Cephalosporin-induced neurotoxicity: clinical manifestations, potential pathogenic mechanisms, and the role of electroencephalographic monitoring

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.

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.

The incidence and predictors of antibiotic-associated encephalopathy: a multicenter hospital-based study

This study aimed to evaluate the incidence and likelihood of antibiotic-associated encephalopathy (AAE), comparing rates among the classes of antibiotics in monotherapy or in combination therapy. We also investigated the associations between the incidence of AAE and the glomerular filtration rate (GFR) and electroencephalogram features. Consecutive admissions that used any kind of antibiotics to treat infectious diseases were identified from six hospitals. We classified antibiotics according to three distinct pathophysiologic mechanisms and clinical subtypes. We searched for the incidence of AAE as the primary outcome. A total of 97,433 admission cases among 56,038 patients was identified. Cases that received type 1 antibiotics had significantly more frequent AAE compared to those that received type 2 antibiotics (adjusted odds ratio [OR], 2.62; 95% confidence interval [CI] 1.15-5.95; P = 0.021). Combined use of type 1 + 2 antibiotics was associated with a significantly higher incidence of AAE compared to the use of type 2 antibiotics alone (adjusted OR, 3.44; 95% CI 1.49-7.93; P = 0.004). Groups with GFR < 60 mL/min/1.73 m2 had significantly higher incidence rates of AAE compared to those with GFRs ≥ 90 mL/min/1.73 m2 among cases that received type 1 + 2 antibiotics. Detection of spike-and-wave or sharp-and-wave patterns on electroencephalogram was significantly more common in the combination therapy group. Combination use of antibiotics was associated with a higher incidence of AAE compared to monotherapy. The incidence of AAE significantly increased as renal function decreased, and epileptiform discharges were more likely to be detected in cases receiving combined antibiotics.

Danger in plain sight: determining who is at highest risk for cefepime induced neurotoxicity and its associated morbidity and mortality

Cefepime is a fourth-generation cephalosporin that is widely used to treat sepsis but is associated with a potentially dangerous neurotoxicity syndrome, cefepime-induced neurotoxicity (CIN). As a result, patients treated with cefepime may be at higher risk for morbidity, including seizures, and mortality. Though the recent ACORN trial concluded that cefepime does not increase the risk of mortality, most of these patients were not critically ill or elderly, two of the most at risk populations for CIN. Further, diagnosis may be difficult in the critical care setting as patients may have multiple reasons for encephalopathy. Therefore, this population in particular should be studied and monitored closely for CIN. Importantly, there are not well defined diagnostic criteria for CIN to guide evaluation and management. Defining the risk factors for CIN and using laboratory and EEG to help support the clinical diagnosis could be helpful in early recognition of CIN to help institute treatment and to rule out seizures. In this mini review, we highlight risk factors for CIN, discuss the possible value of EEG, and propose a diagnostic and management approach in the evaluation and management of CIN.

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.

Cefepime-Associated Neurotoxicity in a Pediatric Patient With Stage V Chronic Kidney Disease

Background: Studies in adult patients suggest cefepime can cause neurotoxicity, including disorientation, seizures, and coma, particularly when present at high concentrations. Patients with underlying kidney dysfunction or central nervous system anomalies are at particularly high risk. There is a relative paucity of pediatric literature on the neurotoxic effects of cefepime. Case Report: Herein is reported the case of a 2-year-old patient with chronic kidney disease receiving cefepime for Serratia marcescens bacteremia who experienced agitation, tremor, and inconsolability in the setting of an elevated cefepime trough that improved with cefepime discontinuation alone. Conclusions: Pediatric patients with acute and chronic kidney disease are at risk of cefepime-related neurologic changes. Therapeutic drug monitoring for cefepime in patients with kidney dysfunction or baseline neurologic abnormalities may help inform appropriate antimicrobial dosing and avoidance of toxicity.

Ceftriaxone-induced encephalopathy in a patient with a normal renal function

Ceftriaxone-induced encephalopathy is an exceptionally rare adverse effect of this commonly used cephalosporin and is generally observed in patients undergoing haemodialysis or suffering from severe renal failure. We present a case of a fit woman in her mid-80s with a normal renal function who developed severe fluctuating neurological symptoms (aphasia, loss of contact, chorea-like tongue movements) while being treated with ceftriaxone for a urinary tract infection with bacteraemia. The symptoms began on day 4 of treatment and an adverse drug reaction was suspected on day 7, after exhaustive investigations failed to reveal another cause. A complete recovery was observed 3 days after discontinuing ceftriaxone. Our case highlights the need to consider the diagnosis of ceftriaxone encephalopathy, even if the traditional risk factors are lacking. In this article, we also provide a brief overview of the pathophysiology as well as a literature review concerning the subject.

Potentially inappropriate prescriptions of antibiotics in geriatric psychiatry-a retrospective cohort study

Introduction

Older patients are frequently affected by infectious diseases and adverse drug reactions (ADRs) of consecutively prescribed antibiotics. Particularly within geriatric psychiatry, high rates of potentially inappropriate prescriptions (PIPs) have been described, significantly complicating pharmacological treatment. Therefore, this study aimed to investigate the frequency and characteristics of antibiotic PIPs in geriatric psychiatry.

Methods

Medication charts of 139 patient cases (mean age 78.8 years; 69.8% female) receiving antibiotic treatment on a geriatric psychiatric ward were analyzed. Utilizing previously published definitions of antibiotic PIPs, adequacy of the antibiotic prescriptions was subsequently assessed.

