Influence of sodium intake on Amphotericin B-induced nephrotoxicity among extremely premature infants

Antifungal peptides from living organisms

In the post-COVID-19 era, people are increasingly concerned about microbial infections, including fungal infections that have risen in recent years. However, the currently available antifungal agents are rather limited. Worse still, the widespread use of the antifungal agents has caused the emergence of antifungal resistance in Candida, Cryptococcus, and Aspergillus species. Therefore, the development of novel antifungals is urgently needed. Antimicrobial peptides (AMPs), as components of the first-line defense of the host, are found to exhibit broad antimicrobial activity against bacteria, fungi, parasites, viruses, and protozoa. AMPs with antifungal activity are specifically referred to as antifungal peptides (AFPs). AFPs are currently regarded as the most promising alternative to conventional antifungal agents due to the fact that they are highly selective and less prone to facilitate the selection of drug resistance. In this review, we present an overview of the origin and classification of natural AFPs as well as their modes of action. Additionally, the production of natural, semisynthetic, and synthetic AFPs with a view to greater levels of exploitation is discussed. Finally, we evaluate the current and potential applications of AFPs in clinics and in the food industry.

Effect of high sodium ion level on the interaction of AmB with a cholesterol-rich phospholipid monolayer

Invasive fungal infections are a primary reason for high mortality in immunocompromised people, especially in critically ill patients, such as intensive care unit (ICU) patients, advanced cancer patients, or severe burn patients. Hypernatremia also can increase mortality in severely ill patients. Amphotericin B (AmB) is the gold standard for treating infections, but in severely ill patients, AmB can cause hematotoxicity when administered intravenously due to its interaction with cholesterol on red blood cell membranes. This results in limited doses of AmB and affects the treatment of infections. The proportion of cholesterol molecules in membrane lipids in red blood cells is as high as 50 mol%, and the sodium ions can influence the interaction between AmB and lipids on the membrane. Therefore, in the complex clinical situation of a severely ill patient with a fungal infection and hypernatremia, the interaction between amphotericin B and the red blood cell membranes is worth studying in depth. In this work, the interaction between AmB and the dipalmitoyl phosphatidylcholine (DPPC)/cholesterol mixed monolayer in the presence of high sodium ion levels was studied when the proportion of cholesterol was 50%. The results show that the effect of AmB on reducing the monolayer's area at a high level of sodium ions is slightly stronger at 30 mN/m. The effect of AmB on reducing the elastic modulus of the DPPC/Chol monolayer is significantly weakened by a high sodium ion level, compared with the level of sodium ions at normal physiological concentration. The higher the sodium ion concentration, the weaker the intermolecular force of the DPPC/Chol/AmB mixed monolayers. The scanning electron microscope (SEM) and atomic force microscopy (AFM) observations suggest that at a high sodium ion level, the presence of AmB significantly reduces the surface roughness of the DPPC/Chol monolayer. AmB may bind to cholesterol molecules, and it isolates cholesterol from the monolayer, resulting in a reduced height of the cholesterol-rich monolayer and an increasingly dispersed monolayer region. The results are beneficial to understanding the mechanism of impact of a high sodium ion level on the relationship between AmB and red blood cell membranes rich in cholesterol and are valuable for understanding the hemolytic toxicity of AmB to red blood cells at a high sodium ion level.

Incidence of Antimicrobial-Associated Acute Kidney Injury in Children: A Structured Review

