A randomized trial of cefepime (BMY-28142) and ceftazidime for the treatment of pneumonia

Potential Antibiotics for the Treatment of Neonatal Sepsis Caused by Multidrug-Resistant Bacteria

Neonatal sepsis causes up to an estimated 680,000 deaths annually worldwide, predominantly in low- and middle-income countries (LMICs). A significant and growing proportion of bacteria causing neonatal sepsis are resistant to multiple antibiotics, including the World Health Organization-recommended empiric neonatal sepsis regimen of ampicillin/gentamicin. The Global Antibiotic Research and Development Partnership is aiming to develop alternative empiric antibiotic regimens that fulfil several criteria: (1) affordable in LMIC settings; (2) activity against neonatal bacterial pathogens, including extended-spectrum β-lactamase producers, gentamicin-resistant Gram-negative bacteria, and methicillin-resistant Staphylococcus aureus (MRSA); (3) a licence for neonatal use or extensive experience of use in neonates; and (4) minimal toxicities. In this review, we identify five antibiotics that fulfil these criteria: amikacin, tobramycin, fosfomycin, flomoxef, and cefepime. We describe the available characteristics of each in terms of mechanism of action, resistance mechanisms, clinical pharmacokinetics, pharmacodynamics, and toxicity profile. We also identify some knowledge gaps: (1) the neonatal pharmacokinetics of cefepime is reliant on relatively small and limited datasets, and the pharmacokinetics of flomoxef are also reliant on data from a limited demographic range and (2) for all reviewed agents, the pharmacodynamic index and target has not been definitively established for both bactericidal effect and emergence of resistance, with many assumed to have an identical index/target to similar class molecules. These five agents have the potential to be used in novel combination empiric regimens for neonatal sepsis. However, the data gaps need addressing by pharmacokinetic trials and pharmacodynamic characterisation.

Clostridium difficile infection following systemic antibiotic administration in randomised controlled trials: a systematic review and meta-analysis

Antibiotics have been the most important risk factor for Clostridium difficile infection (CDI). However, only data from non-randomised studies have been reviewed. We sought to evaluate the risk for development of CDI associated with the major antibiotic classes by analysing data from randomised controlled trials (RCTs). The PubMed, Cochrane and Scopus databases were searched and the references of selected RCTs were also hand-searched. Eligible studies should have compared only one antibiotic versus another administered systemically. Inclusion of studies comparing combinations of antibiotics was allowed only if the second antibiotic was the same or from the same class or if it was administered in a subset of the enrolled patients who were equally distributed in the two arms. Only a minority of the selected RCTs (79/1332; 5.9%) reported CDI episodes. Carbapenems were associated with more CDI episodes than fluoroquinolones [risk ratio (RR) = 2.44, 95% confidence interval (CI) 1.32-4.49] and cephalosporins (RR = 2.24, 95% CI 1.46-3.42), but not penicillins (RR = 2.53, 95% CI 0.87-7.41). Cephalosporins were associated with more CDIs than penicillins (RR = 2.36, 95% CI 1.32-4.23) and fluoroquinolones (RR = 2.84, 95% CI 1.60-5.06). There was no difference in CDI frequency between fluoroquinolones and penicillins (RR = 1.34, 95% CI 0.55-3.25). Finally, clindamycin was associated with more CDI episodes than cephalosporins and penicillins (RR = 3.92, 95% CI 1.15-13.43). In conclusion, data from RCTs showed that clindamycin and carbapenems were associated with more CDIs than other antibiotics.

Cefepime

Cefepime (Maxipime), Maxcef, Cepimax, Cepimex, Axepim, a parenteral fourth-generation cephalosporin, is active against many organisms causative in pneumonia. Cefepime has in vitro activity against Gram-positive organisms including Staphylococcus aureus and penicillin-sensitive, -intermediate and -resistant Streptococcus pneumoniae similar to that of cefotaxime and ceftriaxone. Cefepime also has good activity against Gram-negative organisms, including Pseudomonas aeruginosa, similar to that of ceftazidime. Importantly, cefepime is stable against many of the common plasmid- and chromosome-mediated beta-lactamases and is a poor inducer of AmpC beta-lactamases. As a result, it retains activity against Enterobacteriaceae that are resistant to third-generation cephalosporins, such as derepressed mutants of Enterobacter spp. Cefepime may be hydrolyzed by the extended-spectrum beta-lactamases produced by some members of the Enterobacteriaceae, but to a lesser extent than the third-generation cephalosporins. Monotherapy with cefepime 1 or 2g, usually administered intravenously twice daily, was as effective for clinical and bacteriological response as ceftazidime, ceftriaxone or cefotaxime monotherapy (1 or 2g two or three times daily) in a number of randomized, clinical trials in hospitalized adult, or less commonly, pediatric, patients with generally moderate to severe community-acquired or nosocomial pneumonia. More limited data indicated that monotherapy with cefepime 2g three times daily was also as effective in treating patients with nosocomial pneumonia as imipenem/cilostatin 0.5g four times daily, and when combined with amikacin, cefepime was as effective as ceftazidime plus amikacin. Patients with pneumonia who failed to respond to previous antibacterial therapy with penicillins or other cephalosporins responded to treatment with cefepime. Cefepime is generally well tolerated, with a tolerability profile similar to those of other parenteral cephalosporins. In clinical trials, the majority of adverse events experienced by cefepime recipients were mild to moderate and reversible. The most common adverse events with a causal relationship to cefepime reported in clinical trials included rash and diarrhea. Other, less common, adverse events included pruritus, urticaria, nausea, vomiting oral candidiasis, colitis, headache, fever, erythema and vaginitis.

