The risk of seizures among the carbapenems: a meta-analysis

Role of therapeutic drug monitoring in the treatment of multi-drug resistant tuberculosis

Tuberculosis (TB) is a leading cause of mortality worldwide, and resistance to anti-tuberculosis drugs is a challenge to effective treatment. Multi-drug resistant TB (MDR-TB) can be difficult to treat, requiring long durations of therapy and the use of second line drugs, increasing a patient's risk for toxicities and treatment failure. Given the challenges treating MDR-TB, clinicians can improve the likelihood of successful outcomes by utilizing therapeutic drug monitoring (TDM). TDM is a clinical technique that utilizes measured drug concentrations from the patient to adjust therapy, increasing likelihood of therapeutic drug concentrations while minimizing the risk of toxic drug concentrations. This review paper provides an overview of the TDM process, pharmacokinetic parameters for MDR-TB drugs, and recommendations for dose adjustments following TDM.

Efficacy and safety of antibiotics targeting Gram-negative bacteria in nosocomial pneumonia: a systematic review and Bayesian network meta-analysis

BACKGROUND

Multiple randomized controlled studies have compared numerous antibiotic regimens, including new, recently commercialized antibiotics in the treatment of nosocomial pneumonia (NP). The objective of this Bayesian network meta-analysis (NMA) was to compare the efficacy and the safety of different antibiotic treatments for NP.

METHODS

We conducted a systematic search of PubMed, Medline, Web of Science, EMBASE and the Cochrane Library databases from 2000 through 2021. The study selection included studies comparing antibiotics targeting Gram-negative bacilli in the setting of NP. The primary endpoint was 28 day mortality. Secondary outcomes were clinical cure, microbiological cure and adverse events.

RESULTS

Sixteen studies encompassing 4993 patients were included in this analysis comparing 13 antibiotic regimens. The level of evidence for mortality comparisons ranged from very low to moderate. No significant difference in 28 day mortality was found among all beta-lactam regimens. Only the combination of meropenem plus aerosolized colistin was associated with a significant decrease of mortality compared to using intravenous colistin alone (OR = 0.43; 95% credible interval [0.17-0.94]), based on the results of the smallest trial included. The clinical failure rate of ceftazidime was higher than meropenem with (OR = 1.97; 95% CrI [1.19-3.45]) or without aerosolized colistin (OR = 1.40; 95% CrI [1.00-2.01]), imipemen/cilastatin/relebactam (OR = 1.74; 95% CrI [1.03-2.90]) and ceftazidime/avibactam (OR = 1.48; 95% CrI [1.02-2.20]). For microbiological cure, no substantial difference between regimens was found, but ceftolozane/tazobactam had the highest probability of being superior to comparators. In safety analyses, there was no significant difference between treatments for the occurrence of adverse events, but acute kidney failure was more common in patients receiving intravenous colistin.

CONCLUSIONS

This network meta-analysis suggests that most antibiotic regimens, including new combinations and cefiderocol, have similar efficacy and safety in treating susceptible Gram-negative bacilli in NP. Further studies are necessary for NP caused by multidrug-resistant bacteria. Registration PROSPERO CRD42021226603.

Interprofessional Therapeutic Drug Monitoring of Carbapenems Improves ICU Care and Guideline Adherence in Acute-on-Chronic Liver Failure

(1) Background: Acute-on-chronic liver failure (ACLF) is a severe, rapidly progressing disease in patients with liver cirrhosis. Meropenem is crucial for treating severe infections. Therapeutic drug monitoring (TDM) offers an effective means to control drug dosages, especially vital for bactericidal antibiotics like meropenem. We aimed to assess the outcomes of implementing TDM for meropenem using an innovative interprofessional approach in ACLF patients on a medical intensive care unit (ICU). (2) Methods: The retrospective study was conducted on a medical ICU. The outcomes of an interprofessional approach comprising physicians, hospital pharmacists, and staff nurses to TDM for meropenem in critically ill patients with ACLF were examined in 25 patients. Meropenem was administered continuously via an infusion pump after the application of an initial loading dose. TDM was performed weekly using high-performance liquid chromatography (HPLC). Meropenem serum levels, implementation of the recommendations of the interprofessional team, and meropenem consumption were analyzed. (3) Results: Initial TDM for meropenem showed a mean meropenem serum concentration of 20.9 ± 9.6 mg/L in the 25 analyzed patients. Of note, in the initial TDM, only 16.0% of the patients had meropenem serum concentrations within the respective target range, while 84.0% exceeded this range. Follow-up TDM showed serum concentrations of 15.2 ± 5.7 mg/L (9.0-24.6) in Week 2 and 11.9 ± 2.3 mg/L (10.2-13.5) in Week 3. In Week 2, 41.7% of the patients had meropenem serum concentrations that were within the respective target range, while 58.3% of the patients were above this range. In Week 3, 50% of the analyzed serum concentrations of meropenem were within the targeted range, and 50% were above the range. In total, 100% of the advice given by the interprofessional team regarding meropenem dosing or a change in antibiotic therapy was implemented. During the intervention period, the meropenem application density was 37.9 recommended daily doses (RDD)/100 patient days (PD), compared to 42.1 RDD/100 PD in the control period, representing a 10.0% decrease. (4) Conclusions: Our interprofessional approach to TDM significantly reduced meropenem dosing, with all the team's recommendations being implemented. This method not only improved patient safety but also considerably decreased the application density of meropenem.

Multiple brain abscesses caused by Nocardia asiatica: Case report and literature review

Nocardia are opportunistic pathogens mainly affecting immunocompromised individuals. Nocardia asiatica, a novel species, can cause severe infections. We present a case of multiple brain abscesses due to Nocardia asiatica, discussing its diagnosis and treatment. In January 2022, a 27-year-old Chinese woman with a history of atypical membranous nephropathy presented with low-grade fever, cough, limb weakness, and headaches. Imaging revealed lung and brain lesions. Neurological symptoms worsened over time, culminating in recurrent seizures and severe headaches. A brain MRI confirmed multiple abscesses. Craniotomy and lesion removal were performed, leading to a diagnosis of brain abscesses caused by Nocardia asiatica. Empirical antibiotics were followed by targeted regimen. After successful treatment, the patient remained symptom-free during follow-ups. Nocardia asiatica multiple brain abscesses are exceedingly rare. This case underscores the importance of considering nocardiosis in immunosuppressed patients presenting with neurological symptoms. Timely neurosurgical intervention and effective antibiotic therapy are crucial. Metagenomic next-generation sequencing proved invaluable for rapid diagnosis. Treatment with trimethoprim-sulfamethoxazole (TMP-SMX) and a carbapenem followed by TMP-SMX alone achieved disease control. This case contributes to the understanding of Nocardia asiatica infections and highlights the role of neurosurgical procedures in managing disseminated nocardiosis.

Therapeutic drug monitoring of carbapenem antibiotics in critically ill patients: an overview of principles, recommended dosing regimens, and clinical outcomes

INTRODUCTION

The importance of antibiotic treatment for sepsis in critically ill septic patients is well established. Consistently achieving the dose of antibiotics required to optimally kill bacteria, minimize the development of resistance, and avoid toxicity is challenging. The increasing understanding of the pharmacokinetic and pharmacodynamic (PK/PD) characteristics of antibiotics, and the effects of critical illness on key PK/PD parameters, is gradually re-shaping how antibiotics are dosed in critically ill patients.

AREAS COVERED

The PK/PD characteristics of commonly used carbapenem antibiotics, the principles of the application of therapeutic drug monitoring (TDM), and current as well as future methods of utilizing TDM to optimally devise dosing regimens will be reviewed. The limitations and evidence-base supporting the use of carbapenem TDM to improve outcomes in critically ill patients will be examined.

