Randomised controlled trial of fosfomycin in neonatal sepsis: pharmacokinetics and safety in relation to sodium overload

Efficacy of Antibiotic Regimens for Sepsis or Possible Serious Bacterial Infection in Young Infants Aged 0 to 59 Days: A Systematic Review and Meta-analysis

CONTEXT

Sepsis is a leading cause of young infant mortality.

OBJECTIVE

To evaluate the efficacy of different antibiotic regimens to treat young infant sepsis or possible serious bacterial infection (PSBI) on clinical outcomes.

DATA SOURCES

MEDLINE, Embase, CINAHL, World Health Organization Global Index Medicus, Cochrane Central Registry of Trials.

STUDY SELECTION

We included randomized controlled trials (RCTs) of young infants 0 to 59 days with sepsis or PBSI (population) comparing the efficacy of antibiotic regimens (intervention) with alternate regimens or management (control) on clinical outcomes.

DATA EXTRACTION

We extracted data and assessed risk of bias in duplicate. We performed random-effects meta-analysis, and used Grading of Recommendations, Assessment, Development, and Evaluation to assess certainty of evidence.

RESULTS

Of 2390 publications, we included 41 RCTs (n = 18 054). Thirty-five trials were hospital-based and 6 were nonhospital-based. Meta-analysis of 4 trials demonstrated similar rates of treatment success with intramuscular/intravenous third generation cephalosporins versus intramuscular/intravenous penicillin or ampicillin + gentamicin (RR 1.03, 95% CI 0.93-1.13]; n = 1083; moderate certainty of evidence). Meta-analysis of 3 trials demonstrated similar rates of treatment failure with oral amoxicillin + intramuscular gentamicin versus intramuscular penicillin + gentamicin for nonhospital treatment of clinical severe illness (RR 0.86, 95% CI 0.72-1.02]; n = 5054; low certainty of evidence). Other studies were heterogeneous.

LIMITATIONS

RCTs evaluated heterogeneous regimens, limiting our ability to pool data.

CONCLUSIONS

We found limited evidence to support any single antibiotic regimen as superior to alternate regimens to treat young infant sepsis or PSBI.

Fosfomycin-Containing Regimens for the Treatment of Central Nervous System Infections in a Neonatal Intensive Care Unit: A Case Series Study

Central nervous system infections are among the most severe infectious conditions in the neonatal period and are still burdened by significant mortality, especially in preterm infants and those with a low birth weight or other comorbidities. In this study, we examined the role of fosfomycin-containing antibiotic regimens in neonates with central nervous system infections. We included six neonates over a period of five years: four with meningitis and two with cerebral abscesses. All patients underwent fosfomycin therapy after failing first-line antibiotic regimens. Of the six neonates, two died; two developed neurological and psychomotor deficits and two recovered uneventfully. None of the neonates experienced adverse reactions to fosfomycin, confirming the safety of the molecule in this population. In conclusion, the deep penetration in the central nervous system, the unique mechanism of action, the synergy with other antibiotic therapies, and the excellent safety profile all make fosfomycin an attractive drug for the treatment of neonatal central nervous system infections.

Back to the Future: Intravenous Fosfomycin is Safe and Effective for the Treatment of Complicated Infections in Children

BACKGROUND

Despite its broad spectrum and excellent safety profile, fosfomycin is still rarely used in pediatrics, with very limited experience from clinicians.

METHODS

We retrospectively reviewed the medical records of all children admitted to Bambino Gesù Children's Hospital, IRCCS, Rome, Italy, and treated with fosfomycin for any serious infection. Children with immunodeficiency and oncologic diseases were excluded. Of each, we reported and analyzed demographic and clinical data.

RESULTS

The clinical charts of 20 patients were reviewed and analyzed. The mean age was 10.2 years. Most children were males (85%). Most patients treated had an osteo-articular infection (65%). In our sample, 7 patients (35%) had an underlying comorbidity. The causative agent was isolated in 14 cases (70%). All patients were treated with a combination of 2-3 antibiotics, including fosfomycin. The average duration of antibiotic treatment was 18 days. After treatment, 8 patients (40%) experienced a mild adverse reaction, possibly correlated with the administration of fosfomycin. All patients were discharged in good clinical condition.