CONCLUSION

Cefepime is an established and generally well tolerated parenteral drug with a broad spectrum of antibacterial activity which, when administered twice daily, provides coverage of most of the pathogens that may be causative in pneumonia. In randomized clinical trials in hospitalized patients with generally moderate to severe community-acquired or nosocomial pneumonia, cefepime monotherapy exhibited good clinical and bacteriological efficacy. Cefepime may become a preferred antibacterial agent for infections caused by Enterobacter spp. With prudent use in order to prevent the emergence of resistant organisms, cefepime will continue to be a suitable option for the empiric treatment of pneumonia.

Cefepime: a reappraisal in an era of increasing antimicrobial resistance

Cefepime is a 'fourth-generation' cephalosporin with an in vitro extended-spectrum of activity against Gram-negative and Gram-positive pathogens. Cefepime is approved for the treatment of moderate-to-severe infections, such as pneumonia, uncomplicated and complicated urinary tract infections, skin and soft-tissue infections, intra-abdominal infections and febrile neutropenia. In this article, we provide a critical review of pharmacodynamics, clinical management, pharmacokinetics, metabolism, pharmacodynamic target analyses, clinical efficacy, safety and tolerability of cefepime after more than a decade of clinical use.

Broad-spectrum antimicrobials and the treatment of serious bacterial infections: getting it right up front

The treatment of serious bacterial infections is complicated by the fact that time to initiation of effective antimicrobial therapy is a strong predictor of mortality. Therefore, therapy must be initiated before the causative pathogen is identified. However, inappropriate or inadequate initial empirical therapy is associated with increased mortality, morbidity, and length of hospital stay. Initial empirical therapy with broad-spectrum antimicrobials attempts to address this dilemma by "getting it right up front." The goal is to provide treatment active against the most likely pathogens until culture/susceptibility test results are obtained. After the causative pathogen is identified, streamlining to more-precise therapy of the shortest acceptable duration is implemented. In this way, the risks of death, morbid complications, increased duration of hospital stay (as a result of ineffective initial treatment), and emergence of resistance (due to extended treatment with broad-spectrum agents) are lowered. Improved clinical and economic outcomes after such an approach have been demonstrated.

Efficacy and safety of cefepime: a systematic review and meta-analysis

Cefepime is a broad-spectrum cephalosporin with enhanced coverage against Gram-positive and Gram-negative bacteria. We did a systematic review of randomised trials that compared cefepime with another beta-lactam antibiotic, alone or with the addition of a non-beta-lactam antibiotic to both study groups. We searched Central, PubMed, Embase, Lilacs, new US Food and Drug Administration drug applications, conference proceedings, and references of the included studies. Two reviewers independently did the search and data extraction. 57 trials were included. All-cause mortality-the primary outcome-was higher with cefepime than other beta-lactams (risk ratio [RR] 1.26 [95% CI 1.08-1.49]). Sensitivity analyses by the trials' methodological quality revealed higher RRs for trials reporting adequate allocation-sequence generation (1.52 [1.20-1.92]) and allocation concealment (1.36 [1.09-1.70]). Baseline risk factors for mortality were similar. No significant differences between groups in treatment failure, superinfection, or adverse events were found. This Review provides evidence and offers possible explanations for increased mortality among patients treated with cefepime in randomised trials.

Cefepime versus ceftazidime: considerations for empirical use in critically ill patients

Sepsis and nosocomial infections continue to be a significant problem in intensive care, contributing heavily to mortality and prolonged hospital stay. Early and appropriate antibiotic therapy is critical for optimising outcomes. However, the emergence of highly resistant bacteria, coupled with reduced development of novel antibiotics, means that there is a real threat of development of untreatable nosocomial infections. Cefepime and ceftazidime are broad-spectrum cephalosporins that are widely used to treat Gram-negative nosocomial infections in critically ill patients. Available data suggest that cefepime may have advantages over ceftazidime owing to a broader spectrum of activity and reduced potential for development of bacterial resistance. However, whether either of these agents is superior can only be determined by a head-to-head study evaluating clinical and bacteriological outcomes. Such a study to determine whether apparent differences translate into clinically relevant differences in outcome is indicated.

