Safety and clinical efficacy of linezolid in children: a systematic review and meta-analysis

Pseudo-ternary phase diagram based PEGylated nano-dispersion of linezolid to promote wound regeneration: an in vitro and in vivo evaluation

Open wounds are prone to bacterial infiltration mostly resistant strains like methicillin-resistant Staphylococcus aureus (MRSA), which affects healing of open wounds. Topical linezolid nano-dispersion using essential oils as nanoemulgel can increase solubility of drug and bypass side-effects like GI-irritation of oral administration. Pseudo-ternary phase diagram was built to optimise nanoemulsion. Surfactant/co-surfactant mixture (3:1), deionised water and Oilmix (4:1) with drug were vortexed and then ultrasonicated. 1% carbopol gel of optimised nanoemulsion was prepared and characterised, exposed to antimicrobial study, cytocompatibility study using HEK293 cell-line, and in vivo wound healing study using rat excision model. Histological study was performed to confirm growth of stratum corneum. Optimised formulation has particle size (244.6 ± 178.66 nm), polydispersity index (25%), entrapment efficiency (92.3 ± 3.38%) and in vitro drug release (87.58 ± 4.16%) best fitted in Korsmeyer-Peppas kinetics model. Nanoemulgel F6 (0.2%w/w) was found with viscosity of 5345 ± 6 cP constituting a very excellent antimicrobial effect against MRSA. HEK293 cells had shown good cytocompatibility with formulation. The wound contraction rate was 99.66 ± 0.57% at day 15 on daily application of nanoemulgel and stratum corneum was almost fully regenerated. The developed nanoemulgel has potential antimicrobial efficacy and can promote wound healing.

Population pharmacokinetics and clinical assessment of linezolid in pediatric bacterial infections

The pharmacokinetic profile of linezolid still needs further definition, and insufficient or excessive exposure may lead to treatment failure or development of adverse events. Our study aimed to establish a population pharmacokinetic (PPK) model for linezolid in children with bacterial infections, develop an optimal dosage, and evaluate its efficacy and safety. A total of 157 plasma samples from 80 patients were utilized in PPK modeling. A one-compartment model with first-order elimination was most suitable for describing the PK characteristics of linezolid. Weight and creatinine clearance were the significant covariates for clearance. The outcomes of Monte Carlo revealed that in children under 12 years, the probability of target attainment (PTA) for standard dosage (10 mg/kg q8h) was over 90.0% when minimum inhibitory concentration (MIC) ≤2 µg/mL, with a mere 1.4% probability of surpassing the safety threshold. Meanwhile, in children aged 12 years and above, the PTA for standard dosage (600 mg q12h) was over 83.0%, and the probability of surpassing the safety threshold was 0.0%. To take the results one step further, a total of 67 patients (using standard dosage) were enrolled in the efficacy and safety analysis. Of the patients, 95.5% were cured or improved clinical treatment outcomes, and 22.4% of the patients developed possible adverse events (AEs), and no patient experienced early discontinuation of linezolid due to AEs. The standard dosage of linezolid is effective and safe in children with bacterial infections (MIC ≤2 µg/mL). For pathogens with MIC >2 µg/mL, it is advisable to switch antibiotics or increase dosage.CLINICAL TRIALSThis study is registered with Chinese Clinical Trial Registry as ChiCTR 2200061207.

Vancomycin and linezolid: severe cutaneous adverse reactions to drugs

BACKGROUND

Severe cutaneous adverse reactions (SCARs), including Stevens-Johnson Syndrome (SJS), Toxic Epidermal Necrolysis (TEN), Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS), and Acute Generalized Exanthematous Pustulosis (AGEP), pose significant therapeutic challenges. Vancomycin and linezolid have been linked to these life-threatening conditions, necessitating a better understanding of their associated risks.

