Retrospective review of neurotoxicity induced by cefepime and ceftazidime

Role of the gut microbiota in cefoperazone/sulbactam-induced epilepsy in mice with chronic renal failure

OBJECTIVES

The mechanism of cefoperazone/sulbactam-induced epilepsy in chronic kidney disease (CKD) patients is not yet clear. We hypothesized that cefoperazone/sulbactam-induced epilepsy could be based on two main factors: neurotoxicity caused by drug accumulation after renal failure and an abnormal gut microbiota (GM).

METHODS

A chronic renal failure (CRF) model in mice was established, and then different doses of cefoperazone/sulbactam were injected to induce epilepsy in mice. Normal mouse feces for fecal microbiota transplantation (FMT) were collected. We observed the changes in feces, mental state, and activity of each group of mice. After killing, we collected kidneys and colon for H&E staining. We collected mouse feces for the 16S RNA sequencing of bacteria.

RESULTS

All CRF mice injected with different concentrations of cefoperazone/sulbactam experienced grade-V seizures and eventually died, whereas normal control mice did not. However, after FMT intervention, the time of epilepsy onset and death in mice was delayed. Early FMT intervention resulted in more mice surviving (p = .0359). Moreover, the villi in the mucosal of group-CS layer fell off, goblet cells missed, and crypts disappeared. The mucosal layer and submucosa were clearly separated. The morphology of intestinal tissue of the CFS and FS group was improved. After FMT, the changes of the GM were observed.

CONCLUSIONS

The GM may be involved in the epilepsy induced by cefoperazone/sulbactam in CRF mice. FMT can delay the onset of epilepsy in CRF mice induced by cefoperazone/sulbactam, and the earlier the intervention, the better the effect.

The Safety of Aztreonam Versus Ceftazidime in Patients Labeled With Penicillin Allergy: A Cohort Study

PURPOSE

Penicillin allergy is the most common drug allergy among hospitalized patients. Traditionally, aztreonam is recommended for patients labeled with penicillin allergy (PLWPA) in our institutional empirical antibiotic guidelines. Due to a global aztreonam shortage in December 2022, the antimicrobial stewardship unit recommended ceftazidime as a substitute. There is a paucity of real-world data on the safety profile of ceftazidime in PLWPA. Hence, we evaluated tolerability outcomes of ceftazidime use in PLWPA.

METHODS

This retrospective cohort study compared PLWPA in Singapore General Hospital who received aztreonam (October 2022-December 2022) or ceftazidime (December 2022-February 2023). Patients were stratified according to their risk of allergic reaction (AR) based on history of penicillin allergy. The severity of AR was based on the Delphi study grading system. The primary outcome was development of AR after initiation of aztreonam or ceftazidime. The secondary tolerability outcomes include hepatotoxicity and neurotoxicity.

FINDINGS

There were 168 patients in the study; 69 were men (41.1%) and the median age was 69 years (interquartile range: 59-76 years). Incidence of AR was statistically similar in both arms: 1 of 102 patients (0.98%) in the aztreonam arm vs 2 of 66 patients (3.03%) in the ceftazidime arm (P = 0.33). The patient in the aztreonam arm was deemed at medium risk of having an AR and developed localized rashes (grade 1). Both patients in the ceftazidime arm were deemed at high risk of AR and developed localized skin reaction (grade 1). Hepatotoxicity was observed in 1 patient prescribed aztreonam. No patients in the ceftazidime arm developed adverse events.

IMPLICATIONS

Ceftazidime appears to be better tolerated and cheaper compared with aztreonam in PLWPA, and serves as an antimicrobial stewardship strategy to conserve broader-spectrum antibiotics use.

Ceftazidime-related neurotoxicity in a patient with renal impairment: a case report and literature review

PURPOSE

We present the case of a 67-year-old woman with severely reduced renal clearance suffering from ceftazidime-induced encephalopathy. Subsequently, we search the literature to review and describe the neurotoxicity of ceftazidime.

METHODS

A search string was developed to search PubMed for relevant cases from which relevant information was extracted. Using the collected data a ROC analysis was performed in R to determine a neurotoxicity threshold.

RESULTS

Our patient suffered from progressive loss of consciousness and myoclonic seizures, with improvements noted a few days after discontinuation of treatment. The dose was not appropriately reduced to take into account her reduced renal function. The highest ceftazidime concentration recorded was 234.9 mg/mL. Using the Naranjo score we found a probable relationship between our patient's encephalopathy and ceftazidime administration. In the literature we found a total of 32 similar cases, most of which also had some form of renal impairment. Using our collected data and ceftazidime concentrations provided in the literature, a ROC analysis provided a neurotoxicity threshold of 78 mg/L for ceftazidime neurotoxicity.

CONCLUSION

Ceftazidime-related neurotoxicity is a known issue, especially in patients with severe renal impairment. Yet no concrete toxicity threshold has been reported so far. We propose the first toxicity threshold for ceftazidime of 78 mg/L. Future prospective studies are needed to validate and optimize the neurotoxicity threshold as upper limit for ceftazidime therapeutic drug monitoring.

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.

Ceftazidime/avibactam serum concentration in patients on ECMO

OBJECTIVES

The use of extracorporeal membrane oxygenation (ECMO) may alter blood levels of several drugs, including antibiotics, leading to under dosing of these drugs and thus to potential treatment failure. No data exist on pharmacokinetics of new antimicrobial, in particular ceftazidime/avibactam. We therefore perform this study to evaluate ceftazidime/avibactam blood levels in ECMO patients and find factors associated with underdosing.

METHODS

Retrospective observational study of patients on ECMO having received ceftazidime/avibactam and in whom trough blood levels of ceftazidime and avibactam were available. Main outcome measurement was the number of patients with ceftazidime and avibactam blood levels above predefined cut-off values, derived from the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints for Enterobacteriaceae and Pseudomonas aeruginosa, namely 8 mg/L for ceftazidime and 4 mg/L for avibactam, and explored factors associated with underdosing.

RESULTS

Twenty-three ceftazidime/avibactam trough levels were available in 14 ECMO patients, all of them having received veno-venous ECMO for SARS-CoV-2-associated pneumonia. Although ceftazidime levels were above 8 mg/L in all except one patient, nine (39%) of the avibactam dosages were below 4 mg/L. Increased renal clearance (creatinine clearance > 130 mL/min) was the main factor associated with under dosing, since 7 out of the 10 dosages below the predefined cut-offs were measured in patients with this condition.

CONCLUSIONS

In ECMO patients receiving ceftazidime/avibactam, ceftazidime and avibactam serum levels are above EUCAST breakpoints in most cases, justifying the use of normal dosing in ECMO patients. Increased renal clearance may lead to ceftazidime and avibactam under dosing.