EXPERT OPINION

It is important to understand the principles of TDM in order to correctly inform dosing regimens. Although the concept of TDM is attractive, and the ability to utilize PK software to optimize dosing in the near future is expected to rapidly increase clinicians' ability to meet pre-defined PK/PD targets more accurately, current evidence provides only limited support for the use of TDM to guide carbapenem dosing in critically ill patients.

Seizures associated with antibiotics: a real-world disproportionality analysis of FAERS database

BACKGROUND

Drug-induced seizures are a common occurrence in clinical practice, with research indicating that around 6% of initial seizures are due to drug toxicity. The use of antibiotics is one such cause of drug-related seizures. Previous systematic review has identified specific antibiotics that pose a risk of seizures, but a comprehensive analysis of a large patient sample is needed to determine the risk associated with various drugs.

OBJECTIVE

This study aimed to evaluate the association between seizures and various antibiotics that are presently accessible.

METHODS

To identify potential risk signals from the US Food and Drug Administration adverse event reporting system (FAERS) database, a disproportionality analysis was conducted. The reporting odds ratio (ROR) using the frequency approach and the information component (IC) using the Bayesian approach were used to detect signals. The median time-to-onset of seizure, as well as the Weibull distribution parameters were calculated to analyze the onset time.

RESULTS

A total of 14,407,157 FAERS reports were analyzed.10 antibiotics were associated with seizures that were defined by 41 preferred terms. Onset time were aligned with the wear out failure type profile.

CONCLUSION

This study identified 10 antibiotics that showed significant associations with seizures. Imipenem-cilastatin had the highest seizure ROR.

Clinical impact of carbapenems in critically ill patients with valproic acid therapy: A propensity-matched analysis

Background

Valproic acid (VPA) is one of the most widely used broad-spectrum antiepileptic drugs, and carbapenems (CBPs) remain the drug of choice for severe infection caused by multidrug-resistant bacteria in critically ill patients. The interaction between VPA and CBPs can lead to a rapid depletion of serum VPA level. This may then cause status epilepticus (SE), which is associated with significant mortality. However, the prognostic impact of drug interactions in critically ill patients remains an under-investigated issue.

Objective

The aim of this study was to compare the prognosis of critically ill patients treated with VPA and concomitant CBPs or other broad-spectrum antibiotics.

Methods

Adult patients admitted to a medical center intensive care unit between January 2007 and December 2017 who concomitantly received VPA and antibiotics were enrolled. The risk of reduced VPA serum concentration, seizures and SE, mortality rate, length of hospital stay (LOS), and healthcare expenditure after concomitant administration were analyzed after propensity score matching.

Results

A total of 1,277 patients were included in the study, of whom 264 (20.7%) concomitantly received VPA and CBPs. After matching, the patients who received CBPs were associated with lower VPA serum concentration (15.8 vs. 60.8 mg/L; p < 0.0001), a higher risk of seizures (51.2 vs. 32.4%; adjusted odds ratio [aOR], 2.19; 95% CI, 1.48–3.24; p < 0.0001), higher risk of SE (13.6 vs. 4.7%; aOR, 3.20; 95% CI, 1.51–6.74; p = 0.0014), higher in-hospital mortality rate (33.8 vs. 24.9%; aOR, 1.57; 95% CI, 1.03–2.20; p = 0.036), longer LOS after concomitant therapy (41 vs. 30 days; p < 0.001), and increased healthcare expenditure (US$20,970 vs. US$12,848; p < 0.0001) than those who received other broad-spectrum antibiotics.

Conclusion

The administration of CBPs in epileptic patients under VPA therapy was associated with lower VAP serum concentration, a higher risk of seizures and SE, mortality, longer LOS, and significant utilization of healthcare resources. Healthcare professionals should pay attention to the concomitant use of VPA and CBPs when treating patients with epilepsy. Further studies are warranted to investigate the reason for the poor outcomes and whether avoiding the co-administration of VPA and CBP can improve the outcomes of epileptic patients.

Risk factors for community acquired pediatric urinary tract infection with extended-spectrum-β-lactamase Escherichia coli - A case-control study

INTRODUCTION

Community-acquired (CA) infections caused by extended-spectrum β-lactamase (ESBL) producing Escherichia coli urinary tract infections (UTI) have become increasingly prevalent, posing a serious threat to public health. Risk factors for ESBL UTI have not been extensively studied in the pediatric population. We report findings from a case control study to identify risk factors for CA ESBL-producing E. coli UTI in children.

MATERIALS AND METHOD

A cohort of children with CA ESBL Escherichia coli UTI evaluated at a tertiary referral hospital from January 2014 through April 2021, were matched 1:3 with control group of non-ESBL CA E. coli UTI based on age at first episode of non-ESBL UTI. To identify potential risk factors for ESBL E. coli UTI, conditional logistic regression model was utilized accounting for age matching. Univariate models were fitted for each clinical risk factor. Factors found to be significantly associated with ESBL UTI were simultaneously included in a single model to check for associations adjusted for all other factors.

RESULTS

On conditional multivariate analyses for univariate testing, male sex (P = 0.021), history of Urology care (P = 0.001), and antibiotic treatment within 30 days prior to positive culture (P = 0.004) were identified as independent risk factors for CA ESBL E. coli UTI. Comorbidity scores were assigned to each patient according to pediatric comorbidity index (PCI); children with ESBL UTI were more likely to have higher morbidity risk than non-ESBL UTI children (P < 0.001). From the logistic model, the higher the morbidity scores, the more likely children will have CA ESBL UTI (P < 0.001).

DISCUSSION

Identifying risk factors for ESBL-producing E. coli UTI in children is important because of limited therapeutic options. This knowledge is essential for clinical decision making and to develop intervention strategies to reduce disease burden. Our study found that although females have an increased predisposition to UTIs, we observed that the male sex is an independent risk factor for ESBL E. coli UTI. This finding warrants further investigation to determine underlying cause. Because of the retrospective design of the study, collection of data from a single center, and differences in characteristics between patient populations, treatments, and prescribing patterns in the community, this study may not be generalizable.

CONCLUSIONS

Findings from our case-control study suggest that the male sex, history of Urology care, and previous antibiotic exposure are independent risk factors for CA ESBL-GNB UTI. Children with ESBL E. coli UTI are more likely to have longer admission duration and higher comorbidity index.

Valproate-Induced Encephalopathy Presenting at Therapeutic Blood Concentrations: A Case Report and Literature Review

Patients presenting with hyperammonemic encephalopathy are likely to have hepatic encephalopathy. However, valproate (an anticonvulsant and mood stabilizer) can also cause hyperammonemic encephalopathy and belongs on the differential for patients taking it, especially if there are recent contributory medication changes. We present a case report of a 61-year-old woman with valproate-induced hyperammonemic encephalopathy but with an initial valproate level within the therapeutic range (50-100 mcg/dL). After withholding valproate and before additional treatment could be initiated, she became fully alert and oriented. We present a literature review exploring valproate toxicity and treatment. Our case shows that clinical suspicion for valproate-induced hyperammonemic encephalopathy is warranted even if the valproate level is within the therapeutic range.

Treatment of persistent methicillin-susceptible Staphylococcus aureus bacteremia and presumed osteomyelitis with oxacillin and ertapenem in a premature neonate

Neonatal sepsis remains a high cause of morbidity and mortality in preterm neonates. Methicillin-susceptible Staphylococcus aureus (MSSA) can cause persistent bloodstream infections and invasive disease in neonates. We report the first published case of persistent MSSA bacteremia in a preterm neonate successfully treated with oxacillin and ertapenem combination therapy.

