The safety of cefepime in the treatment of infection

In vitro activity of cefepime/taniborbactam and comparator agents against Gram-negative bacterial bloodstream pathogens recovered from patients with cancer

Background

Taniborbactam is a β-lactamase inhibitor that, when combined with cefepime, may offer a potential treatment option for patients with serious and resistant Gram-negative bacterial (GNB) pathogens.

Objectives

This study evaluated in vitro activity of cefepime/taniborbactam and comparator agents against GNB pathogens isolated from patients with cancer at our institution.

Methods

A total of 270 GNB pathogens (2019-23) isolated from patients with cancer were tested against cefepime/taniborbactam and comparator agents commonly used for these patients. CLSI-approved broth microdilution methods were used. MIC50, MIC90, MIC range and percentage of susceptibility calculations were made using FDA breakpoints when available.

Results

Cefepime/taniborbactam showed highly potent activity against tested Enterobacterales, including isolates producing ESBLs and carbapenem-resistant Enterobacterales. At a provisional breakpoint of ≤16/4 mg/L, cefepime/taniborbactam inhibited most tested species of GNB pathogens, with overall 98.9% susceptibility, which was significantly (P < 0.0001) higher than the susceptibility of the GNB isolates to all other tested comparator agents, ranging from 39.6% for cefepime to 86.3% for ceftazidime/avibactam.

Conclusions

Our results showed that taniborbactam in combination with cefepime improved in vitro activity against GNB pathogens isolated from patients with cancer, including MDR Pseudomonas aeruginosa, carbapenem-resistant Enterobacterales, ESBL-producing Enterobacterales and Stenotrophomonas maltophilia isolates, with highest activity compared with all tested comparator agents, including other β-lactam/β-lactamase inhibitor combinations. Further studies are warranted to explore the efficacy of cefepime/taniborbactam for empirical initial treatment of GNB infections in cancer patients with high rates of febrile neutropenia requiring hospitalization.

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.

Lipidomics Reveals Dysregulated Glycerophospholipid Metabolism in the Corpus Striatum of Mice Treated with Cefepime

Cefepime exhibits a broad spectrum of antimicrobial activity and thus is a widely used treatment for severe bacterial infections. Adverse effects on the central nervous system (CNS) have been reported in patients treated with cefepime. Current explanation for the adverse neurobehavioral effect of cefepime is mainly attributed to its ability to cross the blood-brain barrier and competitively bind to the GABAergic receptor; however, the underlying mechanism is largely unknown. In this study, mice were intraperitoneally administered 80 mg/kg cefepime for different periods, followed by neurobehavioral tests and a brain lipidomic analysis. LC/MS-MS-based metabolomics was used to investigate the effect of cefepime on the brain lipidomic profile and metabolic pathways. Repeated cefepime treatment time-dependently caused anxiety-like behaviors, which were accompanied by reduced locomotor activity in the open field test. Cefepime profoundly altered the lipid profile, acyl chain length, and unsaturation of fatty acids in the corpus striatum, and glycerophospholipids accounted for a large proportion of those significantly modified lipids. In addition, cefepime treatment caused obvious alteration in the lipid-enriched membrane structure, neurites, mitochondria, and synaptic vesicles of primary cultured striatal neurons; moreover, the spontaneous electrical activity of striatal neurons was significantly reduced. Collectively, cefepime reprograms glycerophospholipid metabolism in the corpus striatum, which may interfere with neuronal structure and activity, eventually leading to aberrant neurobehaviors in mice.