Results

16.3% of all screened patient cases (139/851) received an antibiotic treatment during their inpatient stay. 59.5% of antibiotic prescriptions were due to urinary tract infections, followed by pulmonary (13.3%) and skin and soft tissue infections (11.3%). 46.7% of all antibiotic prescriptions fulfilled at least one PIP criterium, with the prescription of an antibiotic course for more than seven days as the most common PIP (15.3%).

Discussion

Antibiotic PIPs can be considered as a frequent phenomenon in geriatric psychiatry. Especially the use of fluoroquinolones and cephalosporins should be discussed critically due to their extensive side effect profiles. Due to the special characteristics of geriatric psychiatric patients, international guidelines on the use of antibiotics should consider frailty and psychotropic polypharmacy of this patient population more closely.

Antibiotic persistence and its impact on the environment

From boon molecules to molecules contributing to rising concern has been the sojourn of antibiotics. The problem of antibiotic contamination has gotten worse due to antibiotics' pervasive use in every aspect of the environment. One such consequence of pollution is the increase in infections with antibiotic resistance. All known antimicrobials being used for human benefit lead to their repetitive and routine release into the environment. The misuse of antibiotics has aggravated the situation to a level that we are short of antibiotics to treat infections as organisms have developed resistance against them. Overconsumption is not just limited to human health care, but also occurs in other areas such as aquaculture, livestock, and veterinary applications for the purpose of improving feed and meat products. Due to their harmful effects on non-target species, the trace level of antibiotics in the aquatic ecosystem presents a significant problem. Since the introduction of antibiotics into the environment is more than their removal, they have been given the status of persistent pollutants. The buildup of antibiotics in the environment threatens aquatic life and may lead to bacterial strains developing resistance. As newer organisms are becoming resistant, there exists a shortage of antibiotics to treat infections. This has presented a very critical problem for the health-care community. Another rising concern is that the development of newer drug molecules as antibiotics is minimal. This review article critically explains the cause and nature of the pollution and the effects of this emerging trend. Also, in the latter sections, why we need newer antibiotics is questioned and discussed.

Utilizing Ceftazidime/Avibactam Therapeutic Drug Monitoring in the Treatment of Neurosurgical Meningitis Caused by Difficult-to-Treat Resistant Pseudomonas aeruginosa and KPC-Producing Enterobacterales

Background

Central nervous system (CNS) infections caused by Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacterales and difficult-to-treat resistant (DTR) Pseudomonas aeruginosa represent a formidable clinical challenge. Antimicrobial regimens that efficiently penetrate the cerebrospinal fluid (CSF) and achieve sufficient concentrations associated with microbiologic and clinical cure are limited. We evaluated therapy with ceftazidime-avibactam (CAZ-AVI) in order to guide precise dosing in the treatment of CNS infections.

Methods

Therapeutic drug monitoring (TDM) was performed in 3 patients with health care-associated ventriculitis and meningitis (HAVM) using CAZ-AVI 2.5 g infused intravenously every 8 hours as standard and extended infusion. Simultaneous CSF and plasma samples were obtained throughout the dosing interval in each patient. Concentrations of CAZ and AVI were determined by liquid chromatography/mass spectrometry.

Results

Bacterial identification revealed KPC-producing Klebsiella pneumoniae (KPC-Kp), DTR Pseudomonas aeruginosa, and KPC-producing Enterobacter cloacae (KPC-Ent.c). All isolates were resistant to carbapenems. The minimum inhibitory concentrations (MICs) of CAZ-AVI were 0.25/4, 4/4, and 0.25/4 μg/mL, respectively. CAZ and AVI concentrations were determined in CSF samples ranging from 29.0 to 15.0 µg/mL (CAZ component) and 4.20 to 0.92 µg/mL (AVI component), respectively. AVI achieved concentrations ≥1 µg/mL in 11 out of 12 CSF samples collected throughout the dosing interval. Clinical and microbiologic cure were attained in all patients.

Conclusions

Postinfusion concentrations of CAZ-AVI were measured in plasma and CSF samples obtained from 3 patients with complicated CNS infections caused by antimicrobial-resistant isolates. The measured concentrations revealed that standard CAZ and AVI exposures sufficiently attained values correlating to 50% fT > MIC, which are associated with efficient bacterial killing.

The tale of antibiotics beyond antimicrobials: Expanding horizons

Antibiotics had proved to be a godsend for mankind since their discovery. They were once the magical solution to the vexing problem of infection-related deaths. German scientist Paul Ehrlich had termed salvarsan as the silver bullet to treatsyphilis.As time passed, the magic of newly discovered silver bullets got tarnished with raging antibiotic resistance among bacteria and associated side-effects. Still, antibiotics remain the primary line of treatment for bacterial infections. Our understanding of their chemical and biological activities has increased immensely with advancement in the research field. Non-antibacterial effects of antibiotics are studied extensively to optimise their safer, broad-range use. These non-antibacterial effects could be both useful and harmful to us. Various researchers across the globe including our lab are studying the direct/indirect effects and molecular mechanisms behind these non-antibacterial effects of antibiotics. So, it is interesting for us to sum up the available literature. In this review, we have briefed the possible reason behind the non-antibacterial effects of antibiotics, owing to the endosymbiotic origin of host mitochondria. We further discuss the physiological and immunomodulatory effects of antibiotics. We then extend the review to discuss molecular mechanisms behind the plausible use of antibiotics as anticancer agents.

