Cefepime-induced neurotoxicity: a systematic review

Challenges of antimicrobial stewardship among older adults

Older adults hospitalized in internal medicine wards or long-term care facilities (LTCF) are progressively increasing. Older adults with multimorbidity are more susceptible to infections, as well as to more vulnerable to adverse effects (and interactions) of antibiotics, resulting in a need for effective and safer strategies for antimicrobial stewardship (ASM), both in hospitalization wards and long-term care facilities. Studies on antimicrobial stewardship in older patients are scarce and guidelines are required. Given the peculiarities of the optimization of antimicrobial prescription in individual older adults for common infections, tactics to overcome barriers need an update. The use of rapid diagnosis tests, biomarkers, de-escalation and switching from intravenous to oral/subcutaneous therapy strategies are examples of successful AMS interventions. AMS interventions are associated with reduced side effects, lower mortality, shorter hospital stays, and reduced costs. The proposed AMS framework in LTCF should focus on five domains: strategic vision, team, interventions, patient-centred care and awareness. Internists can partner with geriatrists, pharmacists and infectious disease specialists to address barriers and to improve patient care.

Cystatin C Outperforms Creatinine in Predicting Cefepime Clearance in Pediatric Stem Cell Transplant Recipients

Pediatric hematopoietic stem cell transplant (HSCT) patients are at risk of developing both sepsis and altered kidney function. Cefepime is used for empiric coverage post-HSCT and requires dose adjustment based on kidney function. Since cefepime's antimicrobial efficacy is determined by the time free concentrations exceed bacterial minimum inhibitory concentration (MIC), it is important to assess kidney function accurately to ensure adequate concentrations. Serum creatinine (SCr) is routinely used to estimate glomerular filtration rate (eGFR) but varies with muscle mass, which can be significantly lower in HSCT patients, making SCr an inaccurate kidney function biomarker. Cystatin C (CysC) eGFR is independent of muscle mass, though steroid use increases CysC. Objectives of this study were to describe how eGFR impacts cefepime pharmacokinetic/pharmacodynamic (PK/PD) target attainment in pediatric HSCT patients, to investigate which method of estimating GFR (SCr, CysC, combined) best predicts cefepime clearance, and to explore additional predictors of cefepime clearance. Patients admitted to the pediatric HSCT unit who received ≥2 cefepime doses were prospectively enrolled. We measured total cefepime peak/trough concentrations between the second and fourth cefepime doses and measured SCr and CysC if not already obtained clinically within 24h of cefepime samples. eGFRs were calculated with Chronic Kidney Disease in Children U25 equations. Bayesian estimates of cefepime clearance were determined with a pediatric cefepime PK model and PK software MwPharm++. Simple linear regression was used to compare cefepime clearance normalized to body surface area (BSA) to BSA-normalized SCr-, CysC-, and SCr-/CysC-eGFRs, while multiple linear regression was used to account for additional predictors of cefepime clearance. For target attainment, we assessed the percentage of time free cefepime concentrations exceeded 1x MIC (%fT>1x MIC) and 4x MIC (%fT>4x MIC) using a susceptibility breakpoint of 8 mg/L for Pseudomonas aeruginosa. We enrolled 53 patients (ages 1 to 30 years, median 8.9 years). SCr- and CysC-eGFRs were lower in patients who attained 100% fT>1xMIC compared to those who did not attain this target: 115 versus 156 mL/min/1.73m2 (p = .01) for SCr-eGFR and 73.5 versus 107 mL/min/1.73m2 (p < .001) for CysC-eGFR. SCr-eGFR was weakly positively correlated with cefepime clearance (adjusted [a]r2= 0.14), while CysC-eGFR and SCr-/CysC-eGFR had stronger positive correlations (ar2 = 0.30 CysC, ar2 = 0.28 combo. There was a weak, significant linear association between increasing CysC-eGFR and decreased %fT>1xMIC (ar2 = 0.32) and %fT>4xMIC (ar2 = 0.14). No patients with a CysC-eGFR >120 mL/min/1.73 m2 achieved 100% fT>1xMIC or 50% fT>4x MIC. In multiple regression models, underlying diagnosis of hemoglobinopathy (in all models) and being pretransplant (in SCr and combined models) were associated with increased cefepime clearance, while concomitant use of calcineurin inhibitors was associated with decreased cefepime clearance in all models. Overall, the combo-eGFR model with timing pretransplant, hemoglobinopathy, and use of calcineurin inhibitors had the best performance (ar2 = 0.63). CysC-based eGFRs (CysC alone and combined) predicted cefepime clearance better than SCr-eGFR, even after considering steroid use. Increasing CysC eGFR correlated with decreased probability of PD target attainment, raising concerns for underdosing at high eGFRs. CysC should be included when estimating kidney function to provide adequate dosing of cefepime in pediatric HSCT patients.

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.

Drug- and Toxin-Induced Opsoclonus - a Systematized Review, including a Case Report on Amantadine-Induced Opsoclonus in Multiple System Atrophy

Background

Opsoclonus is a rare disorder characterized by conjugate multidirectional, horizontal, vertical, and torsional saccadic oscillations, without intersaccadic interval, resulting from dysfunction within complex neuronal pathways in the brainstem and cerebellum. While most cases of opsoclonus are associated with autoimmune or paraneoplastic disorders, infectious agents, trauma, or remain idiopathic, opsoclonus can also be caused by medications affecting neurotransmission. This review was prompted by a case of opsoclonus occurring in a patient with Multiple System Atrophy, where amantadine, an NMDA-receptor antagonist, appeared to induce opsoclonus.

Methods

Case report of a single patient and systematized review of toxic/drug-induced opsoclonus, selecting articles based on predefined criteria and assessing the quality of included studies.

Results

The review included 30 articles encompassing 158 cases of toxic/drug-induced opsoclonus. 74% of cases were attributed to bark scorpion poisoning, followed by 9% of cases associated with chlordecone intoxication. The remaining cases were due to various toxics/drugs, highlighting the involvement of various neurotransmitters, including acetylcholine, glutamate, GABA, dopamine, glycine, and sodium channels, in the development of opsoclonus.

Conclusion

Toxic/drug-induced opsoclonus is very rare. The diversity of toxics/drugs impacting different neurotransmitter systems makes it challenging to define a unifying mechanism, given the intricate neuronal pathways underlying eye movement physiology and opsoclonus pathophysiology.

Enterobacterales carrying chromosomal AmpC β-lactamases in Europe (EuESCPM): Epidemiology and antimicrobial resistance burden from a cohort of 27 hospitals, 2020-2022

INTRODUCTION

The ESCPM group (Enterobacter species including Klebsiella aerogenes - formerly Enterobacter aerogenes, Serratia species, Citrobacter freundii complex, Providencia species and Morganella morganii) has not yet been incorporated into systematic surveillance programs.

METHODS

We conducted a multicentre retrospective observational study analysing all ESCPM strains isolated from blood cultures in 27 European hospitals over a 3-year period (2020-2022). Diagnostic approach, epidemiology, and antimicrobial susceptibility were investigated.