Diet-microbiome-gut-brain nexus in acute and chronic brain injury

In recent years, appreciation for the gut microbiome and its relationship to human health has emerged as a facilitator of maintaining healthy physiology and a contributor to numerous human diseases. The contribution of the microbiome in modulating the gut-brain axis has gained significant attention in recent years, extensively studied in chronic brain injuries such as Epilepsy and Alzheimer’s Disease. Furthermore, there is growing evidence that gut microbiome also contributes to acute brain injuries like stroke(s) and traumatic brain injury. Microbiome-gut-brain communications are bidirectional and involve metabolite production and modulation of immune and neuronal functions. The microbiome plays two distinct roles: it beneficially modulates immune system and neuronal functions; however, abnormalities in the host’s microbiome also exacerbates neuronal damage or delays the recovery from acute injuries. After brain injury, several inflammatory changes, such as the necrosis and apoptosis of neuronal tissue, propagates downward inflammatory signals to disrupt the microbiome homeostasis; however, microbiome dysbiosis impacts the upward signaling to the brain and interferes with recovery in neuronal functions and brain health. Diet is a superlative modulator of microbiome and is known to impact the gut-brain axis, including its influence on acute and neuronal injuries. In this review, we discussed the differential microbiome changes in both acute and chronic brain injuries, as well as the therapeutic importance of modulation by diets and probiotics. We emphasize the mechanistic studies based on animal models and their translational or clinical relationship by reviewing human studies.

Association between Antimicrobial Consumption and the Prevalence of Nosocomial Carbapenem-Resistant Escherichia coli and Klebsiella pneumoniae in a Tertiary Hospital in Northern Taiwan

Carbapenem-resistant Enterobacteriales has become a threat in Taiwan. This is the first local study focusing on the association between carbapenem-resistant Enterobacteriales and antimicrobial consumption. From January 2012 to December 2020, data were collected in a tertiary care hospital in Taipei, Taiwan. Antimicrobial consumption was estimated by the defined daily dose/1,000 patient-days. During the same period, the prevalence of carbapenem-resistant Escherichia coli (CREC) and carbapenem-resistant Klebsiella pneumoniae (CRKP) were collected through routine surveillance data. The following retrospective analyses were conducted: 1) analysis of antimicrobial consumption over time, (2) analysis and forecast of CREC and CRKP prevalence over time, and 3) analysis of correlation between antimicrobial consumption and the prevalence of CREC and CRKP. The consumption of piperacillin/tazobactam (β = 0.615), fluoroquinolones (β = 0.856), meropenem (β = 0.819), and doripenem (β = 0.891) increased during the observation period (P < 0.001), and the consumption of aminoglycosides (β = -0.852) and imipenem/cilastatin (β = -0.851) decreased (P < 0.001). The prevalence of CRKP rose over time (β = 0.522, P = 0.001) and correlated positively with the consumption of fluoroquinolones, levofloxacin, penicillin/β-lactamase inhibitor, piperacillin/tazobactam, meropenem, and doripenem (P < 0.05). The prevalence of CRKP and CREC both correlated negatively with consumption of aminoglycosides (P < 0.01). The prevalence of CRKP in our hospital increased as the forecast predicted based on an autoregressive integrated moving average model. This study provides alarming messages for members participating in antimicrobial stewardship programs, including the increasing prevalence of CRKP, the increasing consumption of broad-spectrum antibiotics, and the positive correlation between them.

Antimicrobial safety considerations in critically ill patients: part II: focused on anti-microbial toxicities

INTRODUCTION

Antibiotic prescription is a challenging issue in critical care settings. Different pharmacokinetic and pharmacodynamic properties, polypharmacy, drug interactions, and high incidence of multidrug-resistant microorganisms in this population can influence the selection, safety, and efficacy of prescribed antibiotics.

AREAS COVERED

In the current article we searched PubMed, Scopus and Google Scholar for neurotoxicities, hematologic toxicity and fluid stewardship in intensive care units.

EXPERT OPINION

Critically ill patients who receive antimicrobial agents should be monitored for neurological, hematologic toxicities especially seizure, thrombocytopenia, and clostridioides infections. Other toxicities including QTc prolongation, electrolyte disturbances, liver enzyme elevation, and infusion-related reactions were being considered. Other changes, including fluid overload, hypoalbuminemia, augmented renal clearance, increased cardiac outputs in septic shock, and acute kidney injury, may influence treatment efficiency and patient outcome.

Interactions between meropenem and renal drug transporters

BACKGROUND

Meropenem is a carbapenem antibiotic and commonly used with other antibiotics for the treatment of bacterial infections. It is primarily eliminated renally by glomerular filtration and renal tubular secretion.

OBJECTIVE

To evaluate the roles of renal uptake and efflux transporters in the excretion of meropenem and potential drug interactions mediated by renal drug transporters.

METHOD

Uptake and inhibition studies were conducted in human embryonic kidney 293 cells stably transfected with organic anion transporter (OAT) 1, OAT3, multidrug and toxin extrusion protein (MATE) 1 and MATE2K, as well as membrane vesicles containing breast cancer resistance-related protein (BCRP), multidrug resistance protein 1 (MDR1) and multidrug resistance-associated protein 2 (MRP2). Probenecid and piperacillin were used to assess potential drug interactions with meropenem in rats.

RESULTS

We observed that meropenem was a low-affinity substrate of OAT1/3 and had a weak inhibitory effect on OAT1/3 and MATE2K. BCRP, MDR1, MRP2, MATE1 and MATE2K could not mediate renal excretion of meropenem. Moreover, meropenem was not an inhibitor of BCRP, MDR1, MRP2 or MATE1. Among five tested antibiotics, moderate inhibition on OAT3-mediated meropenem uptake was observed for linezolid (IC50 value was 69.2 μM), weak inhibition was observed for piperacillin, benzylpenicillin and tazobactam (IC50 values were 282.2, 308.0 and 668.1 μM, respectively), and no inhibition was observed for sulbactam. Although piperacillin had a relatively high drug-drug interaction index (ratio of maximal unbound plasma concentration to IC50 was 1.42) in vitro, it had no meaningful impact on the pharmacokinetics of meropenem in rats.

CONCLUSION

Our results indicate that clinically significant interactions between meropenem and these five antibiotics are low.

Pharmacokinetics of benapenem for injection in subjects with mild to moderate renal impairment

OBJECTIVE

This study evaluated the pharmacokinetic (PK) characteristics of benapenem in subjects with mild to moderate renal impairment to provide a reference for benapenem dosing regimens in this patient population.

METHODS

Eighteen subjects were enrolled in this study. Each subject received a single dose of benapenem intravenously (1.0 g in 100 ml of 0.9% saline) followed by blood and urine collection to measure the concentrations of benapenem and its major metabolite. PK analysis was performed to evaluate the effect of varying degrees of renal impairment on the PK characteristics of benapenem. The safety of benapenem was also evaluated.

RESULTS

In subjects with normal renal function, mild renal impairment, and moderate renal impairment, the maximum plasma benapenem concentrations were 163 ± 6.58 mg/L, 138 ± 17.4 mg/L, and 134 ± 0.11 mg/L, respectively (15.3% and 17.8% lower in subjects with mild and moderate renal impairment, respectively, than in subjects with normal renal function). The areas under the plasma concentration-time curve (AUC_0-inf) were 1153.67 ± 143.2 mg·h/L, 1129.17 ± 241.41 mg·h/L, and 1316.46 ± 229.83 mg·h/L, respectively (P > 0.05); the cumulative urinary excretion rates at 72 h after dosing were 52.61 ± 8.58%, 39.42 ± 8.35%, and 29.84 ± 9.15%, respectively; and the metabolic ratio (AUC_0-inf__KBP-3331/AUC_0-inf__benapenem) were 3.96 ± 0.35%, 5.56 ± 0.82%, and 8.24 ± 0.85%, respectively. No drug-related adverse events (AEs), serious AEs, or AEs leading to withdrawal occurred in this study.

CONCLUSION

No adjustment to benapenem dosing is needed in patients with mild to moderate renal impairment.

CLINICAL TRIAL REGISTRATION

Drug clinical trial registration and information publicity platform: http://www.chinadrugtrials.org.cn/index.html .

REGISTRATION NUMBER

CTR20190760.

