifungal therapy, along with decreased use of broad-spectrum antibacterial antibiotics, may have contributed to this observation.

Antifungal agents and therapy for infants and children with invasive fungal infections: a pharmacological perspective

Invasive fungal infections, although relatively rare, are life-threatening diseases in premature infants and immunocompromised children. While many advances have been made in antifungal therapeutics in the last two decades, knowledge of the pharmacokinetics and pharmacodynamics of antifungal agents for infants and children remains incomplete. This review summarizes the pharmacology and clinical utility of currently available antifungal agents and discusses the opportunities and challenges for future research.

Population pharmacokinetics of intravenous acyclovir in preterm and term infants

BACKGROUND

Acyclovir is used to treat herpes infections in preterm and term infants; however, the influence of maturation on drug disposition and dosing requirements is poorly characterized in this population.

METHODS

We administered intravenous acyclovir to preterm and term infants <31 days postnatal age and collected plasma samples. We performed a population pharmacokinetic analysis. The primary pharmacodynamic target was acyclovir concentration ≥3 mg/L for ≥50% of the dosing interval. The final model was simulated using infant data from a clinical database.

RESULTS

The analysis included 28 infants (median 30 weeks gestation). Acyclovir pharmacokinetics was described by a 1-compartment model: clearance (L/h/kg) = 0.305 × [postmenstrual age (PMA)/31.3 weeks]. This equation predicts a 4.5-fold increase in clearance from 25 to 41 weeks PMA. With proposed dosing, the pharmacodynamic target was achieved in 91% of infants: 20 mg/kg every 12 hours in infants <30 weeks PMA; 20 mg/kg every 8 hours in infants 30 to <36 weeks PMA and 20 mg/kg every 6 hours in infants 36-41 weeks PMA.

CONCLUSIONS

Acyclovir clearance increased with infant maturation. A dosing strategy based on PMA accounted for developmental changes in acyclovir disposition to achieve the surrogate pharmacodynamic target in many infants.

Intestinal fatty-acid binding protein and metronidazole response in premature infants

OBJECTIVES

In premature infants with suspected intra-abdominal infection, biomarkers for treatment response to antimicrobial therapy are lacking. Intestinal fatty acid-binding protein (I-FABP) is specific to the enterocyte and is released in response to intestinal mucosal injury. I-FABP has not been evaluated as a surrogate marker of disease response to antimicrobial therapy. We examined the relationship between metronidazole exposure and urinary I-FABP concentrations in premature infants with suspected intra-abdominal infection.

STUDY DESIGN

We conducted an intravenous metronidazole pharmacokinetic study, collecting ≤3 urine samples per infant for I-FABP concentration measurements. We analyzed the relationship between I-FABP concentrations and measures of metronidazole exposure and pharmacokinetics, maturational factors, and other covariates.

RESULTS

Twenty-six samples from 19 premature infants were obtained during metronidazole treatment. When analyzed without regard to presence of necrotic gastrointestinal disease, there were no significant associations between predictor variables and I-FABP concentrations. However, when the sample was limited to premature infants with necrotic gastrointestinal disease, an association was found between average predicted metronidazole concentration and I-FABP concentration (p = 0.006).

CONCLUSION

While a predictive association between urinary I-FABP and metronidazole systemic exposure was not observed, the data suggest the potential of this endogenous biomarker to serve as a pharmacodynamic surrogate for antimicrobial treatment of serious abdominal infections in neonates and infants.

Sildenafil exposure and hemodynamic effect after Fontan surgery

OBJECTIVE

Determine sildenafil exposure and hemodynamic effect in children after Fontan single-ventricle surgery.

DESIGN

Prospective dose-escalation trial.

SETTING

Single-center pediatric catheterization laboratory.

PATIENTS

Nine children post Fontan single-ventricle surgical palliation and undergoing elective cardiac catheterization: median (range) age and weight, 5.2 years (2.5-9.4 yr) and 16.3 kg (9.5-28.1 kg). Five children (55%) were boys, and six of nine (67%) had a systemic right ventricle.

INTERVENTIONS

Catheterization and echocardiography performed before and immediately after single-dose IV sildenafil (0.25, 0.35, or 0.45 mg/kg over 20 min).