RESULTS

Our study comprised 6,774 ESCPM isolates. MALDI-TOF coupled to mass spectrometry was the predominant technique for bacterial identification. Susceptibility to new β-lactam/β-lactamase inhibitor combinations and confirmation of AmpC overproduction were routinely tested in 33.3% and 29.6% of the centres, respectively. The most prevalent species were E. cloacae complex (44.8%) and S. marcescens (22.7%). Overall, third-generation cephalosporins (3GC), combined third- and fourth-generation cephalosporins (3GC + 4GC) and carbapenems resistance phenotypes were observed in 15.7%, 4.6%, and 9.5% of the isolates, respectively. AmpC overproduction was the most prevalent resistance mechanism detected (15.8%). Among carbapenemase-producers, carbapenemase type was provided in 44.4% of the isolates, VIM- (22.9%) and OXA-48-enzyme (16%) being the most frequently detected. E. cloacae complex, K. aerogenes and Providencia species exhibited the most notable cumulative antimicrobial resistance profiles, with the former displaying 3GC, combined 3GC + 4GC and carbapenems resistance phenotypes in 15.2%, 7.4%, and 12.8% of the isolates, respectively. K. aerogenes showed the highest rate of both 3GC resistant phenotype (29.8%) and AmpC overproduction (32.1%), while Providencia species those of both carbapenems resistance phenotype (42.7%) and carbapenemase production (29.4%). ESCPM isolates exhibiting both 3GC and combined 3GC + 4GC resistance phenotypes displayed high susceptibility to ceftazidime/avibactam (98.2% and 95.7%, respectively) and colistin (90.3% and 90.7%, respectively). Colistin emerged as the most active drug against ESCPM species (except those intrinsically resistant) displaying both carbapenems resistance phenotype (85.8%) and carbapenemase production (97.8%).

CONCLUSIONS

This study presented a current analysis of ESCPM species epidemiology in Europe, providing insights to inform current antibiotic treatments and guide strategies for antimicrobial stewardship and diagnostics.

Tremor as a Rare Manifestation of Cefepime Neurotoxicity

The antibiotic cefepime is a fourth-generation cephalosporin with extended-spectrum coverage against both gram-positive and negative bacteria. It is commonly used in the inpatient setting to treat community-acquired pneumonia or urinary tract infection and has side effects, including diarrhea, nausea, vomiting, pruritus, headache, and, more rarely, hypersensitivity reactions or neurotoxicity. The current report is about an 88-year-old female patient who was brought to the hospital by her daughter due to an acute change in mental status resulting from a urinary tract infection. The patient received intravenous cefepime and subsequently developed a low-frequency tremor after one day of treatment. Cefepime was discontinued with a resolution of tremor in three days. Though neurotoxicity has been documented as a serious adverse event with cefepime, tremor is not one of the known neurotoxic manifestations. This patient is the first reported to develop a tremor as a neurotoxic side effect from taking cefepime. Healthcare providers should be aware of this potential side effect and may consider discontinuing treatment with cefepime if their patient develops a new tremor within days of initiating treatment.

Cefepime-induced encephalopathy in an older patient with polypharmacy and renal insufficiency: a case report

The world population is rapidly aging. Societal aging poses many challenges for individuals, families, nations, and the global healthcare system. Therefore, geriatric care is a crucial issue that demands our attention. In this case report, we describe a woman in her early 70s with multiple comorbidities, polypharmacy, and renal insufficiency who developed cefepime-induced encephalopathy with moderate to severe cerebral dysfunction during treatment of a urinary tract infection. The patient's consciousness level gradually improved, and no further seizures were observed following the discontinuation of cefepime for several days. This case report underscores the fact that polypharmacy and medication safety are significant concerns that are often overlooked when caring for older patients. The report also highlights the increased susceptibility of older individuals to antibiotic-associated adverse reactions during the management of infectious diseases. Therefore, optimization of antibiotic therapy for older patients is a critical issue that requires thorough investigation and consideration in geriatric care.

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.

Analysis of pharmacokinetic profile and ecotoxicological character of cefepime and its photodegradation products

An important problem is the impact of photodegradation on product toxicity in biological tests, which may be complex and context-dependent. Previous studies have described the pharmacology of cefepime, but the toxicological effects of its photodegradation products remain largely unknown. Therefore, photodegradation studies were undertaken in conditions similar to those occurring in biological systems insilico, in vitro, in vivo and ecotoxicological experiments. The structures of four cefepime photodegradation products were determined by UPLC-MS/MS method. The calculated in silico ADMET profile indicates that carcinogenic potential is expected for compounds CP-1, cefepime, CP-2 and CP-3. The Cell Line Cytomotovity Predictor 2.0 tool was used to predict the cytotoxic effects of cefepime and related compounds in non-transformed and cancer cell lines. The results indicate that possible actions include: non-small cell lung cancer, breast adenocarcinoma, prostate cancer and papillary renal cell carcinoma. OPERA models were used to predict absorption, distribution, metabolism and excretion (ADME) endpoints, and potential bioactivity of CP-2, cefepime and CP-4. The results obtained in silico show that after 96h of exposure, cefepime, CP-1, CP-2, and CP-3 are moderately toxic in the zebrafish model, while CP-4 is highly toxic. On the contrary, cefepime is more toxic to T. platyurus (highly toxic) compared to the zebrafish model, similar to products CP-4, CP-3 and CP-2. In vitro cytotoxicity studies were performed by MTT assay and in vivo acute embryo toxicity studies using Danio rerio embryos and larvae. In vitro showed an increase in the cytotoxicity of products with the longest exposure period i.e. for 8 h. Additionally, at a concentration of 200 μg/mL, statistically significant changes in metabolic activity were observed depending on the irradiation time. In vivo studies conducted with Zebrafish showed that both cefepime and its photodegradation products have only low toxicity. Assessment of potential ecotoxicity included Microbiotests on invertebrates (Thamnotoxkit F and Daphtoxkit F), and luminescence inhibition tests (LumiMara). The observed toxicity of the tested solutions towards both Thamnocephalus platyurus and Daphnia magna indicates that the parent substance (unexposed) has lower toxicity, which increases during irradiation. The acute toxicity (Lumi Mara) of nonirradiated cefepime solution is low for all tested strains (<10%), but mixtures of cefepime and its photoproducts showed growth inhibition against all tested strains (except #6, Photobacterium phoreum). Generally, it can be concluded that after UV-Vis irradiation, the mixture of cefepime phototransformation products shows a significant increase in toxicity.

Status epilepticus: what's new for the intensivist

PURPOSE OF REVIEW

Status epilepticus (SE) is a common neurologic emergency affecting about 36.1/100 000 person-years that frequently requires intensive care unit (ICU) admission. There have been advances in our understanding of epidemiology, pathophysiology, and EEG monitoring of SE, and there have been large-scale treatment trials, discussed in this review.

RECENT FINDINGS

Recent changes in the definitions of SE have helped guide management protocols and we have much better predictors of outcome. Observational studies have confirmed the efficacy of benzodiazepines and large treatment trials indicate that all routinely used second line treatments (i.e., levetiracetam, valproate and fosphenytoin) are equally effective. Better understanding of the pathophysiology has indicated that nonanti-seizure medications aimed at underlying pathological processes should perhaps be considered in the treatment of SE; already immunosuppressant treatments are being more widely used in particular for new onset refractory status epilepticus (NORSE) and Febrile infection-related epilepsy syndrome (FIRES) that sometimes revealed autoimmune or paraneoplastic encephalitis. Growing evidence for ICU EEG monitoring and major advances in automated analysis of the EEG could help intensivist to assess the control of electrographic seizures.

