Evaluation of the safety and efficacy of liposomal amphotericin B (L-AMB) in children

Liposomal amphotericin B-the present

Most invasive fungal infections are opportunistic in nature but the epidemiology is constantly changing, with new risk groups being identified. Neutropenia is a classical risk factor for fungal infections, while critically ill patients in the ICU are now increasingly at risk of yeast and mould infections. Factors to be considered when choosing antifungal treatment include the emergence of rarer fungal pathogens, the risk of resistance to azoles and echinocandins and the possibility of drug-drug interactions. Liposomal amphotericin B has retained its place in the therapeutic armamentarium based on its clinical profile: a broad spectrum of antifungal activity with a low risk of resistance, predictable pharmacokinetics with a rapid accumulation at the infection site (including biofilms), a low potential for drug-drug interactions and a low risk of acute and chronic treatment-limiting toxicities versus other formulations of amphotericin B. It is a suitable choice for the first-line empirical or pre-emptive treatment of suspected fungal infections in neutropenic haematology patients and is an excellent alternative for patients with documented fungal disease who can no longer tolerate or continue their first-line azole or echinocandin therapy, both in the haematology setting and in the ICU. Moreover, it is the first-line drug of choice for the treatment of invasive mucormycosis. Finally, liposomal amphotericin B is one of the few antifungal agents approved for use in children of all ages over 1 month and is included in paediatric-specific guidelines for the management of fungal disease.

Persistent dyselectrolytemia in a neonate induced by liposomal amphotericin B. A case report

BACKGROUND

Nephrotoxicity is the most frequent serious adverse effect associated with amphotericin B deoxycholate treatment, for this reason, in recent years it has been relegated from routine clinical practice and replaced by the new liposomal formulations that have less nephrotoxicity. Nevertheless, dyselectrolytemia are a frequent adverse effect of the use of liposomal amphotericin B that usually are resolved with the withdrawal of the drug.

CASE PRESENTATION

We present a preterm neonate of 25 weeks gestation, with preserved renal function and most electrolytes within normal limits for gestational age except for mild hyponatremia in the first month of life. Due to an infection of the central nervous system and growth of Candida albicans, he required treatment with endovenous liposomal amphotericin B as well as intrathecal amphotericin B deoxycholate showing severe hydroelectrolyte disturbances and clinical worsening compatible with possible tubulopathy showing hypokalemia and severe hyponatremia a few days after starting treatment that persisted over time even after withdrawal of both drugs. Subsequently to the main alterations described, hypomagnesemia, hypophosphatemia, glycosuria and tubular proteinuria were also observed. Calcium levels remained stable after amphotericin B administration and did not require supplementation. In preterm or low birth weight newborns who present unjustified, severe and difficult to correct hydroelectrolyte disturbances despite the usual treatment, a possible tubulopathy should be considered, whether hereditary, primary or secondary to toxins or drugs.

WHAT IS NEW AND CONCLUSION

We present the first case reported in a neonate in whom dyselectrolithemia has been maintained over time after withdrawal of liposomal amphotericin B.

Sixty years of Amphotericin B: An Overview of the Main Antifungal Agent Used to Treat Invasive Fungal Infections

Introduced in the late 1950s, polyenes represent the oldest family of antifungal drugs. The discovery of amphotericin B and its therapeutic uses is considered one of the most important scientific milestones of the twentieth century . Despite its toxic potential, it remains useful in the treatment of invasive fungal diseases owing to its broad spectrum of activity, low resistance rate, and excellent clinical and pharmacological action. The well-reported and defined toxicity of the conventional drug has meant that much attention has been paid to the development of new products that could minimize this effect. As a result, lipid-based formulations of amphotericin B have emerged and, even keeping the active principle in common, present distinct characteristics that may influence therapeutic results. This study presents an overview of the pharmacological properties of the different formulations for systemic use of amphotericin B available for the treatment of invasive fungal infections, highlighting the characteristics related to their chemical, pharmacokinetic structures, drug–target interactions, stability, and others, and points out the most relevant aspects for clinical practice.

