Clinical experience with linezolid in infants and children

Therapeutic Options and Outcomes for the Treatment of Children with Gram-Positive Bacteria with Resistances of Concern: A Systematic Review

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant coagulase-negative Staphylococci (MR-CoNS), and vancomycin-resistant Enterococci (VRE) are increasing worldwide and represent a threat for the limited treatment options in pediatric patients and neonates compared to adults. Recommendations in pediatrics are mainly extrapolated from adults' studies.

METHODS

A literature search for the treatment of these pathogens in children (<18 years old) was conducted in Embase, MEDLINE, and Cochrane Library. Studies reporting data on single-patient-level outcomes related to a specific antibiotic treatment for multidrug resistant (MDR) Gram-positive bacterial infection in children were included. Studies reporting data from adults and children were included if single-pediatric-level information could be identified (PROSPERO registration: CRD42022383867).

RESULTS

The search identified 11,740 studies (since January 2000), of which 48 fulfilled both the inclusion and the exclusion criteria and were included in the analysis: 29 for MRSA, 20 for VRE, and seven for MR-CoNS. Most studies were retrospective studies. Vancomycin was mainly used as a comparator, while linezolid and daptomycin were the most studied antimicrobials showing good efficacy.

CONCLUSIONS

Linezolid showed a safety and efficacy profile in a neonatal setting; daptomycin is increasingly used for MRSA, but the evidence is scarce for VRE.

Relationship Between Linezolid Exposure and the Typical Clinical Laboratory Safety and Bacterial Clearance in Chinese Pediatric Patients

Objectives: There have been limited studies concerning the safety and efficacy of linezolid (LZD) in children. This study aimed to evaluate the association between LZD exposure and clinical safety and efficacy in Chinese pediatric patients.

Methods: This retrospective cross-sectional study included patients ≤18 years of age who received ≥3 days of LZD treatment between 31 January 2015, and 31 December 2020. Demographic characteristics, medication information, laboratory test information, and bacterial culture results were collected from the Hospital Information System (HIS). Exposure was defined as AUC₂₄ and calculated by the non-linear mixed-effects modeling program (NONMEM), version 7.2, based on two validated population pharmacokinetic models. Binary logistic regression analyses were performed to analyze the associations between AUC₂₄ and laboratory adverse events, and receiver operating characteristic curves were used to calculate the cut-off values. Efficacy was evaluated by bacterial clearance.

Results: A total of 413 paediatric patients were included, with an LZD median (interquartile range) dose, duration, clearance and AUC₂₄ of 30.0 (28.1-31.6) mg/kg/day, 8 (4‒15) days,1.31 (1.29-1.32) L/h and 81.1 (60.6-108.7) mg/L·h, respectively. Adverse events associated with TBil, AST, ALT, PLT, hemoglobin, WBC, and neutrophil count increased during and after LZD treatment when compared with before medication (p < 0.05), and the most common adverse events were thrombocytopaenia (71/399, 17.8%) and low hemoglobin (61/401, 15.2%) during the LZD treatment. Patients with AUC₂₄ higher than 120.69 mg/L h might be associated with low hemoglobin 1–7 days after the end of the LZD treatment, and those with an AUC₂₄ higher than 92.88 mg/L∙h might be associated with thrombocytopaenia 8–15 days after the end of the LZD treatment. A total of 136 patients underwent bacterial culture both before and after LZD treatment, and the infection was cleared in 92.6% (126/136) of the patients, of whom 69.8% (88/126) had AUC₂₄/MIC values greater than 80.

Conclusion: Hematological indicators should be carefully monitored during LZD treatment, especially thrombocytopaenia and low hemoglobin, and a continuous period of monitoring after LZD withdrawal is also necessary. Since the AUC₂₄ cut-off values for laboratory adverse events were relatively low, a trade-off is necessary between the level of drug exposure required for treatment and safety, and the exposure target (AUC₂₄/MIC) in pediatric patients should be further studied, especially for patients with complications and concomitant medications.