Safety and Pharmacokinetics in Human Volunteers of Taniborbactam (VNRX-5133), a Novel Intravenous β-Lactamase Inhibitor

Taniborbactam (formerly VNRX-5133), an investigational β-lactamase inhibitor active against both serine- and metallo-β-lactamases, is being developed in combination with cefepime to treat serious infections caused by multidrug-resistant Gram-negative bacteria. This first-in-human study evaluated the safety and pharmacokinetics of single and multiple doses of taniborbactam in healthy adult subjects. Single doses of 62.5 to 1,500 mg taniborbactam and multiple doses of 250 to 750 mg taniborbactam every 8 h (q8h) for 10 days were examined; all taniborbactam doses were administered as a 2-h intravenous infusion. No subjects experienced serious adverse events or discontinued treatment due to adverse events. The most common adverse event in both placebo- and taniborbactam-treated subjects was headache. The pharmacokinetics of taniborbactam were similar to the pharmacokinetics reported for cefepime. Taniborbactam demonstrated dose-proportional pharmacokinetics with low intersubject variability. Following single doses and with extended sampling, the mean terminal elimination half-life ranged from 3.4 to 5.8 h; however, the majority of exposure was characterized by an earlier phase with a half-life of about 2 h. Following multiple dosing, there was minimal accumulation of taniborbactam in plasma. At steady-state, approximately 90% of the administered dose of taniborbactam was recovered in urine as intact drug. There was no appreciable metabolism observed in either plasma or urine samples. (This study is registered at clinicaltrials.gov under registration number NCT02955459.)

Characterizing Cefepime Neurotoxicity: A Systematic Review

Neurotoxicity due to cefepime has not been well characterized. We performed a systematic review of the literature and included 5 additional cases from our center. Of the 198 cases found, the mean age was 67 years and 87% of patients had renal dysfunction. The most common clinical features were diminished level of consciousness (80%), disorientation/agitation (47%), and myoclonus (40%). It is worth noting that nonconvulsive status epilepticus was relatively common with 31% of cases, whereas only 11% had convulsive seizures. Single-center estimate of incidence was 1 in 480 courses of cefepime. Cefepime neurotoxicity should be considered in older patients with renal dysfunction and new onset encephalopathy, especially if concurrent myoclonus is present. More work is needed to prospectively assess incidence and outcomes related to cefepime neurotoxicity.

Cefepime effectiveness in Gram-negative bloodstream infections

BACKGROUND

We used a retrospective cohort to evaluate the 28 day all-cause mortality in adult patients with Gram-negative bloodstream infection (BSI) who received cefepime therapy compared with those who received other β-lactam antibiotics with in vitro activity against aerobic Gram-negative bacilli.

METHODS

We identified 398 adult patients who received β-lactam antibiotic monotherapy during hospitalization at Mayo Clinic hospitals in Rochester, MN, USA, for monomicrobial Gram-negative BSI from 1 January 2001 to 31 October 2006. After adjusting for the propensity to receive cefepime, multivariable Cox proportional hazard regression was used to compare the 28 day mortality in patients who were treated with cefepime with that in those who received other β-lactam antibiotics.

RESULTS

The median age of patients with Gram-negative BSI was 65 years (interquartile range 51-77) and 230 (58%) were male. Compared with patients who received other β-lactams, patients treated with cefepime were more likely to have cancer (59% versus 44%, P = 0.007) and immunocompromising conditions (55% versus 21%, P < 0.001). Patients who received cefepime were less likely to have community-acquired infection acquisition (18% versus 33%, P = 0.002) and urinary source of BSI (14% versus 23%, P = 0.04) than those treated with other β-lactam antibiotics. After adjusting for the propensity to receive cefepime and other covariates in the multivariable Cox model, cefepime therapy was not associated with an increased 28 day all-cause mortality (hazard ratio 0.99, 95% confidence interval 0.53-1.79, P = 0.97).

CONCLUSIONS

In adult patients with monomicrobial Gram-negative BSI, cefepime therapy was not associated with increased mortality when compared with other β-lactam antibiotics.

Cefepime and mortality: a real issue?

The fourth-generation cephalosporin, cefepime, has an antimicrobial spectrum that makes it a valuable antibiotic for empirical treatment of neutropenic fever. Randomized trials have proven the efficacy and safety of cefepime in neutropenic fever. However, 2 recent meta-analyses have shown an increased all-cause mortality for cefepime. Since then, many clinicians have been left in doubt about the use of cefepime for this indication. In this paper, we put in perspective some of the methodological and clinical issues and call for further clinical analyses.