SUMMARY

Research into the morbi-mortality of SE has highlighted the potential devastating effects of this condition, emphasizing the need for rapid and aggressive treatment, with particular attention to cardiorespiratory and neurological complications. Although we now have a good evidence-base for the initial status epilepticus management, the best treatments for the later stages are still unclear and clinical trials of potentially disease-modifying therapies are long overdue.

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.

Dose Individualization of Cefepime for Febrile Neutropenia in Patients With Lymphoma or Multiple Myeloma: Implications for Therapeutic Drug Monitoring

BACKGROUND

Optimal cefepime dosing is a challenge because of its dose-dependent neurotoxicity. This study aimed to determine individualized cefepime dosing for febrile neutropenia in patients with lymphoma or multiple myeloma.

METHODS

This prospective study enrolled 16 patients receiving cefepime at a dose of 2 g every 12 hours. Unbound concentrations were determined at 0.5 hours, 7.2 hours [at the 60% time point of the 12 hours administration interval (C7.2h)], and 11 hours (trough concentration) after the first infusion (rate: 2 g/h). The primary and secondary end points were the predictive performance of the area under the unbound concentration-time curve (AUC unbound ) and the effect of unbound cefepime pharmacokinetic parameters on clinical response, respectively.

RESULTS

The mean (SD) AUC unbound was 689.7 (226.6) mcg h/mL, which correlated with C7.2h (R 2 = 0.90), and the Bayesian posterior AUC unbound using only the trough concentration (R 2 = 0.66). Although higher exposure was more likely to show a better clinical response, each parameter did not indicate a statistical significance between positive and negative clinical responses ( P = 0.0907 for creatinine clearance (Ccr), 0.2523 for C7.2h, 0.4079 for trough concentration, and 0.1142 for AUC unbound ). Cutoff values were calculated as 80.2 mL/min for Ccr (sensitivity: 0.889, specificity: 0.714), 18.6 mcg/mL for C7.2h (sensitivity: 0.571, specificity: 1.000), and 9.2 mcg/mL for trough concentration (sensitivity: 0.571, specificity: 1.000). When aiming for a time above 100% the minimum inhibitory concentration, both continuous infusion of 4 g/d and intermittent infusion of 2 g every 8 hours achieved a probability of approximately 100% at a minimum inhibitory concentration of 8 mcg/mL.

CONCLUSIONS

Therapeutic drug monitoring by sampling at C7.2h or trough can facilitate rapid dose optimization. Continuous infusion of 4 g/d was recommended. Intermittent dosing of 2 g every 8 hours was alternatively suggested for patients with a Ccr of 60-90 mL/min.

Pharmacokinetic Analysis of Intravenous Push Cefepime in Burn Patients with Augmented Renal Clearance

Patients with augmented renal clearance (ARC) are a subset of critically ill patients including burn patients that exhibit increased renal elimination of medications beyond that of similarly injured patients. Currently approved maximum regimens of medications primarily eliminated by the kidney, such as cefepime (>90% unchanged in the urine), may be inadequate (eg, compromising the bactericidal activity of cefepime) in patients with ARC. Due to recent resource limitations, centers have changed infusion practices of commonly prescribed medications to intravenous push (IVP), potentially exacerbating the problem of maintaining bactericidal cefepime concentrations. The hypothesis of the study was patients with ARC are not currently achieving adequate target attainment, when receiving cefepime 2 g every 8 h IVP. Eight blood samples were collected from each patient, and concentrations measured via LC-MS/MS. WinNonlin (version 8.3) was used to estimate the pharmacokinetic parameters of cefepime and simulate plasma concentrations of cefepime in each of the ten subjects. Simulations of cefepime plasma concentrations produced by a 2 g dose given every 8 h and a 1 g dose given every 4 h were performed and the time above a MIC of 4 mg/L, 8 mg/L, and 16 mg/L compared. The 2 g every 8 h regimen remained above the breakpoints for 92%, 85%, and 71% of the dosing interval, respectively. The 1 g every 4 h regimen remained above the same breakpoints at a frequency of 100%, 99%, and 92% of the dosing interval. Giving cefepime 1 g every 4 h is a simple approach to increase the likelihood of maintaining the optimal bactericidal activity of cefepime in patients with ARC.

Alterations of Gastrointestinal Microbe Composition in Various Human Diseases and Its Significance in the Early Diagnosis of Diseases

A 100 trillion bacteria, viruses, fungi, and archaea make up the human gut microbe. It has co-evolved with its human host and carries out essential tasks that improve general health. The relationship between gastrointestinal microbes and human health has been a growing field of interest and research in recent times. The gastrointestinal microbes are connected by complex networks and connections, and the host has given birth to the gut-microbe-brain axis, which shows the crucial effect that this circumstance could have on the health and diseases of the brain and spinal cord (or the central nervous system [CNS]). The microbe and the CNS interact bi-directionally via autonomic, neuroendocrine, gastrointestinal, and immune system pathways. The gut microbe has been connected to a range of gastrointestinal and extra-gastrointestinal diseases. The recent investigation supports the suspicion that the gut-microbe-brain axis could play a role in neuropsychiatric disorders including depression, dementia, post-traumatic stress disorder, anxiousness, bipolar disorder, schizophrenia, and obsessive-compulsive disorder, alongside chronic host illnesses such as obesity, diabetes, and inflammation. Studies point to gut microorganisms as possible biomarkers for a wide range of mental health issues. Changes in the gut microbe may be a crucial factor in the onset and advancement of non-alcoholic fatty liver damage. Gut microbes have been seen to influence microglia's response to the CNS's regional signals and thus to pain and inflammation. Data suggest that altering the gut microbe in those with chronic pain may be a successful method for reducing pain. Numerous investigations have documented alterations in the gut microbes made in Alzheimer patients and schizophrenic patients. The risk of breast cancer can be reduced by restoring gut microbe homeostasis and reducing systemic estrogen levels.

Renally Dosed Cefepime Leading to Cefepime-Induced Neurotoxicity: A Case Report

Cefepime is a broad-spectrum fourth-generation cephalosporin with activity against both gram-positive and gram-negative bacteria, including Pseudomonas aeruginosa. Cefepime is most commonly used for urinary tract infections, soft tissue infections, and febrile neutropenia. Up to 15% of ICU patients on cefepime may experience cefepime-induced neurotoxicity (CIN), with risk factors including renal dysfunction, excessive dosage, elevated serum cefepime concentrations, and history of prior brain injury. The adverse effects of CIN, including encephalopathy, seizures, and coma can be resolved with drug cessation, antiepileptics, or hemodialysis. Here, we present the case of CIN in a 59-year-old female patient with long-term cefepime antibiotic prescription for Pseudomonas bacteremia and endocarditis with multiple risk factors for reduced renal function. We discuss the relevant risk factors and preventive measures that may have prevented her from developing CIN, as well as the importance of early recognition and prevention of CIN in patient care.

