Fluconazole prophylaxis in preterm infants: a multicenter case-controlled analysis of efficacy and safety

Prophylaxis of Invasive Fungal Infection in Neonates: A Narrative Review for Practical Purposes

Candida albicans is the most frequent cause of invasive fungal disease in preterm and/or low birth weight neonates, followed by Candida parapsilosis, whilst infections from other species are rare. Considering the severity of the disease, associated with poor clinical signs and diagnostic difficulties, primary prophylaxis becomes relevant. This paper summarizes the pathogenesis and clinical presentation of invasive candidiasis in neonates, focusing on prophylaxis. For late onset invasive disease, e.g., those occurring after the 3rd (or 7th according to some definitions) day of life possible approaches are the use of fluconazole, recommended in case of weight <1000 g or <1500 g if the local incidence of invasive candidiasis is higher than 2%, or the use of nystatin (for patients < 1500 g). Micafungin must be used in case of colonization by Candida auris, or in centers with a high prevalence of this pathogen. Concurrently, correct management of the central venous catheter and isolation procedures, with special regard to patients colonized by resistant strains, are fundamental. Other approaches such as reduced use of H₂ blockers and broad-spectrum antibiotics (e.g., 3rd generation cephalosporins or carbapenems) and promotion of breast feeding proved useful. Reduction of early-onset infections (those occurring in the first 3 days of life) can also be obtained by treating maternal vulvo-vaginal candidiasis, which can represent a fastidious problem during pregnancy. In this case, topic azoles (the only recommendable treatment) can represent a kind of "prophylaxis" of early neonatal candidiasis. However, it must always be remembered that prophylaxis reduces the risk of invasive candidiasis but can not completely eliminate its occurrence, with the parallel risk of selecting for antifungal-resistant strains. Clinicians must maintain a high level of suspicion to start an appropriate therapy and strict epidemiological surveillance to identify the occurrence of clusters and the appearance of strains resistant to prophylaxis.

[Recent research on pharmacological prevention strategies for invasive fungal infection in preterm infants]

There is a relatively high incidence rate of invasive fungal infection (IFI) in preterm infants admitted to the neonatal intensive care unit (NICU), and early diagnosis of IFI is difficult in clinical practice. The patients developing IFI tend to have severe conditions, a long course of treatment, high hospital costs, high mortality, and poor prognosis, and therefore, the prevention of IFI is of particular importance. At present, fluconazole is often used as the first-line drug for the prevention of IFI in preterm infants, but no consensus has been reached on the specific dose and course of treatment, and there are still controversies over the targeted population and prophylactic effect. This article reviews the recent research on the pharmacological prevention strategies for IFI in preterm infants in the NICU, so as to provide a reference for clinicians.

Neonatal invasive candidiasis: updates on clinical management and prevention

Neonatal invasive candidiasis is an important cause of morbidity and mortality in preterm infants. The incidence of invasive candidiasis in this population has been declining in high-income settings, largely due to preventive measures, although there are still considerable variations in incidence between health-care centres. Surveillance data and large, multicentre studies in lower-income settings are not available, although preventive measures in these settings have been shown to decrease the incidence of neonatal invasive candidiasis. Understanding risk factors and pathogenesis are key to the prevention of invasive candidiasis. The difficulty of a definitive diagnosis of invasive candidiasis and the high risk for death or substantial neurodevelopmental impairment, even with appropriate treatment, further increase the need for effective preventive measures. In this Review, we examine the pathogenesis, clinical presentation, and diagnosis of invasive candidiasis. We highlight commonly used and emerging preventive and prophylactic measures, including standardised central line care, antibiotic stewardship, antifungal prophylaxis, and probiotics. Finally, we provide updates on empirical treatment, clinical management in confirmed cases of invasive candidiasis, and antifungal pharmacotherapy.