The Trend of Cefepime-Induced Neurotoxicity: A Systematic Review

There has been increased use of cefepime due to concerns about the nephrotoxic effects of the combined use of vancomycin and Zosyn. However, cefepime is associated with neurotoxicity. We conducted a systematic review using online data to explore the trend of cefepime-induced neurotoxicity over the last 10 years. Forty-six articles met our inclusion criteria, including 73 cases of cefepime-induced neurotoxicity. We noticed a steady increase in the reports of cefepime-induced neurotoxicity, from one case in 2013 to 11 cases in 2022. Individuals aged 65 and older accounted for most cefepime-induced neurotoxicity cases (52%). The top three indications for cefepime administration included bone and joint infections (25%), urinary tract infections (22.7%), and pneumonia (22.7%). Most patients with renal impairment have never had a renal adjustment of their cefepime dosage (either 2 g 12 hours a day or 2 g eight hours a day). Most cases of cefepime-induced neurotoxicity occurred between days two and five (n=29, 71%), while most resolution occurred between days one and five (n=29, 85%). While cefepime continues to be a popularly used and effective antibiotic against gram-negative bacteria like Pseudomonas aeruginosa, its dosage needs to be adjusted in patients with renal impairment to avoid neurotoxicity.

Superiority of ceftazidime off-label high-dose regimen in PK/PD target attainment during treatment of extensively drug-resistant Pseudomonas aeruginosa infections in cancer patients

AIM

The objective of this study was to evaluate off-label high-dose ceftazidime population pharmacokinetics in cancer patients with suspected or proven extensively drug-resistant (XDR) Pseudomonas aeruginosa infections and then to compare the achievement of the pharmacokinetic/pharmacodynamic (PK/PD) target after standard and off-label high-dose regimens using population model-based simulations. A further aim was to clinically observe the occurrence of adverse effects during the off-label high-dose ceftazidime treatment.

METHODS

In patients treated with off-label high-dose ceftazidime (3 g every 6 h), blood samples were collected and ceftazidime serum levels measured using LC-MS/MS. A pharmacokinetic population model was developed using a nonlinear mixed-effects modelling approach and Monte Carlo simulations were then used to compare standard and high-dose regimens for PK/PD target attainment.

RESULTS

A total of 14 cancer patients with serious infection suspected of XDR P. aeruginosa aetiology were eligible for PK analysis. XDR P. aeruginosa was confirmed in 10 patients as the causative pathogen. Population ceftazidime volume of distribution was 13.23 L, while clearance started at the baseline of 1.48 L/h and increased by 0.0076 L/h with each 1 mL/min/1.73 m² of eGFR. High-dose regimen showed significantly higher probability of target attainment (i.e., 86% vs. 56% at MIC of 32 mg/L). This was translated into a very low mortality rate of 20%. Only one case of reversible neurological impairment was observed.

CONCLUSION

We proved the superiority of the ceftazidime off-label high-dose regimen in PK/PD target attainment with very low occurrence of adverse effects. The off-label high-dose regimen should be used to optimize treatment of XDR P. aeruginosa infections.

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.

Acute kidney injury-associated delirium: a review of clinical and pathophysiological mechanisms

Acute kidney injury is a known clinical risk factor for delirium, an acute cognitive dysfunction that is commonly encountered in the critically ill population. In this comprehensive review of clinical and basic research studies, we detail the epidemiology, clinical implications, pathogenesis, and management strategies of patients with acute kidney injury-associated delirium. Specifically addressed are the pathological roles of endogenous toxin or drug accumulation, acute kidney injury-mediated neuroinflammation, and acute kidney injury-associated volume overload as discrete potential biological mechanisms of the condition. The optimization of clinical contributors and normalization of renal function are reviewed as pragmatic management strategies in addition to potential and emerging therapeutic approaches.

Ceftriaxone-induced encephalopathy in a patient with multicentric glioma

Background:

Ceftriaxone is a commonly used antibiotic in a wide range of local and systemic infections. Encephalopathy is a rare complication of ceftriaxone, often seen in older adults and those with renal insufficiency.

Case Description:

A 73-year-old lady with prior history of hypertension and dyslipidemia presented with the complaints of slurred speech, gait imbalance, nocturnal vomiting, and progressively worsening headache. A magnetic resonance imaging of the brain revealed two intracerebral lesions involving the right frontal and temporal lobes, suggestive of multicentric glioma. She underwent craniotomy and excision of these lesions. The biopsy was reported as intra-axial tumors with features suggestive of the WHO Grade IV glioma. Postoperatively, she did not wake up. An electroencephalogram demonstrated triphasic waves suggestive of encephalopathy. The probable diagnosis of ceftriaxone-induced encephalopathy was made after ruling out other causes of delayed awakening after surgery. Ceftriaxone was discontinued and the patient improved within 2 days of withdrawal of ceftriaxone.

Conclusion:

Drug-induced encephalopathy should be considered in the differential diagnosis of patients with delayed awakening after surgery. Discontinuation of the drug leads to the recovery of these patients.

The relationship between antibiotic agent and mortality in patients with febrile neutropenia due to Staphylococcal bloodstream infection: a multicenter cohort study

Background

Methicillin-susceptible Staphylococcus aureus (MSSA) is a common cause of bloodstream infection (BSI) in patients with febrile neutropenia, but treatment practices vary, and guidelines are not clear on the optimal regimen.

Methods

We conducted a multicenter retrospective cohort study of MSSA BSI in febrile neutropenia. We divided patients into 3 treatment groups: (1) broad-spectrum beta-lactams (ie, piperacillin-tazobactam, cefepime, meropenem); (2) narrow-spectrum beta-lactams (ie, cefazolin, oxacillin, nafcillin); and (3) combination beta-lactams (ie, both narrow- and broad-spectrum). We used multivariable logistic regression to compare 60-day mortality and bacteremia recurrence while adjusting for potential confounders.