Cefepime versus ceftazidime for treatment of pneumonia

Consecutive patients with pneumonia, treated with cefepime (n = 66) or ceftazidime (n = 132), were evaluated in a retrospective, observational study. There was no significant difference between the two treatment groups with respect to age, underlying diseases, acute physical and chronic health evaluation score, intensive care unit admission, presence of sepsis, community or hospital acquisition, causative organism, duration of therapy, death, cure or improvement in infection, adverse events, superinfections, presence of vancomycin-resistant enterococcus (VRE) and resistance to therapy. Post-therapy hospitalization (days) and vancomycin co-administration were significantly lower, and time to vancomycin initiation significantly higher, in the cefepime compared with the ceftazidime group. The results suggest a trend towards less resistance on therapy, less VRE, reduced vancomycin use and shorter post-therapy hospitalization in patients treated with cefepime compared with ceftazidime. The clinical outcomes for hospitalized patients treated for serious pneumonia were similar between the two groups.

Cefepime versus imipenem-cilastatin for treatment of nosocomial pneumonia in intensive care unit patients: a multicenter, evaluator-blind, prospective, randomized study

In a randomized, evaluator-blind, multicenter trial, we compared cefepime (2 g three times a day) with imipenem-cilastatin (500 mg four times a day) for the treatment of nosocomial pneumonia in 281 intensive care unit patients from 13 centers in six European countries. Of 209 patients eligible for per-protocol analysis of efficacy, favorable clinical responses were achieved in 76 of 108 (70%) patients treated with cefepime and 75 of 101 (74%) patients treated with imipenem-cilastatin. The 95% confidence interval (CI) for the difference between these response rates (-16 to 8%) failed to exclude the predefined lower limit for noninferiority of -15%. In addition, therapy of pneumonia caused by an organism producing an extended-spectrum beta-lactamase (ESBL) failed in 4 of 13 patients in the cefepime group but in none of 10 patients in the imipenem group. However, the clinical efficacies of both treatments appeared to be similar in a secondary intent-to-treat analysis (95% CI for difference, -9 to 14%) and a multivariate analysis (95% CI for odds ratio, 0.47 to 1.75). Furthermore, the all-cause 30-day mortality rates were 28 of 108 (26%) patients in the cefepime group and 19 of 101 (19%) patients in the imipenem group (P = 0.25). Rates of documented or presumed microbiological eradication of the causative organism were similar with cefepime (61%) and imipenem-cilastatin (54%) (95% CI, -23 to 8%). Primary or secondary resistance of Pseudomonas aeruginosa was detected in 19% of the patients treated with cefepime and 44% of the patients treated with imipenem-cilastatin (P = 0.05). Adverse events were reported in 71 of 138 (51%) and 62 of 141 (44%) patients eligible for safety analysis in the cefepime and imipenem groups, respectively (P = 0.23). Although the primary end point for this study does not exclude the possibility that cefepime was inferior to imipenem, some secondary analyses showed that the two regimens had comparable clinical and microbiological efficacies. Cefepime appeared to be less active against organisms producing an ESBL, but primary and secondary resistance to imipenem was more common for P. aeruginosa. Selection of a single agent for therapy of nosocomial pneumonia should be guided by local resistance patterns.

Continuous versus intermittent administration of ceftazidime in intensive care unit patients with nosocomial pneumonia

A prospective, randomized pilot study was undertaken to compare the efficacy of continuous versus intermittent ceftazidime in ICU patients with nosocomial pneumonia. Ceftazidime was administered either as a 3 g/day continuous infusion (CI) or an intermittent infusion (II) of 2 g every 8 h. In addition, all patients received concomitant once-daily tobramycin. The demographics of the evaluable patients (n = 35) were similar between the groups: age (years), CI 46 +/- 16, II 56 +/- 20; Apache score, CI 14 +/- 4, II 16 +/- 6; time (days) from admission to diagnosis, CI 9 +/- 6, II 9 +/- 6. Clinical efficacy, defined as cure/improvement was similar between groups [n (%), CI 16/17 (94), II 15/18 (83)], while microbiological response was also comparable [n (%), CI 10/13 (76), II 12/15 (80)]. Minimal inhibitory concentrations (MICs) for all isolates were measured throughout the treatment course; there was no development of resistance during therapy for either regimen. While limited clinical data exist, our results suggest that the use of ceftazidime by CI administration maintains clinical efficacy, optimizes the pharmacodynamic profile and uses less antibiotic compared with the standard 2 g every 8 h intermittent dosing regimen.