Ceftazidime Plasma Concentrations and Neurotoxicity: The Importance of Therapeutic Drug Monitoring in Patients Undergoing Different Modalities of Renal Replacement Therapy. A Grand Round

ABSTRACT

Ceftazidime-avibactam (CTZ-AVM) is a novel cephalosporin/beta-lactamase inhibitor with broad-spectrum activity against multidrug-resistant Pseudomonas aeruginosa . Ceftazidime-induced neurotoxicity is a well-described adverse effect, particularly in patients with renal insufficiency. However, appropriate dosing of ceftazidime-avibactam in patients undergoing renal replacement therapy (RRT) is sparsely investigated, and therapeutic drug monitoring to guide dosing remains lacking. Furthermore, when dose adjustment for impaired renal function is based on CTZ-AVM product information, inferior cure rates have been obtained compared with those with the standard therapy for intra-abdominal infections. Maintaining an effective dose while avoiding toxicity in these patients is challenging. Here, the authors describe the case of a critically ill patient, undergoing 2 modalities of RRT, who developed ceftazidime-induced neurotoxicity as confirmed using ceftazidime therapeutic drug monitoring. This case illustrates a therapeutic drug monitoring-based approach for guiding ceftazidime-avibactam dosing in this context and in diagnosing the cause of neurological symptoms and signs.

Towards optimization of ceftazidime dosing in obese ICU patients: the end of the 'one-size-fits-all' approach?

BACKGROUND

Ceftazidime is commonly used as a key antibiotic against Pseudomonas aeruginosa in critically ill patients. ICU patients have severely altered and variable antibiotic pharmacokinetics, resulting in lower antimicrobial concentrations and potentially poor outcome. Several factors, including obesity and renal function, may influence pharmacokinetics. Thus, the objective of the study was to evaluate the impact of obesity and renal function on ceftazidime plasma concentrations and dosing regimen in ICU patients.

METHODS

All consecutive adult patients from six ICUs, treated with continuous ceftazidime infusion and under therapeutic drug monitoring evaluation, were included. Obesity was defined as BMI ≥30 kg/m². Glomerular filtration rate (GFR) was estimated by the Chronic Kidney Disease Epidemiology Collaboration formula. The ceftazidime recommended target for plasma concentrations was between 35 and 80 mg/L.

RESULTS

A total of 98 patients (45 obese), with an average weight of 90 (±25) kg, were included. Mean GFR was 84.1 (±40.4) mL/min/1.73 m2. Recommended ceftazidime plasma concentrations were achieved for only 48.0% of patients, with median dosing regimen of 6 g/day. Obese patients had lower ceftazidime plasma concentrations compared with non-obese patients (37.8 versus 56.3 mg/L; P = 0.0042) despite similar dosing regimens (5.83 g/day versus 5.52 g/day, P = 0.2529). Almost all augmented renal clearance patients were underdosed despite ceftazidime dosing of 6.6 (±0.8) g/day. Weight-based ceftazidime dosing seemed to attenuate such obesity-related discrepancies, regardless of GFR.

CONCLUSIONS

Obese ICU patients required significantly greater ceftazidime doses to achieve the target range. A tailored dosing regimen may be considered based on weight and GFR. Future prospective studies should be performed to confirm this individualized dosing approach.

Piperacillin-Tazobactam Versus Anti-Pseudomonal Cephalosporins and Renal and Neurologic Outcomes in Critically Ill Adults: A Secondary Analysis of the SMART Trial

Background: Prior studies suggest associations between receipt of piperacillin-tazobactam and development of acute kidney injury and receipt of anti-pseudomonal cephalosporins and neurotoxicity. We compared clinically-relevant renal and neurologic outcomes in critically ill patients who received piperacillin-tazobactam versus anti-pseudomonal cephalosporins. Methods: We conducted a secondary analysis of data from the Isotonic Solutions and Major Adverse Renal Events Trial examining patients who received piperacillin-tazobactam or an anti-pseudomonal cephalosporin within 24 h of intensive care unit admission. We performed multivariable analysis using a proportional odds model to examine the association between the first antibiotic received and the outcomes of Major Adverse Kidney Events within 30 days (MAKE30) and days alive and free of delirium and coma to day 28. Results: 3199 were included in the study; 2375 (74%) receiving piperacillin-tazobactam and 824 (26%) receiving anti-pseudomonal cephalosporin. After adjustment for prespecified confounders, initial receipt of piperacillin-tazobactam, compared to anti-pseudomonal cephalosporins, was not associated with higher incidence of MAKE30 (adjusted odds ratio, 1.03; 95% CI, 0.83-1.27; P = .80) but was associated with a greater number of days alive and free of delirium and coma (adjusted odds ratio, 1.18; 95% CI, 1.00-1.38; P = .04). In a sensitivity analysis adjusting for baseline receipt of medications which may impact neuro function, this finding was not significant. Conclusion: Among critically ill adults, receipt of piperacillin-tazobactam was not associated with an increased incidence of death, renal replacement therapy, or persistent renal dysfunction or a greater number of days alive and free of delirium and coma. Randomized trials are needed to inform the choice of antibiotics for empiric treatment infection in critically ill adults.

Pollutants in aquatic system: a frontier perspective of emerging threat and strategies to solve the crisis for safe drinking water

Water is an indispensable natural resource and is the most vital substance for the existence of life on earth. However, due to anthropogenic activities, it is being polluted at an alarming rate which has led to serious concern about water shortage across the world. Moreover, toxic contaminants released into water bodies from various industrial and domestic activities negatively affect aquatic and terrestrial organisms and cause serious diseases such as cancer, renal problems, gastroenteritis, diarrhea, and nausea in humans. Therefore, water treatments that can eliminate toxins are very crucial. Unfortunately, pollution treatment remains a difficulty when four broad considerations are taken into account: effectiveness, reusability, environmental friendliness, and affordability. In this situation, protecting water from contamination or creating affordable remedial techniques has become a serious issue. Although traditional wastewater treatment technologies have existed since antiquity, they are both expensive and inefficient. Nowadays, advanced sustainable technical approaches are being created to replace traditional wastewater treatment processes. The present study reviews the sources, toxicity, and possible remediation techniques of the water contaminants.

Risk Factors and Outcomes of Central Nervous System Infection After Spinal Surgery: A Retrospective Cohort Study

OBJECTIVE

To investigate the risk factor associated with central nervous system infection, a rare and dire complication after spinal surgery.

METHODS

Univariate and multivariate logistic regression analyses were performed to screen for the independent risk factors. According to the different administration methods of antibiotics, patients were divided into intravenous and intrathecal groups. The differences in time needed for body temperature, white blood cells (WBC), and C-reactive protein (CRP) to return to normal and the time of antibiotic application were compared between the 2 groups. In addition, the differences in WBC, neutrophil ratio, CRP, procalcitonin in blood, and WBC in cerebrospinal fluid were compared before intrathecal injection, after the first one, and the last one. The incidence of complications in the 2 groups was observed.

RESULTS

Dural tears, laminectomy, and operation time >3 hours were identified as independent risk factors. The time needed for body temperature, WBC, and CRP to return to normal and the antibiotic application time were significantly different between the 2 groups (all P < 0.05). Before and after the first intrathecal injection and after the last intrathecal injection, the differences in WBCs, neutrophil ratios, CRP, procalcitonin in blood, and cerebrospinal fluid-WBC were statistically significant in overall and pairwise comparisons (P < 0.05). Complications occurred in 2 and 14 cases, respectively.

CONCLUSIONS

The independent risk factors for central nervous system infection after spinal surgery were a dural tear, laminectomy, and operation time > 3 hours. Combined intravenous and intrathecal injections of antibiotics led to a better effect than intravenous injection alone; however, this approach was associated with more complications.

