Cefepime-related neurotoxicity in a haemodialysis patient

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.

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.

Cefepime-induced neurotoxicity: systematic review

BACKGROUND

Cefepime-induced neurotoxicity (CIN) has been well acknowledged among clinicians, although there are no clear diagnostic criteria or specific laboratory testing to help with its diagnosis. We aimed to summarize the existing evidence regarding CIN and provide future agendas for research.

METHODS

Following the PRISMA Extension for Scoping Reviews, we searched MEDLINE and Embase for all peer-reviewed articles using keywords including 'cefepime', 'neurotoxicity', 'encephalopathy' and 'seizure', from their inception to 20 January 2022.

RESULTS

We included 92 articles, including 23 observational studies and 69 cases from case reports and case series, in the systematic review. Among 119 patients with CIN, 23.5% were in the ICU at the time of diagnosis and nearly 90% of the cases showed renal dysfunction.Cefepime overdoses were described in 41%. The median latency period of developing CIN from cefepime initiation was 4 days, and about 12% developed CIN during empirical treatment. CIN patients commonly manifested altered mental status (93%), myoclonus (37%) and non-convulsive seizure epilepticus (28%). A serum cefepime trough level of >20 mg/L would put patients at risk for CIN. CIN-related symptoms were ameliorated in 97.5% by dose reduction or discontinuation of cefepime, with median time to improvement of 3 days. No CIN-associated deaths were reported.

CONCLUSIONS

This systematic review summarizes the current evidence and characteristics of CIN. In the current situation where there are no CIN diagnostic criteria and the drug monitoring platform is not routinely available, candidates for cefepime should be carefully selected. Also, based on these findings, it needs to be appropriately dosed to avoid the development of CIN.

Cefepime-Induced Neurotoxicity in the Setting of Acute Kidney Injury: A Case Series and Discussion of Preventive Measures

Neurotoxicity is a well-described adverse effect of cefepime. Clinical presentation includes mild neurological deficits, aphasia, impairment of consciousness, and even nonconvulsive status epilepticus. Impaired kidney function is considered the most important risk factor for cefepime-induced neurotoxicity (CIN) and frequently occurs during the course of critical diseases with concomitant acute kidney injury (AKI). Physicians should be aware of situations with increased risk of AKI and the preventive actions required to reduce the risk of CIN. We present three patients with AKI who were treated with cefepime for healthcare-associated infections. Subsequently, two patients developed CIN demonstrating very high cefepime levels in plasma. In the third patient, CIN was likely prevented as the increased risk of neurotoxicity was noted and cefepime treatment was ceased immediately. Diagnosis of CIN might be challenging due to various causes of encephalopathy, in particular in the setting of severely ill patients. Electroencephalogram may assist in establishing the diagnosis, in particular when cefepime therapeutic drug monitoring is not available. As CIN is potentially reversible, it is an important differential diagnosis to consider especially in patients with impaired renal function or being susceptible to AKI. Preventive measures of CIN include therapeutic drug monitoring, consideration of a therapeutic alternative, awareness regarding a potential overestimation of the glomerular filtration rate, and electronic health record alerts about risk constellations for potential overdosing.

Cefepime Induced Neurotoxicity Following A Regimen Dose-Adjusted for Renal Function: Case Report and Review of the Literature

Introduction: Cefepime induced neurotoxicity (CIN) is commonly associated with renal dysfunction, however CIN can occur in patients with normal renal function or renally dose-adjusted regimens. Few reports of this kind have obtained cefepime concentrations to assist in diagnosis. Patient Case: A 42-year old female with a complex past medical history was transferred to our facility with chief complaint of worsening shock and respiratory failure, and the patient was also noted to be hypernatremic, experiencing diabetic ketoacidosis (DKA), and acute kidney injury (AKI). Her DKA resolved and hypernatremia and AKI began to improve. As a result, cefepime was dose-adjusted for renal function estimated by the Cockcroft-Gault (CG) equation. Her hospital course was complicated by persistent altered mental status (AMS), preventing extubation. Cefepime was discontinued due to concern for CIN, and a concentration was obtained 13-hours after the last dose which was elevated at 49 µg/mL. Two days following cefepime discontinuation, the patient's mental status improved allowing for successful extubation. The patient remained stable and was discharged to an acute care floor and then ultimately back to home. Conclusion: CIN should be part of a wider differential diagnosis for patients experiencing encephalopathy, and inaccurate renal function estimation may be a risk factor for developing CIN. Furthermore, therapeutic drug monitoring (TDM) may serve as an important clinical tool in diagnosing and managing CIN.

