Lack of evidence of amphotericin B toxicity in very low birth weight infants treated for systemic candidiasis

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.

Neonatal liver abscesses associated with candidemia: three cases and review of literature

BACKGROUND

Our aim was to identify risk factors for the development of neonatal Candida liver abscess and to find useful information to better manage this potentially fatal complication.

METHODS

A computerized search was conducted using PubMed. Overall, three articles describing the history of seven infants were finally considered. The characteristics of these seven cases were analyzed together with those of three new cases that we treated in the recent past.

RESULTS

All the neonates were premature. Previous antibiotic use was reported in all the cases, umbilical venous catheterization in 9/10 and total parenteral nutrition in 8/10. Candida albicans was isolated in 9/10. All the patients presented with aspecific signs of sepsis. Liver abscesses were described as "microabscesses" or "miliary abscesses" in three cases, as solitary lesion in two cases. In one case two lesions and in one four lesions were reported. Three infants died.

CONCLUSIONS

Liver ultrasonography should be performed in all the neonates with signs of sepsis, especially in the presence of candidemia and/or hepatomegaly and/or significant change in liver enzymes. Umbilical venous catheter should be removed, and peripheral IV access should be used until there is documented clearance from the blood with three or more negative blood cultures.

Diagnosis and therapy of Candida infections: joint recommendations of the German Speaking Mycological Society and the Paul-Ehrlich-Society for Chemotherapy

Invasive Candida infections are important causes of morbidity and mortality in immunocompromised and hospitalised patients. This article provides the joint recommendations of the German-speaking Mycological Society (Deutschsprachige Mykologische Gesellschaft, DMyKG) and the Paul-Ehrlich-Society for Chemotherapy (PEG) for diagnosis and treatment of invasive and superficial Candida infections. The recommendations are based on published results of clinical trials, case-series and expert opinion using the evidence criteria set forth by the Infectious Diseases Society of America (IDSA). Key recommendations are summarised here: The cornerstone of diagnosis remains the detection of the organism by culture with identification of the isolate at the species level; in vitro susceptibility testing is mandatory for invasive isolates. Options for initial therapy of candidaemia and other invasive Candida infections in non-granulocytopenic patients include fluconazole or one of the three approved echinocandin compounds; liposomal amphotericin B and voriconazole are secondary alternatives because of their less favourable pharmacological properties. In granulocytopenic patients, an echinocandin or liposomal amphotericin B is recommended as initial therapy based on the fungicidal mode of action. Indwelling central venous catheters serve as a main source of infection independent of the pathogenesis of candidaemia in the individual patients and should be removed whenever feasible. Pre-existing immunosuppressive treatment, particularly by glucocorticosteroids, ought to be discontinued, if feasible, or reduced. The duration of treatment for uncomplicated candidaemia is 14 days following the first negative blood culture and resolution of all associated symptoms and findings. Ophthalmoscopy is recommended prior to the discontinuation of antifungal chemotherapy to rule out endophthalmitis or chorioretinitis. Beyond these key recommendations, this article provides detailed recommendations for specific disease entities, for antifungal treatment in paediatric patients as well as a comprehensive discussion of epidemiology, clinical presentation and emerging diagnostic options of invasive and superficial Candida infections.

Kodamaea ohmeri tricuspid valve endocarditis with right ventricular inflow obstruction in a neonate with structurally normal heart

The yeast Kodamaea (Pichia) ohmeri is a rare human pathogen with infrequent report of neonatal infection. Native valve endocarditis by Kodamaea ohmeri is extremely rare. The current case report describes a case of fatal nosocomial native valve endocarditis without any structural heart defects in a 40dayold baby. The patient was referred to our institute after having ICU stay of 18 days in another hospital for necrotizing enterocolitis and was found to have obstructive tricuspid valve mass and fungemia with Kodamaea ohmeri. In spite of the treatment, patient developed sepsis with disseminated intravascular coagulation and could not be revived.

Nephrotoxicity associated with amphotericin B deoxycholate in neonates

BACKGROUND

The prevalence of nephrotoxicity in neonates receiving amphotericin B deoxycholate (amphoB) is not well-defined. While some studies report a lack of toxicity, others claim a frequency as high as 85%.

METHODS

We reviewed medical records of all infants < or = 90 days of age in the neonatal intensive care unit who received at least 3 doses of amphoB between January 1990 and December 2004. A standardized form was used to collect demographic, therapeutic, microbiologic, and laboratory data for each patient. Nephrotoxicity was defined as a rise in serum creatinine (SCr) of at least 0.4 mg/dL any time during amphoB therapy.