Acute kidney injury (AKI) is a commonly reported adverse effect of administration of antimicrobials. While AKI can be associated with poorer outcomes, there is little information available to understand rates of AKI in children exposed to various antimicrobials. We performed a structured review using the PubMed and Embase databases. Articles were included if they provided an AKI definition in patients who were < 19 years of age receiving an antimicrobial and reported the frequency of AKI. Author-defined AKI rates were calculated for each study and mean pooled estimates for each antimicrobial were derived from among all study participants. Pooled estimates were also derived for those studies that reported AKI according to pRIFLE (pediatric risk, injury, failure, loss, end stage criteria), AKIN (acute kidney injury network), or KDIGO (kidney disease improving global outcomes) creatinine criteria. A total of 122 studies evaluating 28 antimicrobials met the inclusion criteria. Vancomycin was the most commonly studied drug: 11,514 courses across 44 included studies. Among the 27,285 antimicrobial exposures, the overall AKI rate was 13.2% (range 0-42.1% by drug), but the rate of AKI varied widely across studies (range 0-68.8%). Cidofovir (42.1%) and conventional amphotericin B (37.0%) had the highest pooled rates of author-defined AKI. Eighty-one studies used pRIFLE, AKIN, or KDIGO AKI criteria and the pooled rates of AKI were similar to author-defined AKI rates. In conclusion, antimicrobial-associated AKI is reported to occur frequently in children, but the rates of AKI varies widely across studies and drugs. Most published studies examined hospitalized patients and heterogeneity in study populations and in author definitions of AKI are barriers to a comparison of nephrotoxicity risk among antimicrobials in children.

Amphotericin B in Pediatrics: Analysis by Age Stratification Suggests a Greater Chance of Adverse Events from 13 Months of Age Onwards

BACKGROUND AND OBJECTIVE

Amphotericin B deoxycholate (AMB-D) remains an antifungal agent with great therapeutic value in pediatric patients. The currrent consensus is that its use in neonates is safer than in older children. However, childhood presents different periods of development that deserve to be evaluated more precisely. Our goal was to assess the usage profile of AMB-D in stratified pediatric age groups, adapted according to the National Institute of Child Health and Human Development classification.

METHODS

This retrospective cross-sectional observational study was conducted at a Brazilian tertiary children's hospital between January 2014 and December 2019.  Data of patients who received at least two doses of intravenous AMB-D while hospitalized were extracted from electronic health files. Information on patient demographics, underlying diseases and comorbidities, laboratory examinations, fungal infection diagnosis, and AMB-D use were gathered following specific criteria. Nonparametric tests were applied, such as the chi-square test to compare proportions and Fisher's exact test to assess the association between categorical variables or contingency tables.

RESULTS

One hundred and twenty-seven (127) medical records were stratified as preterm neonatal (birth <37 weeks postmenstrual age), term neonatal (birth-27 days), infants (28 days-12 months), toddlers (13 months-2 years), early childhood (3-5 years), middle childhood (6-11 years), and early adolescence (12-18 years). The criteria for the indication of AMB-D followed empirical use as the main indication (n = 74; 58.26%), proven and probable fungal infection (n = 39; 30.71%), and medical suspicion (n = 14; 11.02%). Candida spp. was the main etiologic agent isolated in cultures, with the highest frequency of C. albicans (n = 18; 40%), followed by Candida parapsilosis (n = 14; 31.11%), and Candida tropicalis (n = 6; 13.33%). Very few acute infusion-related adverse effects were observed during the administration of AMB-D in pediatric patients. We found an unfavorable impact of AMB-D use in patients from 13 months of age onwards suggesting this group as a turning point for a greater chance of adverse events, and not soon after the neonatal period.

CONCLUSIONS

Clinical or observational studies based on age stratification are essential to accurately elucidate whether potentially toxic drugs can be used safely in the pediatric population. Our search for a turning point was shown to contribute to the accuracy of the study, as it provided data on the impact of D-AMB in specific pediatric age groups.

Antifungal agents and the kidney: pharmacokinetics, clinical nephrotoxicity, and interactions

INTRODUCTION

Invasive fungal infections continue to be important causes of morbidity and mortality in severely ill and immunocompromised patient populations. The past three decades have seen a considerable expansion in antifungal drug research, resulting in the clinical development of different classes of antifungal agents with different pharmacologic properties. Among drug-specific characteristics of antifungal agents, renal disposition and nephrotoxicity are important clinical considerations as many patients requiring antifungal therapy have compromised organ functions or are receiving other potentially nephrotoxic medications.