Results

We identified 889 patients with MSSA BSI, 128 of whom had neutropenia at the time of the index culture: median age 56 (interquartile range, 43–65) years and 76 (59%) male. Of those, 56 (44%) received broad-spectrum beta-lactams, 30 (23%) received narrow-spectrum beta-lactams, and 42 (33%) received combination therapy. After adjusting for covariates, including disease severity, combination therapy was associated with a significantly higher odds for 60-day all-cause mortality compared with broad spectrum beta-lactams (adjusted odds ratio [aOR], 3.39; 95% confidence interval [CI], 1.29–8.89; P = .013) and compared with narrow spectrum beta-lactams, although the latter was not statistically significant (aOR, 3.30; 95% CI, .80–13.61; P = .071).

Conclusions

Use of combination beta-lactam therapy in patients with MSSA BSI and febrile neutropenia is associated with a higher mortality compared with treatment with broad-spectrum beta-lactam after adjusting for potential confounders. Patients in this study who transitioned to narrow-spectrum beta-lactam antibiotics did not have worse clinical outcomes compared with those who continued broad-spectrum beta-lactam therapy.

Two cases of ceftriaxone-induced encephalopathy treated by hemoperfusion in hemodialysis patients

Ceftriaxone is a third‐generation cephalosporin commonly used to treat infection. However, encephalopathy is an emerging adverse effect of ceftriaxone infusion. These patients present with various symptoms, including those of neurotoxicity, that typically resolve 1 week after discontinuation of ceftriaxone. We experienced two cases of ceftriaxone‐induced encephalopathy that were successfully treated by rapid removal of ceftriaxone by hemoperfusion.

Ensuring target concentrations of antibiotics in critically ill patients through dose adjustment

INTRODUCTION

Antibiotics are commonly prescribed in critical care, and given the large variability of pharmacokinetic (PK) parameters in these patients, drug PK frequently varies during therapy with the risk of either treatment failure or toxicity. Therefore, adequate antibiotic dosing in critically ill patients is very important.

AREAS COVERED

This review provides an overview of the basic principles of PK and pharmacodynamics of antibiotics and the main patient and pathogen characteristics that may affect the dosage of antibiotics and different approaches to adjust doses.

EXPERT OPINION

Dose adjustment should be done for aminoglycosides and glycopeptides based on daily drug concentration monitoring. For glycopeptides, in particular vancomycin, the residual concentration (Cres) should be assessed daily. For beta-lactam antibiotics, a loading dose should be administered, followed by three different possible approaches, as TDM is rarely available in most centers: 1) antibiotic regimens should be adapted according to renal function and other risk factors; 2) nomograms or software can be used to calculate daily dosing; 3) TDM should be performed 24-48 h after the initiation of treatment; however, the results are required within 24 hours to appropriately adjust dosage regimens. Drug dosing should be reduced or increased according to the TDM results.

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.

Cefepime-Induced Encephalopathy in a High-Risk Patient With Renal Insufficiency and Cirrhosis

Cefepime is a fourth-generation, cephalosporin antibiotic commonly used as a first-line empirical treatment in a wide range of bacterial infections. It is predominantly excreted renally; therefore, a reduction in kidney function allows for the accumulation of cefepime to potentially toxic levels. Here we present a case of cefepime-induced encephalopathy (CIE) in a 67 years old male patient with advanced-stage renal insufficiency and cirrhosis who was admitted to our hospital for altered mental status (AMS). The patient was initially treated for hepatic encephalopathy (HE) given an elevated ammonia level (105 µg/dL), which had significantly improved. He was also placed on intravenous (IV) cefepime for Pseudomonas bacteremia. Four days later, the patient became drowsy and confused. A detailed workup for secondary causes of AMS was performed however no significant acute abnormalities were detected. The ammonia level remained within the normal range. There was no acute intracranial pathology reported on a head computerized tomography (CT). Furthermore, an electroencephalograph (EEG) was obtained which showed generalized periodic discharge with a tri-phasic wave pattern suggesting non-convulsive status epilepticus (NCSE). CIE was suspected at that point and cefepime administration was stopped. Following cefepime discontinuation, there was a remarkable improvement in the patient’s mental status for several days after cefepime discontinuation that supported the diagnosis of CIE in our patient.

Although the exact pathophysiology is unclear, CIE should be suspected in elderly patients, patients with renal dysfunction, and critical illness. Meanwhile, liver dysfunction can be an additional risk factor for CIE as it increases the permeability of the blood-brain barrier (BBB), altered neurotransmission, and neuro-inflammation.

The Effect of Antibiotic Treatment of Early Childhood Shigellosis on Long-Term Prevalence of Attention Deficit/Hyperactivity Disorder

It has recently been shown that children with early shigellosis are at increased risk of attention deficit/hyperactivity disorder (ADHD). This study aimed to evaluate the association between antibiotic treatment of shigellosis with long-term ADHD rates. A retrospective cohort study was conducted that included all the Leumit Health Services (LHS) enrollees aged 5-18 years between 2000-2018 with a documented Shigella-positive gastroenteritis before the age of 3 years. Of the 5176 children who were positive for Shigella gastroenteritis before the age of 3 years, 972 (18.8%) were treated with antibiotics early (<5 days), 250 (4.8%) were treated late (≥5 days), and 3954 children (76.4%) were not prescribed antibiotics. Late antibiotic treatment was associated with significantly increased rates of ADHD (adjusted OR = 1.61; 95% CI, 1.1-2.3). Early treatment with antibiotics was not associated with increased ADHD rates (adjusted OR = 1.02; 95% CI, 0.8-1.3). In conclusion, late antibiotic treatment of early childhood shigellosis was associated with increased rates of ADHD.

