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

Drugs with a negative impact on cognitive functions (part 3): antibacterial agents in patients with chronic kidney disease

The relationship between chronic kidney disease (CKD) and cognitive function has received increased attention in recent years. Antibacterial agents (ABs) represent a critical component of therapy regimens in patients with CKD due to increased susceptibility to infections. Following our reviewing work on the neurocognitive impact of long-term medications in patients with CKD, we propose to focus on AB-induced direct and indirect consequences on cognitive function. Patients with CKD are predisposed to adverse drug reactions (ADRs) due to altered drug pharmacokinetics, glomerular filtration decline, and the potential disruption of the blood-brain barrier. ABs have been identified as a major cause of ADRs in vulnerable patient populations. This review examines the direct neurotoxic effects of AB classes (e.g. beta-lactams, fluoroquinolones, aminoglycosides, and metronidazole) on the central nervous system (CNS) in patients with CKD. We will mainly focus on the acute effects on the CNS associated with AB since they are the most extensively studied effects in CKD patients. Moreover, the review describes the modulation of the gut microbiota by ABs, potentially influencing CNS symptoms. The intricate brain-gut-kidney axis emerges as a pivotal focus, revealing the interplay between microbiota alterations induced by ABs and CNS manifestations in patients with CKD. The prevalence of antibiotic-associated encephalopathy in patients with CKD undergoing intravenous AB therapy supports the use of therapeutic drug monitoring for ABs to reduce the number and seriousness of ADRs in this patient population. In conclusion, elucidating AB-induced cognitive effects in patients with CKD demands a comprehensive understanding and tailored therapeutic strategies that account for altered pharmacokinetics and the brain-gut-kidney axis.

Case Report: Cefepime Induced Neurotoxicity Following a Change in Infusion Time

Purpose: Cefepime is an antibiotic associated with cefepime induced neurotoxicity (CIN), particularly in those with reduced renal function, or in cases of inappropriate medication dosing. This report describes a case of CIN associated with a change in infusion duration from 180 to30 minutes, which to the best of our knowledge has not been previously reported in the literature. Summary: A 73-year old male was treated with extended infusion cefepime over 180 minutes while hospitalized with recurrent pneumonia. On discharge, cefepime was continued as outpatient parenteral antimicrobial therapy (OPAT) administered over 30 minutes. The patient began to experience symptoms of neurotoxicity after 1 day of receiving OPAT, which subsequently led to a readmission as neurological symptoms worsened. Cefepime was discontinued and symptoms resolved within 48 hours. Renal function was stable throughout treatment and no other causes for neurotoxicity were noted. Conclusion: This is a unique case of CIN secondary to shortened infusion time, which is clinically relevant, particularly during transitions of care. Further investigation, including more widespread use of therapeutic drug monitoring will be beneficial to further elucidate the relationship between infusion time and CIN development.

Antibiotic-induced neuropsychiatric toxicity: epidemiology, mechanisms and management strategies - a narrative literature review

Antibiotics are amongst the most prescribed medications globally in both inpatient and outpatient settings. Antibiotic-induced neuropsychiatric toxicity is relatively uncommon; yet, when it occurs, it can lead to severe morbidity ranging from dizziness and confusion to seizure and psychosis. However, the actual incidence rate of these adverse events may be higher due to underdiagnosis or misdiagnosis as they are commonly confused with clinical manifestations of different neuropsychiatric conditions. The incidence and mechanism of antibiotic-induced neuropsychiatric toxicity vary between different antibiotic classes and clinical presentation (i.e. neurotoxicity versus psychiatric toxicity). However, the exact mechanism by which antibiotics can cause neuropsychiatric toxicity remains unclear. This article reviews the epidemiology of antibiotic-induced neuropsychiatric toxicity, explores potential mechanisms of this adverse event, investigates variations in frequency and clinical presentations between different antibiotic classes causing neuropsychiatric toxicity, and discusses management strategies.

A Real-World Pharmacovigilance Study of Ceftazidime/Avibactam: Data Mining of the Food and Drug Administration Adverse Event Reporting System Database

Ceftazidime/avibactam (CAZ/AVI) is a combination of a well-known third-generation, broad-spectrum cephalosporin with a new beta-lactamase inhibitor that has been approved for the treatment of various infectious diseases (especially multidrug-resistant Gram-negative bacterial infections) by the Food and Drug Administration (FDA). The current study extensively assessed CAZ/AVI-related adverse events (AEs) in the real world through data mining of the FDA Adverse Event Reporting System (FAERS) database to better understand toxicities. The signals of CAZ/AVI-related AEs were quantified using disproportionality analyses, including the reporting odds ratio, the proportional reporting ratio, the Bayesian confidence propagation neural network, and the multi-item gamma Poisson shrinker algorithms. Out of 10,114,815 records retrieved from the FAERS database, 628 cases were identified, where CAZ/AVI was implicated as the primary suspect drug. A total of 61 preferred terms with significant disproportionality that simultaneously met the criteria of all four algorithms were retained. Several unexpected safety signals may also occur, including melena, hypernatremia, depressed level of consciousness, brain edema, petechiae, delirium, and shock hemorrhagic. The median onset time for AEs associated with CAZ/AVI was 4 days, with most cases occurring within 3 days after CAZ/AVI initiation.

Subacute Neurotoxicity as an Adverse Reaction to Ceftazidime: A Case Report

Neurotoxicity associated with cephalosporins is an increasingly recognized complication, although among cephalosporins, ceftazidime is rarely reported for such an adverse reaction. Moreover, subacute, rather than acute, presentation of neurotoxicity associated with cephalosporins is rare. A 77-year-old female patient with stage 4 chronic renal disease was admitted due to cellulitis in her right lower limb, multiorgan dysfunction complicated by oliguric acute kidney injury, and a need for hemodialysis via a central venous catheter. On the 13th day after admission, she became febrile, and bacteremia associated with a central venous catheter was identified, which prompted the initiation of empirical antibiotic therapy with vancomycin and ceftazidime. After 13 days of antibiotic therapy with vancomycin and ceftazidime, the patient became confused, with temporal-spatial disorientation and myoclonus, especially in the upper limbs, with worsening renal function. Ceftazidime was discontinued, and the patient's condition improved with complete remission of symptoms on the 8th day after symptom onset. Neurotoxicity associated with ceftazidime is a rare but probably underdiagnosed adverse reaction. It is more frequent in elderly patients with previous neurological dysfunction and end-stage kidney disease and/or acute kidney injury, and it usually manifests soon after starting treatment. Early identification and monitoring of risk factors and symptoms should lead the physician to a rapid withdrawal of the offending drug.

A case report of treatment of a streptococcal brain abscess with ceftobiprole supported by the measurement of drug levels in the cerebrospinal fluid

In this paper, we describe the case of a patient admitted to our hospital because of a brain abscess due to Streptococcus intermedius. The management of brain abscess is challenging given the limited potential drug options with effective penetration into both the central nervous system and the abscess capsule to achieve adequate therapeutic concentrations. Due to the high anti-streptococcal activity of ceftobiprole and the availability of ceftobiprole therapeutic drug monitoring in our hospital, we decided to treat the patient with ceftobiprole. To maximize the antimicrobial effect of ceftobiprole, we chose a prolonged intravenous infusion, and we monitored its concentrations in both plasma and cerebrospinal fluid.