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

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

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

Cefepime-Induced Neurotoxicity

Cefepime is a common antibiotic used to treat various infections such as pneumonia, skin infections, and intra-abdominal infections due to its broad gram-positive and gram-negative spectrum. However, patients with acute kidney injury, end-stage renal disease, and renal transplantation are disproportionately at higher risk of developing complications from administration of cefepime, secondary to its predominant renal excretion. Current guidelines prescribe cefepime renal-dosing, dependent on the glomerular filtration rate, to prevent toxicity. This study presents a rare case where an acutely hospitalized patient undergoing chronic renal transplant rejection was administered renal-dose cefepime. Despite renal dosing, the patient developed neurotoxicity that manifested as delirium, inability to tolerate oral intake, and non-convulsive status epilepticus. Solely adjusting for renal dysfunction may be inadequate to prevent the accumulation of cefepime metabolites, which may present in an atypical manner in the patient. Such possibilities emphasize the need for continued evaluation of a patient’s mentation in case of cefepime administration. Cefepime-induced neurotoxicity incidences need to be evaluated and researched thoroughly.

Post-Dialysis Parenteral Antimicrobial Therapy in Patients Receiving Intermittent High-Flux Hemodialysis

Patients with end-stage renal disease (ESRD) requiring intermittent hemodialysis (IHD) are at increased risk of infection, which represents a leading cause of mortality in this population. The use of additional vascular access devices such as peripherally inserted central catheters to treat such infections should be minimized in patients with ESRD requiring IHD in order to mitigate complications such as infection and thrombosis and to maintain venous patency for hemodialysis access. Intravenous antimicrobial dosing following IHD has the advantages of avoiding additional access devices and providing convenience for patients and providers. Vancomycin, cefazolin, and aminoglycosides have historically been regarded as the primary intravenous antimicrobials administered with IHD given their relatively low cost, convenient dosing, and longevity of clinical use. Despite this, a growing body of literature is evaluating the use of an expanded list of antimicrobials that may be employed using post-dialysis dosing for patients requiring IHD; however, the available data are largely limited to pharmacokinetic studies and small cohorts of infected patients or uninfected subjects. Post-dialytic dosing of intravenous antimicrobials may be considered on a patient-by-patient basis after careful consideration of clinical, microbiological, and logistical factors that may influence the probability of treatment success. This document reviews and evaluates currently available information on the post-dialytic administration of an expanded list of intravenous antimicrobials in the setting of thrice-weekly, high-flux IHD.

Cefepime-Induced Encephalopathy

Cefepime, a fourth-generation cephalosporin, remains an essential antibiotic targeting a broad spectrum of Gram-positive and Gram-negative organisms. However, it also remains an important, yet often unrecognized, cause of encephalopathy. We are here to discuss a case of a 74-year-old male with a common bile duct low-grade adenoma who presented to the hospital for lethargy. He was placed on intravenous cefepime for a Pseudomonas-infected hepatobiliary abscess. Approximately five days later, the patient’s spouse reported acutely worsening cognitive changes. The cefepime level was significantly elevated at 160 µg/mL. Although not completely understood, cefepime is felt to antagonize gamma-aminobutyric acid A (GABA-A) receptors and possibly inhibit GABA release. This risk is accentuated in patients with underlying renal dysfunction and increased inflammation across the blood-brain barrier. Clinical manifestations include an impaired level of consciousness, delirium, myoclonus, and seizures. The treatment of choice is the cessation of the antibiotic, which resolves the neurotoxicity within approximately 48 hours. It is important to recognize cefepime as a potential culprit of acute-onset encephalopathy in the appropriate clinical setting, and the cessation of therapy would lead to a complete resolution of its associated neurotoxicity.

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

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

Cefepime neurotoxicity: thresholds and risk factors. A retrospective cohort study

OBJECTIVES

Toxic serum cefepime trough concentrations are not well defined in the current literature. We aimed to define a more precise plasma trough concentration threshold for this antibiotic's neurological toxicity and to identify individuals at risk for developing neurotoxic side effects.

METHODS

Retrospective study including all individuals who underwent cefepime therapeutic drug monitoring (TDM) between 2013 and 2017. Individuals with cefepime concentrations other than trough were excluded. The primary outcome was to assess the incidence of neurotoxicity and its relationship with cefepime plasma trough concentrations. Secondary outcomes were the relationship of renal function, cefepime daily dose, age, and cerebral and general co-morbidities with the occurrence of neurotoxicity. We also compared the mortality rate during hospitalization in individuals with and without neurotoxicity, and the possible impact of neuroprotective co-medications on outcomes.