Incidence and predictors of delirium on the intensive care unit in patients with acute kidney injury, insight from a retrospective registry

Acute kidney injury (AKI) and delirium are common complications on the intensive care unit (ICU). Few is known about the association of AKI and delirium, as well as about incidence and predictors of delirium in patients with AKI. In this retrospective study, all patients with AKI, as defined by the KDIGO (kidney disease improving global outcome) guideline, treated for more than 24 h on the ICU in an university hospital in 2019 were included and analyzed. Delirium was defined by a NuDesc (Nursing Delirium screening scale) ≥ 2, which is evaluated three times a day in every patient on our ICU as part of daily routine. A total of 383/919 (41.7%) patients developed an AKI during the ICU stay. Delirium was detected in 230/383 (60.1%) patients with AKI. Independent predictors of delirium were: age, psychiatric disease, alcohol abuse, mechanical ventilation, severe shock, and AKI stage II/III (all p < 0.05). The primary cause of illness had no influence on the onset of delirium. Among patients with AKI, the duration of the ICU stay correlated with higher stages of AKI and the presence of delirium (stage I/no delirium: median 1.9 (interquartile range (25th–75th) 1.3–2.9) days; stage II/III/no delirium: 2.6 (1.6–5.5) days; stage I/delirium: 4.1 (2.5–14.3) days; stage II/III/delirium: 6.8 (3.5–11.9) days; all p < 0.01). Delirium, defined as NuDesc ≥ 2 is frequent in patients with AKI on an ICU and independently predicted by higher stages of AKI.

Cefepime-Induced Delirium

Cefepime is a fourth-generation cephalosporin usually reserved to treat severe infections or those caused by multi-resistant microorganisms. Neurotoxicity is attributed to its ability to cross the blood-brain barrier and produce gamma-aminobutyric acid antagonism. Neurological symptoms may range from mild somnolence to seizures and coma. Our patient is an 88-year-old man who presented from a nursing home due to worsening pressure ulcers. After cefepime was started, he started developing worsening altered mental status and hallucinations. Cefepime was discontinued and his neurological symptoms improved shortly afterward. He was discharged to a long-term acute facility for antibiotic therapy where he recovered. Our case illustrates a commonly missed side effect of cefepime. Prompt recognition of this adverse effect is paramount to prevent disease progression and avoid permanent neurological damage.

Delirium Associations with Antibiotics: A Pharmacovigilance Study of the FDA Adverse Event Reporting System (FAERS)

Background

Ertapenem, cefepime, imipenem, ofloxacin, ceftazidime, clarithromycin, cefaclor, levofloxacin, linezolid, moxifloxacin, azithromycin, piperacillin–tazobactam, trimethoprim–sulfamethoxazole, metronidazole, ciprofloxacin, and cefuroxime are known to be associated with delirium. Other antibiotics may also lead to delirium, but no study has systemically compared delirium associations for many available antibiotics.

Objective

The objective of this study was to evaluate the association between delirium and antibiotics using the FDA Adverse Event Reporting System (FAERS).

Methods

FAERS reports from January 1, 2004 to December 31, 2018 were included in the study. Reporting odds ratios (RORs) and corresponding 95% confidence intervals (95% CI) for the association between antibiotics and delirium were calculated. An association was considered to be statistically significant when the lower limit of the 95% CI was greater than 1.0.

Results

A total of 10,015,622 reports (including 16,982 delirium reports) were considered, after inclusion criteria were applied. Statistically significant delirium RORs (95% CI) for antibiotics were: ertapenem 21.07 (16.38–27.10), cefepime 9.8 (6.37–15.09), imipenem 9.68 (6.75–13.89), ofloxacin 7.73 (4.00–14.92), ceftazidime 6.09 (2.73–13.62), clarithromycin 5.34 (4.37–6.53), cefaclor 5.32 (1.71–16.58), ampicillin–sulbactam 4.49 (2.13–9.45), levofloxacin 4.47 (3.88–5.16), linezolid 4.33 (3.28–5.72), moxifloxacin 3.51 (2.81–4.38), azithromycin 2.76 (2.09–3.64), piperacillin–tazobactam 2.41 (1.47–3.93), trimethoprim–sulfamethoxazole 2.36 (1.61–3.47), metronidazole 1.85 (1.31–2.60), ciprofloxacin 1.83 (1.44–2.33), and cefuroxime 1.81 (1.03–3.20).

Conclusion

This study found statistically significant increased risk of reporting delirium with ertapenem, cefepime, imipenem, ofloxacin, ceftazidime, clarithromycin, cefaclor, ampicillin–sulbactam, levofloxacin, linezolid, moxifloxacin, azithromycin, piperacillin–tazobactam, trimethoprim–sulfamethoxazole, metronidazole, ciprofloxacin, and cefuroxime.

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.

Impact of extracorporeal membrane oxygenation (ECMO) support on piperacillin exposure in septic patients: a case-control study

OBJECTIVES

To describe the impact of extracorporeal membrane oxygenation (ECMO) devices on piperacillin exposure in ICU patients.

METHODS

This observational, prospective, multicentre, case-control study was performed in the ICUs of two tertiary care hospitals in France. ECMO patients with sepsis treated with piperacillin/tazobactam were enrolled. Control patients were matched according to SOFA score and creatinine clearance. The pharmacokinetics of piperacillin were described based on a population pharmacokinetic model, calculating the proportion of time the piperacillin plasma concentration was above 64 mg/L (i.e. 4× MIC breakpoint for Pseudomonas aeruginosa).