Antibiotic-induced neurological adverse drug reactions

Antibiotics are drugs widely used all around the world. Central nervous system adverse drug reactions (CNS ADRs) are mostly under-suspected with antibiotics. Nevertheless, these ADRs could lead to severe complications such as encephalopathy. To illustrate the clinical patterns of these off-target ADRs, we here present data from pharmacovigilance system, through different populations and points of view (worldwide, French population, vulnerable population and individual). These data could help clinicians to better know about CNS ADRs with antibiotics, to better identify risk factors and vulnerable patients and to highlight the importance to set up the right diagnostic explorations in the best timing to avoid complications. Clinicians should request a pharmacological opinion from pharmacologist (biologists and pharmacovigilance clinicians) in front of vulnerable population before or during antibiotics. Pharmacovigilance advice could help clinicians in the diagnosis and the management of an ADR. Therapeutic drug monitoring is particularly contributive to adjust doses of antibiotics administered in vulnerable patients. Pharmacovigilance advice and TDM are essential to perform personalized medicine, and contribute to the proper use of drugs.

Antibiotic dosing recommendations in critically ill patients receiving new innovative kidney replacement therapy

BACKGROUND

The Tablo Hemodialysis System is a new innovative kidney replacement therapy (KRT) providing a range of options for critically ill patients with acute kidney injury. The use of various effluent rate and treatment durations/frequencies may clear antibiotics differently than traditional KRT. This Monte Carlo Simulation (MCS) study was to develop antibiotic doses likely to attain therapeutic targets for various KRT combinations.

METHODS

Published body weights and pharmacokinetic parameter estimates were used to predict drug exposure for cefepime, ceftazidime, imipenem, meropenem and piperacillin/tazobactam in virtual critically ill patients receiving five KRT regimens. Standard free β-lactam plasma concentration time above minimum inhibitory concentration targets (40-60%fT> MIC and 40-60%fT> MICx4) were used as efficacy targets. MCS assessed the probability of target attainment (PTA) and likelihood of toxicity for various antibiotic dosing strategies. The smallest doses attaining PTA ≥ 90% during 1-week of therapy were considered optimal.

RESULTS

MCS determined β-lactam doses achieving ∼90% PTA in all KRT options. KRT characteristics influenced antibiotic dosing. Cefepime and piperacillin/tazobactam regimens designed for rigorous efficacy targets were likely to exceed toxicity thresholds.

CONCLUSION

The flexibility offered by new KRT systems can influence β-lactam antibiotic dosing, but doses can be devised to meet therapeutic targets. Further clinical validations are warranted.

Ceftriaxone-Induced Encephalopathy in a Patient With Chronic Kidney Disease

Neurotoxicity is an acknowledged side effect of third and fourth-generation cephalosporins, but its occurrence with ceftriaxone is not widely recognized. This article presents a case involving a 56-year-old woman with multiple comorbidities who sought medical attention after experiencing lipothymia. The initial diagnosis suggested a urinary tract infection with acute kidney failure, leading to the initiation of ceftriaxone and hemodialysis. Subsequently, the patient exhibited a progressive deterioration of her neurological state, characterized by agitation and chorea. Metabolic encephalopathy, seizure/nonconvulsive status epilepticus, and acute central nervous system lesions were considered primary differential diagnoses, all of which were subsequently ruled out through thorough investigations. Days later, a remarkable recovery of the patient's neurological state was observed. A retrospective analysis revealed a correlation between the improvement and the fourth day of antimicrobial suspension. Consequently, a presumptive diagnosis of ceftriaxone-induced encephalopathy was made. This unusual case underscores the importance of recognizing the potential for pharmacological encephalopathy, particularly with ceftriaxone, and emphasizes its reversibility upon discontinuation of the implicated drug. Clinicians should remain vigilant to this uncommon adverse effect, promoting timely intervention and improved patient outcomes.

Neurological burden and outcomes of excessive β-lactam serum concentrations of critically ill septic patients: a prospective cohort study

BACKGROUND

Therapeutic drug monitoring (TDM) contributes to optimizing exposure to β-lactam antibiotics. However, how excessive exposure to β-lactams can increase the burden of care of critically ill patients is unclear.

PATIENTS AND METHODS

In a prospective cohort study, we examined whether excessive β-lactam serum concentrations contribute to neurological deterioration and the associated complications of adult septic patients without recent history of neurological disease treated with β-lactams in a medical ICU. Excessive β-lactam concentrations were defined as serum concentrations that exceeded the upper limit of the therapeutic range recommended by the French Societies of Pharmacology and Therapeutics (SFPT) and Anesthesia and Intensive Care Medicine (SFAR). Neurological deterioration was defined as an increase in the neurological Sequential Organ Failure Assessment score (nSOFA) of ≥1 between the day of starting treatment at admission and the day of TDM performed 2 days after treatment initiation.

RESULTS

We included 119 patients [median age: 65 years; males: 78 (65.5%)] admitted for acute respiratory distress [59 (49.6%)] or septic shock [25 (21%)]. In adjusted logistic regression analysis, an excessive β-lactam serum concentration was associated with neurological deterioration [OR (95% CI): 10.38 (3.23-33.35), P < 0.0001]. Furthermore, in adjusted linear regression analysis, an excessive β-lactam serum concentration was associated with longer time to discharge alive (β=0.346, P = 0.0007) and, among mechanically ventilated patients discharged alive, with longer time to extubation following the withdrawal of sedation (β=0.248, P = 0.0030).

CONCLUSIONS

These results suggest that excessive exposure to β-lactams could complicate the management of septic patients in the ICU and confirm the clinical relevance of the upper concentration limits recommended for dose reduction.

Higher cefazolin concentrations in synovial fluid with intraosseous regional prophylaxis in knee arthroplasty: a randomized controlled trial

BACKGROUND

Prophylactic antibiotics reduce the risk of periprosthetic joint infection. However, conventional systemic administration may not provide adequate tissue concentrations against more resistant organisms such as coagulase-negative staphylococci. Intraosseous regional administration is known to achieve significantly higher antibiotic tissue concentrations than systemic administration, but it is unclear how synovial fluid concentrations are affected. We aimed to compare synovial fluid cefazolin concentrations achieved by regional intraosseous versus systemic intravenous administration, and also to compare synovial fluid cefazolin concentrations with those in subcutaneous fat.

METHODS

A total of 60 patients undergoing primary knee arthroplasty were randomized into 2 groups: group IO received 2 g interosseous cefazolin in 100 mL saline through a tibial cannula after tourniquet inflation and before skin incision; group IV received 2 g cefazolin in 100 mL saline via the median basilic or median cephalic vein 30 min before tourniquet inflation. Subcutaneous fat and synovial fluid samples were collected immediately after skin incision, and cefazolin concentrations were measured by high-performance liquid chromatography.

RESULTS

The cefazolin concentration in synovial fluid was 391.3 ± 70.1 μg/ml in group IO and 17.6 ± 3.5 μg/ml in group IV. The cefazolin concentration in subcutaneous fat was 247.9 ± 64.9 μg/g in group IO and 11.4 ± 1.9 μg/g in group IV.

CONCLUSION

Intraosseous regional administration results in several times higher tissue concentrations than systemic administration, especially in the synovial fluid.