Gut Microbiome Distinguishes Patients With Epilepsy From Healthy Individuals

Objective: The gut microecosystem is the largest microecosystem in the human body and has been proven to be linked to neurological diseases. The main objective of this study was to characterize the fecal microbiome, investigate the differences between epilepsy patients and healthy controls, and evaluate the potential efficacy of the fecal microbiome as a diagnostic tool for epilepsy.

Design: We collected 74 fecal samples from epilepsy patients (Eps, n = 24) and healthy controls (HCs, n = 50) in the First Affiliated Hospital of Zhengzhou University and subjected the samples to 16S rRNA MiSeq sequencing and analysis. We set up a train set and a test set, identified the optimal microbial markers for epilepsy after characterizing the gut microbiome in the former and built a diagnostic model, then validated it in the validation group.

Results: There were significant differences in microbial communities between the two groups. The α-diversity of the HCs was higher than that of the epilepsy group, but the Venn diagram showed that there were more unique operational taxonomic unit (OTU) in the epilepsy group. At the phylum level, Proteobacteria and Actinobacteriota increased significantly in Eps, while the relative abundance of Bacteroidota increased in HCs. Compared with HCs, Eps were enriched in 23 genera, including Faecalibacterium, Escherichia-Shigella, Subdoligranulum and Enterobacteriaceae-unclassified. In contrast, 59 genera including Bacteroides, Megamonas, Prevotella, Lachnospiraceae-unclassified and Blautia increased in the HCs. In Spearman correlation analysis, age, WBC, RBC, PLT, ALB, CREA, TBIL, Hb and Urea were positively correlated with most of the different OTUs. Seizure-type, course and frequency are negatively correlated with most of the different OTUs. In addition, twenty-two optimal microbial markers were identified by a fivefold cross-validation of the random forest model. In the established train set and test set, the area under the curve was 0.9771 and 0.993, respectively.

Conclusion: Our study was the first to characterize the gut microbiome of Eps and HCs in central China and demonstrate the potential efficacy of microbial markers as a noninvasive biological diagnostic tool for epilepsy.

Probable Encephalopathy and Spasticity in a Multiple Sclerosis Patient Following Carbapenem Administration: A Case Report and Brief Literature Review

Purpose: The purpose of this case report is to describe spasticity and encephalopathy that developed in a multiple sclerosis patient following carbapenem administration. Summary: A 55-year-old female with multiple sclerosis developed spasticity and encephalopathy within 24 hours of meropenem and ertapenem administration. This was the second time that she had developed encephalopathy following carbapenem administration. The patient gradually recovered over four days following discontinuation of carbapenem therapy. Conclusion: Carbapenem neurotoxicity, a well-documented adverse effect, has been linked to several risk factors, including central nervous system lesions. Despite this, there is little evidence describing the risk of neurotoxicity in patients with multiple sclerosis. It is important to understand the potential adverse effects of carbapenems in specific patient populations to help guide appropriate treatment of infections.

Management dilemmas in Nocardia brain infection

PURPOSE OF REVIEW

Brain nocardiosis is a rare but severe infection mostly occurring among immunocompromised patients. In this review, we present recent data on this infection and address some of the common clinical dilemmas encountered in patients with brain nocardiosis.

RECENT FINDINGS

Strategies used to approach a patient with suspected brain nocardiosis include the 'conservative strategy' (without early neurosurgery) and the 'neurosurgical strategy' (with early aspiration or excision of brain abscess[es]). The advantages and disadvantages of both strategies are summarised. Our opinion is that the use of the 'conservative strategy' should be limited to well-selected patients presenting with an easily accessible extra-neurological lesion(s) and have brain abscesses at low risk of treatment failure. In terms of antimicrobial therapy, we summarise the data supporting the use of a multidrug regimen in patients with brain nocardiosis.Last, we list possible reasons for treatment failure in patients with brain nocardiosis and suggest interventions to overcome them.

SUMMARY

Literature is scarce regarding brain nocardiosis, as a consequence of the rarity of this disease. A multidisciplinary and individualised management is required to optimise the outcome of patients with brain nocardiosis.

Imipenem dosing recommendations for patients undergoing continuous renal replacement therapy: systematic review and Monte Carlo simulations

Background

The appropriate dosing of imipenem for critically ill AKI patients undergoing CRRT remains scarce.

Purpose

This study aimed to (1) gather the available published pharmacokinetic studies conducted in septic patients receiving continuous renal replacement therapy (CRRT) and (2) to define the optimal imipenem dosing regimens in these populations via Monte Carlo simulations.

Methods

The databases of PubMed, Embase, and ScienceDirect were searched from inception to May 2020. We used the Medical Subject Headings of “Imipenem,” “CRRT,” and “pharmacokinetics” or related terms or synonym to identify the studies for systematic reviews. A one-compartment pharmacokinetic model was conducted to predict imipenem levels for the initial 48 h of therapy. The pharmacodynamic target was 40% of free drug level above 4 times of the MIC (40% fT > 4 MIC). The dose that achieved at least 90% of the probability of target attainment was defined as an optimal dose.

Results

Eleven articles were identified and included for our systematic review. The necessary pharmacokinetic parameters such as the volume of distribution and the CRRT clearance were mentioned in 100 and 90.9%, respectively. None of the current studies reported the complete necessary parameters. A regimen of 750 mg q 6 h was the optimal dose for the predilution-CVVH and CVVHD modality with two effluent rates (25 and 35 mL/kg/h) for the pharmacodynamic target of 40% fT > 4MIC.

Conclusions

None of the current studies showed the complete necessary pharmacokinetic parameters for drug dosing. Pharmacodynamic target significantly contributed to imipenem dosing regimens in these patients. Different effluent rates and types of CRRT had minimal impact on dosing regimens. Clinical validation of the recommendation is necessary.

Meropenem concentrations in brain tissue of neurointensive care patients exceed CSF levels

BACKGROUND

Inadequate antibiotic exposure in cerebral infections might have detrimental effects on clinical outcome. Commonly, antibiotic concentrations within the CSF were used to estimate cerebral target levels. However, the actual pharmacological active unbound drug concentration beyond the blood-brain barrier is unknown.

OBJECTIVES

To compare meropenem concentrations in blood, CSF and cerebral microdialysate of neurointensive care patients.

PATIENTS AND METHODS

In 12 patients suffering subarachnoid haemorrhage, 2000 mg of meropenem was administered every 8 h due to an extracerebral infection. Meropenem concentrations were determined in blood, CSF and cerebral microdialysate at steady state (n = 11) and following single-dose administration (n = 5).

RESULTS

At steady state, the free AUC0-8 was 233.2 ± 42.7 mg·h/L in plasma, 7.8 ± 1.9 mg·h/L in CSF and 26.6 ± 14.0 mg·h/L in brain tissue. The brain tissue penetration ratio (AUCbrain/AUCplasma) was 0.11 ± 0.06, which was more than 3 times higher than in CSF (0.03 ± 0.01), resulting in an AUCCSF/AUCbrain ratio of 0.41 ± 0.16 at steady state. After single-dose administration similar proportions were achieved (AUCbrain/AUCplasma = 0.09 ± 0.08; AUCCSF/AUCplasma = 0.02 ± 0.00). Brain tissue concentrations correlated well with CSF concentrations (R = 0.74, P < 0.001), but only moderately with plasma concentrations (R = 0.51, P < 0.001). Bactericidal thresholds were achieved in both plasma and brain tissue for MIC values ≤16 mg/L. In CSF, bactericidal effects were only reached for MIC values ≤1 mg/L.

CONCLUSIONS

Meropenem achieves sufficient bactericidal concentrations for the most common bacterial strains of cerebral infections in both plasma and brain tissue, even in non-inflamed brain tissue. CSF concentrations would highly underestimate the target site activity of meropenem beyond the blood-brain barrier.