AREAS COVERED

The present article reviews incidence, severity and mechanisms of nephrotoxicity associated with antifungal agents used for prevention and treatment of invasive fungal diseases by discussing distribution, metabolism, elimination and drug-related adverse events in the context of safety data from phase II and III clinical studies.

EXPERT OPINION

Based on the available data amphotericin B deoxycholate has the highest relative potential for nephrotoxicity, followed by the lipid formulations of amphotericin B, and, to a much lesser extent and by indirect mechanisms, the antifungal triazoles.

Comprehensive drug utilization review in neonates: liposomal amphotericin B

Objectives

This drug utilization evaluation aims to review current evidence on safety and efficacy of using liposomal amphotericin B (LAMB) in newborns with candidiasis, and compare it to the conventional preparation. Conventional amphotericin B deoxycholate (DAMB) is more commonly used in newborns, but dose-limiting adverse effects may compromise its efficacy. This review will examine the advantages and disadvantages of liposomal amphotericin B and define its place in current practice.

Key Findings

The terms ‘AmBisome’ or ‘liposomal amphotericin B’ and ‘neonatal candidiasis’ were entered in both PubMed and Ovid; studies included focused on safety and efficacy of liposomal amphotericin B in newborns with candidiasis, as well as studies comparing the conventional and the liposomal formulations in newborns as monotherapy. Pertinent references obtained from this search were also included. Additionally, pharmacokinetic studies were reviewed to include available data on dosing. Single case reports were not included in the review due to the limited conclusions that can be drawn from such sample sizes and quality of data.

Summary

Although liposomal amphotericin B may be better tolerated and as efficacious as the conventional formulation based on the published literature, the weakness of the studies available on the subject cannot be overlooked. Additional randomized controlled trials are needed to determine the true benefits of this medication.

Use of Fungal Diagnostics and Therapy in Pediatric Cancer Patients in Resource-Limited Settings

Fungal diseases are an important cause of mortality in immunocompromised hosts, and their incidence in pediatric cancer patients in low- to middle-income countries is underestimated. In this review, we present relevant, up-to-date information about the most common opportunistic and endemic fungal diseases among children with cancer, their geographic distribution, and recommended diagnostics and treatment. Efforts to improve the care of children with cancer and fungal disease must address the urgent need for sustainable and cost-effective solutions that improve training, fungal disease testing capability, and the use of available resources. We hope that the collective information presented here will be used to advise healthcare providers, regional and country health leaders, and policymakers of the current challenges in diagnosing and treating fungal infections in children with cancer in low- to middle-income countries.

Drug-induced acute kidney injury in neonates

PURPOSE OF REVIEW

Acute kidney injury (AKI) is an independent risk factor for morbidity and mortality in critically ill neonates. Nephrotoxic medication exposure is common in neonates. Nephrotoxicity represents the most potentially avoidable cause of AKI in this population.

RECENT FINDINGS

Recent studies in critically ill children revealed the importance of recognizing AKI and potentially modifiable risk factors for the development of AKI such as nephrotoxic medication exposures. Data from critically ill children who have AKI suggest that survivors are at risk for the development of chronic kidney disease. Premature infants are born with incomplete nephrogenesis and are at risk for chronic kidney disease. The use of nephrotoxic medications in the neonatal intensive care unit is very common; yet the effects of medication nephrotoxicity on the short and long-term outcomes remains highly understudied.

SUMMARY

The neonatal kidney is predisposed to nephrotoxic AKI. Our ability to improve outcomes for this vulnerable group depends on a heightened awareness of this issue. It is important for clinicians to develop methods to minimize and prevent nephrotoxic AKI in neonates through a multidisciplinary approach aiming at earlier recognition and close monitoring of nephrotoxin-induced AKI.