Linezolid for resistant Gram-positive bacterial infections in children under 12 years: A meta-analysis

Both linezolid and vancomycin have good efficacy in the treatment of resistant Gram-positive bacterial infections. This systematic review and meta-analysis aimed to compare the efficacy and safety of linezolid vs vancomycin for the treatment of resistant Gram-positive bacterial infections in children under 12 years. Five randomly controlled trials involving 638 children that were treated with linezolid and vancomycin for resistant Gram-positive bacterial infections were searched from medical databases. Meta-analysis showed that linezolid and vancomycin had equivalent efficacies in clinical cure rates in the intent-to-treat population (95% confidence interval [CI] 0.88, 2.09) and microbiologically evaluable patients (95% CI: 0.46, 2.47). Linezolid and vancomycin also had equivalent pathogen eradication rates for Staphylococcus aureus (95% CI: 0.31, 4.81), methicillin-resistant S. aureus (95% CI: 0.36, 5.34), Enterococcus faecalis (95% CI: 0.32, 8.76), and coagulase-negative Staphylococci (95% CI: 0.43, 4.01). Vancomycin resulted in a higher incidence of alanine aminotransferase increase (95% CI: 0.37, 0.97), red man syndrome (95% CI: 0.01, 0.28), and rash (95% CI: 0.11, 0.73) than linezolid. Clinically, linezolid had a superior safety to vancomycin for resistant Gram-positive infections. Linezolid might be prescribed for the treatment of resistant Gram-positive bacterial infections in children under 12 years.

Increasing use of linezolid in a tertiary NICU during a 10-year period: reasons and concerns for the future

Background

Linezolid has been increasingly used in tertiary NICUs. The objectives of this study were to explore the indications of these linezolid prescriptions, to analyze a possible misuse and to provide solutions to avoid such misuse.

Methods

A monocentric retrospective cohort study included all neonates hospitalized in one tertiary NICU between January 1st, 2010 and December 31st, 2019 and who received at least one administration of linezolid. These data were confronted to epidemiological and antibiotic use data from the same NICU. Two independent pediatricians secondarily classified linezolid uses as adequate or not.

Results

During the study period, 66 infections in 57 patients led to linezolid use. Most patients were pre-term and 21 patients (37%) died. Infections were mainly related to methicillin-resistant coagulase negative staphylococci and were frequently either pneumoniae (35%) or isolated bacteremia (48%), including 25 persistent bacteremia (64% of the 39 bacteremia). Need for a better tissue distribution or first-line treatment failure were the main reasons to initiate linezolid. Linezolid was administered for a median duration of 7 [3;10] days. No side effects were reported. Twenty-two (33%) of the 66 linezolid prescriptions were retrospectively classified as inadequate.

Conclusions

A rapid increase in linezolid prescriptions has been observed in our tertiary NICU, from 2014 to 2019, with 33% inadequate uses. This worrisome trend should lead to search for therapeutic alternatives and to work on antibiotic stewardship to prevent the emergence of new antimicrobial bacterial resistance.

A case report of a child with probable drug resistant tuberculous pericarditis with a review of challenges involved in diagnosis, treatment and follow up of children with DR-TB pericarditis

Background

There are unique challenges in the diagnosis and management of multi drug resistant tuberculosis (MDR-TB) in children. It is difficult to obtain confirmatory microbiological diagnosis in TB pericarditis. It is essential to differentiate between drug sensitive and drug resistant forms of TB as it has a major bearing on the regimen used, and inappropriate TB treatment combined with steroid use for pericarditis can lead to deterioration. With lack of samples, the treatment decision relies on the drug resistance pattern of the close contact if available. Therapeutic challenges of MDR-TB management in a child involve use of toxic drugs that need to be judiciously handled. We report a 2 years 4 months old male child who was diagnosed with TB pericarditis and treated based on the resistance pattern of his mother who was on treatment for pulmonary MDR-TB.

Case presentation

This 2 years 4 months old male child was diagnosed with TB involving his pericardium. Getting him started on an appropriate regimen was delayed due to the difficulty in establishing microbiological confirmation and drug susceptibility. He was commenced on a regimen based on his mother’s drug resistance pattern and required surgery due to cardiac failure during the course of his treatment. He successfully completed 2 years of therapy.

Conclusions

This child’s case demonstrates that despite unique challenges in diagnosis and management of drug resistant extra pulmonary tuberculosis in children, treatment of even complex forms can be successful. The need for high suspicion of MDR-TB, especially when there is close contact with pulmonary TB, careful design of an effective regimen that is tolerated by the child, indications for invasive surgical management of pericarditis, appropriate follow-up and management of adverse effects are emphasised.

Pulmonary Mycobacterium abscessus complex in children with cystic fibrosis: A practical management guideline

The treatment of Mycobacterium abscessus complex (MABSC) pulmonary infections is an emerging challenge in patients with cystic fibrosis (CF). Multidrug therapy for prolonged durations is required and carries the significant burden of drug-related toxicity, cost and selective pressure for multiresistant bacteria. International guidelines acknowledge that clinical and in vitro data to support treatment regimens are limited, particularly in children. As part of a collaboration between the infectious diseases and respiratory units at our institution, we have developed a modified treatment guideline that aims to balance the aims of MABSC eradication and slowing disease progression with minimising drug toxicity and resistance. The outcomes of this treatment approach will be monitored and reported. In this manuscript, we discuss the available evidence for treatment choices and present our treatment guideline for paediatric patients with CF and MABSC infection.