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.

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.

Ceftazidime dosing in obese patients: is it time for more?

INTRODUCTION

Ceftazidime is used for the treatment of many bacterial infections, including severe P. aeruginosa infections. Like other beta-lactams, inter-individual variability in ceftazidime pharmacokinetics has been described. Due to its related pathophysiological modifications, obesity might influence ceftazidime pharmacokinetics.

AREAS COVERED

The objective of this review is to assess the current state of knowledge about the impact of obesity on ceftazidime treatment. A literature search was conducted on PubMed-MEDLINE (2016-2021) to retrieve pharmacokinetic studies published in English, matching the terms 'ceftazidime' AND 'pharmacokinetics.'

EXPERT OPINION

The impact of obesity on pharmacokinetics is generally poorly known, mainly because obese patients are often excluded from clinical studies. However, the published literature clearly shows that obese patients have significantly lower ceftazidime concentrations. This could be explained by increased volume of distribution and clearance. This low exposure represents a major factor of therapeutic failure, potentially fatal for critically ill patients. While further studies would be useful to better assess the magnitude and understanding of this variability, the use of higher doses of ceftazidime is needed in obese patients. Moreover, therapeutic drug monitoring for dose adaptation is of major interest for these patients, as the efficacy of ceftazidime seems to be directly related to its plasma concentration.

Incidence and Predictive Factors Associated with Beta-Lactam Neurotoxicity in the Critically Ill: A Retrospective Cohort Study

BACKGROUND

Beta-lactam neurotoxicity is a relatively uncommon yet clinically significant adverse effect in critically ill patients. This study sought to define the incidence of neurotoxicity, derive a prediction model for beta-lactam neurotoxicity, and then validate the model in an independent cohort of critically ill adults.

METHODS

This retrospective cohort study evaluated critically ill patients treated with ≥ 48 h of cefepime, piperacillin/tazobactam, or meropenem. Two separate cohorts were created: a derivation cohort and a validation cohort. Patients were screened for beta-lactam neurotoxicity by using search terms and diagnosis codes, followed by clinical adjudication using a standardized adverse event scoring tool. Multivariable regression models and least absolute shrinkage and selection operator were used to identify surrogates for neurotoxicity and develop a multivariable prediction model.

RESULTS

The overall incidence of beta-lactam neurotoxicity was 2.6% (n/N = 34/1323) in the derivation cohort and 2.1% in the validation cohort (n/N = 16/767). The final multivariable neurotoxicity assessment tool included weight, Charlson comorbidity score, age, and estimated creatinine clearance as predictors of neurotoxicity. Incidence of neurotoxicity reached 4% in those with a body mass index more than 30 kg/m². Use of the candidate variables in the neurotoxicity assessment tool suggested that a score more than 35 would identify a patient at high risk for neurotoxicity with 75% sensitivity and 54% specificity.

CONCLUSIONS

In this single center cohort of critically ill patients, beta-lactam neurotoxicity was demonstrated less frequently than previously reported. We identified obesity as a novel risk factor for the development of neurotoxicity. The prediction model needs to be further refined before it can be used in clinical practice as a tool to avoid drug-related harm.

Quantification of 15 Antibiotics Widely Used in the Critical Care Unit with a LC-MS/MS System: An Easy Method to Perform a Daily Therapeutic Drug Monitoring

Potential under- or overdose of antibiotics may occur in intensive care units due to high variability in plasma concentrations. The risk is either treatment failure or toxicity. Thus, therapeutic drug monitoring of antibiotics may guide dosing adjustment, maximising antibacterial efficacy and minimising toxicity. The aim of this study was to develop and validate a method for the analysis of 15 antibiotics including beta-lactams, linezolid, fluoroquinolones, daptomycin, and clindamycin to have a complete panel in the management of infections. We proposed to develop a fast, sensitive, and quantitative method for the analysis of 15 antibiotics using ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometer (UPLC-MS/MS) technology. this method required only 100 µL of plasma and consisted of a rapid liquid-liquid deproteinisation using methanol. Calibration curves ranged from 0.078 to 500 mg/L depending on the molecules, and were defined according to a therapeutic range. Inter- and intra-assay precisions values were less than 15%. This work described the development and the full validation of a precise, sensitive and accurate assay using UPLC-MS/MS technology. After validation, this new assay was successfully applied to routine therapeutic drug monitoring.

Uremic encephalopathy

Uremic encephalopathy encompasses a wide range of central nervous system abnormalities associated with poor kidney function occurring with either progressive chronic kidney disease or acute kidney injury. The syndrome is likely caused by retention of uremic solutes, alterations in hormonal metabolism, changes in electrolyte and acid-base homeostasis, as well as changes in vascular reactivity, blood-brain barrier transport, and inflammation. There are no defining clinical, laboratory, or imaging findings, and the diagnosis is often made retrospectively when symptoms improve after dialysis or transplantation. The diagnosis is also made difficult because of the many confounding and overlapping conditions seen in patients with chronic kidney disease and acute kidney injury. Thus, institution of kidney replacement therapy should be considered as a trial to improve symptoms in the right clinical context. Neurological symptoms that do not improve after improvement in clearance should prompt a search for other explanations. Further knowledge linking possible uremic retention solutes with neurological symptoms is needed to better understand this syndrome as well as to develop more tailored treatments that aim to improve cognitive function.

A retrospective study to determine the cefepime-induced neurotoxicity threshold in hospitalized patients

OBJECTIVES

Cefepime-induced neurotoxicity (CIN) has been demonstrated to be associated with cefepime plasma concentrations; however, the toxicity threshold remains unclear. The primary objective of this study was to identify the cefepime plasma trough concentration at which neurotoxicity occurs. Secondary objectives were to determine the incidence of CIN at a large tertiary institution and to identify patient factors associated with the development of CIN.

METHODS

A retrospective review of all adult patients administered cefepime between October 2017 and May 2018 in a tertiary hospital was conducted to determine total incidence of CIN. A receiver operating characteristic (ROC) curve was constructed to review the sensitivity and specificity of using various cefepime trough plasma concentrations to predict the development of neurotoxicity. Cefepime plasma concentrations were measured using ultra-HPLC. A regression was conducted to identify patient factors associated with CIN.

RESULTS

In total, 206 patients were administered 259 courses of cefepime, with an overall CIN incidence of 6% (16/259 courses). A total of 64 courses had a cefepime trough concentration measured (24.7%). A cefepime trough concentration of 36 mg/L provided the best differentiation between patients who experienced neurotoxicity and those who did not. No other patient covariates were identified to be significantly associated with neurotoxicity occurring.

CONCLUSIONS

A cefepime trough plasma concentration ≥36 mg/L appears to be the most sensitive and specific cut-off to predict CIN occurring. No patient factors were associated with the development of CIN when accounting for cefepime trough plasma concentrations.