RESULTS

Forty-two patients were included. Median (IQR) age was 60 years (49-66), SOFA score was 11 (9-14) and creatinine clearance was 47 mL/min (5-95). There was no significant difference in the proportion of time piperacillin concentrations were ≥64 mg/L in patients treated with ECMO and controls during the first administration (P = 0.184) or at steady state (P = 0.309). Following the first administration, 36/42 (86%) patients had trough piperacillin concentrations <64 mg/L. Trough concentrations at steady state were similar in patients with ECMO and controls (P = 0.535). Creatinine clearance ≥40 mL/min was independently associated with piperacillin trough concentration <64 mg/L at steady state [OR = 4.3 (95% CI 1.1-17.7), P = 0.043], while ECMO support was not [OR = 0.5 (95% CI 0.1-2.1), P = 0.378].

CONCLUSIONS

ECMO support has no impact on piperacillin exposure. ICU patients with sepsis are frequently underexposed to piperacillin, which suggests that therapeutic drug monitoring should be strongly recommended for severe infections.

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.

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.

Antibiotics: Conventional Therapy and Natural Compounds with Antibacterial Activity-A Pharmaco-Toxicological Screening

Antibiotics are considered as a cornerstone of modern medicine and their discovery offers the resolution to the infectious diseases problem. However, the excessive use of antibiotics worldwide has generated a critical public health issue and the bacterial resistance correlated with antibiotics inefficiency is still unsolved. Finding novel therapeutic approaches to overcome bacterial resistance is imperative, and natural compounds with antibacterial effects could be considered a promising option. The role played by antibiotics in tumorigenesis and their interrelation with the microbiota are still debatable and are far from being elucidated. Thus, the present manuscript offers a global perspective on antibiotics in terms of evolution from a historical perspective with an emphasis on the main classes of antibiotics and their adverse effects. It also highlights the connection between antibiotics and microbiota, focusing on the dual role played by antibiotics in tumorigenesis. In addition, using the natural compounds with antibacterial properties as potential alternatives for the classical antibiotic therapy is discussed.

Moderate Dose of Tranexamic Acid and Complications after Valvular Heart Surgery

BACKGROUND

 In valvular open-heart surgery, data regarding the effect of a moderate dose of tranexamic acid (TXA) on clinical outcomes are limited.

METHODS

 Out of a cohort of 13,293 patients, we performed a propensity-score-matched analysis in 6,106 patients and assessed the risk of convulsive seizures (CS, primary endpoint), stroke, renal replacement therapy, and mortality (secondary endpoints). In the entire study cohort of 13,293 patients, we also assessed the multivariable-adjusted association of CS with postoperative outcomes.

RESULTS

 The risk of CS was significantly higher in the TXA group (2.4%; n = 72) than in the non-TXA group (1.0%; n = 32), with a relative risk ratio (RR) of 2.28 (95% confidence interval [CI]: 1.50-3.47; p < 0.001). The risk of CS was also higher in patients receiving TXA doses ≥25 mg/kg body weight (3.7%; n = 40) than in patients receiving <25 mg/kg body weight (1.6%; n = 32; p < 0.001). Perioperative secondary clinical endpoints and 1-year mortality did not differ significantly between study groups (p-value > 0.05). Compared with non-CS patients (n = 13,000), patients with nonhemorrhagic, nonembolic CS (n = 253) revealed higher multivariable-adjusted in-hospital risks of stroke (RR: 3.82 [95% CI: 2.44-5.60; p < 0.001]) and mortality (RR: 2.07 [95% CI: 1.23-3.48; p = 0.006]), and a higher 1-year mortality risk (RR: 1.85 [95% CI: 1.42-2.41; p < 0.001]).

CONCLUSION

 A moderate TXA dose was associated with a significantly higher risk of seizure, but not with other clinical complications such as stroke, renal replacement therapy, and mortality. However, in the small group of patients experiencing a seizure, the risks of stroke and short- and mid-term mortality were substantially higher than in patients not experiencing a seizure, indicating that the use of a low-dose TXA protocol (<25 mg/kg body weight) should be considered.

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.

New Onset Non-Convulsive Status Epilepticus Despite Cefepime Renal Dose Adjustment

Cefepime, a widely used fourth-generation cephalosporin for coverage of both gram-positive and gram-negative bacteria, has been reported to have associated neurological adverse effects. These effects have been seen mostly in patients mostly with impaired renal function, and currently, dosing is based on creatinine clearance to reduce its toxic effect profile. Despite renal dose adjustment, we present a case of a 40-year-old woman who was managed for Escherichia coli bacteremia, acute kidney injury, and hemorrhagic shock. About 96 hours after cefepime therapy was commenced, she was noted to be twitching with passive movement of her upper limb and myoclonus of the facial muscles. Her workup including computed tomography (CT) scan of the head and magnetic resonance imaging (MRI) brain were negative. Electroencephalograph (EEG) showed 2 Hertz sharply contoured triphasic form rhythmic waves suggestive of nonconvulsive status epilepticus (NCSE). She received antiseizure medications and later had hemodialysis for effective clearance of cefepime. She had significant improvement in her neurological status following hemodialysis and a repeat EEG showed no further seizure activity. Clinicians should be aware of the risk of NCSE in patients on cefepime despite renal dose adjustment. Once identified, immediate discontinuation of the offending drug, treatment with benzodiazepines, and clearance of the medication with hemodialysis is recommended. 

Cefepime Neurotoxicity in a Patient With Acute Tubular Necrosis

Neurotoxicity is a rare side effect of Cefepime use. Cefepime can cross the blood-brain barrier and can be neurotoxic by competitive albeit weak antagonism of the gamma-aminobutyric acid complex. It is cleared by the kidneys which puts individuals with renal impairment at risk of side effects. We describe a case of Cefepime neurotoxicity in the context of nephrotoxicity secondary to the use of other drugs.