A Practical Approach to Antibiotic Use in Critically Ill Obstetric Patients

In recent years, several new antimicrobials have become available that are safer and more effective compared with older agents commonly used in obstetrics. Basic knowledge of these agents is of paramount importance to obstetricians and maternal fetal medicine specialists, as administration of early adequate broad-spectrum empiric antibiotic coverage plays a pivotal role in the management of septic patients. Of particular importance is the critically ill pregnant patient with life-threatening infectious processes in whom poor initial antibiotic selection may result in higher mortality and significant side effects from antibiotics themselves. In this article we aim to provide a guide for clinicians to select an adequate empirical antibiotic regimen for the most common severe infections that may affect pregnant individuals.

Beta-Lactams Toxicity in the Intensive Care Unit: An Underestimated Collateral Damage?

Beta-lactams are the most commonly prescribed antimicrobials in intensive care unit (ICU) settings and remain one of the safest antimicrobials prescribed. However, the misdiagnosis of beta-lactam-related adverse events may alter ICU patient management and impact clinical outcomes. To describe the clinical manifestations, risk factors and beta-lactam-induced neurological and renal adverse effects in the ICU setting, we performed a comprehensive literature review via an electronic search on PubMed up to April 2021 to provide updated clinical data. Beta-lactam neurotoxicity occurs in 10-15% of ICU patients and may be responsible for a large panel of clinical manifestations, ranging from confusion, encephalopathy and hallucinations to myoclonus, convulsions and non-convulsive status epilepticus. Renal impairment, underlying brain abnormalities and advanced age have been recognized as the main risk factors for neurotoxicity. In ICU patients, trough concentrations above 22 mg/L for cefepime, 64 mg/L for meropenem, 125 mg/L for flucloxacillin and 360 mg/L for piperacillin (used without tazobactam) are associated with neurotoxicity in 50% of patients. Even though renal complications (especially severe complications, such as acute interstitial nephritis, renal damage associated with drug induced hemolytic anemia and renal obstruction by crystallization) remain rare, there is compelling evidence of increased nephrotoxicity using well-known nephrotoxic drugs such as vancomycin combined with beta-lactams. Treatment mainly relies on the discontinuation of the offending drug but in the near future, antimicrobial optimal dosing regimens should be defined, not only based on pharmacokinetics/pharmacodynamic (PK/PD) targets associated with clinical and microbiological efficacy, but also on PK/toxicodynamic targets. The use of dosing software may help to achieve these goals.

An overview of cilastatin + imipenem + relebactam as a therapeutic option for hospital-acquired and ventilator-associated bacterial pneumonia: evidence to date

Introduction: Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) are prevalent nosocomial infections with a worrisomely increasing prevalence of multidrug-resistant causative organisms, including those with resistance to carbapenems. The addition of relebactam, a β-lactamase inhibitor, to imipenem treatment restores the antimicrobial activity against the most of multidrug-resistant Gram-negative bacteria, including some carrying β-lactamase enzyme-type carbapenemases.Areas covered: The aim of this article is to summarize the current evidence regarding imipenem/relebactam for the treatment of HAP/VAP. The authors discuss its chemistry, pharmacokinetics/pharmacodynamics, microbiology, tolerance and clinical efficacy. The results of clinical trials have demonstrated an efficacy of imipenem/relebactam similar to that of its comparator for the treatment of patients with HAP/VAP. Different studies have also shown its good safety profile, which is better than that of the combination of other β-lactams with other antibiotics.Expert opinion: This drug should be incorporated as a new therapeutic option for the treatment of patients with HAP/VAP, especially as an alternative treatment in patients with confirmed infections caused by multidrug-resistant Gram-negatives.

Unmasking antibiotic-associated neurological disorders: The underminer in Intensive Care Unit

Psychosis is a common and intractable disorder of hospitalization, especially in patients hospitalized in Intensive Care Unit (ICU). Along with the widely use of multiple antibiotics in community-acquired infection and hospital-acquired infection, the occurrence of antibiotic-associated neurological disorders has become more frequently. However, antibiotic neurotoxicity is often overlooked or misinterpreted. In this review, we summarized the neurological disorders caused by antibacterial agent usage and firstly systematically formulated the pathogenesis of antibiotic-associated neurotoxic reactions. Precautions of the complications are critical in preventing serious clinical outcome as the inducement is curable. Regular neurological physical examination, electroencephalogram (EEG) examination, lumbar puncture and therapeutic drug monitoring closely are essential for early diagnosis and differential diagnosis.

Galactose-Clicked Curcumin-Mediated Reversal of Meropenem Resistance among Klebsiella pneumoniae by Targeting Its Carbapenemases and the AcrAB-TolC Efflux System

In over eighty years, despite successive antibiotics discoveries, the rapid advent of multidrug resistance among bacterial pathogens has jolted our misapprehension of success over them. Resistance is spreading faster than the discovery of new antibiotics/antimicrobials. Therefore, the search for better antimicrobials/additives becomes prudent. A water-soluble curcumin derivative (Curaq) was synthesised, employing a Cu (I) catalysed 1, 3-cyclo addition reaction; it has been evaluated as a potential treatment for multidrug-resistant isolates and as an antibiotic adjuvant for meropenem against hypervirulent multidrug-resistant Klebsiella pneumoniae isolates. We also investigated its solubility and effect over carbapenemase activity. Additionally, we investigated its impact on the AcrAB-TolC system. We found that Curaq inhibited bacterial growth at a minimal concentration of 16 µg/mL; at a 32 µg/mL concentration, it killed bacterial growth completely. Only nine (9.4%) Klebsiella isolates were sensitive to meropenem; however, after synergising with Curaq (8 µg/mL), 85 (88.54%) hvKP isolates became sensitive to the drug. The Curaq also inhibited the AcrAB-TolC efflux system at 1 µg/mL concentration by disrupting the membrane potential and causing depolarisation. The kinetic parameters obtained also indicated its promise as a carbapenemase inhibitor. These results suggest that Curaq can be an excellent drug candidate as a broad-spectrum antibacterial and anti-efflux agent.

Carbapenem use in critically ill patients

PURPOSE OF REVIEW

To review available data on carbapenem use in ICU. Carbapenem is a broad spectrum well tolerated antibiotic family that keep an excellent activity to extended spectrum β-lactamases and AmpC hyperproducer and in susceptible Pseudomonas aeruginosa and Acinetobacter baumannii. It becomes a drug of choice for empirical therapy of suspected sepsis in known or presumably known ESBLE carriers.

RECENT FINDINGS

Carbapenems remained the drug of choice for severe ESBLE infections. In severe critically ill patients, high off-label dose is necessary especially in patients with sepsis and glomerular hyperfiltration. Nevertheless, large spectrum of carbapenems leads to initial overuse. The increase in the overall consumption in the past years with lack of systematic re-evaluation observed is responsible of and carbapenem-selection pressure that contribute to the increase of carbapenem-resistant enterobacteriaceae, A. Baumannii and P. Aeruginosa in ICUs.

SUMMARY

Carbapenems remained a cornerstone of antibiotic therapy of severe infections. Emerging carbapenem resistance is related to the increase of carbapenem consumption. High doses are recommended for early therapy followed by systematic reevaluation on a daily basis with shift to narrow spectrum antimicrobials if possible and early stopping rules.

Clinical and Microbiologic Efficacy and Safety of Imipenem/Cilastatin/Relebactam in Complicated Infections: A Meta-analysis

BACKGROUND

Antimicrobial resistance is on the rise. The use of redundant and inappropriate antibiotics is contributing to recurrent infections and resistance. Newer antibiotics with more robust coverage for Gram-negative bacteria are in great demand for complicated urinary tract infections (cUTIs), complicated intra-abdominal infections (cIAIs), hospital-acquired bacterial pneumonia (HABP), and ventilator-associated bacterial pneumonia (VABP).