Negative myoclonus as a manifestation of cefepime neurotoxicity

Negative myoclonus may present in the early stages of cefepime neurotoxicity. Cefepime neurotoxicity typically presents as reduced consciousness, myoclonus, and seizures; however, negative myoclonus is uncommon. This video shows an older woman with cefepime neurotoxicity that presented as a negative myoclonus of the upper limbs.

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.

The Impact of the Implementation of a Pharmacist-Driven Protocol of Second Dose Cefepime for Adult Patients With Sepsis in the Emergency Department at a Tertiary Care Academic Medical Center

Purpose: Prior literature evaluating the importance of timely second-dose antibiotics in patients with sepsis has led to better outcomes and a possible reduction in mortality, length of mechanical ventilation, and length of time requiring vasopressors. Objective: To evaluate the impact of a newly developed pharmacist-led two-dose cefepime protocol implemented within an emergency department (ED) service. Methods: This was a retrospective, single-center, pre-post observational cohort study. Institutional review board approval was obtained. The primary endpoint was a reduction in time between the first and the second doses of antibiotics for patients with sepsis who present to the emergency department. Secondary endpoints included length of vasopressor therapy, intensive care unit (ICU) length of stay, hospital length of stay, duration of mechanical ventilation, and mortality. Results: A total of 84 patients were included in the pharmacist-led two-dose hospital protocol and 79 patients were included in the historical control. In the control cohort, the median time between the first and second dose of antibiotics was 12 hours vs 8.5 hours in the tested cohort. The average time requiring vasopressors was 1.20 days for the control cohort vs .46 days for the post-implementation group. Lastly, the median hospital length of stay in days was 8 for the control group vs 7 for the tested cohort. Conclusion: Implementation of a pharmacist-led two-dose cefepime protocol was associated with a numerically lower duration between second-dose antibiotics, days requiring vasopressors, and a slight reduction in hospital length of stay.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Cefepime vs Piperacillin-Tazobactam in Adults Hospitalized With Acute Infection: The ACORN Randomized Clinical Trial

Importance

Cefepime and piperacillin-tazobactam are commonly administered to hospitalized adults for empirical treatment of infection. Although piperacillin-tazobactam has been hypothesized to cause acute kidney injury and cefepime has been hypothesized to cause neurological dysfunction, their comparative safety has not been evaluated in a randomized clinical trial.

Objective

To determine whether the choice between cefepime and piperacillin-tazobactam affects the risks of acute kidney injury or neurological dysfunction.

Design, Setting, and Participants

The Antibiotic Choice on Renal Outcomes (ACORN) randomized clinical trial compared cefepime vs piperacillin-tazobactam in adults for whom a clinician initiated an order for antipseudomonal antibiotics within 12 hours of presentation to the hospital in the emergency department or medical intensive care unit at an academic medical center in the US between November 10, 2021, and October 7, 2022. The final date of follow-up was November 4, 2022.

Interventions

Patients were randomized in a 1:1 ratio to cefepime or piperacillin-tazobactam.

Main Outcomes and Measures

The primary outcome was the highest stage of acute kidney injury or death by day 14, measured on a 5-level ordinal scale ranging from no acute kidney injury to death. The 2 secondary outcomes were the incidence of major adverse kidney events at day 14 and the number of days alive and free of delirium and coma within 14 days.

Results

There were 2511 patients included in the primary analysis (median age, 58 years [IQR, 43-69 years]; 42.7% were female; 16.3% were Non-Hispanic Black; 5.4% were Hispanic; 94.7% were enrolled in the emergency department; and 77.2% were receiving vancomycin at enrollment). The highest stage of acute kidney injury or death was not significantly different between the cefepime group and the piperacillin-tazobactam group; there were 85 patients (n = 1214; 7.0%) in the cefepime group with stage 3 acute kidney injury and 92 (7.6%) who died vs 97 patients (n = 1297; 7.5%) in the piperacillin-tazobactam group with stage 3 acute kidney injury and 78 (6.0%) who died (odds ratio, 0.95 [95% CI, 0.80 to 1.13], P = .56). The incidence of major adverse kidney events at day 14 did not differ between groups (124 patients [10.2%] in the cefepime group vs 114 patients [8.8%] in the piperacillin-tazobactam group; absolute difference, 1.4% [95% CI, -1.0% to 3.8%]). Patients in the cefepime group experienced fewer days alive and free of delirium and coma within 14 days (mean [SD], 11.9 [4.6] days vs 12.2 [4.3] days in the piperacillin-tazobactam group; odds ratio, 0.79 [95% CI, 0.65 to 0.95]).

Conclusions and Relevance

Among hospitalized adults in this randomized clinical trial, treatment with piperacillin-tazobactam did not increase the incidence of acute kidney injury or death. Treatment with cefepime resulted in more neurological dysfunction.

Trial Registration

ClinicalTrials.gov Identifier: NCT05094154.

The spectrum of sepsis-associated encephalopathy: a clinical perspective

Sepsis-associated encephalopathy is a severe neurologic syndrome characterized by a diffuse dysfunction of the brain caused by sepsis. This review provides a concise overview of diagnostic tools and management strategies for SAE at the acute phase and in the long term. Early recognition and diagnosis of SAE are crucial for effective management. Because neurologic evaluation can be confounded by several factors in the intensive care unit setting, a multimodal approach is warranted for diagnosis and management. Diagnostic tools commonly employed include clinical evaluation, metabolic tests, electroencephalography, and neuroimaging in selected cases. The usefulness of blood biomarkers of brain injury for diagnosis remains limited. Clinical evaluation involves assessing the patient's mental status, motor responses, brainstem reflexes, and presence of abnormal movements. Electroencephalography can rule out non-convulsive seizures and help detect several patterns of various severity such as generalized slowing, epileptiform discharges, and triphasic waves. In patients with acute encephalopathy, the diagnostic value of non-contrast computed tomography is limited. In septic patients with persistent encephalopathy, seizures, and/or focal signs, magnetic resonance imaging detects brain injury in more than 50% of cases, mainly cerebrovascular complications, and white matter changes. Timely identification and treatment of the underlying infection are paramount, along with effective control of systemic factors that may contribute to secondary brain injury. Upon admission to the ICU, maintaining appropriate levels of oxygenation, blood pressure, and metabolic balance is crucial. Throughout the ICU stay, it is important to be mindful of the potential neurotoxic effects associated with specific medications like midazolam and cefepime, and to closely monitor patients for non-convulsive seizures. The potential efficacy of targeted neurocritical care during the acute phase in optimizing patient outcomes deserves to be further investigated. Sepsis-associated encephalopathy may lead to permanent neurologic sequelae. Seizures occurring in the acute phase increase the susceptibility to long-term epilepsy. Extended ICU stays and the presence of sepsis-associated encephalopathy are linked to functional disability and neuropsychological sequelae, underscoring the necessity for long-term surveillance in the comprehensive care of septic patients.