Clinical Experience with Off-Label Intrathecal Administration of Selected Antibiotics in Adults: An Overview with Pharmacometric Considerations

Drain-associated intracerebral infections are life-threatening emergencies. Their treatment is challenging due to the limited penetration of antibiotics to the site of infection, resulting in potentially inadequate exposure. The emergence of multidrug-resistant pathogens might force the use of off-label intrathecal (IT) doses of antibiotics. We reviewed the literature on general aspects determining intrathecal dosing regimen, using pharmacometric knowledge. We summarised clinical experience with IT doses of antibiotics that are usually not used intrathecally, as well as the outcome of the cases and concentrations reached in the cerebrospinal fluid (CSF). Factors determining the IT regimen are the size of the ventricle system and the CSF drainage volume. With regard to pharmacometrics, pharmacokinetic/pharmacodynamic indices are likely similar to those in non-cerebral infections. The following number (N) of cases were described: benzylpenicillin (>50), ampicillin (1), ceftazidime (2), cephaloridine (56), ceftriaxone (1), cefotiam (1), meropenem (57), linezolid (1), tigecycline (15), rifampicin (3), levofloxacin (2), chloramphenicol (3) and daptomycin (8). Many side effects were reported for benzylpenicillin in the 1940-50s, but for the other antibiotics, when administered correctly, all side effects were minor and reversible. These data might help when choosing an IT dosing regimen in case there is no alternative option due to antimicrobial resistance.

A Rare Case of Late-Onset Ertapenem-Induced Encephalopathy

Encephalopathy is a rare side effect associated with carbapenem antibiotics, typically presenting within one week of initiating treatment. It is almost exclusively seen in patients with poor renal function. We present a case of a middle-aged male with a history of cerebral vascular accident and normal renal function admitted for agitation, delirium, and insomnia more than two weeks after starting ertapenem to treat osteomyelitis. He was empirically treated for meningitis on admission, and ertapenem was discontinued. After an extensive negative workup for infectious and neurological etiologies of encephalopathy, a presumptive diagnosis of ertapenem-induced encephalopathy was made. The patient returned to his baseline mental status five days after discontinuing ertapenem. The nature of his neurological symptoms and timely resolution after stopping ertapenem is consistent with ertapenem-induced encephalopathy and represents a notably delayed symptom onset compared to previously described cases.

Ertapenem-Induced Neurotoxicity: A Literature Review of Clinical Characteristics and Treatment Outcomes

Background

Neurotoxicity is a rare adverse event for ertapenem. Given the limited evidence, large patient data are needed to aid in the identification and management of this fatal complication. Aim of the review, we summarize the characteristics, risk factors, and treatment of ertapenem-induced neurotoxicity.

Methods

Pubmed, Web of Science, Embase, Cochrane library, Wanfang, CNKI, China VIP database were searched up from 31 October 2001 to 31 December 2022. All articles concerning neurotoxicity induced by ertapenem were included. The retrieved articles were screened by two experienced clinicians by reading the titles, abstracts, and full texts.

Results

A total of 66 patients were included, with a median age of 71.5 years (range 40-92), of whom 45 (68.2%) were male. Twelve patients (18.2%) received irrational doses (exceeding the recommended dose), and 30 patients (45.5%) had chronic renal insufficiency. The median time to symptom onset was 5 (range 1-14). Epileptiform seizures (42.4%), visual hallucinations (36.4%), altered mental status (25.8%), and confusion (22.7%) were the most common symptoms of ertapenem-induced neurotoxicity. Of the 29 patients with reported albumin levels, 25 had serum albumin <3.5 g/dl. Ertapenem was discontinued in 95.5% of patients, and 90.9% recovered completely. Median time to symptom recovery was 7 days (range 1-42) after intervention including antiepileptic administration, or hemodialysis.

Conclusion

Neurotoxicity is a rare adverse event for ertapenem, especially in patients with advanced age, renal insufficiency, pre-existing neurological disease, and hypoalbuminemia. This adverse reaction usually resolves with medication interruption, or antiepileptic administration and hemodialysis.

The Epidemiology of Antibiotic-Related Adverse Events in the Treatment of Diabetic Foot Infections: A Narrative Review of the Literature

The use of antibiotics for the treatment of diabetic foot infections (DFIs) over an extended period of time has been shown to be associated with adverse events (AEs), whereas interactions with concomitant patient medications must also be considered. The objective of this narrative review was to summarize the most frequent and most severe AEs reported in prospective trials and observational studies at the global level in DFI. Gastrointestinal intolerances were the most frequent AEs, from 5% to 22% among all therapies; this was more common when prolonged antibiotic administration was combined with oral beta-lactam or clindamycin or a higher dose of tetracyclines. The proportion of symptomatic colitis due to Clostridium difficile was variable depending on the antibiotic used (0.5% to 8%). Noteworthy serious AEs included hepatotoxicity due to beta-lactams (5% to 17%) or quinolones (3%); cytopenia's related to linezolid (5%) and beta-lactams (6%); nausea under rifampicin, and renal failure under cotrimoxazole. Skin rash was found to rarely occur and was commonly associated with the use of penicillins or cotrimoxazole. AEs from prolonged antibiotic use in patients with DFI are costly in terms of longer hospitalization or additional monitoring care and can trigger additional investigations. The best way to prevent AEs is to keep the duration of antibiotic treatment short and with the lowest dose clinically necessary.

Safety and Tolerability of Antimicrobial Agents in the Older Patient

Older patients are at high risk of infections, which often present atypically and are associated with high morbidity and mortality. Antimicrobial treatment in older individuals with infectious diseases represents a clinical challenge, causing an increasing burden on worldwide healthcare systems; immunosenescence and the coexistence of multiple comorbidities determine complex polypharmacy regimens with an increase in drug-drug interactions and spread of multidrug-resistance infections. Aging-induced pharmacokinetic and pharmacodynamic changes can additionally increase the risk of inappropriate drug dosing, with underexposure that is associated with antimicrobial resistance and overexposure that may lead to adverse effects and poor adherence because of low tolerability. These issues need to be considered when starting antimicrobial prescriptions. National and international efforts have been made towards the implementation of antimicrobial stewardship (AMS) interventions to help clinicians improve the appropriateness and safety of antimicrobial prescriptions in both acute and long-term care settings. AMS programs were shown to decrease consumption of antimicrobials and to improve safety in hospitalized patients and older nursing home residents. With the abundance of antimicrobial prescriptions and the recent emergence of multidrug resistant pathogens, an in-depth review of antimicrobial prescriptions in geriatric clinical practice is needed. This review will discuss the special considerations for older individuals needing antimicrobials, including risk factors that shape risk profiles in geriatric populations as well as an evidence-based description of antimicrobial-induced adverse events in this patient population. It will highlight agents of concern for this age group and discuss interventions to mitigate the effects of inappropriate antimicrobial prescribing.

Better Outcome of Off-Label High-Dose Ceftazidime in Hemato-Oncological Patients with Infections Caused by Extensively Drug-Resistant Pseudomonas Aeruginosa

Background

P. aeruginosa sepsis in immunocompromised patients is a serious complication of cancer treatment, especially in the case of an Extensively Drug Resistant (XDR) pathogen. The aim of the study is to evaluate the efficacy of high-dose ceftazidime in the treatment of XDR P. aeruginosa infection and to compare it with the conventionally treated cohort in hemato-oncological patients.