Administration and Dosing of Systemic Antifungal Agents in Pediatric Patients

Neonates and immunosuppressed/immunocompromised pediatric patients are at high risk of invasive fungal diseases. Appropriate antifungal selection and optimized dosing are imperative to the successful prevention and treatment of these life-threatening infections. Conventional amphotericin B was the mainstay of antifungal therapy for many decades, but dose-limiting nephrotoxicity and infusion-related adverse events impeded its use. Despite the development of several new antifungal classes and agents in the past 20 years, and their now routine use in at-risk pediatric populations, data to guide the optimal dosing of antifungals in children are limited. This paper reviews the spectra of activity for approved antifungal agents and summarizes the current literature specific to pediatric patients regarding pharmacokinetic/pharmacodynamic data, dosing, and therapeutic drug monitoring.

ESCMID-ECMM guideline: diagnosis and management of invasive aspergillosis in neonates and children

SCOPE

Presenting symptoms, distributions and patterns of diseases and vulnerability to invasive aspergillosis (IA) are similar between children and adults. However, differences exist in the epidemiology and underlying conditions, the usefulness of newer diagnostic tools, the pharmacology of antifungal agents and in the evidence from interventional phase 3 clinical trials. Therefore, the European Society for Clinical Microbiology and Infectious Diseases (ESCMID) and the European Confederation of Medical Mycology (ECMM) have developed a paediatric-specific guideline for the diagnosis and management of IA in neonates and children.

METHODS

Review and discussion of the scientific literature and grading of the available quality of evidence was performed by the paediatric subgroup of the ESCMID-ECMM-European Respiratory Society (ERS) Aspergillus disease guideline working group, which was assigned the mandate for the development of neonatal- and paediatric-specific recommendations.

QUESTIONS

Questions addressed by the guideline included the epidemiology of IA in neonates and children; which paediatric patients may benefit from antifungal prophylaxis; how to diagnose IA in neonates and children; which antifungal agents are available for use in neonates and children; which antifungal agents are suitable for prophylaxis and treatment of IA in neonates and children; what is the role of therapeutic drug monitoring of azole antifungals; and which management strategies are suitable to be used in paediatric patients. This guideline provides recommendations for the diagnosis, prevention and treatment of IA in the paediatric population, including neonates. The aim of this guideline is to facilitate optimal management of neonates and children at risk for or diagnosed with IA.

Invasive Aspergillosis in Children: Update on Current Guidelines

Invasive aspergillosis (IA) is an important cause of infectious morbidity and mortality in immunocompromised paediatric patients. Despite improvements in diagnosis, prevention, and treatment, IA is still associated with high mortality rates. To address this issue, several international societies and organisations have proposed guidelines for the management of IA in the paediatric population. In this article, we review current recommendations of the Infectious Diseases Society of America, the European Conference on Infection in Leukaemia and the European Society of Clinical Microbiology and Infectious Diseases for the management and prevention of IA in children.

Diagnosis and management of Aspergillus diseases: executive summary of the 2017 ESCMID-ECMM-ERS guideline

The European Society for Clinical Microbiology and Infectious Diseases, the European Confederation of Medical Mycology and the European Respiratory Society Joint Clinical Guidelines focus on diagnosis and management of aspergillosis. Of the numerous recommendations, a few are summarized here. Chest computed tomography as well as bronchoscopy with bronchoalveolar lavage (BAL) in patients with suspicion of pulmonary invasive aspergillosis (IA) are strongly recommended. For diagnosis, direct microscopy, preferably using optical brighteners, histopathology and culture are strongly recommended. Serum and BAL galactomannan measures are recommended as markers for the diagnosis of IA. PCR should be considered in conjunction with other diagnostic tests. Pathogen identification to species complex level is strongly recommended for all clinically relevant Aspergillus isolates; antifungal susceptibility testing should be performed in patients with invasive disease in regions with resistance found in contemporary surveillance programmes. Isavuconazole and voriconazole are the preferred agents for first-line treatment of pulmonary IA, whereas liposomal amphotericin B is moderately supported. Combinations of antifungals as primary treatment options are not recommended. Therapeutic drug monitoring is strongly recommended for patients receiving posaconazole suspension or any form of voriconazole for IA treatment, and in refractory disease, where a personalized approach considering reversal of predisposing factors, switching drug class and surgical intervention is also strongly recommended. Primary prophylaxis with posaconazole is strongly recommended in patients with acute myelogenous leukaemia or myelodysplastic syndrome receiving induction chemotherapy. Secondary prophylaxis is strongly recommended in high-risk patients. We strongly recommend treatment duration based on clinical improvement, degree of immunosuppression and response on imaging.