The clinical application of beta-lactam antibiotic therapeutic drug monitoring in the critical care setting

Critically ill patients have increased variability in beta-lactam antibiotic (beta-lactam) exposure due to alterations in their volume of distribution and elimination. Therapeutic drug monitoring (TDM) of beta-lactams, as a dose optimization and individualization tool, has been recommended to overcome this variability in exposure. Despite its potential benefit, only a few centres worldwide perform beta-lactam TDM. An important reason for the low uptake is that the evidence for clinical benefits of beta-lactam TDM is not well established. TDM also requires the availability of specific infrastructure, knowledge and expertise. Observational studies and systematic reviews have demonstrated that TDM leads to an improvement in achieving target concentrations, a reduction in potentially toxic concentrations and improvement of clinical and microbiological outcomes. However, a small number of randomized controlled trials have not shown a mortality benefit. Opportunities for improved study design are apparent, as existing studies are limited by their inclusion of heterogeneous patient populations, including patients that may not even have infection, small sample size, variability in the types of beta-lactams included, infections caused by highly susceptible bacteria, and varied sampling, analytical and dosing algorithm methods. Here we review the fundamentals of beta-lactam TDM in critically ill patients, the existing clinical evidence and the practical aspects involved in beta-lactam TDM implementation.

Delayed Diagnosis of an Invisible Seizure: Cefepime-Induced Non-convulsive Status Epilepticus

Cefepime-induced non-convulsive status epilepticus (NCSE) is a recognized adverse event of cefepime. Risk factors for this adverse event include older age, underlying renal dysfunction, previous brain injury, diabetes, and severe infection. We present a case of a 79-year-old woman with no prior seizure history, who was admitted for Pseudomonas aeruginosa surgical wound infection for which she was on cefepime. She developed acute encephalopathy with associated, occasional, right-sided myoclonic facial twitches 11 days into her admission. Electroencephalogram (EEG) confirmed NCSE as evident by epileptiform activity described as generalized periodic discharges with predominantly triphasic morphology. Cefepime was substituted with piperacillin-tazobactam> 24 hours after symptom onset. NCSE completely resolved two days after the discontinuation of cefepime. This case highlights the fact that NCSE can occur even when precautions such as renal dosing of cefepime are observed. Clinicians need to have a high index of suspicion for the condition when taking care of at-risk patients on cefepime, as delayed diagnosis correlates with potentially fatal outcomes.

Electroencephalography as a Biomarker of Prognosis in Acute Brain Injury

Electroencephalography (EEG) is a noninvasive tool that allows the monitoring of cerebral brain function in critically ill patients, aiding with diagnosis, management, and prognostication. Specific EEG features have shown utility in the prediction of outcomes in critically ill patients with status epilepticus, acute brain injury (ischemic stroke, intracranial hemorrhage, subarachnoid hemorrhage, and traumatic brain injury), anoxic brain injury, and toxic-metabolic encephalopathy. Studies have also found an association between particular EEG patterns and long-term functional and cognitive outcomes as well as prediction of recovery of consciousness following acute brain injury. This review summarizes these findings and demonstrates the value of utilizing EEG findings in the determination of prognosis.

Significant Publications on Infectious Diseases Pharmacotherapy in 2022

Purpose: To provide summarization of the most significant infectious diseases (ID) pharmacotherapy articles published in peer-reviewed literature in 2022. Summary: Members of the Houston Infectious Diseases Network (HIDN) nominated notable articles providing significant contributions to ID pharmacotherapy in 2022. Article nominations included those pertaining to general ID, as well as those including coronavirus disease 2019 (COVID-19), and human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) pharmacotherapy. A total of 71 articles were nominated by HIDN. Members: 68 articles pertaining to general ID pharmacotherapy and 3 articles focusing on HIV/AIDS. To aid selection of the most these most notable articles of 2022, a survey was created and distributed to members of the Society of Infectious Diseases Pharmacists (SIDP). Of the 153 SIDP members who participated in the survey, there were 128 recorded votes for the top 10 general ID pharmacotherapy articles and 30 votes recorded for the top HIV/AIDS article. The most notable publications are summarized. Conclusion: Post pandemic significant advances in antimicrobial stewardship and infectious disease states continues to occur in a world recently focused on the coronavirus disease 2019 (COVID-19) global pandemic. Continuous growth in publication of ID-related articles over the past year lends towards the aims of this review to aid clinicians in remaining current on key practice-changing ID pharmacotherapy publications from 2022.

Clinical Outcomes of Third-Generation Cephalosporin Definitive Therapy for Bloodstream Infections Due to Enterobacterales with Potential AmpC Induction: A Single-Center Retrospective Study

The recommended therapy for severe infections caused by AmpC-inducible Enterobacterales (AmpC-E) typically involves cefepime or carbapenems. In an era of emerging resistance to these antimicrobials, we aim to assess the impact of third-generation cephalosporins (3GCs) vs. alternative antibiotics on clinical outcomes in bloodstream infections (BSIs) due to AmpC-E. We retrospectively included hospitalized adult patients with BSIs caused by 3GC-susceptible AmpC-E between 2012 and 2022, comparing the outcomes of 3GC and non-3GC definitive therapies. The primary outcome was overall treatment failure (OTF), encompassing 90-day all-cause mortality, 90-day reinfection, and 90-day readmission. Secondary outcomes comprised components of the OTF, in-hospital all-cause mortality, and length-of-stay. Within a total cohort of 353 patients, OTF occurred in 46.5% and 41.5% in the 3GC- and non-3GC-therapy groups, respectively (p = 0.36). The 3GC-therapy group exhibited a longer length-of-stay (38 vs. 21 days, p = 0.0003) and higher in-hospital mortality (23.3% vs. 13.4%, p = 0.019). However, the 90-day mortality, 90-day reinfection, and 90-day readmission were comparable between the therapy groups. Subgroup analyses involving high-risk AmpC-E and 3GC vs. standard-of-care yielded similar conclusions. Overall, our findings suggest that 3GC definitive therapy may not result in poorer clinical outcomes for the treatment of BSIs caused by AmpC-E.

Making the case for precision dosing: visualizing the variability of cefepime exposures in critically ill adults

OBJECTIVE

To investigate and describe the variability in cefepime exposures among 'real-world', critically ill patients by using population pharmacokinetic modelling and simulations, and with translation of these findings to visualizations.

METHODS

A cohort of adult medical ICU patients who received cefepime with therapeutic drug monitoring was studied. Two compartment models were developed to estimate cefepime clearance (Model 1) and simulate cefepime exposures among 1000 patients, each with identical creatinine clearance of 60 mL/min and receiving a regimen of cefepime 1 gram IV over 30 minutes, every 8 hours (Model 2). Variability in the relationship between cefepime clearance and creatinine clearance (CrCL) was visualized, and a random, representative sample of 10 simulated patients was utilized to illustrate variability in cefepime exposures.

RESULTS

A total of 75 adult medical ICU patients (52% female) and 98 serum cefepime samples were included in the study. Population parameter estimates for cefepime displayed a wide range of variation in Model 1 (CV: 45% to 95%), with low bias at the individual level at 0.226 mg/L but high bias in the population model 10.6 mg/L. Model 2 displayed similar fits, demonstrating that correcting for individual patient creatinine clearance slightly improves the bias of the population model (bias = 4.31 mg/L). Among 10 simulated patients that a clinician would deem similar from a dosing perspective (i.e. equivalent creatinine clearance), maximum concentrations after three simulated doses varied more than 8-fold from 41.2 to 339 mg/L at the 5th and 95th percentiles, and clearance profiles were highly different.