Recommendations for treating children with drug-resistant tuberculosis

Tuberculosis (TB) is still one of the most difficult infectious diseases to treat, and the second most frequent cause of death due to infectious disease throughout the world. The number of cases of multidrug-resistant (MDR-TB) and extensively drug-resistant TB (XDR-TB), which are characterised by high mortality rates, is increasing. The therapeutic management of children with MDR- and XDR-TB is complicated by a lack of knowledge, and the fact that many potentially useful drugs are not registered for pediatric use and there are no formulations suitable for children in the first years of life. Furthermore, most of the available drugs are burdened by major adverse events that need to be taken into account, particularly in the case of prolonged therapy. This document describes the recommendations of a group of scientific societies on the therapeutic approach to pediatric MDR- and XDR-TB. On the basis of a systematic literature review and their personal clinical experience, the experts recommend that children with active TB caused by a drug-resistant strain of Mycobacterium tuberculosis should always be referred to a specialised centre because of the complexity of patient management, the paucity of pediatric data, and the high incidence of adverse events due to second-line anti-TB treatment.

Safety and tolerability profile of second-line anti-tuberculosis medications

Tuberculosis (TB) remains a major public health problem, representing the second leading cause of death from infectious diseases globally, despite being nearly 100 % curable. Multidrug-resistant (MDR)-TB, a form of TB resistant to isoniazid and rifampicin (rifampin), two of the key first-line TB drugs, is becoming increasingly common. MDR-TB is treated with a combination of drugs that are less effective but more toxic than isoniazid and rifampicin. These drugs include fluoroquinolones, aminoglycosides, ethionamide, cycloserine, aminosalicyclic acid, linezolid and clofazimine among others. Minor adverse effects are quite common and they can be easily managed with symptomatic treatment. However, some adverse effects can be life-threatening, e.g. nephrotoxicity due to aminoglycosides, cardiotoxicity due to fluoroquinolones, gastrointestinal toxicity due to ethionamide or para-aminosalicylic acid, central nervous system toxicity due to cycloserine, etc. Baseline evaluation may help to identify patients who are at increased risk for adverse effects. Regular clinical and laboratory evaluation during treatment is very important to prevent adverse effects from becoming serious. Timely and intensive monitoring for, and management of adverse effects caused by, second-line drugs are essential components of drug-resistant TB control programmes; poor management of adverse effects increases the risk of non-adherence or irregular adherence to treatment, and may result in death or permanent morbidity. Treating physicians should have a thorough knowledge of the adverse effects associated with the use of second-line anti-TB drugs, and routinely monitor the occurrence of adverse drug reactions. In this review, we have compiled safety and tolerability information regarding second-line anti-TB drugs in both adults and children.

Efficacy and safety of linezolid for the treatment of infections in children: a meta-analysis

Linezolid is an oxazolidinone antibacterial agent, with activity against Gram-positive bacteria. This study aimed to evaluate the efficacy and safety of linezolid in children with infections caused by Gram-positive pathogens. A systematic search was conducted by two independent reviewers to identify published studies up to September 2013. The accumulated relevant literature was subsequently systematically reviewed, and a meta-analysis was conducted. Eligible studies were randomized controlled trials assessing the clinical efficacy and safety of linezolid in children versus other antimicrobial agents for infections caused by Gram-positive bacteria. The primary outcome was treatment success in patients who received at least one dose of study drug, had clinical evidence of disease, and had complete follow-up. Meta-analysis was conducted with random effects models because of heterogeneity across the trials. Two randomized controlled trials (RCTs), involving 815 patients, were included. Linezolid was slightly more effective than control antibiotic agents, but the difference was not statistically significant [odds ratio (OR) = 1.39, 95 % confidence interval (CI) 0.98-1.98]. Treatment with linezolid was not associated with more adverse effects in general (OR = 0.61, 95 % CI 0.25-1.48). Eradication efficiency did not differ between linezolid and control regimens, but the sample size for these comparisons was small.

CONCLUSION

The use of linezolid cannot be steadily supported from the results of the current meta-analysis. It appears to be slightly more effective than control antibiotic agents, but the difference was not significant, and the serious limitations present in this study restrict its use. Further studies providing evidence for clinical and microbiological efficacy of linezolid will support its use.