A focus on intra-abdominal infections

Complicated intra-abdominal infections are an important cause of morbidity and are frequently associated with poor prognosis, particularly in higher risk patients.

Well defined evidence-based recommendations for intra-abdominal infections treatment are partially lacking because of the limited number of randomized-controlled trials.

Factors consistently associated with poor outcomes in patients with intra-abdominal infections include increased illness severity, failed source control, inadequate empiric antimicrobial therapy and healthcare-acquired infection.

Early prognostic evaluation of complicated intra-abdominal infections is important to select high-risk patients for more aggressive therapeutic procedures.

The cornerstones in the management of complicated intra-abdominal infections are both source control and antibiotic therapy.

The timing and the adequacy of source control are the most important issues in the management of intra-abdominal infections, because inadequate and late control of septic source may have a negative effect on the outcomes.

Recent advances in interventional and more aggressive techniques could significantly decrease the morbidity and mortality of physiologically severe complicated intra-abdominal infections, even if these are still being debated and are yet not validated by limited prospective trials.

Empiric antimicrobial therapy is nevertheless important in the overall management of intra-abdominal infections. Inappropriate antibiotic therapy may result in poor patient outcomes and in the appearance of bacterial resistance.

Antimicrobial management is generally standardised and many regimens, either with monotherapy or combination therapy, have proven their efficacy. Routine coverage especially against Enterococci and candida spp is not always recommended, but can be useful in particular clinical conditions. A de escalation approach may be recommended in patients with specific risk factors for multidrug resistant infections such as immunodeficiency and prolonged antibacterial exposure.

Therapy should focus on the obtainment of adequate source control and adequate use of antimicrobial therapy dictated by individual patient risk factors. Other critical issues remain debated and more controversies are still open mainly because of the limited number of randomized controlled trials.

Cefepime and mortality in pediatric acute myelogenous leukemia: a retrospective cohort study

BACKGROUND

Based on 2 meta-analyses, the Food and Drug Administration issued a communication in 2009 regarding the potential risk of death in patients treated with cefepime. Pediatric patients with acute myelogenous leukemia (AML) have frequent episodes of fever necessitating the use of antibiotics such as cefepime. We evaluated the association of cefepime and other beta-lactam antibiotic exposures with all cause in-hospital mortality in pediatric AML patients.

METHODS

We performed a retrospective cohort study using the Pediatric Health Information System, an inpatient database. Exposure to cefepime, ceftazidime, antipseudomonal penicillin, and carbapenems was evaluated for each 30-day period within the first year from AML diagnosis. Cox regression analysis was used to compute hazard ratios (HR) for death adjusting for demographics, clinical variables, and clustering by hospital. The final analysis used 2 distinct time periods (0-3 months and >3-12 months) to account for variation in proportional hazards over time.

RESULTS

No differences between the HRs for mortality were observed for the time period of 0 to 3 months (cefepime vs. ceftazadime: HR=1.33, 95% CI: 0.70-2.52; cefepime vs. antipseudmonal penicillin: HR=0.86, 95% CI: 0.34-2.13; and cefepime vs. carbapenems: HR=1.08, 95% CI: 0.50-2.35) or the time period of >3 to 12 months after diagnosis (cefepime vs. ceftazadime: HR=1.29, 95% CI: 0.53-3.15; cefepime vs. antipseudomonal penicillin: HR=1.08, 95% CI: 0.44-2.66; and cefepime vs. carbapenems: HR=1.03, 95% CI: 0.45-2.33).

CONCLUSIONS

In this cohort of pediatric AML patients, cefepime exposure in the 30 days preceding death did not result in an increased mortality risk when compared with ceftazidime, antipseudomonal penicillins, or carbapenems.