Serum (1 → 3)-β-D-glucan could be useful to rule out invasive candidiasis in neonates with an adapted cut-off

AIM

We assessed the diagnostic accuracy of serum (1 → 3)-β-D-glucan (BDG) for neonatal invasive candidiasis (NIC) using the recommended cut-off usually used in adults for detecting invasive candidiasis and searched for an optimal cut-off for ruling out NIC.

METHODS

We conducted a prospective cross-sectional study at Nantes University medical centre from January 2017 to July 2018. All consecutive newborn infants of less than 28 days of corrected age, with clinically suspected NIC, who underwent BDG assay, were included. Sensitivity and specificity were calculated by using the recommended cut-off of 80 pg/mL. Receiver operating characteristic curve analysis was used to identify an optimal cut-off value.

RESULTS

We included 55 newborn infants with 61 episodes of suspected NIC. Their median gestational and chronological ages were 28.0 weeks (interquartile range [IQR] 26.4-34.1) and 10.0 days (IQR 6.0-22.0), respectively. Of 61 episodes, seven revealed NIC. Sensitivity and specificity were 85.7% (95% confidence interval [CI] 42.1%-99.6%) and 51.9% (37.8%-65.7%) with the recommended cut-off, respectively. An optimal cut-off of 174 pg/mL offered the same sensitivity but higher specificity 77.8% (64.4%-88.0%).

CONCLUSION

The recommended cut-off of 80 pg/mL was probably too low for ruling out NIC. A higher cut-off might have been more appropriate.

Fluconazole Prophylaxis of Candida Infections in Preterm Neonates

Infections belong to the most serious health problems in neonates. Invasive candidiases are one of the leading causes of mortality and morbidity in Neonatal intensive care units (NICUs). A more cautious approach is adequate when dealing with fungal infections in premature neonates. Sometimes it is necessary to cure an infection at the very beginning just before manifestation of clinical symptoms. Neonatal colonization due to Candida albicans or non-albicans Candidae predisposes to invasive candidiasis. Pregnancies complicated by preterm delivery should be considered for screening and treatment of maternal Candida colonization to decrease the occurrence of neonatal fungal colonization and its consequences. It is important to prevent infection to spread among patients and avoid complications. Prophylaxis in neonates must be safe and effective. Most authors prefer selective prophylaxis. Fluconazole is the drug of choice for prophylaxis in extremely low birth weight (ELBW) neonates. The prophylaxis is beneficial especially in NICUs with high rates of invasive candidiases. The authors describe benefits and trends in prophylaxis. They also summarize evidence on timing, dosing, and effect of fluconazole prophylaxis.

Comparison of Antifungal Azole Interactions with Adult Cytochrome P450 3A4 versus Neonatal Cytochrome P450 3A7

Adult drug metabolism is dominated by cytochrome P450 3A4 (CYP3A4), which is often inhibited by antifungal azole drugs, resulting in potential alterations in drug metabolism and adverse drug/drug interactions. In the fetal and neonatal stages of life, the 87% identical cytochrome P450 3A7 (CYP3A7) is expressed but not CYP3A4. Azole antifungals developed for adults are also used in neonates, assuming they interact similarly with both enzymes, but systematic information is lacking. Herein a method was developed for generating recombinant purified CYP3A7. Thirteen different azoles were then evaluated for binding and inhibition of purified human CYP3A4 versus CYP3A7. All imidazole-containing azoles bound both enzymes via coordination to the heme iron and inhibited both with IC₅₀ values ranging from 180 nM for clotrimazole to the millimolar range for imidazole itself. Across this wide range of potencies, CYP3A4 was consistently inhibited more strongly than CYP3A7, with clotrimazole being the least selective (1.5-fold) inhibitor and econazole the most selective (12-fold). Observations for 1,2,4-triazole-containing azoles were more varied. Most bound to CYP3A4 via coordination to the heme iron, but several also demonstrated evidence of a distinct binding mode at low concentrations. However, only posaconazole inhibited CYP3A4. Of the triazoles, only posaconazole inhibited CYP3A7, again less potently than CYP3A4. Spectral evidence for binding was weak or nonexistent for all triazoles. Overall, although the details of binding interactions do vary, the same azole compounds inhibit both enzymes, albeit with weaker interactions with CYP3A7 compared with CYP3A4.