Prolonged Infusion of β-Lactams Decreases Mortality in Patients with Septic Shock: A Retrospective before-and-after Study

Septic shock substantially alters the pharmacokinetic properties of β-lactams with a subsequently high risk of insufficiently low serum concentrations and treatment failure. Considering their pharmacokinetic (PK)/pharmacodynamic (PD) index, prolonged infusions (PI) of β-lactams extend the time that the unbound fraction of the drug remains above the minimal inhibitory concentration MIC (ft _>MIC) and may improve patient survival. The present study is a monocentric, retrospective before-and-after analysis of septic shock patients treated with β-lactams. Patients of the years 2015–2017 received intermittent bolus application whereas patients of 2017–2020 received PI of β-lactams. The primary outcome was mortality at day 30 and 90 after diagnosis of septic shock. Mortality rates in the PI group were significantly lower on day 30 (PI: 41%, n = 119/290 vs. IB: 54.8%, n = 68/114; p = 0.0097) and day 90 (PI: 47.9%, n = 139/290 vs. IB: 62.9%, n = 78/124; p = 0.005). After propensity-score matching, 30- and 90-day mortality remained lower for the PI group (−10%, p = 0.14). PI was further associated with a reduction in the duration of invasive ventilation and a stronger decrease in SOFA scores within a 14 day-observation period. PI of β-lactams was associated with a significant reduction of mortality in patients with septic shock and may have beneficial effects on invasive ventilation and recovery from sepsis-related organ failure.

A Case of Cefepime-Induced Neurotoxicity: Renal Function Missing in Action

Cefepime is a renally excreted, fourth-generation cephalosporin used in the treatment of severe abdominal, skin, soft tissue, and urinary tract infections due to its broad-spectrum coverage. Cefepime-induced neurotoxicity is a rare but serious side effect that has increased in recent years likely due to increased antibiotic use, increased drug resistance, and increased symptom recognition. While decreased glomerular filtration rate is an important risk factor for developing elevated serum cefepime levels, recent literature has suggested that a significant proportion of patients with normal renal function can also develop neurotoxicity from cefepime. Here, we present a case of cefepime-induced neurotoxicity to demonstrate the importance of monitoring mental status changes in all patients being treated with cefepime.

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.

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.

Pyridine levels in ceftazidime - peritoneal dialysis admixtures stored at body temperature

BACKGROUND

For the treatment of peritoneal dialysis-associated peritonitis (PDAP), ceftazidime is routinely admixed with peritoneal dialysis (PD) solutions before its intraperitoneal administration. One of the major degradation products of ceftazidime is pyridine, a potentially toxic compound. Depending on the type of PD solution, ceftazidime is exposed to an environment with acidic or basic pH, and depending on the type of dosing and individual unit practices related to preparation and storage, ceftazidime can be at body temperature for 4-10 h, resulting in potentially varying rates of degradation to pyridine by-product. No study has investigated whether the amount of generated pyridine exceeds the maximum daily exposure limit of 2 mg when ceftazidime-PD admixtures are kept at body temperature. Therefore, the current study aimed to determine the levels of pyridine generated in PD-ceftazidime admixtures kept at 37°C for various time points.

METHODS

Ceftazidime was admixed with 2 L Dianeal (1.5%, 2.5% and 4.25% dextrose) and 2 L Physioneal (1.36%, 2.27% and 3.86% glucose) PD solutions to obtain a concentration of 125 mg/L (continuous dosing model) or 500 mg/L (intermittent dosing model). A total of 36 PD admixtures (3 bags for each type of PD solution and 3 bags for each type of dosing) were prepared and stored at 37°C for 10 h. An aliquot was withdrawn at time 0 (baseline) and after 2, 6, 8 and 10 h of storage. The withdrawn samples were then analysed to determine the concentrations of ceftazidime and pyridine using high-performance liquid chromatography.

RESULTS

With the intermittent dosing model (500 mg/L), ceftazidime was found to be stable for only 2 and 6 h when admixed with 3.86% and 2.27% glucose Physioneal PD solutions, respectively. While ceftazidime (500 mg/L) retained more than 90% of its initial concentration in the three types of Dianeal and 1.36% dextrose Physioneal solutions for 10 and 8 h, respectively, the generated amount of pyridine ranged between approximately 290% and 371% more than the daily recommended limit. With the continuous dosing model (125 mg/L), ceftazidime was found to be stable for 6 h in all three types of Physioneal PD solutions, but the total amount of generated pyridine with four daily exchanges (6 h each) was estimated to be 170-360% over the daily recommended limit. Ceftazidime (125 mg/L) was chemically stable when admixed with three types of Dianeal PD solutions and stored at 37°C for 10 h, and the levels of pyridine were estimated to be less than the maximum recommended daily limit.

CONCLUSIONS

Until the outcomes of this in vitro study are confirmed by appropriate in vivo studies, continuous dosing of ceftzadime-Dianeal admixtures for the treatment of PDAP may be preferred over continuous dosing of ceftazidime-Physioneal admixtures, and intermittent dosing of ceftazidime-Physioneal and ceftazidime-Dianeal admixtures, as ceftazidime remains stable and the generated levels of pyridine are below the maximum recommended daily exposure.

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.

Intraperitoneal Cefepime Monotherapy Versus Combination Therapy of Cefazolin Plus Ceftazidime for Empirical Treatment of CAPD-Associated Peritonitis: A Multicenter, Open-Label, Noninferiority, Randomized, Controlled Trial

RATIONALE & OBJECTIVE

Compared to combination therapy, intraperitoneal (IP) cefepime monotherapy for continuous ambulatory peritoneal dialysis (CAPD)-associated peritonitis may provide potential benefits in lowering staff burden, shortening time-consuming antibiotic preparation, and reducing bag contamination risk. This study sought to evaluate whether cefepime monotherapy is noninferior to combination regimens.

STUDY DESIGN

Multicenter, open-label, noninferiority, randomized, controlled trial.

SETTING & PARTICIPANTS

Adult incident peritoneal dialysis (PD) patients with CAPD-associated peritonitis in 8 PD centers in Thailand.

INTERVENTIONS

Random assignment to either IP monotherapy of cefepime, 1g/d, or IP combination of cefazolin and ceftazidime, 1g/d, both given as continuous dosing.

OUTCOMES

Primary end point: resolution of peritonitis at day 10 (primary treatment response).

SECONDARY OUTCOMES

initial response (day 5), complete cure (relapse/recurrence-free response 28 days after treatment completion), relapsing/recurrent peritonitis, and death from any cause. Noninferiority would be confirmed for the primary outcome if the lower margin of the 1-sided 95% CI was not less than-10% for difference in the primary response rate. A 2-sided 90% CI was used to demonstrate the upper or lower border of the 1-sided 95% CI.

RESULTS

There were 144 eligible patients with CAPD-associated peritonitis, of whom 70 and 74 patients were in the monotherapy and combination-therapy groups, respectively. Baseline demographic and clinical characteristics were not different between the groups. The primary response was 82.6% in the monotherapy group and 81.1% in the combination-therapy group (treatment difference, 1.5%; 90% CI, -9.1% to 12.1%; P=0.04). There was no significant difference in the monotherapy group compared with the combination-therapy group in terms of initial response rate (65.7% vs 60.8%; treatment difference, 4.9%; 95% CI, -10.8% to 20.6%; P=0.5) and complete cure rate (80.0% vs 80.6%; treatment difference, -0.6%; 95% CI, -13.9% to 12.8%; P=0.7). Relapsing and recurrent peritonitis occurred in 4.6% and 4.6% of the monotherapy group and 4.2% and 5.6% of the combination-therapy group (P=0.9and P=0.8, respectively). There was nominally higher all-cause mortality in the monotherapy group (7.1% vs 2.7%; treatment difference, 4.4%; 95% CI, -2.6% to 11.5%), but this difference was not statistically significant (P = 0.2).