Methods

We identified 27 patients with XDR P. aeruginosa infection during the 2008-2018 period, 16 patients served as a conventionally treated cohort with an antipseudomonal beta-lactam antibiotic in standard dose (cohort A), and 11 patients were treated with high-dose ceftazidime (cohort B). Most of the patients were neutropenic and under active treatment for their cancer in both cohorts.

Results

Mortality and related mortality were statistically significantly better for cohort B than cohort A; it was 18.2% and 9.1% for cohort B and 68.8% and 68.8% for cohort A, respectively. More patients in cohort A needed mechanical ventilation and renal replacement therapy, 75% and 50% for cohort A and 27.3% and 9.9% for cohort B, respectively. It corresponded well with the worst sequential organ failure score (SOFA) in cohort A compared to cohort B, 16 versus 7, respectively. Reversible neurotoxicity was seen only in two patients in cohort B.

Conclusion

Ceftazidime in high doses is a very potent antibiotic (ATB) for treating XDR P. aeruginosa infections in neutropenic cancer with acceptable toxicity.

A carbapenem antibiotic inhibiting a mammalian serine protease: structure of the acylaminoacyl peptidase-meropenem complex

The structure of porcine AAP (pAAP) in a covalently bound complex with meropenem was determined by cryo-EM to 2.1 Å resolution, showing the mammalian serine-protease inhibited by a carbapenem antibiotic. AAP is a modulator of the ubiquitin-proteasome degradation system and the site of a drug-drug interaction between the widely used antipsychotic, valproate and carbapenems. The active form of pAAP - a toroidal tetramer - binds four meropenem molecules covalently linked to the catalytic Ser587 of the serine-protease triad, in an acyl-enzyme state. AAP is hindered from fully processing the antibiotic by the displacement and protonation of His707 of the catalytic triad. We show that AAP is made susceptible to the association by its unusually sheltered active pockets and flexible catalytic triads, while the carbapenems possess sufficiently small substituents on their β-lactam rings to fit into the shallow substrate-specificity pocket of the enzyme.

Optimal antipseudomonal ꞵ-lactam drug dosing recommendations in critically-ill Asian patients receiving CRRT

INTRODUCTION

The average body weight is smaller in Asian patients compared with Western patients, but influence of body weight in antibiotic dosing is unknown. This study was to predict the optimal ceftazidime, cefepime, meropenem, piperacillin/tazobactam doses in Asian patients undergoing continuous venovenous hemofiltration (CVVH).

METHODS

Monte Carlo simulations (MCS) were performed using published Asian demographics and pharmacokinetics parameters in 5000 virtual patients at three CVVH effluent rates (Qeff; 20, 30, 40 mL/kg/h). Various dosing regimens were assessed for the probability of target attainments using 60% fT > 1 × MIC or 4xMIC and neurotoxicity risk at 48-h using suggested neurotoxicity thresholds.

RESULTS

Ceftazidime 1 g q12h, meropenem 1 g q12h, and piperacillin/tazobactam 3.375 g q6h were optimal for all Qeff settings against fT > 1 × MIC. Cefepime 2 g q24h and 2 g q12h were optimal at 20 and 30-40 mL/kg/h respectively. For the aggressive PD target (4 × MIC), optimal ceftazidime regimens were 1.25 g q8h (20-30 mL/kg/h) and 1.5 g q8h (40 mL/kg/h). Cefepime 2 g q8h and meropenem 1 g q8h were optimal at all Qeff settings. No simulated piperacillin doses attained the aggressive PD target. Increased neurotoxicity risk was predicted with ceftazidime and cefepime doses attaining the efficacy.

CONCLUSION

MCS enabled the prediction of optimal β-lactam dosing regimens for Asian patients receiving CVVH at varying Qeff. Clinical validation is warranted.

Ertapenem-induced neurotoxicity in an end-stage renal disease patient on intermittent haemodialysis: a case report

Background

Carbapenem-induced neurotoxicity is an unusual side effect, with seizure being the most commonly reported symptom. Among the carbapenems, imipenem-cilastin is classically associated with the most severe neurotoxicity side effects. Carbapenem is mainly excreted by the kidney and its half-life is significantly increased in patients with chronic kidney disease (CKD). Therefore, dose adjustment is necessary in such patients. Ertapenem-associated neurotoxicity is increasingly being reported in CKD patients, but rarely seen in patients with recommended dose adjustment.

Case presentation

We report a case of a 56-year-old male patient with chronic kidney disease 5 on dialysis(CKD 5D). The patient presented with a history of fever, chills and rigours during a session of haemodialysis (HD). He was diagnosed with Enterobacter cloacae catheter-related blood stream infection and was started on ertapenem. After 13 days of ertapenem, he experienced an acute confusional state and progressed to having auditory and visual hallucinations. His blood investigations and imaging results revealed no other alternative diagnosis. Hence a diagnosis of ertapenem-induced neurotoxicity was made. He had complete resolution of symptoms after 10 days’ discontinuation of ertapenem.

Conclusion

Our case draws attention to the risk of potentially serious toxicity of the central nervous system in HD patients who receive the current recommended dose of ertapenem. It also highlights that renal dosing in CKD 5D patients’ needs to be clinically studied to ensure antibiotic safety.

Ceftazidime encephalopathy developed without the elevation of cerebrospinal fluid concentration of ceftazidime: A case report of two cases

BACKGROUND

Ceftazidime encephalopathy is reported to be caused by the repeated administration of ceftazidime in patients with renal impairment because of the high serum concentration of ceftazidime. Ceftazidime encephalopathy has been considered to be caused by the elevation of the cerebrospinal fluid (CSF) concentration. However, as no reports have measured CSF concentrations, the relationship with ceftazidime encephalopathy and CSF concentration has not been clarified.

CASE PRESENTATION

Case 1: An 80-year-old Japanese man under a combination therapy with peritoneal dialysis and hemodialysis, who had been treated for a cellulitis with ceftazidime, developed altered consciousness and was diagnosed as ceftazidime encephalopathy. His serum concentration of ceftazidime was elevated, but CSF concentration was only under 0.1 μg/mL. Case 2: An 88-year-old Japanese man with chronic kidney disease, who had been treated for a urinary tract infection with ceftazidime, developed altered consciousness and was diagnosed as ceftazidime encephalopathy. His serum concentration of ceftazidime was elevated, but CSF concentration was within the therapeutic range. However, his serum and CSF concentration of quinolinic acid was markedly increased.

CONCLUSIONS

Patients with renal failure are more likely to develop ceftazidime encephalopathy. We need to pay attention to the dosage of ceftazidime and to the appearance of neurological symptoms. Ceftazidime encephalopathy was considered to be caused by the high CSF concentration, but it could be caused by quinolinic acid as neurotoxic substance.

Analysis of the frequency of ceftriaxone-induced encephalopathy using the Japanese Adverse Drug Event Report database

BACKGROUND

The profile of ceftriaxone-induced encephalopathy is not well understood.

AIM

To identify risk factors associated with ceftriaxone-induced encephalopathy.

METHOD

In this observational study, anonymised patient data were retrieved from the open-access Japanese Adverse Drug Event Report database for ceftriaxone users aged 20 years or higher.