MATERIALS AND METHODS

We performed this meta-analysis to evaluate the efficacy and safety profile of a new antibiotic, Imipenem/cilastatin/relebactam, compared to other broad-spectrum antibiotics for complicated infections. We conducted a systemic review search on PubMed, Embase, and Central Cochrane Registry. We included randomized clinical trials-with the standard of care as comparator arm with Imipenem/cilastatin/relebactam as intervention arm. For continuous variables, the mean difference was used. For discrete variables, we used the odds ratio. For effect sizes, we used a confidence interval of 95%. A P-value of less than 0.05 was used for statistical significance. Analysis was done using a random-effects model irrespective of heterogeneity. Heterogeneity was evaluated using the I² statistic.

RESULTS

The authors observed similar efficacy at clinical and microbiologic response levels on early follow-up and late follow-up compared to the established standard of care. The incidence of drug-related adverse events, serious adverse events, and drug discontinuation due to adverse events were comparable across both groups.

CONCLUSION

Imipenem/cilastatin/relebactam has a non-inferior safety and efficacy profile compared to peer antibiotics to treat severe bacterial infections (cUTIs, cIAIs, HABP, VABP).

Effect of drug interactions between carbapenems and valproate on serum valproate concentration: a systematic review and meta-analysis

Background: Concurrent use of valproate and carbapenem antibiotics may decrease serum valproate concentration (SVC). This study evaluated the effects of carbapenem-valproate drug interactions. Research design and methods: We screened PubMed, EMBASE, and Cochrane databases for eligible prospective or retrospective studies that evaluated the effect of concurrent use of carbapenem and valproate compared with valproate alone on SVC. Primary outcomes were the change in SVC from before the addition of the carbapenem to the SVC during the use of carbapenems and after carbapenem discontinuation, and seizure-related outcomes. Secondary outcomes were the influence of valproate or carbapenem dose on SVC and Drug Interaction Probability Scale scores. Results: Twelve studies (633 patients) were included. Compared with valproate alone, combination treatment with carbapenem substantially decreased mean SVC (mean difference, -43.98 mg/L; 95% confidence interval, -48.18 to -39.78). The onset of SVC decreases was within 1-3 days following carbapenem initiation. Seizure frequency increased by 26.3% during combination treatment. No difference was found in mean SVC between the different doses of valproate or carbapenem during combination treatment. Mean SVC increased to similar pre-carbapenem level within 1 to 2 weeks after carbapenem discontinuation. Conclusions: The drug interaction between valproate and carbapenem causes substantial SVC decreases, even to subtherapeutic levels, which may increase the risk of seizures.

Epilepsy: Workup and Management in Adults

When managing epilepsy, there is a temptation to focus care with respect to the last and the next seizure. However, epilepsy is a multifaceted chronic condition and should be treated as such. Epilepsy comes with many physical risks, psychological effects, and socioeconomic ramifications, demanding a long-term commitment from the treating physician. Patients with epilepsy, compared to other chronically ill patient populations, have a worse quality of life, family function, and less social support. The majority of patients are well controlled on antiseizure drugs. However, approximately one-third will continue to have seizures despite optimized medical management. The primary aim of this article is to explore the long-term management of chronic epilepsy, and to address some of the particular needs of patients with chronic epilepsy.

Principles of Pharmacotherapy of Seizures and Status Epilepticus

Status epilepticus is a neurological emergency with an outcome that is highly associated with the initial pharmacotherapy management that must be administered in a timely fashion. Beyond first-line therapy of status epilepticus, treatment is not guided by robust evidence. Optimal pharmacotherapy selection for individual patients is essential in the management of seizures and status epilepticus with careful evaluation of pharmacokinetic and pharmacodynamic factors. With the addition of newer antiseizure agents to the market, understanding their role in the management of status epilepticus is critical. Etiology-guided therapy should be considered in certain patients with drug-induced seizures, alcohol withdrawal, or autoimmune encephalitis. Some patient populations warrant special consideration, such as pediatric, pregnant, elderly, and the critically ill. Seizure prophylaxis is indicated in select patients with acute neurological injury and should be limited to the acute postinjury period.

Antibiotic-induced epileptic seizures: mechanisms of action and clinical considerations

In recent years, there has been growing interest in the development of epileptic seizures as an adverse effect of antibiotic therapy. The most commonly accepted mechanisms underlying the development of antibiotic-induced seizures include direct- and indirect gamma-aminobutyric acid (GABA) antagonism, inhibition of GABA synthesis, and glutaminergic N-methyl-D-Aspartate (NMDA) receptor agonistic activity. Inhibitory pathway inhibition leads to increased neuronal excitability and lowered seizure threshold. Blockage of myoneural presynaptic acetylcholine release, mitochondrial dysfunction, interference of neural protein synthesis, and oxidative stress caused by the generation of neurotoxic radicals also contributes to the development of neurotoxicity. Patients with pre-existing risk factors such as renal or hepatic insufficiency, central nervous system pathology, neurological diseases, history of epilepsy or seizures, critical illness, and increased age are more susceptible to seizure development as a consequence of antibiotic therapy. Administration of antibiotics, together with antiseizure drugs, may also lead to enhanced seizure risk due to drug interactions, which predisposes to alterations in drug metabolism and therapeutic efficacy.

Double-carbapenem therapy in the treatment of multidrug resistant Gram-negative bacterial infections: a systematic review and meta-analysis

BACKGROUND

To compare the efficacy and safety of double-carbapenem therapy (DCT) with other antibiotics for the treatment of multidrug resistant (MDR) Gram-negative bacterial infections.

METHODS

Cochrane Library, PubMed, Embase and Web of Science as well as Chinese databases were searched from database establishment to February 2019. All types of studies were included if they had evaluated efficacy and safety of DCT regimens in patients with MDR Gram-negative bacterial infections. Clinical response, microbiological response, adverse events and mortality were the main outcomes. The protocol was registered with PROSPERO No. CRD42019129979.

RESULTS

Three cohort or case-control studies consisting of 235 patients and 18 case series or case reports consisting of 90 patients were included. The clinical and microbiological responses were similar between DCT and other regimens in patients with carbapenem-resistant Enterobacteriaceae (CRE) infection. DCT achieved a lower mortality than comparators in patients with CRE infection (OR = 0.44, 95% CI = 0.24-0.82, P = 0.009). Ertapenem was the most reported antibiotic in DCT regimens in case series or case reports. Moreover, clinical and microbiological improvements were found in 59 (65.6%) and 63 (70%) in total 90 cases, respectively.

CONCLUSIONS

DCT was as effective as other antibiotics in treating MDR Gram-negative bacterial infections, with similar efficacy response and lower mortality. DCT could be an alternative therapeutic option in the treatment of MDR Gram-negative bacterial infections. High-quality randomized controlled trials were required to confirm the beneficial effects of DCT.

Disseminated Nocardia beijingensis Masquerading as Pulmonary Tuberculosis in a Patient With Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome

Case of disseminated Nocardia beijingensis, initially diagnosed and treated by health department as tuberculosis, presented with worsening symptoms and new lesions. Adjustment to antinocardial treatment resulted in significant clinical and radiographic improvement. Maintain a high index of suspicion for Nocardia in patients diagnosed with tuberculosis with worsening lesions despite therapy.

Meropenem vs standard of care for treatment of neonatal late onset sepsis (NeoMero1): A randomised controlled trial

Background

The early use of broad-spectrum antibiotics remains the cornerstone for the treatment of neonatal late onset sepsis (LOS). However, which antibiotics should be used is still debatable, as relevant studies were conducted more than 20 years ago, recruited in single centres or countries, evaluated antibiotics not in clinical use anymore and had variable inclusion/exclusion criteria and outcome measures. Moreover, antibiotic-resistant bacteria have become a major problem in many countries worldwide. We hypothesized that efficacy of meropenem as a broad-spectrum antibiotic is superior to standard of care regimens (SOC) in empiric treatment of LOS and aimed to compare meropenem to SOC in infants aged <90 days with LOS.