RESULTS

A total of 92 infants met entry criteria. Median gestational age was 26 (range: 23-41) weeks and median birth weight was 863 (range: 546-4000) grams. Overall, 15 (16%) infants experienced nephrotoxicity, and 16 (17%) developed hypokalemia (<3.0 mmol/L). There were no differences between infants who did or did not develop nephrotoxicity in terms of gestational age, birth weight, gender, underlying medical conditions, or use of other potentially nephrotoxic medications. AmphoB exposure and duration of therapy were similar between infants who developed nephrotoxicity and those who did not, with a mean cumulative dose of 13.5 +/- 9.6 mg/kg and duration of 16.3 +/- 10.4 days. With the exception of 1 infant, the elevated SCr values resolved in all infants by the end of amphoB therapy.

CONCLUSION

AmphoB administration does not appear to be associated with lasting measurable nephrotoxicity in neonates. Because of changes in serum creatinine and potassium, renal function and potassium levels should be monitored closely in infants receiving amphoB.

Antifungal agents in neonates: issues and recommendations

Fungal infections are responsible for considerable morbidity and mortality in the neonatal period, particularly among premature neonates. Four classes of antifungal agents are commonly used in the treatment of fungal infections in pediatric patients: polyene macrolides, fluorinated pyrimidines, triazoles, and echinocandins. Due to the paucity of pediatric data, many recommendations for the use of antifungal agents in this population are derived from the experience in adults. The purpose of this article was to review the published data on fungal infections and antifungal agents, with a focus on neonatal patients, and to provide an overview of the differences in antifungal pharmacology in neonates compared with adults. Pharmacokinetic data suggest dosing differences in children versus adult patients with some antifungals, but not all agents have been fully evaluated. The available pharmacokinetic data on the amphotericin B deoxycholate formulation in neonates exhibit considerable variability; nevertheless, the dosage regimen suggested in the neonatal population is similar to that used in adults. More pharmacokinetic information is available on the liposomal and lipid complex preparations of amphotericin B and fluconazole, and it supports their use in neonates; however, the optimal dosage and duration of therapy is difficult to establish. All amphotericin-B formulations, frequently used in combination with flucytosine, are useful for treating disseminated fungal infections and Candida meningitis in neonates. Fluconazole, with potent in vitro activity against Cryptococcus neoformans and almost all Candida spp., has been used in neonates with invasive candidiasis at dosages of 6 mg/kg/day, and for antifungal prophylaxis in high-risk neonates. There are limited data on itraconazole, voriconazole, and posaconazole use in neonates. Caspofungin, which is active against Candida spp. and Aspergillus spp., requires higher doses in children relative to adults, and dosing is best accomplished based on body surface area. Micafungin shows a clear trend toward lower levels in the smallest patients. There are no data on the use of other new antifungal drugs (ravuconazole and anidulafungin) in neonates. In summary, the initial data suggest dosage differences in neonates for some antifungal agents, although the newer agents have not been fully tested for optimal administration in these patients.

Antifungal therapy in children with invasive fungal infections: a systematic review

Invasive fungal infections are associated with significant morbidity and mortality. Differences between children and adults are reported, yet few trials of antifungal agents have been performed in pediatric populations. We performed a systematic review of the literature to guide appropriate pediatric treatment recommendations. From available trials that compared antifungal agents in either prolonged febrile neutropenia or invasive candidal or Aspergillus infection, no clear difference in treatment efficacy was demonstrated, although few trials were adequately powered. Differing antifungal pharmacokinetics between children and adults were demonstrated, requiring dose modification. Significant differences in toxicity, particularly nephrotoxicity, were identified between classes of antifungal agents. Therapy needs to be guided by the pathogen or suspected pathogens, the degree of immunosuppression, comorbidities (particularly renal dysfunction), concurrent nephrotoxins, and the expected length of therapy.

Prevention and treatment of Candida infections in neonates

Invasive Candia infections have become the third most common cause of late-onset infection among very low birth weight infants in most neonatal intensive care units. Significant risk factors include birth weight less than 1000 g, exposure to more than two antibiotics, third generation cephalosporin exposure, parenteral nutrition including lipid emulsion, central venous catheter, and abdominal surgery. The majority of neonatal Candida infections are caused by C. albicans and C. parapsilosis, although other nonalbicans species are being reported more frequently. Standard therapy has been amphotericin B; however, successful use of fluconazole as a single agent has also been reported and a small comparison trial demonstrated similar efficacy. The addition of new antifungal agents, including voriconazole and the echinocandins may further improve our ability to effectively treat these infections and possibly reduce the development of complications. Antifungal chemoprophylaxis has been studied in single-center and cohort studies, primarily using fluconazole. Although it is clear that fluconazole prophylaxis decreases the risk of fungal colonization and infection, identification of potential harm, particularly the development of or selection for resistant strains, requires further investigation with multicenter trials before widespread use is recommended outside of the clinical trial setting.