LIMITATION

Not double blind.

CONCLUSIONS

IP cefepime monotherapy was noninferior to conventional combination therapy for resolution of CAPD-associated peritonitis at day 10 and may be a reasonable alternative first-line treatment.

FUNDING

This study is supported by The Kidney Foundation of Thailand (R5879), Thailand; Rachadaphiseksompotch Fund (RA56/006) and Rachadaphicseksompotch Endorsement Fund (CU-GRS_61_06_30_01), Chulalongkorn University, Thailand; National Research Council of Thailand (156/2560), Thailand; and Thailand Research Foundation (IRG5780017), Thailand.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov with study number NCT02872038.

Uremic encephalopathy in patients undergoing assisted peritoneal dialysis: a case series and literature review

We sometimes hesitate to switch renal replacement therapy from peritoneal dialysis (PD) particularly in elderly patients due to their physical tolerance levels and lifestyles. Here, we describe the cases of three patients treated with PD alone despite an anuric status who subsequently developed uremic encephalopathy, which was successfully treated with hemodialysis (HD). The first patient was a 75-year-old woman who developed uremic encephalopathy with an anuric status and inadequate PD after 7 months of treatment. HD immediately improved her condition; encephalopathy did not recur with combined therapy of PD and HD. The second patient was a 69-year-old woman who developed anuria and was treated with combined therapy. Her arteriovenous fistula was obstructed; therefore, she was treated with PD alone. Total weekly Kt/V was sufficiently high at 1.95; however, she developed uremic encephalopathy the following month, which was successfully treated with HD. The third patient was an 84-year-old woman who developed anuria, but was treated with PD alone with adequate total weekly Kt/V of 2.2. PD could not be performed for 2 days because of myocardial infarction intervention; subsequently, she developed uremic encephalopathy, which was successfully treated with HD. These cases are the first of their kinds, wherein patients undergoing PD, developed uremic encephalopathy without any obvious triggers, including drugs, and illustrate the necessity of initiating combined therapy for such patients considering the risk of developing severe uremia leading to uremic encephalopathy, in spite of it being less preferable for elderly patients due to their physical conditions and lifestyles.

Delirium induced by levofloxacin

Delirium is the most frequent complication of hospitalization for elders and a potentially devastating problem. It is accompanied by high morbidity and mortality rate, and despite sensitive methods for its detection, delirium often is unrecognized and is missed by clinicians in up to 70% of delirious patients. Medications are considered one of the most common causes of delirium with sedatives, narcotics, dihydroperidines, antihistamines, and anticholinergics are most often implicated in its causation. Antibiotic-induced delirium has been infrequently reported where cephalosporins and macrolides are implicated in the majority of cases published. Delirium associated with fluoroquinolones has rarely been reported, and to the best of our knowledge only eight cases of levofloxacin-induced delirium have been described until yet in the medical literature, two of which from our medical ward. We describe another case of delirium associated with levofloxacin treatment in an elderly patient who was hospitalized in our medical ward for acute bronchitis. Description of three cases of levofloxacin-induced delirium from one medical ward (ours) and the other six from the rest of the world reflects the extreme under-recognition and under-diagnosis of drug-induced delirium generally, and levofloxacin-induced delirium specifically by physicians world-wide. It also seems likely that this severe and potentially fetal adverse effect of levofloxacin is much more common than previously reported. The present case and the other previously reported emphasize the urgent need of much more awareness by physicians to the occurrence of this serious but preventable and potentially reversible CNS complication of levofloxacin.

Serious central nervous system side effects of cephalosporins: A national analysis of serious reports registered in the French Pharmacovigilance Database

INTRODUCTION

Among antibiotics, Central Nervous System (CNS) adverse drug reactions (ADRs) are often under-suspected and overlooked. Cephalosporins are an important cause of drug-induced CNS ADRs but the characteristics of such ADR have not been fully explored. We aimed to characterize the profile of cephalosporins serious CNS ADRs.

METHOD

We performed an analysis of serious reports recorded in the French Pharmacovigilance database from 1987 to 2017.

RESULTS

A total of 511 serious ADRs reports was analyzed. Patients had a mean age of 67.1 years and were mainly men (52.5%), with a mean creatinine clearance of 32.9 ml/min. The most involved molecules were cefepime (33.1%), ceftriaxone (29.7%), ceftazidime (19.6%), cefotaxime (9%) and cefazoline (2.9%), mostly administered intravenously (87.3%). A CNS history was observed in 25% of the reports (n = 128). Patients exhibited encephalopathy (30.3%), confusional state (19.4%), convulsion (15.1%), myoclonia (9.4%), status epilepticus (9.2%), coma (6.3%) and hallucination (4.3%). The mean time of onset was 7.7 days and the mean duration was 6 days. Cephalosporin plasma levels were recorded for 153 patients (29.9%) and 107 were above the standards including 62 (57.9%) related to renal impairment. Electroencephalograms were performed in 38.2% (n = 195) of the patients and 81% (n = 158) were abnormal.

CONCLUSION

This study characterizes an off-target CNS ADRs of several cephalosporins. Ceftriaxone represented a large part of our reports after cefepime and it would be relevant to warn healthcare professionals. Investigations (EEG, though plasma levels and renal function) can be precious tools for clinicians to make a prompt diagnosis and improve patients' outcomes.

Cefepime-induced encephalopathy: Neural mass modeling of triphasic wave-like generalized periodic discharges with a high negative component (Tri-HNC)

AIM

Cefepime, a fourth-generation cephalosporin, acts as a GABA_A receptor antagonist. Cefepime-induced encephalopathy (CIE) is frequently overlooked. We aimed to clarify the clinical features, characteristic electroencephalography (EEG), and mechanisms of CIE to aid in its early recognition.

METHODS

CIE cases documented by a single-center consultation-liaison team between April 2015 and March 2017 were retrospectively reviewed. For further investigation, neural mass modeling was performed in silico.

RESULTS

Three patients with CIE refused medication/examination and showed overt pain, palilalia, and much greater deterioration of eye and verbal response than the motor response, which was possibly related to GABAergic dysfunction. Triphasic wave-like generalized periodic discharges with a high negative component (Tri-HNC) were identified on the EEG of all three cases. The simulation reproduced the characteristic feature of 2-3 Hz Tri-HNC and recovery course on EEG, and a possible involvement of individual differences in pharmacological intervention. It also suggested that auto-inhibition (synaptic inputs from interneuron to interneuron) dysregulation contributed to generating Tri-HNC in CIE.

CONCLUSION

As CIE is iatrogenic and continues unless cefepime is stopped, early recognition is crucial. Physicians should be vigilant about altered mental status, pain, and verbal changes in patients taking cefepime. Tri-HNC on EEG can expedite the diagnosis of CIE, and the association between Tri-HNC and CIE suggests that an excitatory and inhibitory imbalance due to the dysfunction of GABAergic interneurons is the underlying mechanism. This modeling may offer a new method of investigating disorders related to GABAergic dysfunction.