MEASUREMENTS AND MAIN RESULTS

Peak sildenafil and desmethyl sildenafil concentration, change in hemodynamic variables measured by cardiac catheterization and echocardiography. Maximum sildenafil concentrations ranged from 124 to 646 ng/mL and were above the in vitro threshold needed for 77% phosphodiesterase type-5 inhibition in eight of nine children and 90% inhibition in seven of seven children with doses more than or equal to 0.35 mg/kg. Sildenafil improved stroke volume (+22%, p = 0.05) and cardiac output (+10%, p = 0.01) with no significant change in heart rate in eight of nine children. Sildenafil also lowered systemic (-16%, p = 0.01) and pulmonary vascular resistance index in all nine children (median baseline pulmonary vascular resistance index 2.4 [range, 1.3-3.7]; decreased to 1.9 [0.8-2.7] Wood Units × m; p = 0.01) with no dose-response effect. Pulmonary arterial pressures decreased (-10%, p = 0.02) and pulmonary blood flow increased (9%, p = 0.02). There was no change in myocardial performance index and no adverse events.

CONCLUSIONS

After Fontan surgery, sildenafil infusion acutely improves cardiopulmonary hemodynamics, increasing cardiac index. For the range of doses studied, exposure was within the acute safety range reported in adult subjects.

Safety and pharmacokinetic profiles of repeated-dose micafungin in children and adolescents treated for invasive candidiasis

BACKGROUND

Micafungin is an echinocandin with proven efficacy against a broad range of fungal infections, including those caused by Candida spp.

OBJECTIVE

To evaluate the safety and pharmacokinetics of once-daily 3 mg/kg and 4.5 mg/kg micafungin in children with proven, probable or suspected invasive candidiasis.

METHODS

Micafungin safety and pharmacokinetics were assessed in 2 phase I, open-label, repeat-dose trials. In Study 2101, children aged 2-16 years were grouped by weight to receive 3 mg/kg (≥25 kg) or 4.5 mg/kg (<25 kg) intravenous micafungin for 10-14 days. In Study 2102, children aged 4 months to <2 years received 4.5 mg/kg micafungin. Study protocols were otherwise identical.

RESULTS

Safety was analyzed in 78 and 9 children in Studies 2101 and 2102, respectively. Although adverse events (AEs) were experienced by most children (2101: n=62; 2102: n=9), micafungin-related AEs were less common (2101: n=28; 2102: n=1), and the number of patients discontinuing due to AEs was low (2101: n=4; 2102: n=1). The most common micafungin-related AEs were infusion-associated symptoms, pyrexia and hypomagnesemia (Study 2101), and liver function abnormalities (Study 2102). The micafungin pharmacokinetic profile was similar to that seen in other studies conducted in children, but different than that observed in adults.

CONCLUSIONS

In this small cohort of children, once-daily doses of 3 mg/kg and 4.5 mg/kg micafungin were well tolerated. Pharmacokinetic data will be combined in a population pharmacokinetic analysis to support US dosing recommendations in children.

Neurodevelopmental outcome of extremely low birth weight infants with Candida infection

OBJECTIVE

Candida remains an important cause of late-onset infection in preterm infants. Mortality and neurodevelopmental outcome of extremely low birth weight (ELBW) infants enrolled in the Candida study were evaluated based on infection status.

STUDY DESIGN

ELBW infants born at Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network (NRN) centers between March 2004 and July 2007 who were screened for suspected sepsis were eligible for inclusion in the Candida study. Primary outcome data for neurodevelopmental impairment (NDI) or death were available for 1317 of the 1515 infants (87%) enrolled in the Candida study. The Bayley Scales of Infant Development-II or -III was administered at 18 months' adjusted age. A secondary comparison was performed with 864 infants enrolled in the NRN Generic Database during the same cohort who were never screened for sepsis and therefore not eligible for the Candida study.

RESULTS

Among ELBW infants enrolled in the Candida study, 31% with Candida and 31% with late-onset non-Candida sepsis had NDI at 18 months. Infants with Candida sepsis and/or meningitis had an increased risk of death and were more likely to have the composite outcome of death and/or NDI compared with uninfected infants in adjusted analysis. Compared with infants in the NRN registry never screened for sepsis, overall risk for death were similar but those with Candida infection were more likely to have NDI (OR 1.83, 95% CI 1.01-3.33, P = .047).

CONCLUSIONS

In this cohort of ELBW infants, those with infection and/or meningitis were at increased risk for death and/or NDI. This risk was highest among those with Candida sepsis and/or meningitis.

Adverse events associated with meropenem versus imipenem/cilastatin therapy in a large retrospective cohort of hospitalized infants

BACKGROUND

Carbapenems are commonly used in hospitalized infants despite a lack of complete safety data and associations with seizures in older children. We compared the incidence of adverse events in hospitalized infants receiving meropenem versus imipenem/cilastatin.