METHODS

We conducted a retrospective analysis using data from the FDA Adverse Event Reporting System (FAERS) database. Disproportionality and Bayesian statistical analyses were applied to evaluate the associations between vancomycin, linezolid, and SCARs, comparing the outcomes induced by these drugs.

RESULTS

Of the 11,737,133 data, there were a total of 1024 vancomycin-associated SCARs and 125 cases of linezolid-associated SCARs. Vancomycin was strongly associated with DRESS, showing a Reporting Odds Ratio (ROR) of 53.79 (95% CI: 49.75-58.16), Proportional Reporting Ratio (PRR) of 50.38, and Empirical Bayesian Geometric Mean (EBGM) of 2.32. For SJS and TEN, vancomycin reported RORs of 8.04 and 15.63, respectively. Linezolid demonstrated lower associations, with RORs of 5.14 for DRESS and 2.36 for SJS.

CONCLUSIONS

Vancomycin presents a higher risk of SCARs compared to linezolid, particularly for DRESS. Underscoring the need for cautious use and the potential benefit of personalized medicine practices to improve patient safety.

Evaluation of pharmacokinetic target attainment and hematological toxicity of linezolid in pediatric patients

BACKGROUND

Linezolid is commonly used to treat severe and/or resistant Gram-positive infections. Few studies have assessed its pharmacokinetic (PK) target attainment in pediatrics.

OBJECTIVE

To evaluate the percentage of pediatrics achieving the PK targets of linezolid with standard dosing regimens and to assess the incidence and risk factors associated with its hematologic toxicity.

METHODS

This prospective observational study included pediatric patients aged 0-14 who received linezolid for suspected or proven Gram-positive infections. Linezolid trough concentrations and the 24-h area under the curve (AUC24) were estimated, and hematologic toxicity was assessed.

RESULTS

Seventeen pediatric patients (5 neonates and 12 older pediatrics) were included. A wide variability was observed in linezolid's trough and AUC24 (ranging from 0.5 to 14.4 mg/L and from 86 to 700 mg.h/L, respectively). The median AUC24 was significantly higher in neonates than older pediatrics (436 [350-574] vs. 200 [134-272] mg,h/L, P = 0.01). Out of all patients, only 41% achieved adequate drug exposure (AUC24 160-300 mg.h/L and trough 2-7 mg/L), with 24% having subtherapeutic, and 35% having higher-than-optimal exposures. Hematological toxicity was observed in 53% of cases. Identified risk factors include treatment duration over 7 days, baseline platelet counts below 150 × 109/L, sepsis/septic shock, and concomitant use of meropenem.

CONCLUSIONS

Linezolid's standard dosing failed to achieve its PK targets in approximately half of our pediatric cohort. Our findings highlight the complex interplay between the risk factors of linezolid-associated hematological toxicity and underscore the importance of its vigilant use and monitoring, particularly in pediatrics with concomitant multiple risk factors.

Assessment of Antibiotic Resistance in Pediatric Infections: A Romanian Case Study on Pathogen Prevalence and Effective Treatments

Antibiotic misuse in Romania has exacerbated the issue of antibiotic resistance, as patients often use antibiotics without proper medical consultation. This study aimed to assess the resistance of prevalent bacteria to different antibiotics. In this observational study conducted over six months, we analyzed 31 pediatric patients aged from 12 days to 13 years using the disk diffusion method. We identified 31 bacterial isolates, including 8 Gram-negative and 8 Gram-positive strains, with the most common being Pseudomonas aeruginosa, Escherichia coli, Streptococcus pneumoniae, methicillin-resistant Staphylococcus aureus, Streptococcus species, and Elizabethkingia meningoseptica. Our findings revealed that the most effective antibiotics were linezolid, ertapenem, and teicoplanin. In contrast, nearly all tested bacteria exhibited resistance to penicillin, followed by oxacillin and ampicillin. Resistance to cephalosporins varied with generation, showing higher resistance to lower-generation cephalosporins. The study highlights significant antibiotic resistance among common bacterial pathogens in Romanian pediatric patients, emphasizing the urgent need for controlled antibiotic use and alternative treatment strategies to combat this growing issue. Effective antibiotics such as linezolid and ertapenem offer potential solutions, whereas reliance on penicillin and lower-generation cephalosporins is increasingly futile.