CONCLUSION

Creatinine clearance estimates alone are inadequate for predicting cefepime exposures. Wide variations in cefepime exposure exist among ICU patients, even for those with similar kidney function estimates. Current population adjustment schemes based solely on creatinine clearance will result in unintended high and low exposures leading to safety and efficacy concerns, respectively.

β-Lactam Pharmacokinetic/Pharmacodynamic Target Attainment in Intensive Care Unit Patients: A Prospective, Observational, Cohort Study

BACKGROUND

The aims of this study were to describe pharmacokinetic/pharmacodynamic target attainment in intensive care unit (ICU) patients treated with continuously infused ß-lactam antibiotics, their associated covariates, and the impact of dosage adjustment.

METHODS

This prospective, observational, cohort study was performed in three ICUs. Four ß-lactams were continuously infused, and therapeutic drug monitoring (TDM) was performed at days 1, 4, and 7. The primary pharmacokinetic/pharmacodynamic target was an unbound ß-lactam plasma concentration four times above the bacteria's minimal inhibitory concentration during the whole dosing interval. The demographic and clinical covariates associated with target attainment were evaluated.

RESULTS

A total of 170 patients were included (426 blood samples). The percentages of empirical ß-lactam underdosing at D1 were 66% for cefepime, 43% for cefotaxime, 47% for ceftazidime, and 14% for meropenem. Indexed creatinine clearance was independently associated with treatment underdose if increased (adjusted odds ratio per unit, 1.01; 95% CI, 1.00 to 1.01; p = 0.014) or overdose if decreased (adjusted odds ratio per unit, 0.95; 95% CI, 0.94 to 0.97; p < 0.001). Pharmacokinetic/pharmacodynamic target attainment was significantly increased after ß-lactam dosage adjustment between day 1 and day 4 vs. no adjustment (53.1% vs. 26.2%; p = 0.018).

CONCLUSIONS

This study increases our knowledge on the optimization of ß-lactam therapy in ICU patients. A large inter- and intra-patient variability in plasmatic concentrations was observed, leading to inadequate exposure. A combined indexed creatinine clearance and TDM approach enables adequate dosing for better pharmacokinetic/pharmacodynamic target attainment.

Cefepime Population Pharmacokinetics, Antibacterial Target Attainment, and Estimated Probability of Neurotoxicity in Critically Ill Patients

Cefepime has been reported to cause concentration-related neurotoxicity, especially in critically ill patients with renal failure. This evaluation aimed to identify a dosing regimen providing a sufficient probability of target attainment (PTA) and the lowest justifiable risk of neurotoxicity in critically ill patients. A population pharmacokinetic model was developed based on plasma concentrations over four consecutive days obtained from 14 intensive care unit (ICU) patients. The patients received a median dose of 2,000 mg cefepime by 30-min intravenous infusions with dosing intervals of every 8 h (q8h) to q24h. A time that the free drug concentration exceeds the MIC over the dosing interval (fT>MIC) of 65% and an fT>2×MIC of 100% were defined as treatment targets. Monte Carlo simulations were carried out to identify a dosing regimen for a PTA of 90% and a probability of neurotoxicity not exceeding 20%. A two-compartment model with linear elimination best described the data. Estimated creatinine clearance was significantly related to the clearance of cefepime in nondialysis patients. Interoccasion variability on clearance improved the model, reflecting dynamic clearance changes. The evaluations suggested combining thrice-daily administration as an appropriate choice. In patients with normal renal function (creatinine clearance, 120 mL/min), for the pharmacodynamics target of 100% fT>2×MIC and a PTA of 90%, a dose of 1,333 mg q8h was found to be related to a probability of neurotoxicity of ≤20% and to cover MICs up to 2 mg/L. Continuous infusion appears to be superior to other dosing regimens by providing higher efficacy and a low risk of neurotoxicity. The model makes it possible to improve the predicted balance between cefepime efficacy and neurotoxicity in critically ill patients. (This study has been registered at ClinicalTrials.gov under registration no. NCT01793012).

Anti-SOX-1 Antibody-Positive Paraneoplastic Limbic Encephalitis Diagnosed During Small Cell Lung Cancer Treatment

Paraneoplastic neurological syndrome (PNS) mostly presents its symptoms prior to cancer treatment. We present a case of anti-Sry-like high mobility group box 1 (SOX-1) antibody-positive PNS diagnosed during the treatment of small-cell lung cancer (SCLC). A 65-year-old woman with a history of smoking and SCLC (T3N1M0) was hospitalized to receive chemo-radiation therapy. On day 14, the course was complicated by left mastitis associated with febrile neutropenia. Drainage was performed for the left mastitis, and cefepime was initiated. The fever subsided within a few days, but the patient became agitated accompanied by logorrhea. With the exception of mental status, her neurological examination was unremarkable. Due to mildly impaired renal function, cefepime encephalopathy was considered in the differential diagnosis, but the agitation grew worse despite cefepime discontinuation. Further evaluations, including brain magnetic resonance imaging without contrast and cerebrospinal fluid analysis, were unremarkable. Acyclovir and steroid pulse therapy were initiated empirically for herpes simplex virus (HSV) and PNS, respectively. On day 22, acyclovir was discontinued because the HSV polymerase chain reaction test result was negative. On day 26, the serum anti-SOX-1 antibody test was reported to be positive. Other paraneoplastic syndrome-associated antibodies, including anti-amphiphysin, CV2, PNMA2, Ri, Yo, Hu, recoverin, titin, zic 4, GAD 65, Tr, and N-methyl-D-aspartate receptor antibodies, were negative. The agitation improved gradually following the continuation of chemotherapy and steroid treatment. The patient was discharged on day 55 in stable condition. Although PNS mostly presents prior to cancer treatment, it is important to recognize that it may develop during the course of cancer treatment. Evaluation and empirical treatment for PNS should be considered in patients who develop encephalopathy during cancer treatment, as early treatment can lead to a better outcome.

Treatment of septic encephalopathy and encephalitis - a critical appraisal

INTRODUCTION

The central nervous system is frequently involved during severe sepsis. Patients either develop septic encephalopathy characterized by delirium and coma or focal neurological signs as a consequence of septic-embolic or septic-metastatic encephalitis.

AREAS COVERED

In this review, a summary of currently available literature on established and some promising experimental treatment options for septic encephalopathy and encephalitis is provided, with a focus on the clinical utility of published studies.