Acute Delirium Associated With Levofloxacin

Delirium is considered as the most common complication afflicting hospitalized elderly patients, accompanied by high morbidity and mortality rate; and despite its high prevalence, it often remains unrecognized. Drug-induced delirium is a well-known entity with sedatives, narcotics and anticholinergics most often implicated in its causation. Delirium attributed to antibiotics, mainly cephalosporins and macrolids, has been infrequently reported, and until yet only seven cases of levofloxacin-induced delirium have been described in the medical literature. We describe another case of delirium associated with levofloxacin in an elderly patient who was hospitalized in our medical ward for pneumonia. The present case and the other cases previously reported should raise the awareness of physicians to this serious, underestimated, and underdiagnosed adverse effect of a commonly used antibiotic, levofloxacin.

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

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

Too much of a good thing: a retrospective study of β-lactam concentration-toxicity relationships

Objectives

To determine the existence of concentration-toxicity relationships for common β-lactam antibiotic adverse effects and define thresholds above which toxicity is more likely.

Patients and methods

Retrospective review of consecutive patients treated with piperacillin, meropenem or flucloxacillin who underwent therapeutic drug monitoring (TDM) at St Vincent's Hospital (Sydney, Australia) between January 2013 and December 2015. Adverse events investigated included neurotoxicity, nephrotoxicity, hepatotoxicity and opportunistic Clostridium difficile infection. Toxicity was measured using observational grading criteria, clinical assessment and relevant serum biomarkers. These findings were correlated with trough TDM measurements at the time of toxicity presentation.

Results

TDM results from 378 patients (piperacillin = 223, meropenem = 94 and flucloxacillin = 61) were investigated. There was no difference in baseline patient characteristics across antibiotic groups. A statistically significant elevation in mean serum trough concentrations (Cmin) was found in patients diagnosed with neurotoxicity (piperacillin, P < 0.01; meropenem, P = 0.04; flucloxacillin, P = 0.01) and those who developed nephrotoxicity whilst being treated with piperacillin (P < 0.01) or meropenem (P < 0.01). Incidence of hepatotoxicity and C. difficile was not related to Cmin. Threshold concentrations for which there is 50% risk of developing a neurotoxicity event (piperacillin, Cmin >361.4 mg/L; meropenem, Cmin >64.2 mg/L; flucloxacillin, Cmin >125.1 mg/L) or nephrotoxicity (piperacillin, Cmin >452.65 mg/L; meropenem, Cmin >44.45 mg/L) varied across antibiotics.

Conclusions

Our data reveal an association between toxic concentrations for a number of β-lactam agents and neurotoxic/nephrotoxic effects. We have defined threshold concentrations above which these toxicities become more likely. Clinicians should balance concerns for therapeutic efficacy with potential toxicity when considering aggressive therapy.

Myoclonus from Antibiotic Therapy (Ceftazidime-induced Neurotoxicity): A Case Report and Review

A 78-year-old Chinese man with a history of end-stage renal disease (ESRD) presented with fever of one-day duration. He was treated for catheter-related sepsis with intravenous piperacillin and tazobactam, which was later switched to vancomycin and ceftazidime secondary to persistent fever with negative cultures. On the fifth day of treatment with vancomycin and ceftazidime, he developed new-onset upper limb myoclonus which progressed to bilateral upper limb ataxia. A provisional diagnosis of myoclonus and ataxia secondary to neurotoxicity related to ceftazidime was made and the ceftazidime was ceased. His symptoms resolved over three days and he returned to his baseline neurological status by day 5 following cessation.

Cefepime-induced neurotoxicity: a systematic review

BACKGROUND

Cefepime is a widely used antibiotic with neurotoxicity attributed to its ability to cross the blood-brain barrier and exhibit concentration-dependent ϒ-aminobutyric acid (GABA) antagonism. Neurotoxic symptoms include depressed consciousness, encephalopathy, aphasia, myoclonus, seizures, and coma. Data suggest that up to 15% of ICU patients treated with cefepime may experience these adverse effects. Risk factors include renal dysfunction, excessive dosing, preexisting brain injury, and elevated serum cefepime concentrations. We aimed to characterize the clinical course of cefepime neurotoxicity and response to interventions.

METHODS

A librarian-assisted search identified publications describing cefepime-associated neurotoxicity from January 1980 to February 2016 using the CINAHL and MEDLINE databases. Search terms included cefepime, neurotoxicity, encephalopathy, seizures, delirium, coma, non-convulsive status epilepticus, myoclonus, confusion, aphasia, agitation, and death. Two reviewers independently assessed identified articles for eligibility and used the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) for data reporting.

RESULTS

Of the 123 citations identified, 37 (representing 135 patient cases) were included. Patients had a median age of 69 years, commonly had renal dysfunction (80%) and required intensive care (81% of patients with a reported location). All patients exhibited altered mental status, with reduced consciousness (47%), myoclonus (42%), and confusion (42%) being the most common symptoms. All 98 patients (73% of cohort) with electroencephalography had abnormalities, including non-convulsive status epilepticus (25%), myoclonic status epilepticus (7%), triphasic waves (40%), and focal sharp waves (39%). As per Food and Drug Administration (FDA)-approved dosing guidance, 48% of patients were overdosed; however, 26% experienced neurotoxicity despite appropriate dosing. Median cefepime serum and cerebrospinal fluid (CSF) concentrations were 45 mg/L (n = 21) and 13 mg/L (n = 4), respectively. Symptom improvement occurred in 89% of patients, and 87% survived to hospital discharge. The median delay from starting the drug to symptom onset was 4 days, and resolution occurred a median of 2 days after the intervention, which included cefepime discontinuation, antiepileptic administration, or hemodialysis.

CONCLUSIONS

Cefepime-induced neurotoxicity is challenging to recognize in the critically ill due to widely varying symptoms that are common in ICU patients. This adverse reaction can occur despite appropriate dosing, usually resolves with drug interruption, but may require additional interventions such as antiepileptic drug administration or dialysis.

Cefepime induced neurotoxicity: A case series and review of the literature

Cefepime is a fourth generation cephalosporin which is bactericidal for broad spectrum of organisms. This is a case-series of three patients who presented to our hospital with confusion secondary to cefepime use to treat urinary tract infection (UTI) and health care associated pneumonia (HCAP), after excluding other common etiologies of altered mental status (AMS). Of these three patients, one had progressive expressive aphasia and the other two demonstrated asynchronous myoclonic activity of the limbs. The symptoms were seen within four to five days of initiating the treatment and resolved within three days of discontinuation of cefepime. Acute structural abnormalities were excluded by computed tomography (CT) and magnetic resonance imaging (MRI) of the brain. Electroencephalogram (EEG) showed diffuse slowing activity with triphasic waves consistent with encephalopathy. In one patient, renal function was within normal limits, whereas it was abnormal in two patients. To our knowledge, this is the first report of cefepime induced asynchronous myoclonus and expressive aphasia in a patient with normal kidney function.

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Recognizing cefepime neurotoxicity could be challenging in acute care settings.

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Caution is recommended in patients with renal and hepatic impairments.

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Patients may present with expressive aphasia and/or myoclonus even with normal kidney function.