RESULTS

Data of 256,788 individuals and 12,160 cases of encephalopathy were extracted, and 2,939 ceftriaxone users, of whom 193 had encephalopathy, were identified. A disproportionate prevalence of encephalopathy was observed among the ceftriaxone users (reported odds ratio = 1.42; 95% confidence interval [CI] = 1.23-1.65; p < 0.001). Multivariate logistic regression analysis of 2,057 ceftriaxone users showed encephalopathy was associated with female sex (odds ratio [OR] = 1.52; 95% CI, 1.05-2.19; p = 0.027), chronic kidney disease (OR = 2.32; 95% CI, 1.47-3.67; p < 0.001), a ceftriaxone dosage of > 2 g/day (OR = 2.66; 95% CI, 1.66-4.26; p < 0.001), and a treatment duration of > 14 days (OR = 1.94; 95% CI, 1.21-3.11; p = 0.006).

CONCLUSION

Patients with chronic kidney disease, receiving ceftriaxone at a dosage of > 2 g/day, being treated for over 14 days, and/or females may be at an increased risk of ceftriaxone-induced encephalopathy.

Ceftriaxone-induced encephalopathy in a patient with a solitary kidney

Ceftriaxone (CRO) is a long-acting third-generation cephalosporin antibiotic. We present a case of CRO-induced encephalopathy in an 84-year-old male patient with a solitary right kidney, admitted with bilateral pneumonia and right pyelonephritis. Intravenous CRO (2 g, every 24 hr) was started for the infection, but tonic-clonic seizures of the left face and left upper extremity appeared on the 8th day. To examine the relationship between CRO administration and the seizures, we measured CRO concentrations in the patients' plasma/serum and cerebrospinal fluid (CSF). The CRO concentration in blood at the onset of encephalopathy was estimated to have been approximately 60 μg/mL based on a simulation curve. We also calculated the pharmacokinetic parameters after CRO administration. The patient had about one-tenth of the total body clearance and one-third of the volume of distribution compared with healthy adults, and the elimination half-life was about 3 times longer.

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.

Temocillin: Applications in Antimicrobial Stewardship as a Potential Carbapenem-Sparing Antibiotic

Temocillin is an old antibiotic, but given its particular characteristics, it may be a suitable alternative to carbapenems for treating infections due to ESBL-producing Enterobacterales and uncomplicated UTI due to KPC-producers. In this narrative review, the main research question was to summarize current evidence on temocillin and its uses in infectious diseases. A search was run on PubMed using the terms (‘Temocillin’ [Mesh]) AND (‘Infection’ [Mesh]). Current knowledge regarding temocillin in urinary tract infection, blood-stream infections, pneumonia, intra-abdominal infections, central nervous system infections, skin and soft tissues infections, surgical sites infections and osteoarticular Infections were summarized. Temocillin retain a favourable profile on microbiota and risk of Clostridioides difficile infections and could be an option for treating outpatients. Temocillin may be a valuable tool to treat susceptible pathogens and for which a carbapenem could be spared. Other advantages in temocillin use are that it is well-tolerated; it is associated with a low rate of C. difficile infections; it is active against ESBL, AmpC, and KPC-producing Enterobacterales; and it can be used in the OPAT clinical setting.

Ertapenem neurotoxicity in liver transplantation

Carbapenems are antibiotics of the cephalosporin family with good penetrance into the central nervous system. Neurotoxicity is a rare adverse effect, most often associated with Imipenem (0.4-10%), being unusual with Ertapenem. It usually presents as seizures, although encephalopathy or hallucinations may develop.

Ceftriaxone-induced Encephalopathy: A Pharmacokinetic Approach

We report a case of ceftriaxone-induced encephalopathy correlated with a high concentration of the drug in cerebrospinal fluid (CSF). Cephalosporin neurotoxicity is increasingly reported, especially in association with fourth-generation cephalosporins. The factors influencing CSF concentration are plasma concentration, liposolubility, ionization, molecular weight, protein binding and efflux. In our patient, high levels of ceftriaxone (27.9 mg/l) were found in CSF. β-Lactam-associated neurotoxicity is mainly due to similarities between GABA and the β-lactam ring. Because of differences in CSF/plasma ratios and blood-brain barrier efflux among patients, plasma drug monitoring cannot be used to estimate CSF concentration. As far as we know, this is the first reported case of ceftriaxone-induced encephalopathy associated with a high CSF concentration.

LEARNING POINTS

Ceftriaxone dose adjustment and clinical surveillance are strongly recommended in patients with renal failure.Measuring ceftriaxone cerebrospinal fluid concentration could be useful for confirming ceftriaxone-induced encephalopathy.

Antibiotics and the Nervous System-Which Face of Antibiotic Therapy Is Real, Dr. Jekyll (Neurotoxicity) or Mr. Hyde (Neuroprotection)?

Antibiotics as antibacterial drugs have saved many lives, but have also become a victim of their own success. Their widespread abuse reduces their anti-infective effectiveness and causes the development of bacterial resistance. Moreover, irrational antibiotic therapy contributes to gastrointestinal dysbiosis, that increases the risk of the development of many diseases, including neurological and psychiatric. One of the potential options for restoring homeostasis is the use of oral antibiotics that are poorly absorbed from the gastrointestinal tract (e.g., rifaximin alfa). Thus, antibiotic therapy may exert neurological or psychiatric adverse drug reactions which are often considered to be overlooked and undervalued issues. Drug-induced neurotoxicity is mostly observed after beta-lactams and quinolones. Penicillin may produce a wide range of neurological dysfunctions, including encephalopathy, behavioral changes, myoclonus or seizures. Their pathomechanism results from the disturbances of gamma-aminobutyric acid-GABA transmission (due to the molecular similarities between the structure of the β-lactam ring and GABA molecule) and impairment of the functioning of benzodiazepine receptors (BZD). However, on the other hand, antibiotics have also been studied for their neuroprotective properties in the treatment of neurodegenerative and neuroinflammatory processes (e.g., Alzheimer's or Parkinson's diseases). Antibiotics may, therefore, become promising elements of multi-targeted therapy for these entities.

Excessive unbound cefazolin concentrations in critically ill patients receiving veno-arterial extracorporeal membrane oxygenation (vaECMO): an observational study

The scope of extracorporeal membrane oxygenation (ECMO) is expanding, nevertheless, pharmacokinetics in patients receiving cardiorespiratory support are fairly unknown leading to unpredictable drug concentrations. Currently, there are no clear guidelines for antibiotic dosing during ECMO. This study aims to evaluate the pharmacokinetics (PK) of cefazolin in patients undergoing ECMO treatment. Total and unbound plasma cefazolin concentration of critically ill patients on veno-arterial ECMO were determined. Observed PK was compared to dose recommendations calculated by an online available, free dosing software. Concentration of cefazolin varied broadly despite same dosage in all patients. The mean total and unbound plasma concentration were high showing significantly (p = 5.8913 E−09) greater unbound fraction compared to a standard patient. Cefazolin clearance was significantly (p = 0.009) higher in patients with preserved renal function compared with CRRT. Based upon the calculated clearance, the use of dosing software would have led to lower but still sufficient concentrations of cefazolin in general. Our study shows that a “one size fits all” dosing regimen leads to excessive unbound cefazolin concentration in these patients. They exhibit high PK variability and decreased cefazolin clearance on ECMO appears to compensate for ECMO- and critical illness-related increases in volume of distribution.