EXPERT OPINION

Treatment relies on proper identification of the causative pathogen and rapidly initiated adequate empirical or (after identification of the pathogen) tailored antibiotic therapy, fluid and electrolyte management. In the presence of brain abscess(es) or mycotic aneurysm(s), surgery or interventional neuroradiology must be considered. Pharmacological approaches to prevent delirium of different etiology include the use of dexmedetomidine and (with limitations) of melatonin and its derivatives. In the absence of a specific pharmacological treatment, non-pharmacological bundles of interventions (e.g. promotion of sleep, cognitive stimulation, early mobilization and adequate therapy of pain) are of proven efficacy to prevent delirium of different etiology including sepsis. Experimental promising therapies include the use of non-bacteriolytic antibiotics and the reduction of the toxic effects of microglial activation.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Outcomes of Intravenous Push versus Intermittent Infusion Administration of Cefepime in Critically Ill Patients

The equivalence of intravenous push (IVP) and piggyback (IVPB) administration has not been evaluated in the critically ill population for most medications, but it is especially relevant for antibiotics, such as cefepime, that exhibit time-dependent bactericidal activity. A single center, retrospective, observational pre/post-protocol change study included critically ill adults who received cefepime as empiric therapy between August 2015 and 2021. The primary outcome was treatment failure, which was defined as a composite of escalation of antibiotic regimen or all-cause mortality. Secondary outcomes included adverse drug events, days of cefepime therapy, total days of antibiotic therapy, and ICU and hospital length of stay. Outcomes were compared using Chi-squared, Mann Whitney U, and binary logistic regression as appropriate. A total of 285 patients were included: 87 IVPB and 198 IVP. Treatment failure occurred in 18% (n = 16) of the IVPB group and 27% (n = 54) of the IVP group (p = 0.109). There were no significant differences in secondary outcomes. Longer duration of antibiotics (odds ratio [OR] 1.057, 95% confidence interval [CI] 1.013-1.103), SOFA score (OR 1.269, 95% CI 1.154-1.397) and IVP administration of cefepime (OR 2.370, 95% CI 1.143-4.914) were independently associated with treatment failure. Critically ill patients who received IVP cefepime were more likely to experience treatment failure in an adjusted analysis. The current practice of IVP cefepime should be reevaluated, as it may not provide similar clinical outcomes in the critically ill population.

Population pharmacokinetics and target attainment analyses to identify a rational empirical dosing strategy for cefepime in critically ill patients

OBJECTIVES

We aimed to identify rational empirical dosing strategies for cefepime treatment in critically ill patients by utilizing population pharmacokinetics and target attainment analysis.

PATIENTS AND METHODS

A prospective and opportunistic pharmacokinetic (PK) study was conducted in 130 critically ill patients in two ICU sites. The plasma concentrations of cefepime were determined using a validated LC-MS/MS method. All cefepime PK data were analysed simultaneously using the non-linear mixed-effects modelling approach. Monte Carlo simulations were performed to evaluate the PTA of cefepime at different MIC values following different dose regimens in subjects with different renal functions.

RESULTS

The PK of cefepime in critically ill patients was best characterized by a two-compartment model with zero-order input and first-order elimination. Creatinine clearance and body weight were identified to be significant covariates. Our simulation results showed that prolonged 3 h infusion does not provide significant improvement on target attainment compared with the traditional intermittent 0.5 h infusion. In contrast, for a given daily dose continuous infusion provided much higher breakpoint coverage than either 0.5 h or 3 h intermittent infusions. To balance the target attainment and potential neurotoxicity, cefepime 3 g/day continuous infusion appears to be a better dosing regimen than 6 g/day continuous infusion.

CONCLUSIONS

Continuous infusion may represent a promising strategy for cefepime treatment in critically ill patients. With the availability of institution- and/or unit-specific cefepime susceptibility patterns as well as individual patients' renal function, our PTA results may represent useful references for physicians to make dosing decisions.

Neurologic Complications of Critical Medical Illness

OBJECTIVE

This article reviews the neurologic complications encountered in patients admitted to non-neurologic intensive care units, outlines various scenarios in which a neurologic consultation can add to the diagnosis or management of a critically ill patient, and provides advice on the best diagnostic approach in the evaluation of these patients.

LATEST DEVELOPMENTS

Increasing recognition of neurologic complications and their adverse impact on long-term outcomes has led to increased neurology involvement in non-neurologic intensive care units. The COVID-19 pandemic has highlighted the importance of having a structured clinical approach to neurologic complications of critical illness as well as the critical care management of patients with chronic neurologic disabilities.

ESSENTIAL POINTS

Critical illness is often accompanied by neurologic complications. Neurologists need to be aware of the unique needs of critically ill patients, especially the nuances of the neurologic examination, challenges in diagnostic testing, and neuropharmacologic aspects of commonly used medications.

Renal and Electrolyte Disorders and the Nervous System

OBJECTIVE

Neurologic complications are a major contributor to death and disability in patients with renal disease. Oxidative stress, endothelial dysfunction, accelerated arteriosclerosis, and uremic inflammatory milieu affect both the central and peripheral nervous systems. This article reviews the unique contributions of renal impairment to neurologic disorders and their common clinical manifestations as the prevalence of renal disease increases in a globally aging population.

LATEST DEVELOPMENT

Advances in the understanding of the pathophysiologic interplay between the kidneys and brain, also referred to as the kidney-brain axis, have led to more widespread recognition of associated changes in neurovascular dynamics, central nervous system acidification, and uremia-associated endothelial dysfunction and inflammation in the central and peripheral nervous systems. Acute kidney injury increases mortality in acute brain injury to nearly 5 times that seen in matched controls. Renal impairment and its associated increased risks of intracerebral hemorrhage and accelerated cognitive decline are developing fields. Dialysis-associated neurovascular injury is increasingly recognized in both continuous and intermittent forms of renal replacement therapy, and treatment strategies for its prevention are evolving.

ESSENTIAL POINTS

This article summarizes the effects of renal impairment on the central and peripheral nervous systems with special considerations in acute kidney injury, patients requiring dialysis, and conditions that affect both the renal and nervous systems.

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.

How I treat unique and difficult-to-manage cases of CAR T-cell therapy-associated neurotoxicity

With growing indications for chimeric antigen receptor (CAR) T-cell therapy, toxicity profiles are evolving. There is an urgent and unmet need of approaches to optimally manage emerging adverse events that extend beyond the standard paradigm of cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome (ICANS). Although management guidelines exist for ICANS, there is little guidance on how to approach patients with neurologic comorbidities, and how to manage rare neurotoxicity presentations, such as CAR T-cell therapy-related cerebral edema, severe motor complications or late-onset neurotoxicity. In this study, we present 3 scenarios of patients treated with CAR T cells who develop unique types of neurotoxicity, and we describe an approach for the evaluation and management based on experience because objective data are limited. The goal of this study is to develop an awareness of emerging and unusual complications, discuss treatment approaches, and help institutions and health care providers establish frameworks to navigate how to best address unusual neurotoxicities to ultimately improve patient outcomes.

Optimization of Antimicrobial Stewardship Programs Using Therapeutic Drug Monitoring and Pharmacokinetics-Pharmacodynamics Protocols: A Cost-Benefit Review

PURPOSE

Antimicrobial stewardship programs are important for reducing antimicrobial resistance because they can readjust antibiotic prescriptions to local guidelines, switch intravenous to oral administration, and reduce hospitalization times. Pharmacokinetics-pharmacodynamics (PK-PD) empirically based prescriptions and therapeutic drug monitoring (TDM) programs are essential for antimicrobial stewardship, but there is a need to fit protocols according to cost benefits. The cost benefits can be demonstrated by reducing toxicity and hospital stay, decreasing the amount of drug used per day, and preventing relapses in infection. Our aim was to review the data available on whether PK-PD empirically based prescriptions and TDM could improve the cost benefits of an antimicrobial stewardship program to decrease global hospital expenditures.