Neonatal candidiasis: analysis of epidemiology, drug susceptibility, and molecular typing of causative isolates

A prospective observational study of invasive candidiasis was conducted in the neonatal intensive care unit of Aristotle University in Hippokration Hospital between 1994 and 2000. During this period, 59 neonates developed invasive candidiasis (58 cases of candidemia and 1 case of peritonitis), resulting in an overall incidence of 1.28% that showed a decreasing trend over the study period. Eleven (18.6%) cases developed within the first week of life and the others within a mean (+/-SEM) of 13.4+/-1.7 days after birth. The three most frequent causative species were Candida albicans (65.5%), Candida parapsilosis (15.5%), and Candida tropicalis (7%). C. albicans was the predominant species between 1994 and 1998, whereas, non-albicans Candida spp., particularly C. parapsilosis, were the most frequent species during the period 1999-2000 (P<0.001). While the overall mortality due to candidemia was 29% (17 of 59 cases), mortality associated with C. albicans and C. parapsilosis was 39.5% and 11.1%, respectively (P=0.032), and that observed in the 1999-2000 period was 0% (P=0.011). Virtually all isolates were susceptible to amphotericin B, flucytosine, fluconazole, and itraconazole, and no increases in minimal inhibitory concentrations were observed during these years. With the exception of a limited cluster of cases due to genotypically identical isolates, no clonal relation of C. albicans isolates was found. Moreover, no clonal persistence of C. albicans and no decrease in antifungal drug susceptibility occurred over the 6-year study period. Non-albicans Candida spp., mostly C. parapsilosis, have emerged as important pathogens in neonatal intensive care units, with infected patients having better outcomes as compared to patients infected with C. albicans.

Antifungals in systemic neonatal candidiasis

Fungal infections are common in the newborn period, especially among premature neonates, and are responsible for considerable morbidity and mortality. Currently, three classes of antifungals are commonly used in the treatment of systemic fungal infections in neonates: the polyene macrolides (e.g. amphotericin B [deoxycholate and lipid preparations]); the azoles (e.g. fluconazole); and the fluorinated pyrimidines (e.g. flucytosine). The echinocandins (e.g. caspofungin and micafungin) are a newer class of antifungals which shows promise in this population.The available kinetic data on amphotericin B deoxycholate in neonates are derived from very small studies and exhibit considerable variability. There are no kinetic data available for the use of lipid preparations in this population and, again, much has been inferred from adult studies. The information available for flucytosine is also limited but appears similar to what is observed in adults. Fluconazole has the most neonatal pharmacokinetic data, which show slightly less variability than the other antifungals. Genomic factors which affect the metabolism of amphotericin B and fluconazole may explain some of the observed variability. Most of the data for the efficacy of antifungal drugs in neonates are derived from retrospective studies and case reports. The data for amphotericin B deoxycholate and flucytosine are limited. There are more data for the liposomal and lipid complex preparations of amphotericin B and for fluconazole in this population. These support the use of these drugs in neonates, but because of their largely noncomparative nature they can not define the optimal dosage or duration of therapy. Amphotericin B deoxycholate is primarily nephrotoxic. It also induces electrolyte abnormalities and is to a lesser degree cardiotoxic. This toxicity in neonates appears similar to published data in older children and adults. While the lipid preparations of amphotericin B owe their existence to a presumed decrease in toxicity, the observed toxicity in neonates appears to be equal to that seen with the deoxycholate, although it should be noted that the lipid preparations are usually given at much higher dosages. Fluconazole toxicity appears to be milder and less frequent in this population than is seen with amphotericin B. In the final analysis, we do not have sufficient data to define the pharmacokinetic profiles, optimal dose or duration of therapy, or toxicity for any of these compounds in neonates. Further studies are necessary if the optimisation of antifungal therapy in this population is to continue.

Fungal infection in the very low birthweight infant

PURPOSE OF REVIEW

Fungal infections are prevalent in very low birthweight (<1500 g) infants and are associated with significant morbidity and mortality. A better understanding of the adherence factors, molecular diagnostics and risk factors for invasive fungal infection are important in treatment and prevention.

RECENT FINDINGS

Animal studies have demonstrated that Candida readily adheres to apical microvilli and the junctions between enterocytes. Although antibiotics facilitate colonization, dissemination occurs with immunosuppression. The INT1 gene is associated with enhanced colonization and dissemination in these animal models. Dissemination is probably caused by yeast cell adherence and invasion, whereas tissue injury may be related to filamentous formation. Polymerase chain reaction techniques have demonstrated promise in neonatal patients and may not only detect bloodstream infection, but fungal infection at other sites. At the time of fungal sepsis, less than 28 weeks' gestation, thrombocytopenia, and previous exposure to broad-spectrum antibiotics continue to be risk factors for infection. Empiric therapy is still being defined and investigated. Fluconazole prophylaxis should be strongly considered in the most immature infants.