Linezolid and vancomycin for nosocomial infections in pediatric patients: a systematic review

OBJECTIVE

To investigate the effectiveness of linezolid and vancomycin for the treatment of nosocomial infections in children under 12 years old.

DATA SOURCES

This is a systematic review in which five randomized clinical trials about the effectiveness of linezolid and vancomycin, involving a total of 429 children with nosocomial infections, were evaluated. They were searched in scientific databases: PubMed, Bvs, and SciELO.

SUMMARY OF FINDINGS

The main nosocomial infections that affected children were bacteremia, skin, and soft tissue infections followed by nosocomial pneumonia. Most infections were caused by Gram-positive bacteria, which all studies showed infections caused by Staphylococcus aureus, with methicillin-resistant S. aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci strains being isolated. Both linezolid and vancomycin showed high therapeutic efficacy against different types of nosocomial infections, ranging from 84.4% to 94% for linezolid and 76.9% to 90% for vancomycin. Patients receiving linezolid had lower rates of rash and red man syndrome compared to those receiving vancomycin. However, despite the adverse reactions, antimicrobials can be safely administered to children to treat nosocomial infections caused by resistant Gram-positive bacteria.

CONCLUSION

Both linezolid and vancomycin showed good efficacy in the treatment of bacterial infections caused by resistant Gram-positive bacteria in hospitalized children. However, linezolid stands out regarding its pharmacological safety. Importantly, to strengthen this conclusion, further clinical trials are needed to provide additional evidence.

Adverse drug events associated with linezolid administration: a real-world pharmacovigilance study from 2004 to 2023 using the FAERS database

Introduction: Linezolid is an oxazolidinone antibiotic that is active against drug-resistant Gram-positive bacteria and multidrug-resistant Mycobacterium tuberculosis. Real-world studies on the safety of linezolid in large populations are lacking. This study aimed to determine the adverse events associated with linezolid in real-world settings by analyzing data from the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS). Methods: We retrospectively extracted reports on adverse drug events (ADEs) from the FAERS database from the first quarter of 2004 to that of 2023. By using disproportionality analysis including reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), along with the multi-item gamma Poisson shrinker (MGPS), we evaluated whether there was a significant association between linezolid and ADE. The time to onset of ADE was further analyzed in the general population and within each age, weight, reporting population, and weight subgroups. Results: A total of 11,176 reports of linezolid as the "primary suspected" drug and 263 significant adverse events of linezolid were identified, including some common adverse events such as thrombocytopenia (n = 1,139, ROR 21.98), anaemia (n = 704, ROR 7.39), and unexpected signals that were not listed on the drug label such as rhabdomyolysis (n = 90, ROR 4.33), and electrocardiogram QT prolonged (n = 73, ROR 4.07). Linezolid-induced adverse reactions involved 27 System Organ Class (SOC). Gender differences existed in ADE signals related to linezolid. The median onset time of all ADEs was 6 days, and most ADEs (n = 3,778) occurred within the first month of linezolid use but some may continue to occur even after a year of treatment (n = 46). Conclusion: This study reports the time to onset of adverse effects in detail at the levels of SOC and specific preferred term (PT). The results of our study provide valuable insights for optimizing the use of linezolid and reducing potential side effects, expected to facilitate the safe use of linezolid in clinical settings.