CONCLUSIONS

The present study reports on a sample of pediatric patients with complicated infections where administration of fosfomycin led to eradication of the disease with little or no side effects. Role of the underlying condition and concomitant medication in causing the reaction could not be ruled out. These data suggest that fosfomycin is an effective and safe antibiotic in the pediatric population, particularly for deep-seated infections sustained by multi-drug resistant pathogens.

Intravenous fosfomycin in combination regimens as a treatment option for difficult-to-treat infections due to multi-drug-resistant Gram-negative organisms: A real-life experience

AIM

To investigate the efficacy of intravenous (IV) fosfomycin as combination therapy for treatment of difficult-to-treat (DTT) acute and subacute infections with multi-drug-resistant (MDR) Gram-negative bacteria (GNB), and risk factors associated with 90-day mortality.

METHODS

A retrospective, observational, monocentric study enrolled patients treated with IV fosfomycin in combination regimens (≥72 h) for proven DTT-MDR-GNB infection. Multi-variate regression analysis identified independent risk factors for 90-day mortality. A propensity score for receiving fosfomycin was performed to control for confounding factors.

RESULTS

In total, 70 patients were included in this study: 54.3% had carbapenem-resistant isolates, 31.4% had ceftazidime/avibactam-resistant isolates and 28.6% had ceftolozane/tazobactam-resistant isolates. The main pathogens were Pseudomonas aeruginosa (57.1%) and Klebsiella pneumoniae (22.9%). The most prevalent infections were nosocomial pneumonia (42.9%), osteomyelitis (17.1%) and intra-abdominal infections. All-cause 30- and 90-day mortality were 15.7% and 31.4%, respectively (18.9% and 50% considering acute DTT-MDR-GNB infections alone). Relapse at 30 days occurred in 22.9% of cases (29% with emergence of fosfomycin resistance). Mortality at 90 days was independently associated with septic shock and ceftolozane/tazobactam resistance. The relationship between resistance to ceftolozane/tazobactam and 90-day mortality was confirmed to be significant after adjustment by propensity score analysis (hazard ratio 5.84, 95% confidence interval 1.65-20.68; P=0.006).

CONCLUSIONS

Fosfomycin seems to be a promising salvage, combination treatment in DTT-MDR-GNB infections. Resistance to ceftolozane/tazobactam seems to be independently associated with treatment failure. Randomized clinical trials focusing on pathogen and infection sites are needed urgently to demonstrate the superiority of fosfomycin in combination with other agents for the resolution of DTT-MDR-GNB infections.

Reintroduction of Legacy Antibiotics in Neonatal Sepsis: The Special Role of Fosfomycin and Colistin

Neonatal sepsis is a leading cause of morbidity and mortality in neonates, particularly in low- and middle-income countries. The emergence of antimicrobial resistance is a rapidly growing global problem. A significant proportion of the pathogens that commonly cause neonatal sepsis are resistant to multiple antibiotics. Therefore, for the empirical treatment of neonatal sepsis, the repurposing of older antibiotics that are effective against multidrug-resistant pathogens is being investigated. This review aims to provide an overview of current research and experience using the repurposed antibiotics colistin and fosfomycin for the empirical treatment of neonatal sepsis. Based on current knowledge, colistin and fosfomycin may be potentially helpful for the empirical treatment of sepsis in neonates due to their efficacy against a wide range of pathogens and acceptable safety profile.

Use of Newer and Repurposed Antibiotics against Gram-Negative Bacteria in Neonates

Antimicrobial resistance has become a significant public health problem globally with multidrug resistant Gram negative (MDR-GN) bacteria being the main representatives. The emergence of these pathogens in neonatal settings threatens the well-being of the vulnerable neonatal population given the dearth of safe and effective therapeutic options. Evidence from studies mainly in adults is now available for several novel antimicrobial compounds, such as new β-lactam/β-lactamase inhibitors (e.g., ceftazidime-avibactam, meropenem-vaborbactam, imipenem/cilastatin-relebactam), although old antibiotics such as colistin, tigecycline, and fosfomycin are also encompassed in the fight against MDR-GN infections that remain challenging. Data in the neonatal population are scarce, with few clinical trials enrolling neonates for the evaluation of the efficacy, safety, and dosing of new antibiotics, while the majority of old antibiotics are used off-label. In this article we review data about some novel and old antibiotics that are active against MDR-GN bacteria causing sepsis and are of interest to be used in the neonatal population.