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Fortunately in most cases, neurotoxicity is reversible upon discontinuation of cefepime.

Cefepime-Induced Neurotoxicity Despite Dose Adjustment for Renal Disease: A Brief Report and Review of the Literature

Cefepime is increasingly used as empiric treatment for fever in the setting of neutropenia. We present a patient with acute-on-chronic renal disease who received cefepime at the appropriate dose for his glomerular filtration rate but developed cefepime-associated encephalopathy. Here, we review neurologic toxicities of cefepime and present suggestions for work-up and management.

Prognosis of neurologic complications in critical illness

Neurologic complications of critical illness require extensive clinical and neurophysiologic evaluation to establish a reliable prognosis. Many sequelae of intensive care unit (ICU) treatment, such as delirium and ICU-acquired weakness, although highly associated with adverse outcomes, are less suitable for prognostication, but should rather prompt clinicians to seek previously unnoticed persisting underlying illnesses. Prognostication can be confounded by drug administration particularly because its clearance is abnormal in critical illness. Some neurological complications are severe, and can last for months or years after discharge from ICU. The most important ethical aspects regarding neurologic complications in critically ill patients are prevention, recognition, and identification, and prevention of self-fulfilling prophecies. This chapter summarizes the tool of prognostication of major neurological complications of critical illness.

Cefepime-induced encephalopathy in end-stage renal disease patients

OBJECTIVES

Impaired renal function is a risk factor for cefepime (CFPM)-induced encephalopathy (CFPMIE) in patients treated with CFPM; dose-titration to renal function is recommended to prevent CFPMIE. However, available evidence on the incidence of CFPMIE or preventive efficacy of dose adjustment against CFPMIE in end-stage renal disease (ESRD) patients is limited.

METHODS

Single-centre, retrospective observational study. We reviewed consecutive in-hospital adult patients treated with adjusted-dose of CFPM in the period between September 2012 and September 2016, and assessed the CFPMIE in ESRD patients treated with adjusted-dose of CFPM.

RESULTS

Out of 422 eligible patients, 6 patients (1.4%) were diagnosed with CFPMIE. The incidence of CFPMIE in ESRD patients was 7.5% (5/67). Among ESRD patients, pre-existing central nervous system (CNS) morbidity was significantly associated with the risk of CFPMIE. CFPMIE occurred in ESRD patients regardless of daily dose, and even with 0.5g/day of CFPM.

CONCLUSIONS

Pre-existing CNS morbidity may be associated with an increased risk of CFPMIE in ESRD patients. No significant association was observed between CFPM dose and incidence of CFPMIE in ESRD patients, and future investigation on the safer dose-adjustment strategy in ESRD patients is required for achieving balance between successful infectious treatment and reducing CFPMIE.

Lesson of the month 2: An easily missed cause of confusion

We describe the case of an 85-year-old woman who developed acute confusion, acute kidney injury and temperature spikes while on extended courses of beta-lactams for osteomyelitis. The cause of her deterioration was felt to be due to sepsis when in fact it was as a result of toxicity from antibiotics. This was demonstrated by a rapid resolution in her condition following haemodialysis. We also performed a literature review to appraise the neuro and nephrotoxicity of various antibiotics and how best to manage toxicity when it occurs.

Peritoneal Dialysis-Related Infection in the Older Population

With appropriate training and adequate support, it is possible to keep the peritonitis rate of elderly peritoneal dialysis (PD) patients at a highly respectable level. In general, the latest recommendations for the treatment and prevention of PD-related infections by the International Society for Peritoneal Dialysis (ISPD) are applicable to older patients. However, there are minor differences in the spectrum of causative organisms amongst elderly patients, with coagulase-negative staphylococcal species (CNSS) and Enterobacteriaceae species being more common in elderly patients. Elderly PD patients who develop peritonitis have an excessive short-term mortality, and, amongst elderly patients, a high burden of comorbid load increases the risk of relapsing episodes. In addition, technical problems, social difficulties, and concomitant comorbid diseases often have profound effects on the risk of peritonitis as well as its management.

Complicated Intra-Abdominal Infections: The Old Antimicrobials and the New Players

Complicated intra-abdominal infections (cIAIs) are an important cause of morbidity and mortality worldwide. They are diagnosed when the initial abdominal organ infection has spread into the peritoneal space. Successful treatment relies on adequate source control and appropriate empiric antimicrobial therapy. Inappropriate antimicrobial therapy may result in poor patient outcomes and increases in healthcare costs. Current guidelines recommend several single and combination antimicrobial regimens; however, empiric antimicrobial treatment has been complicated by the increasing rates of resistant organisms, especially the extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. Additionally, the overuse of carbapenems to combat these resistant pathogens has contributed to the rise of carbapenemase-producing microorganisms, especially Klebsiella pneumoniae. This increasing resistance has prompted the development of novel antimicrobials like ceftazidime-avibactam and ceftolozane-tazobactam, whose activity extends to ESBL-producing microorganisms. Furthermore, the optimal duration of antimicrobial therapy is still unknown, and further research is necessary to find a definitive answer. This review will focus on antimicrobial therapies recommended by the current guidelines, the individual properties of these agents, appropriate duration of therapy, recent clinical trials, and place in therapy of the antimicrobial agents recently approved for the treatment of cIAIs.

The β-Lactams Strike Back: Ceftazidime-Avibactam

Gram-negative resistance has reached a crucial point, with emergence of pathogens resistant to most or all available antibiotics. Ceftazidime-avibactam is a newly approved agent combining ceftazidime and a novel β-lactamase inhibitor with activity against multidrug-resistant gram-negative bacteria. Avibactam has increased potency and expanded spectrum of inhibition of class A and C β-lactamases relative to available β-lactamase inhibitors, including extended-spectrum β-lactamases, AmpC, and Klebsiella pneumoniae carbapenemase (KPC) enzymes. Avibactam expands ceftazidime's spectrum of activity to include many ceftazidime- and carbapenem-resistant Enterobacteriaceae and Pseudomonas aeruginosa. Early clinical data indicate that ceftazidime-avibactam is effective and well tolerated in patients with complicated urinary tract infections (cUTIs) and complicated intraabdominal infections (cIAI). In a phase II trial of patients with cUTIs, ceftazidime-avibactam produced similar rates of clinical and microbiologic success compared with imipenem-cilastatin (70.5% and 71.4% microbiologic success rates, respectively). Likewise, patients receiving ceftazidime-avibactam plus metronidazole in a phase II study of patients with cIAI had similar response rates to those receiving meropenem (91.2% and 93.4% clinical success rates, respectively). Based on available in vitro, in vivo, and phase II trial data, as well as preliminary phase III trial results in ceftazidime-resistant, gram-negative cUTI and cIAI, ceftazidime-avibactam received U.S. Food and Drug Administration approval for treatment of cUTI, including pyelonephritis, and cIAI, in combination with metronidazole, in adult patients with limited or no alternative treatment options. The approved dosage, ceftazidime 2 g-avibactam 0.5 g administered as a 2-hour infusion every 8 hours, was selected based on pharmacodynamic analysis and available clinical data. This dosage is under further investigation in patients with cUTI, cIAI, and nosocomial or ventilator-associated pneumonia. The current body of evidence suggests that ceftazidime-avibactam is a promising addition to our therapeutic armamentarium with potential to answer an urgent unmet medical need. Further data in highly resistant gram-negative infections, particularly those caused by KPC-producing Enterobacteriaceae, are needed. As it is introduced into clinical use, careful stewardship and rational use are essential to preserve ceftazidime-avibactam's potential utility.