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.

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.

Ceftolozane/tazobactam exposure in critically ill patients undergoing continuous renal replacement therapy: a PK/PD approach to tailor dosing

OBJECTIVES

To investigate the influence of continuous renal replacement therapy (CRRT) intensity on the clearance of ceftolozane/tazobactam in critical care patients, and to evaluate if the reported doses would achieve an optimal pharmacokinetic/pharmacodynamic (PK/PD) target against Pseudomonas aeruginosa exhibiting different MICs.

METHODS

The MEDLINE-PubMed database was searched from inception to January 2020 to retrieve observational studies or case reports investigating the PK behaviour of ceftolozane/tazobactam during CRRT. Relevant CRRT settings and PK variables were extracted, and the influence of CRRT intensity on ceftolozane/tazobactam total clearance (CLtot) was determined by simple linear regression. The optimal PK/PD target for the reported doses was deemed to be achieved when ceftolozane trough concentrations (Cmin) were above the MIC (less intensive target) or four times the MIC (intensive target) for P. aeruginosa.

RESULTS

Data from six studies including 11 patients (mean age 56.6 years) were analysed. Mean blood flow rate and effluent flow rate were 161.8 mL/min and 2383.4 mL/h, respectively. Ceftolozane Cmin ranged from 25.8 to 79.4 mg/L. A significant correlation was found for ceftolozane CLtot and effluent flow rate (P = 0.027). The intensive PK/PD target was achieved by 100% and 50% of the reported doses for MIC, respectively, up to 4 and 8 mg/L.

CONCLUSIONS

A significant correlation between effluent flow rate and ceftolozane clearance during CRRT could be identified. Higher dosing regimens coupled with continuous/extended infusion may be required in the case of higher CRRT intensity, deep-seated infections or poorly susceptible isolates. Larger studies assessing ceftolozane PK in different CRRT settings are warranted.

Stability and Validation of a High-Throughput LC-MS/MS Method for the Quantification of Cefepime, Meropenem, and Piperacillin and Tazobactam in Serum

BACKGROUND

The class of antibiotics known as β-lactams are a commonly used due to their effectiveness and safety. Therapeutic drug monitoring has been proposed but requires an accurate assay along with well-characterized preanalytic stability, as β-lactams are known to be relatively unstable.

METHODS

A high-throughput LC-MS/MS assay validation and stability study was performed for cefepime, meropenem, and piperacillin and tazobactam in serum. Patient samples, standards, and QCs were crashed with acetonitrile containing internal standard. Following centrifugation, an aliquot of the supernatant was diluted with clinical laboratory reagent water and analyzed by LC-MS/MS.

RESULTS

The assay showed linearity between 0.5 and 60 µg/mL for each analyte. The intra- and interassay reproducibility at 3 different concentrations (approximately 2, 25, and 40 µg/mL) was <5% for each analyte. Accuracy studies for each analyte were compared using linear regression and demonstrated: slope = 1.0 ± 0.1; r2 ≥ 0.980; and y intercept 95% CI that included zero. Minimal ion suppression or enhancement was observed, and no significant carryover was observed up to 500 µg/mL of each analyte. Stability studies demonstrated significant loss in serum for each analyte at ambient and refrigerated temperatures (2-8 °C) and at -20 °C over days or weeks. In contrast, when stored at -80 °C, no significant loss was observed.

CONCLUSIONS

The LC-MS/MS assay showed acceptable performance characteristics for quantitation of β-lactams. With well-characterized stability, this assay can be used with residual specimens for pharmacokinetic modeling, which may lead to individualized dosing and improved patient care.

Setting the Beta-Lactam Therapeutic Range for Critically Ill Patients: Is There a Floor or Even a Ceiling?

Beta-lactam antibiotics exhibit high interindividual variability in drug concentrations in patients with critical illness which led to an interest in the use of therapeutic drug monitoring to improve effectiveness and safety. To implement therapeutic drug monitoring, it is necessary to define the beta-lactam therapeutic range-in essence, what drug concentration would prompt a clinician to make dose adjustments up or down. This objective of this narrative review was to summarize evidence for the "floor" (for effectiveness) and "ceiling" (for toxicity) for the beta-lactam therapeutic range to be used with individualized therapeutic drug monitoring.

DATA SOURCES

Research articles were sourced from PubMed using search term combinations of "pharmacokinetics," "pharmacodynamics," "toxicity," "neurotoxicity," "therapeutic drug monitoring," "beta-lactam," "cefepime," "meropenem," "piperacillin/tazobactam," "ICU," and "critical illness."

STUDY SELECTION

Articles were selected if they included preclinical, translational, or clinical data on pharmacokinetic and pharmacodynamic thresholds for effectiveness and safety for beta-lactams in critical illness.

DATA SYNTHESIS

Experimental data indicate a beta-lactam concentration above the minimum inhibitory concentration of the organism for greater than or equal to 40-60% of the dosing interval is needed, but clinical data indicate that higher concentrations may be preferrable. In the first 48 hours of critical illness, a free beta-lactam concentration at or above the susceptibility breakpoint of the most likely pathogen for 100% of the dosing interval would be reasonable (typically based on Pseudomonas aeruginosa). After 48 hours, the lowest acceptable concentration could be tailored to 1-2× the observed minimum inhibitory concentration of the organism for 100% of the dosing interval (often a more susceptible organism). Neurotoxicity is the primary dose-dependent adverse effect of beta-lactams, but the evidence remains insufficient to link a specific drug concentration to greater risk.

CONCLUSIONS

As studies advance the understanding of beta-lactam exposure and response in critically ill patients, it is essential to clearly define the acceptable therapeutic range to guide regimen selection and adjustment.

Pharmacokinetics, pharmacodynamics, and safety of single- and multiple-dose intravenous ceftobiprole in healthy Chinese participants

BACKGROUND

Ceftobiprole is a novel β-lactam cephalosporin with activity against Gram-positive and -negative bacteria. The aim of the present study was to investigate the pharmacokinetics (PK), pharmacokinetics/pharmacodynamics (PK/PD), safety and tolerance of ceftobiprole in Chinese participants, to evaluate this dosage regimen for the treatment of community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP) in China.

METHODS

The use of ceftobiprole was investigated in a single-center, open-label, single- and multiple-dose study using 12 healthy Chinese participants (6 males and 6 females). Ceftobiprole plasma and urine concentrations were analyzed using a validated liquid chromatography-tandem mass spectrometry assay. The PK/PD characteristics of 500 mg ceftobiprole every 8 h at 1.5-, 2-, 3-, or 4-h infusion time were analyzed by Monte Carlo simulations (MCS).

RESULTS

The maximum plasma concentration of ceftobiprole was observed 2 h after dosage; its terminal half-life was about 3 h. Ceftobiprole was predominantly eliminated in urine, and the cumulative excretion in 24 h was >90%. There was no accumulation after multiple dosing. Both single and multiple doses were well tolerated, with no severe or serious adverse events (AEs). PK/PD analysis indicated that Staphylococcus pneumoniae (S. pneumoniae) and Staphylococcus aureus (S. aureus) were sensitive to ceftobiprole. About half of extended-spectrum β-lactamase (ESBL) non-producing Enterobacteriaceae are sensitive to ceftobiprole, according to PK/PD results of ceftobiprole. For Pseudomonas aeruginosa (P. aeruginosa), no regimen was found to be effective against strains.