Challenges in the Implementation of the NeoOBS Study, a Global Pragmatic Observational Cohort Study, to Investigate the Aetiology and Management of Neonatal Sepsis in the Hospital Setting

Neonatal sepsis is a significant cause of mortality and morbidity in low- and middle-income countries. To deliver high-quality data studies and inform future trials, it is crucial to understand the challenges encountered when managing global multi-centre research studies and to identify solutions that can feasibly be implemented in these settings. This paper provides an overview of the complexities faced by diverse research teams in different countries and regions, together with actions implemented to achieve pragmatic study management of a large multi-centre observational study of neonatal sepsis. We discuss specific considerations for enrolling sites with different approval processes and varied research experience, structures, and training. Implementing a flexible recruitment strategy and providing ongoing training were necessary to overcome these challenges. We emphasize the attention that must be given to designing the database and monitoring plans. Extensive data collection tools, complex databases, tight timelines, and stringent monitoring arrangements can be problematic and might put the study at risk. Finally, we discuss the complexities added when collecting and shipping isolates and the importance of having a robust central management team and interdisciplinary collaborators able to adapt easily and make swift decisions to deliver the study on time and to target. With pragmatic approaches, appropriate training, and good communication, these challenges can be overcome to deliver high-quality data from a complex study in challenging settings through a collaborative research network.

A multicentre, retrospective audit of fosfomycin use for urinary tract infections in Australian children and adolescents

BACKGROUND

Urinary tract infections (UTIs) due to MDR organisms are increasingly common. The lack of paediatric data on efficacious antibiotics makes UTI treatment particularly challenging. Data on the efficacy of fosfomycin use for UTI in children are variable.

METHODS

We conducted a retrospective audit of children aged 0-18 years who were treated with fosfomycin for UTI at seven tertiary paediatric hospitals in Australia over a 7 year period, from 2014 to 2020.

RESULTS

Ninety-one children with a median age of 5 years (range 2 months to 18 years) received oral fosfomycin for UTI. The majority (57/91, 63%) had one or more comorbidity, with the most common being renal tract anomalies (24/91, 26%). Fifty-nine (65%) had febrile UTI, 14/91 (15%) had pyelonephritis and 1/91 (1%) was bacteraemic. A majority (80/91, 88%) of urinary cultures had an ESBL-producing Gram-negative pathogen isolated. Fosfomycin susceptibility was evident in all 80 isolates tested. For uncomplicated UTI, the most common dose in children aged <1, 1-12 and >12 years was 1, 2 and 3 g, respectively. For complicated UTI, doses of 2 and 3 g were most common. The median duration of fosfomycin administration was 5 days (range 1-82). Clinical cure was achieved in 84/90 (93%); the six with treatment failure had underlying comorbidities. Overall, 2/91 (2%) children experienced drug-related adverse effects comprising gastrointestinal symptoms in both, which resolved after treatment discontinuation.

CONCLUSIONS

Fosfomycin is well tolerated and associated with favourable treatment outcomes in children with UTI. Further research on the optimal dosing strategy is required.

Developmental Pharmacokinetics of Antibiotics Used in Neonatal ICU: Focus on Preterm Infants