Analysis of Hypokalemia as a Side Effect of Liposomal Amphotericin in Pediatric Patients

BACKGROUND

Liposomal amphotericin (L-AMB) is a widely used broad-spectrum antifungal drug. Although L-AMB demonstrates better safety compared with amphotericin, renal dysfunction and hypokalemia are well-known adverse effects of L-AMB.

METHOD

We analyzed 56 episodes in 40 children and adolescents who received L-AMB therapy to determine risk factors of hypokalemia.

RESULTS

Hypokalemia (<3.0 mEq/L continuously for more than 2 episodes) was observed in 31 of 56 episodes (55.4%). The median onset of hypokalemia was at 10 days on L-AMB (range, 3-54 days), and the median cumulative dose of L-AMB at occurrence of hypokalemia was 25 mg/kg (range, 10-167.5 mg/kg). None of the patients with hypokalemia had solid tumors, and they had significantly higher estimated glomerular filtration rates than those with normokalemia (P = 0.013). Seven of 25 (28.0%) patients in the normokalemia group and 1 of 31 (3.2%) patients in the hypokalemia group had eGFRs of <90 mL/min/1.73 m(2) (P = 0.017).

CONCLUSION

Although the reason for the association between estimated glomerular filtration rates and hypokalemia is unclear, assessing the estimated glomerular filtration rates before L-AMB administration may predict the development of hypokalemia.

Potential Usefulness of Early Potassium Supplementation for Preventing Severe Hypokalemia Induced by Liposomal Amphotericin B in Hematologic Patients: A Retrospective Study

PURPOSE

Liposomal amphotericin B (L-AMB) is an essential antifungal agent for patients with hematologic diseases; however, the drug causes severe hypokalemia at a high frequency. Meanwhile, there is little evidence regarding the risk factors for L-AMB-induced severe hypokalemia, and the prevention protocol has not been established. The goal of this study was to identify the risk factors related to severe hypokalemia induced by L-AMB in hematologic patients.

METHODS

Seventy-eight hematologic patients with a first administration of L-AMB were enrolled in the study. Eleven patients who had serum potassium levels <3.0 mmol/L before L-AMB administration and 12 patients who received L-AMB administration within 3 days were excluded. Patients who had a serum potassium level <3.0 mmol/L during L-AMB administration were classified into a hypokalemia group (n = 26), and those who had a serum potassium level ≥3.0 mmol/L were classified into a non-hypokalemia group (n = 29). The patient characteristics were analyzed retrospectively. In addition, the usefulness of potassium supplementation was analyzed for those patients who received potassium formulations (non-hypokalemia group, n = 15; hypokalemia group, n = 24).

FINDINGS

Twenty-six patients had hypolalemia after L-AMB administration. Hypokalemia with serum potassium levels <3.0 mmol/L was observed ~7 days after starting L-AMB administration. The patient characteristics, L-AMB dose, and L-AMB administration period did not differ between the 2 groups. In the patients who received potassium formulations, the period between starting L-AMB administration and starting potassium supplementation was significantly shorter in the non-hypokalemia group than in the hypokalemia group (median, 0 vs 4 days, respectively; P < 0.01); the potassium dose was not different between the 2 groups. A receiver-operating characteristic curve revealed that the cutoff time for the start of potassium supplementation to reduce the incidence of L-AMB-induced hypokalemia was 3 days. Multivariate logistic regression analysis revealed that beginning potassium supplementation within 2 days from the start of L-AMB administration was an independent factor reducing the risk of L-AMB-induced hypokalemia (odds ratio, 0.094 [95% CI, 0.019-0.47]).

IMPLICATIONS

This study showed that starting administration of a potassium formulation within 2 days from the start of L-AMB administration was a risk reduction factor for L-AMB-induced hypokalemia. This finding indicates that early potassium supplementation should be incorporated into the regimen of hypokalemia management when L-AMB is used.

Pediatric Invasive Aspergillosis

Invasive aspergillosis (IA) is a disease of increasing importance in pediatrics due to growth of the immunocompromised populations at risk and improvements in long-term survival for many of these groups. While general principles of diagnosis and therapy apply similarly across the age spectrum, there are unique considerations for clinicians who care for children and adolescents with IA. This review will highlight important differences in the epidemiology, clinical manifestations, diagnosis, and therapy of pediatric IA.