METHODS

A narrative review based on PubMed search with the relevant studies of vancomycin, aminoglycosides, beta-lactams, and voriconazole.

RESULTS

TDM protocols demonstrated important cost benefit for patients treated with vancomycin, aminoglycosides, and voriconazole mainly due to reduce toxicities and decreasing the hospital length of stay. In addition, PK-PD strategies that used infusion modifications to meropenem, piperacillin-tazobactam, ceftazidime, and cefepime, such as extended or continuous infusion, demonstrated important cost benefits, mainly due to reducing daily drug needs and lengths of hospital stays.

CONCLUSIONS

TDM protocols and PK-PD empirically based prescriptions improve the cost-benefits and decrease the global hospital expenditures.

Safety and Tolerability of Antimicrobial Agents in the Older Patient

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

Update on Therapeutic Drug Monitoring of Beta-Lactam Antibiotics in Critically Ill Patients—A Narrative Review

Beta-lactam antibiotics remain one of the most preferred groups of antibiotics in critical care due to their excellent safety profiles and their activity against a wide spectrum of pathogens. The cornerstone of appropriate therapy with beta-lactams is to achieve an adequate plasmatic concentration of a given antibiotic, which is derived primarily from the minimum inhibitory concentration (MIC) of the specific pathogen. In a critically ill patient, the plasmatic levels of drugs could be affected by many significant changes in the patient’s physiology, such as hypoalbuminemia, endothelial dysfunction with the leakage of intravascular fluid into interstitial space and acute kidney injury. Predicting antibiotic concentration from models based on non-critically ill populations may be misleading. Therapeutic drug monitoring (TDM) has been shown to be effective in achieving adequate concentrations of many drugs, including beta-lactam antibiotics. Reliable methods, such as high-performance liquid chromatography, provide the accurate testing of a wide range of beta-lactam antibiotics. Long turnaround times remain the main drawback limiting their widespread use, although progress has been made recently in the implementation of different novel methods of antibiotic testing. However, whether the TDM approach can effectively improve clinically relevant patient outcomes must be proved in future clinical trials.

Quantitation of 10 antibiotics in plasma: sulfosalicylic acid combined with 2D-LC-MS/MS is a robust assay for beta-lactam therapeutic drug monitoring

Therapeutic drug monitoring (TDM) of antibiotics is particularly important in populations with high pharmacokinetic variabilities, such as critically ill patients, leading to unpredictable plasma concentrations and clinical outcomes. Here, we i) describe an original method for the simultaneous quantification of ten antibiotics (cefepime, ceftazidime, ampicillin, piperacillin/tazobactam, cefotaxime, amoxicillin, cloxacillin, oxacillin, linezolid) using 5-sulfosalicylic acid dihydrate (SSA) solution for protein precipitation together with 2D-LC-MS/MS, and ii) evaluate its impact in a one-year retrospective study. The method involved simple dilution with an aqueous mix of deuterated internal standards and plasma protein precipitation with SSA. Twenty microliters of the supernatant was injected into a C8 SPE online cartridge (30 × 2.1 mm) without any evaporation step and back-flushed onto a C18 UHPLC (100 × 2.1 mm) analytical column. Mass spectrometry detection (Xevo TQD) was performed in positive electrospray, in scheduled MRM mode. Overall analytical runtime was 7 min. Due to analytical constraints and the physicochemical properties of the antibiotics, protein precipitation using organic solvents could not be applied. As an alternative, SSA used with 2D-LC offered various advantages: i) lack of dilution resulting in better assay sensitivity, and ii) good chromatography of hydrophilic compounds. Ten microliters of 30% SSA in water eliminated>90% of plasma proteins, including the most abundant high molecular weight proteins at 55 and 72 kDa. The assay was successfully validated according to FDA and EMA guidelines for all the antibiotics, and the coefficients of variation of the quality control (QC) run during sample analysis over one year were below 10%, whatever the QC levels or the antibiotics. The use of 2D-LC combined with SSA precipitation allowed development of a robust, sensitive and rapid quantification assay. Feedback to clinicians was reduced to 24 h, thus allowing rapid dosage adjustment. During one year, 3,304 determinations were performed in our laboratory: 41% were not in the therapeutic range, 58% of which were sub-therapeutic, underlining the importance of early TDM of antibiotics to limit therapeutic failures and the emergence of bacterial resistance.

Outpatient Parenteral Antibiotic Therapy in Older Adults

Outpatient parenteral antimicrobial therapy (OPAT) for older adults is a complex process that involves multiple stakeholders and care coordination, but it is a useful and patient-centered tool with opportunities for the treatment of complicated infections, improved patient satisfaction, and reduced health-care costs. Older age should not be an exclusion for OPAT but rather prompt the OPAT provider to thoroughly evaluate candidacy and safety. Amid the on-going COVID-19 pandemic, innovations in OPAT are needed to shepherd OPAT care into a more patient-centered, thoughtful practice, whereas minimizing harm to older patients from unnecessary health-care exposure and thus health-care associated infections.

Gut Microbiota and Alzheimer's Disease: How to Study and Apply Their Relationship

Gut microbiota (GM), the microorganisms in the gastrointestinal tract, contribute to the regulation of brain homeostasis through bidirectional communication between the gut and the brain. GM disturbance has been discovered to be related to various neurological disorders, including Alzheimer's disease (AD). Recently, the microbiota-gut-brain axis (MGBA) has emerged as an enticing subject not only to understand AD pathology but also to provide novel therapeutic strategies for AD. In this review, the general concept of the MGBA and its impacts on the development and progression of AD are described. Then, diverse experimental approaches for studying the roles of GM in AD pathogenesis are presented. Finally, the MGBA-based therapeutic strategies for AD are discussed. This review provides concise guidance for those who wish to obtain a conceptual and methodological understanding of the GM and AD relationship with an emphasis on its practical application.

Cefepime-Induced Neurotoxicity Can Be Confused With Neuroleptic Malignant Syndrome, Catatonia and Serotonin Syndrome: A Case Report

Cefepime is a commonly used antibiotic. However, cefepime-induced neurotoxicity (CIN) is less commonly recognized. We describe a 75-year-old female on sertraline and risperidone who has been on cefepime for 28 days for treatment of osteomyelitis and presented with mutism, generalized rigidity, hyperreflexia, generalized stimulus-induced myoclonus, and reactive dilated pupils and found to have developed acute kidney injury. Although the diagnosis of serotonin syndrome (SS) and neuroleptic malignant syndrome (NMS) was suggested initially, the clinical picture was more compatible with CIN. Hemodialysis was suggested but gradual improvement in renal function allowed for gradual neurological recovery. This case highlights the importance of considering CIN in those who have been on Cefepime and present with altered mental status, especially in the appropriate clinical context and presence of risk factors. The overlap in clinical presentation between CIN, SS, NMS, and Catalonia may lead to a diagnostic challenge. Myoclonus seems to be characteristic of CIN and serves as a good clue to hint toward the diagnosis. This case helps to display the similarities and differences in the clinical presentation of these entities and therefore helps avoid confusion and prevents unnecessary therapeutic interventions.