What is the optimal loading dose of broad-spectrum β-lactam antibiotics in septic patients? Results from pharmacokinetic simulation modelling

Optimal loading doses of β-lactams to rapidly achieve adequate drug concentrations in critically ill patients are unknown. This was a post-hoc analysis of a prospective study that evaluated broad-spectrum β-lactams [piperacillin (PIP), ceftazidime (CAZ), cefepime (FEP) and meropenem (MEM)] pharmacokinetics (PKs) in patients with sepsis or septic shock (n = 88). Monte Carlo simulation was performed for 1000 virtual patients using specific sets of covariates for various dosing regimens and different durations of administration. Pharmacodynamic (PD) targets were considered as drug concentrations exceeding at least 50% of time above four times the minimum inhibitory concentration (T_>4 × MIC) of Pseudomonas aeruginosa, according to EUCAST criteria, for PIP, 70%T_>4 × MIC for CAZ and FEP and 40%T_>4 × MIC for MEM. The probability of target attainment (PTA) was derived by calculating the percentage of patients who attained the PK/PD target at each MIC. The optimal loading dose was defined as the one associated with a ≥90% probability to achieve the PD targets. Our simulation model identified an optimal loading dose for PIP of 8 g given as a 3-h infusion (PTA of 96.2%), for CAZ and FEP of 4 g given as a 3-h infusion (PTA of 96.5% and 98.4%, respectively), and for MEM of 2 g given as a 30-min infusion (PTA of 93.4%), with the following antibiotic dose administered 6 h thereafter regardless of the drug. A higher first dose of broad-spectrum β-lactams should be given to adequately treat less-susceptible pathogens in septic patients. These findings need to be validated in a prospective study.

Population pharmacokinetics of continuous-infusion ceftazidime in febrile neutropenic children undergoing HSCT: implications for target attainment for empirical treatment against Pseudomonas aeruginosa

OBJECTIVES

To conduct a population pharmacokinetic analysis of continuous-infusion ceftazidime in a retrospective cohort of paediatric HSCT patients who were empirically treated for febrile neutropenia (FN) and who underwent therapeutic drug monitoring of ceftazidime steady-state plasma concentrations (Css) for optimization of drug exposure.

METHODS

A non-parametric approach with Pmetrics was used for pharmacokinetic analysis and covariate evaluation. Monte Carlo simulations were performed to calculate the PTA of the pharmacodynamic determinant of efficacy (Css/MIC ≥4) against Pseudomonas aeruginosa with continuous-infusion ceftazidime dosages of 1-6 g daily. The Css safety threshold was arbitrarily placed at 100 mg/L and advisable dosages were used.

RESULTS

A total of 46 patients with 70 ceftazidime Css values were included. Estimated glomerular filtration rate (eGFR) and body surface area were the covariates associated with drug clearance. At the EUCAST clinical breakpoint of 8 mg/L, simulations showed that continuous-infusion ceftazidime dosages of 4-6 g daily attained optimal PTAs (>90%) across most of 16 different clinical scenarios based on four classes of eGFR (50-145, 145.1-200, 200.1-286 and 286.1-422 mL/min/1.73 m2) and body surface area (0.30-0.64, 0.65-0.88, 0.89-1.34 and 1.35-1.84 m2). In patients with body surface area 0.30-0.64 m2 and eGFR ≤200 mL/min/1.73 m2 the advisable dose of 3 g daily allowed only suboptimal PTAs (<75%). The cumulative fraction of response against MIC distribution of P. aeruginosa was >87%.

CONCLUSIONS

Continuous-infusion ceftazidime dosages ranging from 3 to 6 g daily according to different classes of eGFR and body surface area may allow optimized empirical treatment of P. aeruginosa infections in paediatric HSCT patients with FN.

Cefepime-Induced Seizures: The Overlooked Outpatient Adverse Reaction

Cefepime is a 4th generation cephalosporin often used for its ability to cover gram-positives, gram negatives, anaerobic bacteria, and, most importantly, pseudomonas. Prior to initiation of cefepime, the medication is dosed based on the renal function to avoid a multitude of its toxicity profiles, including encephalopathy, aphasia, myoclonus, seizures, and nonconvulsive status epilepticus. These risks are increased in the presence of renal impairment. We present a case of a 65-year-old woman who had presented to the emergency department (ED) two weeks after initiation of outpatient IV cefepime therapy with concerns of altered mentation and decreased oral intake. In the ED, the patient was noted to have a creatinine: 5.77 (baseline of 0.76) and urea: 94. During evaluation by the ED provider, the patient was noted to have transient slurring of speech, speech arrest, and tonic-clonic movements on the right. CT of the head, followed by CT angiography of the head and neck, demonstrated no acute intracranial pathology. Spot EEG revealed generalized slowing with unclear left-sided epileptiform discharges. There was a concern for complex partial seizures. Neurology and nephrology were consulted. The patient was given 1 g of levetiracetam, and emergent dialysis was performed. After dialysis, no other epileptiform activity was noted with the improvement of her encephalopathy. The patient returned to her baseline mentation. Here we emphasize the importance of recognizing cefepime’s toxicity profile while triaging patients. In the rare event of toxicity, immediate treatment is discontinuing the offending agent and initiation of emergent hemodialysis.

Tolerability of high-dose ceftriaxone in CNS infections: a prospective multicentre cohort study

BACKGROUND

Ceftriaxone is widely used to treat community-acquired CNS bacterial infections. French guidelines for meningitis in adults promote 75-100 mg/kg/day ceftriaxone without an upper limit for dosage, yet little is known about the pharmacology and tolerability of such regimens.