CONCLUSIONS

The PK/PD results indicated that 500 mg ceftobiprole every 8 h at 2-h infusion time is expected to achieve good microbiological efficacy in the treatment of CAP and HAP in China.

Cefepime use: A need for antimicrobial stewardship

OBJECTIVES

Unlike other 3GCs, Cefepime is a cephalosporin that has, in animal model studies, shown a low risk of selecting resistant mutants. It also enables carbapenems to be saved in treatment of Pseudomonasaeruginosa and the CESP group (Citrobacter, Enterobacter, Serratia and Providencia, as well as the genus Klebsiellaaerogenes, Morganella and Hafnia), consequently producing cephalosporinase. We aimed to determine whether its prescription in a French teaching hospital met criteria for proper use.

PATIENTS AND METHODS

We conducted a retrospective study of proper cefepime use between March 1st, 2018 and February 28th, 2019, to assess indication, antimicrobial stewardship, dosing schedule, microbiological documentation, reevaluation, and treatment duration. Prescriptions were then compared to local guidelines established from international literature.

RESULTS

Out of 142 cefepime prescriptions, 97.2% were prescribed as validated according to indication. The duration of the documented treatments matched the guidelines for 56.5% of patients, dosage was adapted to the indication for 77.4% and to kidney function for 97.2%. Bacteriological documentation was performed in all cases and an antibiogram was generated in 99.2% of cases. The treatment was reassessed between 48 and 72h and between the 7th and 10th day for 44.2% and 60.9% of the prescriptions respectively. The antimicrobial stewardship team managed half of the prescriptions. Only 13.4% of prescriptions met all criteria for proper use.

CONCLUSION

Notwithstanding a highly sizable majority of validated indications, a very small proportion of cefepime prescriptions met all the criteria for proper use. In the context of increased cefepime consumption, which is favored by its increased place in the latest recommendations published in 2019, proper use of cefepime prescriptions needs to be more effectively promoted.

Serious Neurological Adverse Events of Ceftriaxone

We described ceftriaxone-induced CNS adverse events through the largest case series of Adverse Drug Reactions (ADRs) reports, from 1995 to 2017, using the French Pharmacovigilance Database. In total, 152 cases of serious CNS ADRs were analyzed; 112 patients were hospitalized or had a prolonged hospitalization (73.7%), 12 dead (7.9%) and 16 exhibited life-threatening ADRs (10.5%). The median age was 74.5 years, mainly women (55.3%), with a median creatinine clearance of 35 mL/min. Patients mainly exhibited convulsions, status epilepticus, myoclonia (n = 75, 49.3%), encephalopathy (n = 45, 29.6%), confused state (n = 34, 22.4%) and hallucinations (n = 16, 10.5%). The median time of onset was 4 days, and the median duration was 4.5 days. The mean daily dose was 1.7 g mainly through an intravenous route (n = 106, 69.7%), and three patients received doses above maximal dose of Summary of Product Characteristics. Ceftriaxone plasma concentrations were recorded for 19 patients (12.5%), and 8 were above the toxicity threshold. Electroencephalograms (EEG) performed for 32.9% of the patients (n = 50) were abnormal for 74% (n = 37). We described the world's biggest case series of ceftriaxone-induced serious CNS ADRs. Explorations (plasma concentrations, EEG) are contributive to confirm the ceftriaxone toxicity-induced. Clinicians may be cautious with the use of ceftriaxone, especially in the older age or renal impairment population.

Ceftaroline-Associated Encephalopathy: A Rare Adverse Effect

In this case report, we present a patient who suffered ceftaroline-associated encephalopathy, while receiving ceftaroline for acute bacterial skin and skin structure infections (aBSSSIs) that resolved after cessation of the suspected agent. We recommend close monitoring for encephalopathy in patients with creatinine clearance (CrCl) of <50 mL/min receiving ceftaroline.

Ceftazidime-Induced Neurotoxicity in an 80-Year-Old Female With Renal Dysfunction: A Case Report

Neurological toxicity is a relatively rare adverse reaction reported in elderly patients treated with cephalosporins. We present a case of ceftazidime-induced encephalopathy in the context of acute kidney injury in an 80-year-old female treated for a Pseudomonas aeruginosa prosthetic joint infection. During the course of treatment, the patient developed sudden confusion and disorientation. The patient's mental state progressively worsened, eventually leading to intubation and admission to the intensive care unit. As imaging and laboratory analyses revealed no alternative causes explaining the patient's symptoms, ceftazidime was stopped under the suspicion of drug-induced neurotoxicity. Shortly after ceftazidime discontinuation, the patient's condition drastically improved and returned to baseline within 5 days. This case reveals the potential severity of cephalosporin-induced neurotoxicity in elderly patients and highlights the importance of quickly detecting such adverse events in order to prevent dire outcomes.

Serious adverse events with novel beta-lactam/beta-lactamase inhibitor combinations: a large-scale pharmacovigilance analysis

The purpose of this study is to characterize adverse events (AEs) of clinical interest reported with ceftolozane-tazobactam and ceftazidime-avibactam, as an aid in monitoring patients affected by severe multidrug-resistant Gram-negative infections. We queried the worldwide FDA Adverse Event Reporting System (FAERS) and performed disproportionality analysis, selecting only designated medical events (DMEs) where ceftolozane-tazobactam and ceftazidime-avibactam were reported as suspect. Serious neurological AEs were further investigated. The reporting odds ratios were calculated, deemed significant by the lower limit of the 95% confidence interval (LL95% CI) > 1. All other drugs/events recorded in FAERS and cephalosporins showing clinical evidence of neurological AEs were respectively selected as comparator for analysis of DMEs and neurotoxicity. Qualitative analysis including case-by-case assessment and deduplication was also performed. Overall, 654 and 506 reports mentioning respectively ceftolozane-tazobactam and ceftazidime-avibactam were found, with DMEs accounting respectively for 13.1% and 10.9% of cases. Agranulocytosis (N = 12; LL95% CI = 12.40) and pancytopenia (14; 6.18) emerged as unexpected AEs with ceftolozane-tazobactam, while acute pancreatitis (7; 8.63) was an over-reported unexpected DME with ceftazidime-avibactam. After deduplication, four unequivocally different cases of agranulocytosis with ceftolozane-tazobactam were retained, occurring on average after 8.8 days. Causality was probable and possible respectively in three and one case. Among neurological AEs exhibiting significant disproportionality, encephalopathy with both antibiotics and mental status changes with ceftazidime-avibactam were retained in at least three cases after deduplication. Although rare, clinicians should monitor high-risk patients (i.e. individuals affected by haematological malignances, HIV infection, or treated with concomitant myelotoxic agents) for early unexpected occurrence of agranulocytosis with ceftolozane-tazobactam.