RESULTS

Cefepime concentrations were determined in 584 individuals. Among 319 individuals with available trough concentrations included, the overall incidence of neurotoxicity was 23.2% (74 of 319 individuals). Higher cefepime plasma trough concentrations were significantly associated with risk of neurotoxicity (no neurotoxicity 6.3 mg/L (interquartile range (IQR) 4.1-8.6) versus with neurotoxicity 21.6 mg/L (IQR 17.0-28.6), p <0.001). Individuals with presumed cefepime neurotoxicity had a significantly lower renal function (estimated glomerular filtration rate 82.0 mL/min/1.73 m² (IQR 45.0-105.0) versus 35.0 mL/min/1.73 m² (IQR 23.3-53.3], p <0.001), and significantly higher in-hospital mortality (19 (7.8%) versus 26 (35.1%) individuals, p <0.001). No neurotoxic side effects were seen below a trough concentration of 7.7 mg/L. Levels ≥38.1 mg/L always led to neurological side effects.

CONCLUSION

In individuals with risk factors for cefepime neurotoxicity, such as renal insufficiency, TDM should be systematically performed, aiming at trough concentrations <7.5 mg/L.

Cefepime dosing regimens in critically ill patients receiving continuous renal replacement therapy: a Monte Carlo simulation study

Background

Cefepime can be removed by continuous renal replacement therapy (CRRT) due to its pharmacokinetics. The purpose of this study is to define the optimal cefepime dosing regimens for critically ill patients receiving CRRT using Monte Carlo simulations (MCS).

Methods

The CRRT models of cefepime disposition during 48 h with different effluent rates were developed using published pharmacokinetic parameters, patient demographic data, and CRRT settings. Pharmacodynamic target was the cumulative percentage of a 48-h period of at least 70% that free cefepime concentration exceeds the four times susceptible breakpoint of Pseudomonas aeruginosa (minimum inhibitory concentration, MIC of 8). All recommended dosing regimens from available clinical resources were evaluated for the probability of target attainment (PTA) using MCS to generate drug disposition in a group of 5000 virtual patients for each dose. The optimal doses were defined as achieving the PTA at least 90% of virtual patients with lowest daily doses and the acceptable risk of neurotoxicity.

Results

Optimal cefepime doses in critically ill patients receiving CRRT with Kidney Disease: Improving Global Outcomes (KDIGO) recommended effluent rates were a regimen of 2 g loading dose followed by 1.5–1.75 g every 8 h for Gram-negative infections with a neurotoxicity risk of < 17%. Cefepime dosing regimens from this study were considerably higher than the recommended doses from clinical resources.

Conclusion

All recommended dosing regimens for patients receiving CRRT from available clinical resources failed to achieve the PTA target. The optimal dosing regimens were suggested based on CRRT modalities, MIC values, and different effluent rates. Clinical validation is warranted.

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.

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 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.

A case of Cefepime encephalopathy, being difficult to distinguish from non-convulsive status epilepticus during the treatment of bacterial meningitis

A 64-year-old man with fever, appetite loss, and pain in the back of the neck visited our hospital. We diagnosed him as having bacterial meningitis because of pleocytosis of the cerebrospinal fluid, and started treatment with antibiotics. Multiple cerebral infarcts were found on brain MRI. We suspected that the origin of the bacterial meningitis was infective endocarditis, and administered Cefepime and Gentamicin according to the guidelines for treatment of infective endocarditis. Three days later, he became drowsy and had myoclonus and flapping of the extremities. An electroencephalograph showed generalized periodic discharge and a triphasic wave pattern. We thought that the cause of disturbance in consciousness was Cefepime-induced encephalopathy, and stopped administration of Cefepime. A few days later, he became clear, and the myoclonus and flapping disappeared. It was difficult to distinguish between non-convulsive status epilepticus and Cefepime-induced encephalopathy. However, since stopping Cefepime treatment had made the patient clear, we diagnosed his condition as Cefepime-induced encephalopathy, which often occurs in patients with renal or liver dysfunction, or in brain infarction or meningitis, which results in blood-brain barrier disruption. Thus, care should be taken when administering Cefepime to such patients.