PATIENTS AND METHODS

A multicentre prospective cohort study was conducted in adult patients to assess the adverse drug reactions (ADRs) of high-dose ceftriaxone (i.e. daily dosage ≥4 g or ≥75 mg/kg) in CNS infections and to analyse their related factors. Drug causality was systematically assessed by an expert committee who reviewed the medical charts of all included patients.

RESULTS

A total of 196 patients were enrolled over a 31 month period. Median dosage and duration of ceftriaxone were 96.4 mg/kg/day (7 g/day) and 8 days, respectively. Nineteen ceftriaxone-related ADRs (mainly neurological) occurred in 17 patients (8.7%), with only one case of treatment discontinuation (biliary pseudolithiasis). In univariate analysis, older age, male gender, renal impairment and high trough ceftriaxone plasma concentration were associated with ceftriaxone-related ADRs.

CONCLUSIONS

High-dose ceftriaxone for CNS infection administered as recommended by French guidelines in adults was well tolerated overall, suggesting these recommendations could be applied and generalized. In patients with advanced age or renal insufficiency, prescription should be done with caution and therapeutic drug monitoring could be useful.

Paradoxical Anticonvulsant Effect of Cefepime in the Pentylenetetrazole Model of Seizures in Rats

Many β-lactam antibiotics, including cephalosporins, may cause neurotoxic and proconvulsant effects. The main molecular mechanism of such effects is considered to be γ-aminobutyric acid type a (GABAa) receptor blockade, leading to the suppression of GABAergic inhibition and subsequent overexcitation. We found that cefepime (CFP), a cephalosporin, has a pronounced antiepileptic effect in the pentylenetetrazole (PTZ)-induced seizure model by decreasing the duration and severity of the seizure and animal mortality. This effect was specific to the PTZ model. In line with findings of previous studies, CFP exhibited a proconvulsant effect in other models, including the maximal electroshock model and 4-aminopyridine model of epileptiform activity, in vitro. To determine the antiepileptic mechanism of CFP in the PTZ model, we used whole-cell patch-clamp recordings. We demonstrated that CFP or PTZ decreased the amplitude of GABAa receptor-mediated postsynaptic currents. PTZ also decreased the current decay time constant and temporal summation of synaptic responses. In contrast, CFP slightly increased the decay time constant and did not affect summation. When applied together, CFP prevented alterations to the summation of responses by PTZ, strongly reducing the effects of PTZ on repetitive inhibitory synaptic transmission. The latter may explain the antiepileptic effect of CFP in the PTZ model.

Jerky Movement with Ceftazidime: A Case of Ceftazidime-Induced Neurotoxicity with a Review of the Literature

Neurotoxicity manifested as confusion and seizures has been recognized as a side effect of multiple cephalosporins including ceftazidime. Renal impairment and inappropriate dosing are the most common contributors to the development of neurological abnormalities in patients receiving these antibiotics. The presence of baseline neurological abnormalities likely contributes to the frequency of these adverse events. Here, we present a case of a 78-year-old man that developed altered mental status and myoclonic movement after initiation of ceftazidime in the setting of mild renal dysfunction. Resolution of clinical picture was evident after 48 hours of discontinuation of the antibiotic without additional interventions.

High Pyridine Generation in Ceftazidime-Icodextrin Admixtures Used to Treat Peritoneal Dialysis-associated Peritonitis

PURPOSE

To investigate the amount of pyridine generated from degradation of ceftazidime in icodextrin peritoneal dialysis (PD) solutions.

METHODS

PD solutions that contained 1 and 1.5 g of ceftazidime were stored at 25 °C for 12 hours and then at 37 °C for 14 hours. An aliquot was withdrawn at predefined time points and analyzed for the concentrations of ceftazidime and pyridine.

FINDINGS

The amount of pyridine generated was >225% and 400% of its maximum recommended daily exposure in the 1- and 1.5-g ceftazidime-PD admixtures, respectively.

IMPLICATIONS

Until these results are confirmed with appropriate in vivo studies, intermittent intraperitoneal dosing of ceftazidime admixed with icodextrin should be used with caution and appropriate clinical monitoring or a suitable alternative antibiotic should be used.

Reversible Choreoathetosis in a Patient with End-stage Renal Disease from Administration of Ceftriaxone

A wide spectrum of neurological manifestations may be induced in patients with impaired renal function when receiving beta-lactam antibiotics due to the altered pharmacokinetics. Beta-lactam antibiotics is commonly chosen for treatment in patients with end-stage renal disease due to its good penetration into the cerebrospinal fluid and long half-life.

Here, we present a case of a 73-year-old Malay lady with end-stage renal disease who was admitted for treatment of gastroenteritis. She presented with acute onset of diarrhoea and vomiting for two days. She was febrile during admission and was prescribed intravenous ceftriaxone 2 grams daily for coverage of bacterial gastroenteritis. Among the investigations done, white cell count were raised together with the C-reactive protein. Stool and blood cultures were also sent for further investigations. Over a three-day period, her general condition improved and she was discharged home. The onset of clinical manifestation of choreoathetosis was noticed by her caregiver on the same day of discharge. She was brought back to the emergency department and was readmitted for further workup of the new presenting complain of abnormal movement and disorientation. Haemodialysis was arranged and immediately commenced during her admission. The renal nurses reported that her neurological symptoms were noticeably improved after completion of the initial dialysis without any treatment.

Ceftriaxone including other beta lactam antibiotics penetrates the blood-brain barrier and induces glutamate in excess in the striatum and cerebral cortex, resulting in neurological hyper excitability disorders despite appropriate renal adjusted dosage for end-stage renal disease patients on haemodialysis.