Ertapenem neurotoxicity in patients with kidney damage: A case report

Ertapenem, a member of the carbapenem group of antibiotics, is a broad-spectrum antibiotic that is effective against multidrug-resistant gram-positive and gram-negative infections. In patients with acute or chronic kidney damage, one of the most serious side effects of ertapenem is neurotoxicity. Various clinical conditions such as seizures, hallucinations, delirium, confusion, and nystagmus may occur. Previous history of cerebral pathologies is a known risk factor for ertapenem-associated neurotoxicity. Immediate discontinuation of treatment is required. Although the symptoms usually resolve rapidly, cases with longer duration of symptoms have also been reported. Close monitoring of neurological status in such patients is essential.

Ensuring Sufficient Trough Plasma Concentrations for Broad-Spectrum Beta-Lactam Antibiotics in Children With Malignancies: Beware of Augmented Renal Clearance!

Introduction: Broad-spectrum beta-lactams are commonly prescribed for empirical or selective treatment of bacterial infections in children with malignancies. In the immunocompromised, appropriate concentration exposure is crucial to ensure antimicrobial efficacy. Augmented renal clearance (ARC) is increasingly recognized in this population, and raises concern for unmet concentration targets. We conducted a retrospective evaluation of meropenem and piperacillin exposure in our hospital's pediatric hematology-oncology patients. Materials and Methods: We compared trough levels of meropenem and piperacillin in a cohort of unselected pediatric hematology-oncology patients stratified based on their estimated renal function as decreased, normal or with ARC, and on their neutrophil count. Results: Thirty-two children provided a total of 51 meropenem and 76 piperacillin samples. On standard intermittent intravenous regimen, 67% of all trough plasma concentrations were below targeted concentrations. In neutropenic children with bacterial infection, all meropenem and 60% of piperacillin levels were below target. Nearly two-thirds of total samples came from children with ARC. In these patients, antimicrobial exposure was insufficient in 85% of cases (compared to 36% in the decreased or normal renal function groups), despite a dosage sometimes exceeding the maximum recommended daily dose. Under continuous infusion of piperacillin, only 8% of plasma levels were insufficient. Discussion: Intermittent administration of meropenem and piperacillin often fails to ensure sufficient concentration exposure in children treated for malignancies, even at maximal recommended daily dosage. This can in part be attributed to ARC. We recommend thorough assessment of renal function, resolute dosage adjustment, continuous infusion whenever possible and systematic therapeutic drug monitoring.

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.

Interactions between carbapenems and valproic acid among the patients in the intensive care units

PURPOSE

To evaluate risk factors for epileptic seizures or status epilepticus (SE) in patients concomitantly receiving valproic acid (VPA) and carbapenems.

MATERIALS AND METHODS

Adult patients in the intensive care units (ICUs) who concomitantly received VPA and carbapenems from 2007 to 2017 were included. The impacts of different carbapenems on serum concentration of VPA were compared.

RESULTS

Among 162 patients included, 104 (64.2%) and 45 (27.8%) developed epileptic seizures and SE, respectively. The risk factors for epileptic seizures were age (per year increase, adjusted odds ratio [aOR], 1.03), initial antiepileptic regimen (monotherapy and polytherapy, aOR, 0.43 and 0.18, respectively), and VPA serum concentration after concomitant carbapenem administration (per 1 μg/mL increase, aOR, 0.96). VPA serum concentration after concomitant carbapenem administration was an independent risk factor for SE (per μg/mL increase, aOR, 0.98). Concomitant imipenem/cilastatin administration did not significantly decrease VPA serum concentration compared to that by meropenem or ertapenem. The length of stay and number of days on ventilation after concomitant carbapenem administration in the ICUs were significantly more in those with epileptic seizures or SE.

CONCLUSIONS

Carbapenems decreased VPA serum concentration and increased the risk of epileptic seizures and SE, which led to increased length of ICU stay.

[Pharmacokinetic modifications and pharmacokinetic/pharmacodynamic optimization of beta-lactams in ICU]

Pharmacokinetic modifications in critically ill patients and those induced by ICU therapeutics raise a lot of issues about antibiotic dose adaptation. Beta-lactams are anti-infectious widely used in ICU. Frequent beta-lactam underdoses induce a risk of therapeutic failure potentially lethal and of emergence of bacterial resistance. Overdoses expose to a neurotoxic and nephrotoxic risk. Therefore, an understanding of pharmacokinetics modifications appears to be essential. A global pharmacokinetic/pharmacodynamic approach is required, including use of prolonged or continued beta-lactam infusions to optimise probability of pharmacokinetic/pharmacodynamic target attainment. Beta-lactam therapeutic drug monitoring should also be considered. Experts agree to target a free plasma betalactam concentration above four times the MIC of the causative bacteria for 100 % of the dosing interval. Bayesian methods could permit individualized doses adaptations.

A case series of confusional states and other neurotoxic effects caused by ertapenem

Ten cases of ertapenem neurotoxicity, mainly confusional states, are described, some of them with fatal outcomes. The majority of patients (90%) had a creatinine clearance (CrCl) < 50 mL/min/1.73m² at some point during treatment and hypoalbuminaemia was always present when ertapenem treatment was started. The pharmacokinetic and pharmacodynamic properties of this carbapenem could favour a different profile, and approved doses can be excessive in some patients with moderate renal failure (CrCl 31-59 mL/min/1.73 m² ). It may be necessary to re-evaluate renal function during treatment and adjust doses or reconsider the adequacy of treatment based on clinical judgement, especially if relevant changes in the CrCl occur (i.e. a reduction to ≤30 mL/min/1.73 m² ) or unexplained behavioural disorders are detected. The onset of the symptoms of ertapenem neurotoxicity can be insidious and go unnoticed, and so a knowledge and early suspicion of confusional states are important to improve the patient prognosis.

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.

Continuous infusion of cefepime and neurotoxicity: a retrospective cohort study

OBJECTIVES

Neurotoxicity related to cefepime is increasingly reported in the literature but specific data concerning continuous infusion (CI) of the drug are still lacking. Our primary objective was to evaluate the incidence of neurotoxicity related to CI of cefepime and the associated risk factors. Our secondary objectives were to analyse the plasma cefepime concentrations and to define the threshold above which neurotoxicity occurs.

METHODS

In this single-centre retrospective cohort study, all adult patients who underwent at least one cefepime therapeutic drug monitoring (TDM) and were treated with CI of 4 g/day between January 2017 and June 2019 were included. Neurotoxicity was evaluated according to a strict definition and was correlated with steady-state concentration at the time of toxicity presentation.

RESULTS

Ninety-eight patients with 201 cefepime TDM studies were included, with an incidence of neurotoxicity of 14.3% (14/98). Patients with neurotoxicity had more often underlying brain disease (35.7% (5/14) vs 11.9% (10/84), p = 0.030)) and higher steady-state concentrations (mean ± standard deviation 71.8 ± 32.9 mg/L vs 49.6 ± 30.6, p = 0.036) than the others. A receiver operating characteristic curve analysis yielded a cefepime steady-state concentration of 63.2 mg/L as the best cut-off point between patients with or without neurotoxicity. A mean steady-state concentration of 46.4 mg/L was achieved if the dosages of cefepime were adapted to renal function which was under our threshold concentration but above our highest pharmacokinetic/pharmacodynamic target of 32-40 mg/L.

CONCLUSIONS

Our results suggest that 4 g/day of cefepime adapted to renal function and infused over 24 h is a trade-off for the risk/benefit ratio, when used empirically.