Fluconazole prophylaxis in preterm infants: a systematic review

OBJECTIVE

This article aims to review the use of antifungal prophylaxis with intravenous fluconazole in premature newborns and the occurrence of Invasive Candidiasis.

METHODS

This is a systematic review with search at databases: PubMed, Capes Portal, Virtual Health Library (BVS - Biblioteca Virtual em Saúde)/Lilacs, Scopus and Cochrane. The keywords used were: "Antifungal", "Candida" "Fluconazole prophylaxis" and "Preterm infants".

RESULTS

Invasive Candidiasis was evaluated in all the twelve items. In eleven of them, there was a statistically significant difference between the groups receiving prophylactic fluconazole, with lower frequency of Invasive Candidiasis, compared to placebo or no prophylaxis group. Colonization by Candida species was also evaluated in five studies; four of them presented statistically lower proportion of colonization in patients with Fluconazole prophylaxis, compared to placebo or no drugs. In one study, there was a significant difference, favoring the use of fluconazole, and reduction of death.

CONCLUSION

Studies indicate the effectiveness of prophylaxis with fluconazole, with reduction in the incidence of colonization and invasive fungal disease. The benefits of prophylaxis should be evaluated considering the incidence of candidiasis in the unit, the mortality associated with candidiasis, the safety and toxicity of short and long-term medication, and the potential for development of resistant pathogens.

Parenteral Nutrition-Associated Cholestasis in Very Low Birth Weight Infants: A Single Center Experience

PURPOSE

Parenteral nutrition (PN)-associated cholestasis (PNAC) is one of the most common complications in very low birth weight infants (VLBWIs). The aim of this study is to evaluate the risk factors of PNAC in VBLWIs.

METHODS

We retrospectively reviewed the medical records of 322 VLBWIs admitted to the neonatal intensive care unit of our hospital from July 1, 2009 to December 31, 2013. We excluded 72 dead infants; 6 infants were transferred to another hospital, and 57 infants were transferred to our hospital at 2 weeks after birth. The infants were divided into the cholestasis and the non-cholestasis groups. PNAC was defined as a direct bilirubin level of ≥2.0 mg/dL in infants administered with PN for ≥2 weeks.

RESULTS

A total of 187 VLBWI were enrolled in this study; of these, 46 infants developed PNAC. Multivariate logistic regression analysis showed that the risk factors of PNAC in VLBWI were longer duration of antimicrobial use (odds ratio [OR] 4.49, 95% confidence interval [95% CI] 4.42-4.58), longer duration of PN (OR 2.68, 95% CI 2.41-3.00), long-term lack of enteral nutrition (OR 2.89, 95% CI 2.43-3.37), occurrence of necrotizing enterocolitis (OR 2.40, 95% CI 2.16-2.83), and gastrointestinal operation (OR 2.19, 95% CI 2.03-2.58).

CONCLUSION

The results of this study suggest that shorter PN, aggressive enteral nutrition, and appropriate antimicrobial use are important strategies in preventing PNAC.

New antifungal and antiviral dosing

Neonatal fungal and viral infections are associated with mortality and neurologic impairment among survivors. Advances in pharmacokinetics (PK) and pharmacodynamics (PD) of antimicrobial medications have led to improved dosing guidance for neonates. This article discusses the basic PK/PD properties and dosing of the most common antifungal and antiviral medications used in neonates.

Infectious causes of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency among premature infants. Although a large body of research has focused on understanding its pathogenesis, the exact mechanism has not been elucidated. Of particular interest is the potential causative role of infectious culprits in the development of NEC. A variety of reports describe bacterial, viral, and fungal infections occurring in association with NEC; however, no single organism has emerged as being definitively involved in NEC pathogenesis. In this review, the authors summarize the literature on infectious causes of NEC.