Intermittent hemodialysis treatment in cefepime-induced neurotoxicity: case report, pharmacokinetic modeling, and review of the literature

Cefepime is a broad-spectrum cephalosporin indicated for in-hospital treatment of severe infections. Acute neurotoxicity, an increasingly recognized adverse effect of this drug in an overdose, predominantly affects patients with reduced renal function. Although dialytic approaches have been advocated to treat this condition, their role in this indication remains unclear. We report the case of an 88-year-old female patient with impaired renal function who developed life-threatening neurologic symptoms during cefepime therapy. She was treated with two intermittent 3-hour high-flux, high-efficiency hemodialysis sessions. Serial pre-, post-, and peridialytic (pre- and postfilter) serum cefepime concentrations were measured. Pharmacokinetic modeling showed that this dialytic strategy allowed for serum cefepime concentrations to return to the estimated nontoxic range 15 hours earlier than would have been the case without an intervention. The patient made a full clinical recovery over the next 48 hours. We conclude that at least 1 session of intermittent hemodialysis may shorten the time to return to the nontoxic range in severe clinically patent intoxication. It should be considered early in its clinical course pending chemical confirmation, even in frail elderly patients. Careful dosage adjustment and a high index of suspicion are essential in this population.

Neurotoxic effects associated with antibiotic use: management considerations

The clinical manifestations of antibiotic-induced neurotoxic effects, the underlying mechanisms and management strategies have been reviewed. PubMed and OVID searches (January 1960-June 2010) were conducted using search terms such as antibiotics, side effects, neurotoxicity and encephalopathy which yielded approximately 300 articles. All relevant case reports, case series, letters and retrospective reviews describing neurotoxic effects and those discussing mechanisms of neurotoxicity were included. Antibiotic-induced neurotoxic side effects can have a myriad of neurologic presentations. Patients with prior central nervous system (CNS) disease, renal insufficiency and advanced age may be particularly vulnerable. Treatment consists of discontinuation of the offending agent, use of antiepileptic drugs in the case of seizures or status epilepticus and haemodialysis in certain cases. The risk of CNS toxicity may be reduced via dosage adjustments in high risk populations. Awareness of the potential neurotoxic clinical manifestations of various antibiotics and high degree of vigilance in critically ill patients is essential in identifying a potentially serious, though reversible complications of antibiotic therapy particularly with the advent of newer antimicrobial agents.

Cefepime-Induced Neurotoxicity: A Review of the Evidence

Purpose

Cefepime-induced neurotoxicity is a relatively underappreciated and unrecognized adverse event in current clinical practice. Because cefepime is widely used in many hospitals, it is vital that clinicians be aware of this adverse event.

Methods

A systematic review of the literature was conducted to highlight the current evidence linking cefepime and neurotoxicity.

Results

More than 40 case reports were identified and analyzed for evidence of cefepime-induced neurotoxicity. Confusion, encephalopathy, coma, myoclonus, nonconvulsive status epilepticus, and frank seizures have been described. Most cases occurred in patients with impaired renal function. Onset of neurotoxicity ranged from 1 to 16 days. On discontinuation of cefepime, neurologic function returned to baseline.

Conclusions

Cefepime-induced neurotoxicity occurs primarily in patients with impaired renal function; however, several cases have occurred in patients with normal renal function. Most cases of neurotoxicity have arisen in patients who did not receive appropriate dose adjustment for renal impairment. The range of toxicity and latency are broad, thus clinicians must be aware of this adverse event and take all of the necessary steps to prevent the occurrence of neurotoxicity.

Nonconvulsive status epilepticus: high incidence in dialysis-dependent patients

Nonconvulsive status epilepticus is defined as a mental status change from baseline of at least a 30-min duration associated with constant or near-continuous ictal discharges on an electroencephalogram (EEG). Nonconvulsive status epilepticus is an often-overlooked diagnosis as a cause of acute confusional state. There are few case reports in dialysis patients. We are reporting 5 patients on chronic dialysis treatment who presented with an acute confusional state. Nonconvulsive status epilepticus was diagnosed by EEG and response to intravenous benzodiazepines. We recommend early EEG to be considered in the evaluation of dialysis patients with an acute confusional state.

Cefepime neurotoxicity: case report, pharmacokinetic considerations, and literature review

A 67-year-old woman with diabetes mellitus, chronic renal insufficiency, and recurrent urinary tract infections experienced encephalopathy and myoclonus while receiving cefepime. The adverse drug event was accompanied by elevated cefepime levels and abnormal electroencephalograms. This syndrome resolved after discontinuation of cefepime. Neurotoxicity is a known but possibly underreported adverse event associated with cefepime in patients with renal impairment who receive relatively excessive doses. Most cases reverse on drug cessation. In patients with renal disease, the maintenance dosage should be reduced and the patient monitored for neurotoxicity. Cefepime toxicity should be suspected whenever a patient receiving the drug experiences a change in mental status or myoclonus.