Infectious complications in children with acute lymphoblastic leukemia treated in low-middle-income countries

Infections are the most important cause of morbidity and mortality in children treated for acute lymphoblastic leukemia (ALL). The rates of infection-associated mortality are up to 10-times higher in low- and middle-income countries (LMIC) than in high-income countries. The prevention, early recognition and management of infectious complications is especially challenging in LMIC because of disease and poverty-related factors, as well as the shortage of trained personnel, supplies, diagnostic tools and adequate organizational infrastructure. Children in LMIC with ALL, who are frequently underweight, are at increased risk of community-acquired pathogens, nosocomial multidrug-resistant pathogens and opportunistic microorganisms. This review summarizes the challenges of managing the major categories of infections in children receiving treatment for ALL and provides updated practical recommendations for preventing and managing these infections in LMIC.

The interplay between drugs and the kidney in premature neonates

The kidney plays a central role in the clearance of drugs. However, renal drug handling entails more than glomerular filtration and includes tubular excretion and reabsorption, and intracellular metabolization by cellular enzyme systems, such as the Cytochrome P450 isoenzymes. All these processes show maturation from birth onwards, which is one of the reasons why drug dosing in children is not simply similar to dosing in small adults. As kidney development normally finishes around the 36th week of gestation, being born prematurely will result in even more immature renal drug handling. Environmental effects, such as extra-uterine growth restriction, sepsis, asphyxia, or drug treatments like caffeine, aminoglycosides, or non-steroidal anti-inflammatory drugs, may further hamper drug handling in the kidney. Dosing in preterm neonates is therefore dependent on many factors that need to be taken into account. Drug treatment may significantly hamper postnatal kidney development in preterm neonates, just like renal immaturity has an impact on drug handling. The restricted kidney development results in a lower number of nephrons that may have several long-term sequelae, such as hypertension, albuminuria, and renal failure. This review focuses on the interplay between drugs and the kidney in premature neonates.

Deoxycholate amphotericin B and nephrotoxicity in the pediatric setting

Since the introduction of amphotericin B as an antifungal agent, the morbidity and mortality of pediatric patients with mycotic infections have increased, primarily because of the increased immunocompromised patients. Despite the fact that deoxycholate amphotericin B was once the primary drug used for mycotic infections, its administration to children older than neonates is currently controversial because of its nephrotoxic effects. Three lipid-associated formulations have been developed and have reportedly shown similar efficacy and fewer nephrotoxic effects in adults than conventional amphotericin B, but the conclusions from comparative studies in children evaluating the nephrotoxicity risks of the 4 agents are controversial. Nevertheless, guidelines favor liposomal or lipid complex amphotericin B when polyene antifungal therapy is recommended in this age group. However, high acquisition costs often preclude their prescription in economically poor regions. Thus, physicians must consider all of these factors when determining the most cost-effective polyene antifungal treatment for their pediatric patients. This is particularly pertinent in developing countries where resources are scarce. Adjuvant sodium supplementation has been reported to be effective in protecting kidney function in extremely low birth weight infants prescribed deoxycholate amphotericin B. Further pharmacokinetic and pharmacodynamic studies of the drug in children could also provide information for rational dosing regimens designed to decrease nephrotoxicity. Conventional amphotericin B, with appropriate kidney protective measures, still plays a role in the treatment of empiric invasive mycotic infections in most pediatric patients. Liposomal and lipid complex amphotericin B should be reserved for those receiving long-term nephrotoxic agents or with altered renal function or disease. Antifungal susceptibility, renal compromise and the clinical status of the patient should determine treatment for culture-proven infections. Under the current cost limitations, undertaking and evaluating low-cost, kidney-sparing, deoxycholate amphotericin B treatments for children should be a primary concern.

Are salt loading and prolonging infusion period effective in prevention of amphotericin B-induced nephrotoxicity?

INTRODUCTION

Nephrotoxicity is generally considered as the most clinically significant adverse reaction of amphotericin B, and has been reported in up to 80% of amphotericin B recipients during the first 2 weeks of treatment. Numerous experimental and clinical investigations have been performed over the past 4 decades, to find appropriate interventions for preventing or minimizing the nephrotoxic effects of amphotericin B.