Early-onset neonatal sepsis

Early-onset sepsis remains a common and serious problem for neonates, especially preterm infants. Group B streptococcus (GBS) is the most common etiologic agent, while Escherichia coli is the most common cause of mortality. Current efforts toward maternal intrapartum antimicrobial prophylaxis have significantly reduced the rates of GBS disease but have been associated with increased rates of Gram-negative infections, especially among very-low-birth-weight infants. The diagnosis of neonatal sepsis is based on a combination of clinical presentation; the use of nonspecific markers, including C-reactive protein and procalcitonin (where available); blood cultures; and the use of molecular methods, including PCR. Cytokines, including interleukin 6 (IL-6), interleukin 8 (IL-8), gamma interferon (IFN-γ), and tumor necrosis factor alpha (TNF-α), and cell surface antigens, including soluble intercellular adhesion molecule (sICAM) and CD64, are also being increasingly examined for use as nonspecific screening measures for neonatal sepsis. Viruses, in particular enteroviruses, parechoviruses, and herpes simplex virus (HSV), should be considered in the differential diagnosis. Empirical treatment should be based on local patterns of antimicrobial resistance but typically consists of the use of ampicillin and gentamicin, or ampicillin and cefotaxime if meningitis is suspected, until the etiologic agent has been identified. Current research is focused primarily on development of vaccines against GBS.

Safety and efficacy of linezolid in 16 infants and children in Japan

Linezolid, an oxazolidinone antibiotic, exhibits a broad spectrum of activity against Gram-positive bacteria. It has been licensed for adult use in Japan since 2006 for MRSA infections, and has also been used off-label for pediatric patients. At our university hospital, a total of 16 infants and children (including one non-Japanese Asian) were administered linezolid owing to infection with multidrug-resistant Gram-positive bacteria, after consent had been provided. All patients had severe underlying diseases or indications for surgery. Eighty-eight percent of the causal microorganisms were methicillin-resistant Staphylococcus aureus (MRSA) or methicillin-resistant coagulase-negative Staphylococcus and all were sensitive to linezolid. Linezolid was administered because the antecedent anti-MRSA medications were ineffective or contraindicated, or intravenous-to-oral switch therapy was requested owing to cardiac or orthopedic surgical-site infections. The median duration of administration was 13 days (range 3-31 days). The overall efficacy was 91 % (10/11) in those for whom efficacy could be evaluated. Only two patients (both teen-aged) encountered linezolid-related adverse effects (13 %, 2/16). One patient showed elevation of liver enzymes (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]), requiring that administration be withdrawn, but enzyme levels returned to normal after the patient had been switched to vancomycin. The other patient showed transiently decreased platelet counts. Linezolid is considered generally safe and effective for children in Japan, especially for those who cannot use other anti-MRSA medications or those who require oral antibiotics for infections with multidrug-resistant Gram-positive bacteria.

Linezolid: safety and efficacy in special populations

Linezolid has been in general use in the UK since 2000. Although toxicity, particularly haematological and neurological, has been an issue, linezolid has proved to be an effective alternative to glycopeptides in the treatment of Gram-positive infections. Since its original licence for the treatment of skin and soft tissue infections and pneumonia, there have been reports of its successful use in the treatment of bone and joint infections, endocarditis, and other difficult-to-treat infections.

Use of linezolid in infants and children: a retrospective multicentre study of the Italian Society for Paediatric Infectious Diseases

OBJECTIVES

Because of the spread of drug-resistant Gram-positive bacteria, the use of linezolid for treating severe infections is increasing. However, clinical experience in the paediatric population is still limited. We undertook a multicentre study to analyse the use of linezolid in children.

METHODS

Hospitalized children treated with linezolid for a suspected or proven Gram-positive or mycobacterial infection were analysed retrospectively. Side effects were investigated, focusing on younger children and long-term treatments.

RESULTS

Seventy-five patients (mean age 6.8 years, range 7 days to 17 years) were studied. Mean ± SD linezolid treatment duration was 26.13 ± 17 days. Clinical cure was achieved in 74.7% of patients. The most frequent adverse events were diarrhoea and vomiting. Two patients had severe anaemia, two neutropenia and one thrombocytopenia. Two cases of grade 3 liver function test elevation and one case of pancreatitis were reported. The overall frequency of adverse events was similar between patients treated for >28 days and those receiving shorter treatments (30.8% versus 28.6%, P = 0.84). Children aged <2 years received linezolid for a shorter duration than older children (21.2 days versus 28.4 days, P = 0.05), whereas the frequency of adverse events was similar in the two age groups.

CONCLUSIONS

In our paediatric population, linezolid appeared safe and effective for the treatment of selected Gram-positive and mycobacterial infections. The adverse reactions encountered were reversible and appeared comparable to those reported in paediatric clinical trials. Nevertheless, the potential for haematological toxicity of linezolid in children means that careful monitoring is required during treatment.