Optimizing antimicrobial therapy for gram-positive bloodstream infections in patients on hemodialysis

Infections with gram-positive organisms are highly prevalent in hemodialysis patients and are a major cause of morbidity and mortality in this population. Antimicrobial therapy is widely used to treat these infections, and prolonged therapy with these agents is often necessary. Extensive use of antimicrobials in hemodialysis patients has resulted in a growing threat of resistance, especially among gram-positive bacteria such as Enterococcus spp and Staphylococcus aureus. Vancomycin-resistant enterococci and S. aureus isolates with reduced susceptibility to vancomycin are increasingly being reported in hemodialysis patients. Additionally, resistance of these organisms to newer agents, such as linezolid and daptomycin, has been documented. Appropriate utilization of antimicrobial therapy to treat these organisms requires an understanding of the pharmacokinetic and pharmacodynamic principles to optimize therapy and avoid adverse drug events. The pharmacokinetic and pharmacodynamic profile of antimicrobial agents can be significantly altered in patients with chronic kidney disease. This review will describe mechanisms of antimicrobial resistance among common gram-positive organisms. The pharmacokinetic and pharmacodynamic principles of cephalosporins, vancomycin, aminoglycosides, linezolid, and daptomycin and applications for use of these agents in the treatment of patients with bloodstream infections on hemodialysis are discussed.

Retrospective review of neurotoxicity induced by cefepime and ceftazidime

We reviewed 42 cases of cefepime-induced neurotoxicity and 12 cases of ceftazidime-induced neurotoxicity from the literature and our institution. Clinical characteristics and timing of diagnosis were examined. Common findings were confusion with temporospatial disorientation (96% of patients), myoclonus (33%), and seizures (13%). These neurologic disorders frequently are encountered in uremic and elderly patients, who often are in a confused state when they visit their physician. The risk of delayed diagnosis was greater with cefepime than ceftazidime neurotoxicity. The median interval between symptom onset and diagnosis of cefepime versus ceftazidime neurotoxicity was 5 and 3 days, respectively (p=0.005). Delayed diagnosis of cefepime neurotoxicity may be due to lack of awareness of the adverse effect. Data gathered since these two broad-spectrum antibiotics were first marketed underscore the potential for neurologic adverse events secondary to their administration. Thus, clinicians' awareness must be increased so that the time between symptom onset and diagnosis can be reduced.

Cefepime versus vancomycin plus netilmicin therapy for continuous ambulatory peritoneal dialysis-associated peritonitis

Cefepime is a cephalosporin with a broad spectrum of activity against most gram-positive and gram-negative pathogens. In this study, we attempted to compare the safety and efficacy of cefepime monotherapy against the potentially more toxic combination of vancomycin and netilmicin in the treatment of continuous ambulatory peritoneal dialysis (CAPD)-associated bacterial peritonitis. Eighty-one consecutive CAPD patients who presented with peritonitis from January 1, 1998, to June 30, 2000, were recruited for study. Patients were randomized to be administered either intraperitoneal (IP) cefepime, 1 g once daily (group A), or intravenous vancomycin and netilmicin at conventional doses (group B) for 10 days. Bacterial growth was obtained in 52 episodes (66%), and pathogens identified included gram-positive organisms (30 episodes; 38%), gram-negative organisms (14 episodes; 18%), mixed organisms (2 episodes; 2.5%), and fungus (6 episodes; 8%). Eight patients were excluded after randomization for various reasons (6 patients, fungal peritonitis; 2 patients, wrong diagnoses). Because of the relatively low peritonitis rate after the use of a disconnect system, the sample size of this study was relatively small, giving a power of 0.45. There were no significant differences in primary response rates and cure rates (no relapse >28 days after completion of antibiotic therapy) between both groups of patients (group A versus group B, 82% [32 of 39 patients] versus 85% [29 of 34 patients] and 72% [28 of 39 patients] versus 76% [26 of 34 patients], respectively; P = not significant). No significant side effect was encountered in either group. Total peritonitis-related hospitalizations were 84 patient-days (1, 7, 8, 11, 20, and 37 patient-days) and 115 patient-days (3, 6, 9, 14, 21, 21, and 41 patient-days), whereas total costs per patient cure were estimated to be US $1,039 and US $1,371 in groups A and B, respectively. We conclude that once-daily 1-g IP cefepime monotherapy is a simple, safe, and cost-effective alternative to vancomycin and netilmicin therapy in the treatment of CAPD-associated bacterial peritonitis.