AREAS COVERED

The aim of this literature review was to collect available clinical data regarding interventions to prevent amphotericin B-induced nephrotoxicity in human populations. A literature search was performed in the following databases: Scopus, Medline, Embase, Cochrane central register of controlled trials, and Cochrane database systematic reviews. The key words used as search terms were 'amphotericin', 'amphotericin B', 'nephrotoxicity', 'renal failure', 'renal damage', 'renal dysfunction', 'renal impairment', 'prevention', 'preventive measures', and 'preventive interventions'.

EXPERT OPINION

Studies in humans have clearly demonstrated that salt loading can prevent or alleviate an amphotericin B-induced rise in serum creatinine, or decrease in glomerular filtration rate, without beneficial effects on tubular toxicity of amphotericin B. Current clinical data regarding the prolongation of amphotericin B duration of infusion in the prevention of nephrotoxicity is controversial and associated with several clinical and practical drawbacks.

Long-term effects of neonatal drugs on the kidney

Several drugs have been shown to produce an adverse affect on kidneys, mainly when exposure occurred during active nephrogenesis (pregnancy or prematurity). Several experimental studies on drug-related renal injury have been done on animal models. Observational reports on early drug-related nephrotoxicity in humans are increasing. The investigations regard nephrotoxicity from antibiotics (particularly aminoglycosides), angiotensin-converting enzyme (ACE) inhibitors, non-steroidal anti-inflammatory drugs and antifungins. Few reports have been specifically on the long-term effects on kidneys of drugs given to newborns during active nephrogenesis. Most observations were targeted to investigate long-term renal effects of prematurity and intrauterine growth retardation (IUGR). Nephrotoxic medication taken during fetal life and during postnatal nephrogenesis could interfere with nephron generation contributing to a particular magnitude of damage. Such adjunctive damage could further increase the risk of renal failure in the adulthood of children born prematurely.

Antifungal treatment of small animal veterinary patients

Antifungal therapy has progressed significantly with the development of new drugs directed at various processes in fungal cell metabolism. Within veterinary medicine, treatment options for systemic mycoses remain limited to amphotericin B, ketoconazole, fluconazole, and itraconazole. However, newer triazoles, echinocandins, and lipid-based formulations of amphotericin B are now approved for use in humans. This article provides a comprehensive review of the antifungal medications available for veterinary patients, and includes a brief discussion of the newer, presently cost-prohibitive, antifungal therapies used for systemic mycoses in humans.

Challenging issues in neonatal candidiasis

In an era of quality improvement and 'getting to zero (infections and/or related mortality),' neonatal candidiasis is ripe for evidence-based initiatives. Knowledge of each institution's invasive Candida infection (ICI) incidence and infection-related mortality is critical to evaluate disease burden and effective interventions. Evidenced-based interventions include: antifungal prophylaxis, starting with appropriate dosing, and prompt removal of central venous catheters (CVC). There is A-I evidence supporting antifungal prophylaxis with fluconazole, and it should be considered in every neonatal intensive care unit (NICU). The literature supports targeting infants <1000 g and/or <or=27 weeks, because this group has high infection-related mortality and neurodevelopmental impairment in 57% of survivors. Antifungal prophylaxis has been shown to nearly eliminate infection-related mortality. Interventions start with prenatal initiatives, with women being treated for vaginal candidiasis, especially with preterm labor or complications. Targeting modifiable risk factors, including restriction policies for use of third- and fourth-generation cephalosporins, carbapenems, H2-antagonists, proton pump inhibitors, and postnatal steroids; guidelines for CVC care and removal; and feeding practices, with promotion of early feedings and breast milk, may also reduce risk. A few studies have emerged on empiric antifungal therapy with sepsis evaluations for preterm infants <1500 g and other high-risk patients that have shown favorable effects of eliminating mortality, but these have not been compared to appropriate antifungal therapy and central line removal. Further study of empiric therapy, prospective treatment studies with higher targeted dosing of amphotericin B preparations, fluconazole, and new antifungals with prompt CVC removal may contribute to a 100% survival rate for those infants >1000 g and >or=28 weeks not receiving antifungal prophylaxis. Evaluation of ICI incidence and mortality by gestational age and birth week should be followed in each NICU, to evaluate infection control and prevention.