Compassionate use of contezolid in a toddler with severe community-acquired pneumonia induced by staphylococcus aureus: a case report and follow-up

Background

Initial choices of antimicrobial therapy for most cases of community-acquired pneumonia (CAP) in children under 5 years of age are typically based on local epidemiology, risk factors assessment, and subsequent clinical parameters and positive cultures, which can lead to the underdiagnosis and underestimation of lung infections caused by uncommon pathogens. Contezolid, an orally administered oxazolidinone antibiotic, gained approval from the National Medical Products Administration (NMPA) of China in June 2021 for managing complicated skin and soft tissue infections (cSSTI) caused by staphylococcus aureus (SA), streptococcus pyogenes, or streptococcus agalactis. Owing to its enhanced safety profile and ongoing clinical progress, the scope of contezolid's clinical application continues to expand, benefiting a growing number of patients with Gram-positive bacterial infections.

Case summary

In this report, we present the first use of contezolid in a toddler with severe CAP caused by SA, aiming to avoid potential adverse drug reactions (ADRs) associated with vancomycin and linezolid.

Conclusion

Although contezolid has not been officially indicated for CAP, it has been shown to be effective and safe in the management of SA-induced severe CAP in this toddler, suggesting its potential as an alternative option in the dilemma, especially for patients who are susceptible or intolerant to ADRs associated with first-line anti-methicillin-resistant staphylococcus aureus (MRSA) antimicrobial agents.

Synergistic properties of linezolid against Enterococcus spp. isolates: a systematic review from in vitro studies

PURPOSE

Vancomycin-resistant enterococci (VRE) are a leading cause of hospital-acquired infections with limited therapeutic options. Combination of at least two antimicrobials is a possible strategy to obtain rapid and sustained bactericidal effects and overcome the emergence of resistance. We revised the literature on linezolid synergistic properties from in vitro studies to assess its activity in combination with molecules belonging to other antibiotic classes against Enterococcus spp.

METHODS

We performed a systematic review of the literature from three peer-reviewed databases including papers evaluating linezolid synergistic properties in vitro against Enterococcus spp. isolates.

RESULTS

We included 206 Enterococcus spp. isolates (92 E. faecalis, 90 E. faecium, 2 E. gallinarum, 3 E. casseliflavus, 19 Enterococcus spp.) from 24 studies. When an isolate was tested with different combinations, each combination was considered independently for further analysis. The most frequent interaction was indifferent effect (247/343, 72% of total interactions). The highest synergism rates were observed when linezolid was tested in combination with rifampin (10/49, 20.4% of interactions) and fosfomycin (16/84, 19.0%, of interactions). Antagonistic effect accounted for 7/343 (2.0%) of total interactions.

CONCLUSION

Our study reported overall limited synergistic in vitro properties of linezolid with other antibiotics when tested against Enterococcus spp. The clinical choice of linezolid in combination with other antibiotics should be guided by reasoned empiric therapy in the suspicion of a polymicrobial infection or targeted therapy on microbiological results, rather than on an intended synergistic effect of the linezolid-based combination.

Risk factors for thrombocytopenia in patients receiving linezolid therapy: a systematic review and meta-analysis

PURPOSE

The incidence of linezolid-induced thrombocytopenia (LIT) has been reported to vary widely across studies. We performed a meta-analysis to identify the risk factors for thrombocytopenia among patients who received linezolid treatment.

METHODS

The PubMed, Embase and Cochrane Library databases were searched from inception to November 2022 to identify eligible studies. Data on the potential predictors of incidence in LIT were pooled using a random effects model. Sensitivity analyses were performed to determine the robustness of the results when significant heterogeneity was observed.

RESULTS

Forty observational studies involving 6454 patients treated with linezolid were included in the analysis. LIT was estimated to occur in 37% of patients. The following important factors were associated with the incidence of LIT: advanced age, body mass index, concurrent renal impairment or liver disease, abnormal laboratory parameters (including white blood cell count, serum creatinine, baseline platelet count, albumin, creatinine clearance rate, and estimated glomerular filtration rate), treatment duration and renal replacement therapy.

CONCLUSIONS

A variety of risk factors related to the occurrence of LIT were revealed in our analysis. Early identification of these factors could help patients improve clinical outcomes.