Methods and findings

NeoMero-1 was a randomized, open-label, phase III superiority trial conducted in 18 neonatal units in 6 countries. Infants with post-menstrual age (PMA) of ≤44 weeks with positive blood culture and one, or those with negative culture and at least with two predefined clinical and laboratory signs suggestive of LOS, or those with PMA >44 weeks meeting the Goldstein criteria of sepsis, were randomized in a 1:1 ratio to receive meropenem or one of the two SOC regimens (ampicillin+gentamicin or cefotaxime+gentamicin) chosen by each site prior to the start of the study for 8–14 days. The primary outcome was treatment success (survival, no modification of allocated therapy, resolution/improvement of clinical and laboratory markers, no need of additional antibiotics and presumed/confirmed eradication of pathogens) at test-of-cure visit (TOC) in full analysis set. Stool samples were tested at baseline and Day 28 for meropenem-resistant Gram-negative organisms (CRGNO). The primary analysis was performed in all randomised patients and in patients with culture confirmed LOS. Proportions of participants with successful outcome were compared by using a logistic regression model adjusted for the stratification factors. From September 3, 2012 to November 30th 2014, total of 136 patients (instead of planned 275) in each arm were randomized; 140 (52%) were culture positive. Successful outcome at TOC was achieved in 44/136 (32%) in the meropenem arm vs. 31/135 (23%) in the SOC arm (p = 0.087). The respective numbers in patients with positive cultures were 17/63 (27%) vs. 10/77 (13%) (p = 0.022). The main reason of failure was modification of allocated therapy. Treatment emergent adverse events occurred in 72% and serious adverse events in 17% of patients, the Day 28 mortality was 6%. Cumulative acquisition of CRGNO by Day 28 occurred in 4% of patients in the meropenem and 12% in the SOC arm (p = 0.052).

Conclusions

Within this study population, we found no evidence that meropenem was superior to SOC in terms of success at TOC, short term hearing disturbances, safety or mortality were similar in both treatment arms but the study was underpowered to detect the planned effect. Meropenem treatment did not select for colonization with CRGNOs. We suggest that meropenem as broad-spectrum antibiotic should be reserved for neonates who are more likely to have Gram-negative LOS, especially in NICUs where microorganisms producing extended spectrum- and AmpC type beta-lactamases are circulating.

Emerging roles for the intestinal microbiome in epilepsy

The gut microbiome is emerging as a key regulator of brain function and behavior and is associated with symptoms of several neurological disorders. There is emerging evidence that alterations in the gut microbiota are seen in epilepsy and in response to seizure interventions. In this review, we highlight recent studies reporting that individuals with refractory epilepsy exhibit altered composition of the gut microbiota. We further discuss antibiotic treatment and infection as microbiome-related factors that influence seizure susceptibility in humans and animal models. In addition, we evaluate how the microbiome may mediate effects of the ketogenic diet, probiotic treatment, and anti-epileptic drugs on reducing both seizure frequency and severity. Finally, we assess the open questions in interrogating roles for the microbiome in epilepsy and address the prospect that continued research may uncover fundamental insights for understanding risk factors for epilepsy, as well as novel approaches for treating refractory epilepsy.

Combinatorial Antimicrobial Susceptibility Testing Enabled by Non-Contact Printing

We demonstrate the utility of non-contact printing to fabricate the mAST—an easy-to-operate, microwell-based microfluidic device for combinatorial antibiotic susceptibility testing (AST) in a point-of-care format. The wells are prefilled with antibiotics in any desired concentration and combination by non-contact printing (spotting). For the execution of the AST, the only requirements are the mAST device, the sample, and the incubation chamber. Bacteria proliferation can be continuously monitored by using an absorbance reader. We investigate the profile of resistance of two reference Escherichia coli strains, report the minimum inhibitory concentration (MIC) for single antibiotics, and assess drug–drug interactions in cocktails by using the Bliss independence model.

Higher rates of carbapenem-related seizures in older hospitalised adults

Clinical experience suggests higher occurrence of carbapenem-associated seizures in the elderly than what is reported in the available literature (range between 0.2% and 0.7%). An audit of 1345 patients with age 60 years or older, who received imipenem, ertapenem or meropenem during their acute hospitalisation found 32 (2.4%) subjects developed seizures. Subjects with more than one central nervous system disorders were 11.6 times more likely to develop seizures (odds ratio 11.61, P < 0.001) and subjects with prior history of seizures is associated with four times greater risks (odds ratio 4.02, P = 0.005). Physicians should exercise caution when prescribing carbapenems in elderly, especially those with known epilepsy and a high number of intracranial pathologies.

In Vitro Activity of Imipenem-Relebactam Alone or in Combination with Amikacin or Colistin against Pseudomonas aeruginosa

Relebactam is a novel class A/C β-lactamase inhibitor that restores imipenem in vitro activity against multidrug-resistant and carbapenem-nonsusceptible Pseudomonas aeruginosa Time-kill analyses were performed to evaluate the potential role of imipenem-relebactam in combination with amikacin or colistin against P. aeruginosa Ten clinical P. aeruginosa isolates (9 imipenem nonsusceptible) with imipenem-relebactam MICs ranging from 1/4 to 8/4 μg/ml were included. The isolates had varied susceptibilities to imipenem (1 to 32 μg/ml), amikacin (4 to 128 μg/ml), and colistin (0.5 to 1 μg/ml). Duplicate 24-h time-kill studies were conducted using the average steady-state concentrations (Css_avg) observed after the administration of imipenem-relebactam at 500 mg/250 mg every 6 hours (q6h) alone and in combination with the Css_avg of 25 mg/kg of body weight/day amikacin and 360 mg/day colistin in humans. Imipenem-relebactam alone resulted in 24-h bacterial densities of -2.93 ± 0.38, -1.67 ± 0.29, +0.38 ± 0.96, and +0.15 ± 0.65 log₁₀ CFU/ml at imipenem-relebactam MICs of 1/4, 2/4, 4/4, and 8/4 μg/ml, respectively. No synergy was demonstrated against the single imipenem-susceptible isolate. Against the imipenem-nonsusceptible isolates (n = 9), imipenem-relebactam combined with amikacin resulted in synergy (-2.61 ± 1.50 log₁₀ CFU/ml) against all amikacin-susceptible isolates and in two of three amikacin-intermediate (i.e., MIC, 32 μg/ml) isolates (-2.06 ± 0.19 log₁₀ CFU/ml). Synergy with amikacin was not observed when the amikacin MIC was >32 μg/ml. Imipenem-relebactam combined with colistin demonstrated synergy in eight out of the nine imipenem-resistant isolates (-3.17 ± 1.00 log₁₀ CFU/ml). Against these 10 P. aeruginosa isolates, imipenem-relebactam combined with either amikacin or colistin resulted in synergistic activity against the majority of strains. Further studies evaluating combination therapy with imipenem-relebactam are warranted.

Management of ventilator-associated pneumonia (VAP) caused by resistant gram-negative bacteria: which is the best strategy to treat?

Introduction: Treatment of ventilator-associated pneumonia (VAP) is a major challenge. The increase in multi-drug resistant bacteria has not been accompanied by the validation of new drugs, or by any new antimicrobial strategies to exploit the available agents. VAP due to Gram-negative bacteria has increased mortality, both due to the resistant pathogens themselves and due to inappropriate treatment. Local epidemiology, patients' characteristics and clinical responses provide the most important information for therapeutic decision-making. Moreover, data on VAP therapy due to resistant bacteria are lacking, and the choice of treatment is often based on clinical practice and individual experience. Areas covered: This review summarizes the strategies available for treating the three most prevalent resistant Gram-negative organisms causing VAP: Pseudomonas aeruginosa, Acinetobacter baumannii and Enterobacteriaceae. The review covers the results of a Pubmed search, clinical practice guidelines and reviews, and the authors' experience. Expert opinion: The existing evidence focuses on bloodstream infections or other sites rather than pneumonia and there are no recommendations for the treatment of VAP by multi-drug resistant Gram-negative bacteria, especially for combination regimens. The approval of new drugs is needed to provide effective and safe alternatives for treating carbapenemase-producing strains. Precision medicine and personalized approach are also fundamental in future research.