Convulsions following rapid ceftazidime administration for preinduction antibiotic prophylaxis during neurosurgical procedure

Ceftazidime is a widely used antibiotic with broad spectrum activity against Gram-positive and Gram-negative microbes and is used prophylactically in neurosurgical patients prior to surgery. Neurotoxicity is a recognized complication of ceftazidime use but is reported predominantly after repeated administration in patients with impaired renal status. We encountered a patient with an intracranial tumor who developed generalized convulsions following a single dose of ceftazidime, which was infused rapidly and attempt to provide an explanation of this uncommon occurrence.

Post-hemodialysis dosing of 1 vs. 2 g of ceftazidime in anuric end-stage renal disease patients on low-flux dialysis and its pharmacodynamic implications on clinical use

Ceftazidime is a cost-effective antimicrobial against Gram-negative pathogens associated with sepsis in end-stage renal disease (ESRD) hemodialysis patients with potential for wider use with the advent of ceftazidime-avibactam. Dosing ceftazidime post-hemodialysis appears attractive and convenient, but limited in vivo data on pharmacodynamic efficacy (PE) attainment, defined as >70% of the interdialytic period drug concentrations exceed susceptible pathogens minimal inhibitory concentrations (MICs) (%TMIC), warrants further assessment. We therefore evaluated PE and tolerability of 1 against 2 g regime in anuric ESRD patients on low-flux hemodialysis. Two doses of 1 or 2 g ceftazidime were administered post-hemodialysis prior to 48- and 72-hour interdialytic intervals in ESRD inpatients without active infections. Peak and trough concentrations (mg/L) were assayed using a validated liquid chromatography-tandem mass spectrometry method. Proportion of patients achieving PE for known pathogens with MICs ≤ 8 mg/L and adverse effects were assessed. Six (43%) and eight (57%) adult patients received 1 and 2 g dose, respectively. Median (25th-75th percentile), peak, 48- and 72-hour trough ceftazidime concentrations were 78 (60-98) vs. 158 (128-196), 37 (23-37) vs. 49 (39-71), and 13 (12-20) vs. 26 (21-41) mg/L, respectively, resulting in 100% TMIC for both doses. One patient on the 1-g dose experienced mild pruritus. Reliable and safe PE attainment over both 48- and 72-hour interdialytic interval was achievable with 1 g of ceftazidime dosed post-hemodialysis. The 2 g dose was equally effective and well tolerated but may not be necessary. These findings need validation in non-anuric patients, high-flux hemodialysis, and during avibactam co-administration.

Probable Nonconvulsive Status Epilepticus With the Use of High-Dose Continuous Infusion Ceftazidime

Multidrug resistant (MDR) bacterial infections are a major concern of health care providers due to their increasing incidence and associated mortality. In some cases, few or no antibiotics have preserved activity. Beta-lactam administration via continuous infusion can optimize time over minimum inhibitory concentration (MIC). In some cases, use of high-dose continuous infusion (HDCI) may be necessary to achieve serum levels in excess of nonsusceptible MIC values. The use of HDCI beta-lactams is not without risk, specifically neurotoxic adverse effects, which appear dose related. We describe a 64-year-old male who experienced myoclonus and nonconvulsive status epilepticus while receiving HDCI ceftazidime for treatment of multidrug resistant Pseudomonas aeruginosa bacteremia. This report serves as a cautionary example of the potential toxicities associated with HDCI beta-lactams and supports the importance of risk-benefit analysis prior to and during treatment. Additionally, the use of serum drug level monitoring may be necessary to better prevent or predict toxicity.

Cefepime and Ceftazidime Safety in Hospitalized Infants

BACKGROUND

Cefepime and ceftazidime are cephalosporins used for the treatment of serious Gram-negative infections. These cephalosporins are used off-label in the setting of minimal safety data for young infants.

METHODS

We identified all infants discharged from 348 neonatal intensive care units managed by the Pediatrix Medical Group between 1997 and 2012 who were exposed to either cefepime or ceftazidime in the first 120 days of life. We reported clinical and laboratory adverse events occurring in infants exposed to cefepime or ceftazidime and used multivariable logistic regression to compare the odds of seizures and death between the 2 groups.

RESULTS

A total of 1761 infants received 13,293 days of ceftazidime, and 594 infants received 4628 days of cefepime. Laboratory adverse events occurred more frequently on days of therapy with ceftazidime than with cefepime (373 vs. 341 per 1000 infant days, P < 0.001). Seizure was the most commonly observed clinical adverse event, occurring in 3% of ceftazidime-treated infants and 4% of cefepime-treated infants (P = 0.52). Mortality was similar between the ceftazidime and cefepime groups (5% vs. 3%, P = 0.07). There was no difference in the adjusted odds of seizure [odds ratio (OR) = 0.96 (95% confidence interval: 0.89-1.03)] or the combined outcome of mortality or seizures [OR = 1.00 (0.96-1.04)] in infants exposed to ceftazidime versus those exposed to cefepime.

CONCLUSIONS

In this cohort of infants, cefepime was associated with fewer laboratory adverse events than ceftazidime, although this may have been due to a significant difference in clinical exposures and severity of illness between the 2 groups. There was no difference in seizure risk or mortality between the 2 drugs.

Cefepime induced acute interstitial nephritis--a case report

Background

Nephrotoxicity due to drugs especially beta lactams and cephalosporins has been well recognised. Cefepime is a fourth-generation cephalosporin that is widely prescribed with few severe adverse reactions reported. Although cefepime induced neurotoxicity has frequently been reported, there is yet no reported case of acute interstitial nephritis caused by this drug. We report a biopsy proven case of acute kidney injury due to acute interstitial nephritis associated with use of cefepime for treatment of mastoiditis and temporal bone osteomyelitis.

Case presentation

A 62-year-old Caucasian female presented with symptoms of right sided mastoiditis. A brain Magnetic Resonance Imaging scan revealed presence of right sided mastoiditis with concurrent temporal bone osteomyelitis. Microbiological specimen isolated an Escherichia coli. Therapy was commenced with intravenous cefepime. After 4 weeks of therapy with intravenous cefepime she developed acute kidney injury. No other medications were taken by the patient. Urine analysis revealed non-nephrotic range proteinuria. There was no red cell casts or white cell casts. Renal biopsy confirmed acute interstitial nephritis as cause of acute kidney injury. Cefepime therapy was ceased and treatment with ciprofloxacin was given to complete the treatment course. Renal function improved only partially with conservative management without any corticosteroid use. To our knowledge this is the first report of cefepime induced interstitial nephritis.

Conclusions

Although cefepime has been considered to be a safe antibiotic from nephrotoxicity point, like other cephalosporins this adverse effect can occur rarely. Physicians need to be mindful of nephrotoxicity associated with its use and careful monitoring of renal parameters should be performed in patients on prolonged therapy with cefepime.