Pharmacokinetic evaluation of liposomal amphotericin B (L-AMB) in patients with invasive fungal infection: Population approach in Japanese pediatrics

The pharmacokinetic characteristics of liposomal amphotericin B (L-AMB; AmBisome(®)) in patients with invasive fungal infection were investigated. A population pharmacokinetic (PK) model in Japanese pediatric patients was developed based on 159 serum amphotericin B (AMPH-B) concentrations obtained in a post-marketing clinical study. The subjects were 39 patients with a mean age of 8.4 years (SD 4.5) and mean body weight of 27.1 kg (SD 14.1). A two-compartment PK model with zero-order input and first-order elimination was fitted to serum AMPH-B concentrations for L-AMB doses of 1.0, 2.5, and 5.0 mg/kg/day. Body weight showed significant correlations with PK parameters, such as clearance (CL) and distribution volume of the central compartment (Vc). The predicted Cmax/dose and AUC0-24/dose in Japanese pediatric patients were similar to those in non-Japanese pediatric patients and Japanese adult patients. Extremely large increases in Ctrough compared with predicted values were observed in some Japanese pediatric patients, but no relationships with demographic characteristics, clinical laboratory test values, or representative adverse drug reaction (decreased potassium) were found. The population PK parameters in this study are useful for simulating PK profiles of L-AMB and will be helpful for PK exposure comparisons among different populations and in investigations of pharmacokinetic-pharmacodynamic characteristics in patients.

CHEMICAL COMPOUNDS

Amphotericin B Deoxycholate (PubChem CID:23668620); amphotericin B (PubChem CID:5280965); 3-nitrophenol (PubChem CID:11137); methanol (PubChem CID:887).

Role of nebulized amphotericin B in the management of allergic bronchopulmonary aspergillosis in cystic fibrosis: Case report and review of literature

OBJECTIVES

To review the data available in literature about nebulized amphotericin B (AMB) in the treatment of allergic bronchopulmonary aspergillosis (ABPA) in cystic fibrosis (CF) and to report our experience in the use of this drug, with a particular therapeutic scheme.

CASE REPORT

We used nebulized liposomal amphotericin B (L-AMB) in a patient affected by CF, complicated by ABPA. The previous combined treatment with oral steroids and azoles had no respiratory benefit and caused relevant side effects. Amphotericin B has always been well tolerated and permitted a slight steroid tapering. We also observed benefits in pulmonary function and laboratory tests.

CONCLUSIONS

Few data are available in literature about the use of nebulized AMB in CF and there are no RCTs evaluating antifungals in CF-ABPA. In our opinion, the reported case suggests that nebulized L-AMB could represent a possible strategy in ABPA management in CF patients.

Evaluation of hypokalemia and potassium supplementation during administration of liposomal-amphotericin B

Patients prescribed liposomal-amphotericin B (L-AMB) frequently require supplemental potassium to prevent hypokalemia. The aim of this retrospective study was to examine the appropriate potassium supplementation conditions to treat hypokalemia induced by L-AMB. The subjects were 100 hematological patients who received L-AMB for the first time between April 2012 and March 2013. A total of seven patients were excluded. Of the remaining 93 patients, 48 (51.6%) were assigned to the group receiving supplemental potassium (supplementation group), and 45 (48.4%) were assigned to the group without potassium supplementation (non-supplementation group). Hypokalemia greater than grade 3 was exhibited by 50 of the 93 (53.8%) patients. Multivariate analysis revealed that the minimum serum potassium levels during L-AMB administration (≤2.98 mEq/l) were an independent factor significantly contributing to the effectiveness of potassium supplementation [odds ratio (OR), 3.62; 95% confidence interval (CI), 1.44–9.59; P<0.01]. In addition, multivariate analysis revealed that the serum potassium levels (≥2.83 mEq/l) prior to the potassium supplementation were an independent factor significantly contributing to the development of proper potassium supplementation (OR, 14.21; 95% CI, 1.95–310.72; P=0.02), and no significant difference was observed in the dosage of the potassium supplementation administered to the patients who recovered from hypokalemia and those who did not. In conclusion, it is necessary to begin potassium supplementation prior to the reduction of the serum potassium levels to <2.83 mEq/l. Potassium supplementation at an early stage of L-AMB treatment is important to prevent severe electrolyte abnormalities.