Comparative efficacy of doripenem versus meropenem for hospital-acquired and ventilator-associated pneumonia

BACKGROUND

Doripenem shows good in vitro activity against common nosocomial pathogens, such as extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter baumannii. However, the use of doripenem for hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) remains controversial. The aim of this study was to compare the efficacy and safety between doripenem and meropenem for patients with HAP or VAP.

METHODS

Adult patients diagnosed with HAP and VAP at National Taiwan University Hospital, who received doripenem or meropenem for more than 48 h between January 2015 and November 2017, were retrospectively reviewed. All-cause mortality on the 30th day was used as the primary outcome measurements.

RESULTS

Fifty-seven patients with doripenem and 252 patients with meropenem were analyzed. Compared to the meropenem group, the doripenem group was younger and had a higher Sequential Organ Failure Assessment (SOFA) score. Multivariable Cox regression analysis revealed that presence of solid organ malignancies (adjusted hazard ratio [AHR], 1.82; 95% CI, 1.04-3.19, p = 0.003) and SOFA score (AHR, 1.10; 95% CI, 1.03-1.17, p = 0.003) were independent factors associated with mortality. There was no survival difference of 30-day mortality between patients receiving doripenem and meropenem for HAP or VAP (log-rank p = 0.113). However, a poorer outcome was observed among patients with hematological disease in the doripenem group (log-rank p = 0.012).

CONCLUSION

Our results demonstrate that doripenem has similar efficacy as meropenem in HAP or VAP patients. With an aim to enhance antibiotic diversity, doripenem could be an alternative choice for patients with HAP or VAP, except for those with hematological malignancies.

Augmented Renal Clearance

Augmented renal clearance (ARC) is a phenomenon in critically ill patients characterized by increased creatinine clearance and elimination of renally eliminated medications. Patients with severe neurologic injury, sepsis, trauma, and burns have been consistently identified as at risk of ARC, with mean creatinine clearances ranging from 170 ml/minute to more than 300 ml/minute. Several potential mechanisms may contribute to the occurrence of ARC including endogenous responses to increased metabolism and solute production, alterations in neurohormonal balance, and therapeutic maneuvers such as fluid resuscitation. Augmented renal clearance is associated with suboptimal exposure to critical medications, including β-lactams and vancomycin, increasing the risk of treatment failure. Although definitive screening tools are not yet known, critical care pharmacists must be vigilant in recognizing when ARC may be a contributing factor affecting expected treatment outcomes in individual patients. Optimizing dosing strategies in critically ill patients with ARC remains a goal of continued research. The current review discusses the clinical characteristics and methods of identifying patients at risk of ARC, potential mechanisms for ARC, and describes pharmacotherapy dosing considerations in patients with ARC.

Treatment of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBLs) infections: what have we learned until now?

The spread of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-PE) has dramatically increased worldwide, and this “evolving crisis” is currently regarded as one of the most important public health threats. The growing problem of ESBL-PE antimicrobial resistance seems to have a dual face between “Scylla and Charybdis”: on one hand the potential for rapid spread and dissemination of resistance mechanisms and on the other hand the injudicious overuse of antimicrobial agents and the inadequate infection control measures, especially in the health-care setting. Given the World Health Organization’s warning against a “post antibiotic era”, health-care providers are at a critical standpoint to find a “balance” between safe and effective ESBL-PE treatment and avoidance of inducing further resistance mechanisms. The aim of the review is to summarize the updated published knowledge in an attempt to answer basic everyday clinical questions on how to proceed to effective and the best ESBL-PE treatment options based on the existing published data.

Anti-infective treatment of brain abscess

INTRODUCTION

Brain abscess is an uncommon and potentially life-threatening infection of the CNS that can be caused by a range of different pathogens including bacteria, fungi, and parasites. A multidisciplinary approach is important and anti-infective treatment remains crucial. Here, we review anti-infective treatment of brain abscess. Areas covered: We used the terms '(Brain abscess[ti] AND (antibiotic* OR treatment)) NOT case report'), to conduct a search in the PubMed. Additional papers were identified by cross-reference checking and by browsing textbooks of infectious diseases and neurology.

COMMENTARY

Empiric treatment of bacterial brain abscess consists of cefotaxime and metronidazole with the addition of vancomycin if meticilline-resistant Staphylococcus aureus is suspected. For severely immuno-suppressed patients, for example transplant recipients, voriconazole and trimethoprim-sulfamethoxazole or sulfadiazine should be added. Increased knowledge of the pharmacokinetic profile of anti-infective treatments may help to improve the treatment of brain abscess. Future studies should address efficacy and safety of continuous abscess drainage, mode of anti-infective administration (continuous vs. bolus), and anti-infective treatments in immuno-suppressed patients.

Neurological Adverse Effects Attributable to β-Lactam Antibiotics: A Literature Review

β-lactam antibiotics are commonly prescribed antibiotic drugs. To describe the clinical characteristics, risk markers and outcomes of β-lactam antibiotic-induced neurological adverse effects, we performed a general literature review to provide updated clinical data about the most used β-lactam antibiotics. For selected drugs in each class available in France (ticarcillin, piperacillin, temocillin, ceftazidime, cefepime, cefpirome, ceftaroline, ceftobiprole, ceftolozane, ertapenem and aztreonam), a systematic literature review was performed up to April 2016 via an electronic search on PubMed. Articles that reported original data, written in French, Spanish, Portuguese or English, with available individual data for patients with neurological symptoms (such as seizure, disturbed vigilance, confusional state, myoclonia, localising signs, and/or hallucinations) after the introduction of a β-lactam antibiotic were included. The neurological adverse effects of piperacillin and ertapenem are often described as seizures and hallucinations (>50 and 25% of cases, respectively). Antibiotic treatment is often adapted to renal function (>70%), and underlying brain abnormalities are seen in one in four to one in three cases. By contrast, the neurological adverse drug reactions of ceftazidime and cefepime often include abnormal movements but few hallucinations and seizures. These reactions are associated with renal insufficiency (>80%) and doses are rarely adapted to renal function. Otherwise, it appears that monobactams do not have serious neurological adverse drug reactions and that valproic acid and carbapenem combinations should be avoided. The onset of disturbed vigilance, myoclonus, and/or seizure in a patient taking β-lactam antibiotics, especially if associated with renal insufficiency or underlying brain abnormalities, should lead physicians to suspect adverse drug reactions and to consider changes in antibacterial therapy.

Differences in suppression of regrowth and resistance despite similar initial bacterial killing for meropenem and piperacillin/tazobactam against Pseudomonas aeruginosa and Escherichia coli

We described bacterial killing and resistance emergence at various fixed concentrations of meropenem and piperacillin/tazobactam against Pseudomonas aeruginosa and Escherichia coli. Time-kill studies were conducted utilizing nine isolates and a large range of concentrations. Within each strain and antibiotic, initial killing was similar, with concentrations ≥2×MIC. At many (strain-specific) concentrations causing substantial initial killing, regrowth occurred at 24-48h. For remaining concentrations, growth typically remained suppressed (<5-log₁₀ cfu/mL). The concentrations of meropenem required to suppress regrowth ranged from 2-8×MIC for P. aeruginosa and 2-64×MIC for E. coli. For piperacillin/tazobactam, the equivalent concentrations ranged from 8-16×MIC for P. aeruginosa and 4-16×MIC for E. coli. The number of less-susceptible bacteria increased with rising concentrations before decreasing at even higher concentrations. Suppression of regrowth and resistance was substantially improved with higher concentrations (typically ≥8×MIC), suggesting a benefit of higher β-lactam concentrations beyond those required for maximum initial killing.