Neonatal Infections are among the most common reasons for admission to the intensive care unit. Neonatal sepsis (NS) significantly contributes to mortality rates. Empiric antibiotic therapy of NS recommended by current international guidelines includes benzylpenicillin, ampicillin/amoxicillin, and aminoglycosides (gentamicin). The rise of antibacterial resistance precipitates the growth of the use of antibiotics of the Watch (second, third, and fourth generations of cephalosporines, carbapenems, macrolides, glycopeptides, rifamycins, fluoroquinolones) and Reserve groups (fifth generation of cephalosporines, oxazolidinones, lipoglycopeptides, fosfomycin), which are associated with a less clinical experience and higher risks of toxic reactions. A proper dosing regimen is essential for effective and safe antibiotic therapy, but its choice in neonates is complicated with high variability in the maturation of organ systems affecting drug absorption, distribution, metabolism, and excretion. Changes in antibiotic pharmacokinetic parameters result in altered efficacy and safety. Population pharmacokinetics can help to prognosis outcomes of antibiotic therapy, but it should be considered that the neonatal population is heterogeneous, and this heterogeneity is mainly determined by gestational and postnatal age. Preterm neonates are common in clinical practice, and due to the different physiology compared to the full terms, constitute a specific neonatal subpopulation. The objective of this review is to summarize the evidence about the developmental changes (specific for preterm and full-term infants, separately) of pharmacokinetic parameters of antibiotics used in neonatal intensive care units.

Prevalence and whole genome phylogenetic analysis reveal genetic relatedness between antibiotic resistance Salmonella in hatchlings and older chickens from farms in Nigeria

The presence of Salmonella in hatchlings is the single most important risk factor for the introduction of Salmonella into poultry farms, and resistant strains are particularly worrisome, as they could affect treatment outcomes in humans infected through consumption of contaminated poultry products. This study estimated Salmonella prevalence, determined resistance profiles of strains recovered from hatchlings in Nigeria, and determined genetic relatedness between hatchling strains and strains from poultry farms. In this study, 300 fecal samples were collected. Salmonella was isolated by culture and confirmed by PCR, and isolates were tested for susceptibility to antimicrobials by the disk diffusion method. Strains were pair-end sequenced, and genomes were used to obtain serotypes and antibiotic resistance genes. Whole-genome based phylogenetic analysis was used to determine genetic relatedness between these isolates and strains from previously characterized older chicken within the same geographical area. A prevalence of 10.7% was obtained belonging to 13 Salmonella serovars. Resistance to kanamycin (30/32), ciprofloxacin (22/32), nalidixic acid (22/32), and sulfonamides (22/32) were the most commonly observed phenotypic resistances. Twenty-two (68.8%) isolates showed multidrug resistance. In silico predictions identified 36 antimicrobial resistance genes. Four (12.5%) and 22 (68.8%) strains showed point mutations in gyrA and parC. Commonly observed acquired resistance genes included sul1, sul2, sul3, and tet(A) as well as a variety of aminoglycoside-modifying genes. Eleven (34.4%) isolates were predicted to have genes that confer resistance to fosfomycin (fosA7, fosB). A strain of S. Stanleyville was predicted to have optrA, which confers resistance to furazolidone. Strains of S. Kentucky, S. Muenster, and S. Menston obtained from hatchlings showed close genetic relatedness by having less than 30 SNPs difference to strains recovered from chickens at farms previously receiving hatchlings from the same sources.

New ways of using old antibiotics in pediatrics: Focus on fosfomycin

Fosfomycin, originally named phosphonomycin when it was first isolated from fermentation broth of Streptomyces species and synthesized at Merck in 1969. The phosphonic acid containing a structurally strained and reactive epoxide ring confers broad spectrum, bactericidal activity against gram-positive and gram-negative bacteria. Fosfomycin's small size and hydrophilicity permits broad tissues penetration. Although only fosfomycin tromethamine oral is approved for urinary tract infections (UTI) in the United States since 1996, the intravenous form has been utilized worldwide for over four decades. The increasing rates of multidrug-resistant (MDR) infections with few novel treatment options available has spurred the recent interest in fosfomycin. Fosfomycin's high urinary concentration, broad spectrum of activity against MDR pathogens, and favorable safety profile offers a valuable oral option for treating UTI, one of the most common bacterial infections in childhood. The ability of fosfomycin to penetrate biofilm and reported activity against intracellular pathogens may further its importance in childhood diseases such as Chronic Granulomatous Disease, Salmonellosis, and Listeriosis. More data are needed to further define optimal Pharmacodynamic target, as well as Pharmacokinetic, safety and outcomes for repeated oral and intravenous dosing of fosfomycin in infants and children in systemic infections.