METHODS

We conducted a retrospective cohort study of 5566 infants treated with meropenem or imipenem/cilastatin in neonatal intensive care units managed by the Pediatrix Medical Group between 1997 and 2010. Multivariable conditional logistic regression was performed to evaluate the association between carbapenem therapy and adverse events, controlling for infant factors and severity of illness.

RESULTS

Adverse events were more common with use of meropenem compared with imipenem/cilastatin (62.8/1000 infant days versus 40.7/1000 infant days, P < 0.001). There was no difference in seizures with meropenem versus imipenem/cilastatin (adjusted odds ratio 0.96; 95% confidence interval: 0.68, 1.32). The incidence of death, as well as the combined outcome of death or seizure, was lower with meropenem use-odds ratio 0.68 (0.50, 0.88) and odds ratio 0.77 (0.62, 0.95), respectively.

CONCLUSION

In this cohort of infants, meropenem was associated with more frequent but less severe adverse events when compared with imipenem/cilastatin.

Sildenafil exposure and hemodynamic effect after stage II single-ventricle surgery

OBJECTIVES

To determine sildenafil exposure and hemodynamic effect in children after stage II single-ventricle surgery.

DESIGN

Prospective, dose escalation trial.

SETTING

Single-center, pediatric catheterization laboratory.

PATIENTS

Twelve children poststage II single-ventricle surgical palliation and undergoing elective cardiac catheterization: median age 1.9 years (range, 0.8, 4.0), weight 11 kg (8, 13), nine females, and 10 with a single right ventricle.

INTERVENTIONS

Catheterization and echocardiography performed before and immediately after single-dose IV sildenafil (0.125, 0.25, 0.35, or 0.45 mg/kg over 20 min).

MEASUREMENTS

Peak sildenafil and desmethyl sildenafil concentration, change in hemodynamic parameters measured by cardiac catheterization and echocardiography including indexed pulmonary vascular resistance, and myocardial performance.

MAIN RESULTS

Maximum sildenafil concentrations ranged from 92 to 775 ng/mL and were above the in vitro threshold needed for 77% phosphodiesterase type 5 (PDE-5) inhibition in 80% of subjects and 90% inhibition in 80% of subjects with doses ≥0.35 mg/kg. Sildenafil lowered pulmonary vascular resistance index in all 12 subjects (median pulmonary vascular resistance index 2.2 [range, 1.6, 7.9]; decreased to 1.7 [1.2, 5.4] WU × m; p < 0.01) with no dose-response effect. Sildenafil improved pulmonary blood flow (+8% [0, 20], p = 0.04) and saturations (+2% [0, 16], p = 0.04) in those with baseline pulmonary vascular resistance index ≥ 2 WU × m (n = 7). Change in saturations correlated inversely with change in pulmonary vascular resistance index (r = 0.74, p < 0.01). Sildenafil also lowered mean blood pressure (-12% [-20, +10]; p = 0.04). There was no change in cardiac index and no effect on myocardial performance. There were no adverse events.

CONCLUSIONS

Sildenafil demonstrated nonlinear exposure with high interindividual variability but was well tolerated and effectively lowered pulmonary vascular resistance index in all subjects. Sildenafil did not acutely improve myocardial performance or increase cardiac index.

Pharmacological resolution of a multiloculated Candida spp. liver abscess in a preterm neonate

We report the case of a 31-week gestational age neonate with Candida albicans sepsis and a hepatic abscess. Diagnosis relied on clinical and radiological signs of sepsis, liver function impairment and culture isolation of Candida spp. from sterile sites. Liver ultrasound documented the presence of a multiloculated abscess. Treatment with micafungin (3 mg/kg/day) resulted in normalization of liver function and inflammatory laboratory values and improvement of clinical condition. After 30 days of treatment, the liver abscess resolved and at the 8-month follow up the infant is doing well. Prompt diagnosis and antifungal treatment avoided surgical drainage and liver surgery in this high-risk neonate.

Candida pneumonia in a term infant after prolonged use of inhaled corticosteroids for bronchopulmonary dysplasia (BPD)

Candida spp. frequently cause invasive fungal disease in neonates, and many organs or apparatus can be involved through bloodstream dissemination. Though Candida spp. can heavily colonize the upper and lower respiratory tract, an end-organ localization to the lung is not frequent and acquisition via descending/respiratory route is a questioned entity. Here we report the case of a young infant affected by bronchopulmonary dysplasia (BPD) and treated with inhaled steroids who developed Candida pneumonia likely acquired through descending route.