SUMMARY

Preventative strategies against fungal colonization and infection are critical in high-risk very low birthweight infants. Also promising is the ability of molecular diagnostics to detect infection earlier, allowing for prompt treatment, including central venous catheter removal. Identifying the highest risk very low birthweight infants for prophylaxis and empiric therapy may lead to better outcomes. Multicenter clinical trials of fluconazole prophylaxis to confirm its safety and efficacy, and of empiric treatment to test safety and outcomes are urgently needed.

Antifungal pharmacotherapy for neonatal candidiasis

Candida is a leading cause of late onset infection (> 3 days of age) in the premature infant. Therefore, decisions about the diagnosis and management of infections caused by Candida are commonplace in the neonatal intensive care unit. Despite this fact, there are few comparative trials about treatment of neonatal Candida infections to guide the practitioner. New antifungals have been developed in the past decade and some clinical experience has been reported that can be used to guide the treatment of infants with serious Candida infections. This article reviews recent pertinent data with regard to dosing guidelines, efficacy, and toxicities of available systemic antifungal agents in the newborn.

Candidal renal and urinary tract infection in neonates

Candida species are a common cause of urinary tract infection in newborns requiring intensive care. Renal candidiasis is frequently associated with these urinary tract infections and is manifest by "fungus balls" or renal parenchymal infiltration. Candidal urinary tract infections in high-risk newborns are often associated with candidemia, thereby warranting systemic antifungal therapy. Sonography is useful in diagnosing renal candidiasis, obstruction from "fungus balls," and abscesses. The sonographic appearance of "fungus balls" may persist long after clinical resolution of Candida infection in neonates and should not affect duration of antifungal therapy. Amphotericin B is currently the drug of choice for neonates with renal candidiasis and candidal urinary tract infection. Surgical management should be reserved for decompression of obstructive candidiasis and drainage of abscesses.

Neonatal Candida meningitis

Candida: spp. are becoming one of the most common pathogens associated with sepsis in the setting of neonatal intensive care. Invasive therapies aimed at improving patient survival, particularly among premature infants, contribute significantly to this alteration in the distribution of neonatal pathogens. Prematurity is one of the principle risk factors associated with the development of neonatal meningitis in this patient population. Untreated, neonatal candidal meningitis is associated with a poor outcome both in terms of morbidity and mortality. However, early diagnosis with timely initiation of antifungal therapy will improve outcome significantly. The following review outlines the pathogenesis, clinical features, diagnosis, and current treatment options for neonatal candidal meningitis.

Review of 49 neonates with acquired fungal sepsis: further characterization

BACKGROUND

Neonatal acquired fungal sepsis (AFS) is a risky condition that warrants every effort for early diagnosis and management.

METHODS

We retrospectively reviewed the medical charts of all 4445 neonatal intensive care unit (NICU) admissions in the past 10 years and detected 49 neonates with AFS. We then compared their data with those of 49 matched control neonates who did not have AFS. The following details were collected: gestational, perinatal and neonatal courses; bacterial sepsis; antibacterial therapy; laboratory and imaging investigations; and antifungal therapy and its complications.

RESULTS

The incidence of AFS was.4 to 2 cases per 1000 live-births and 3.8% to 12.9% of very low birth weight (VLBW) infants. Compared with 1989 through 1992, between 1993 and 1995 the rate of AFS in VLBW neonates significantly increased (3. 8%-5.6% --> 9.6%-12.9%), along with a significant increase of NICU admission rate (369-410 --> 496-510 admissions/year). Compared with controls, AFS neonates had significantly longer hospitalizations, higher rates of mechanical ventilation, umbilical vein catheterization, and previous treatment with broad-spectrum antibacterial agents (amikacin, vancomycin, ceftazidime, or imipenem). At the onset of AFS, 42.8% of patients had hyperthermia and 40.9% had normal white blood cell count. Causative fungi were as follows: Candida albicans-42.8% of cases, Candida parapsilosis-26.5%, and Candida tropicalis-20.4%. Fungal dissemination was rare, complications of antifungal therapy were infrequent, and no deaths occurred.

CONCLUSIONS

First, non-albicans Candida have become more frequent in neonatal AFS. Second, mechanical ventilation and antibacterial agents are significant risk factors for AFS. Third, hyperthermia is a frequent presenting sign of AFS. Fourth, a normal white blood cell count does not rule out AFS. Fifth, meningeal involvement in neonatal AFS should be ruled out before initiation of antifungal therapy. Sixth, the policy of empiric antifungal therapy for AFS should be considered on an individual NICU basis.newborn infant, fungal sepsis, clinical signs, risk factors.