A randomized trial of cefepime and ceftazidime for the treatment of community-acquired pneumonia

We compared the effectiveness and safety of ceftazidime and cefepime in hospitalized patients with community-acquired pneumonia. The 148 enrolled patients received 2 g ceftazidime three times daily or 2 g cefepime twice daily. The clinical success rate was the same for both drugs. Even the microbiological effectiveness was similar. Both drug regimens were well tolerated. We conclude that 2 g ceftazidime three times daily were as effective as 2 g cefepime twice daily for the treatment of community-acquired pneumonia in hospitalized patients. The cost of ceftazidime treatment was, however, higher than the cost of cefepime treatment.

Efficacy and safety of cefepime treatment in Chinese patients with severe bacterial infections: in comparison with ceftazidime treatment

An open label, randomized comparative study was conducted to evaluate the safety and efficacy of cefepime, in comparison with ceftazidime, in the treatment of adult hospitalized Chinese patients with severe bacterial infections. Forty patients with severe infections including septicemia, urinary tract infection and bacterial pneumonia were randomly assigned to receive treatment with cefepime (2 g intravenously every 12 h) or ceftazidime (2 g intravenously every 8 h). The cefepime group (20 evaluable patients) and ceftazidime group (16 evaluable patients) were comparable with respect to age, sex, underlying diseases and distribution of infection type. In both groups urinary tract infection was the most common type of infection and Escherichia coli was the most common etiologic microorganism. The rates of satisfactory clinical response were similar in the cefepime and ceftazidime groups (95 versus 93.7%; 95% confidence interval: -0.14 - 0.17, P = 0.87). The bacteriological response rates of the cefepime and ceftazidime groups did not differ significantly (88.9 versus 85.7%; 95% confidence interval: -0.30 - 0.36, P = 0.85). Both cefepime and ceftazidime were well tolerated, with similar incidence of side effects. The results of this study suggest that cefepime is as safe and effective as ceftazidime for the treatment of serious infections in adult hospitalized Chinese patients.

Cefepime versus ceftriaxone for empiric treatment of hospitalized patients with community-acquired pneumonia. The Cefepime Study Group

Effective empiric treatment of pneumonia requires antibiotic coverage against gram-negative and gram-positive pathogens, including drug-resistant isolates. We compared the safety and efficacy of intravenous (i.v.) cefepime (2 g administered every 12 h) to those of i.v. ceftriaxone (1 g administered every 12 h) for the empiric treatment of hospitalized patients with community-acquired pneumonia. Of the 115 patients randomized to the study, 86 (cefepime recipients, n = 40; ceftriaxone recipients, n = 46) were evaluated for clinical efficacy (clinically evaluated patients). Favorable clinical outcomes (cure or improvement) were comparable among clinically evaluated patients in the cefepime and ceftriaxone treatment arms (95.0 versus 97.8%, respectively; 95% confidence interval for treatment difference [data for ceftriaxone group minus data for cefepime group], -5.1 to +10.8%). The most common bacteria isolated from patients in both treatment groups were Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus. In clinically evaluated patients with a microbiologic response, all (100%) of the 32 pathogens from cefepime-treated patients and 97.4% (38 of 39) of the pathogens from ceftriaxone-treated patients were eradicated (documented or presumed eradication). The one persistent infection in the ceftriaxone group was caused by Pseudomonas fluorescens. Both treatments were well tolerated. Our data thus suggest that cefepime and ceftriaxone have comparable safety and efficacy for the treatment of pneumonia in hospitalized patients.

Bacteriologic and clinical applications of a new extended-spectrum parenteral cephalosporin

Although third-generation cephalosporins have been considered the backbone of antibiotic therapy for the treatment of many kinds of serious infections, including those in hospitalized patients, lack of activity against some important pathogens still exists among currently available drugs. In addition, increasing accounts of antibiotic resistance, particularly in the hospital environment, are of deep concern and have thus led to the need for the development of newer antimicrobial agents. Cefepime is a now parenteral cephalosporin with an extended spectrum of antibacterial activity that includes both aerobic gram-negative and gram-positive bacteria. It is also active against many gram-negative organisms resistant to ceftriaxone and cefotaxime, as well as many strains of Enterobacter and Citrobacter resistant to ceftazidime. Cefepime appears to be less likely to select out resistant organisms, and it may be less likely to change hospital flora than currently available antimicrobials. Cefepime has been shown to be very well tolerated and effective in the treatment of a variety of infections including moderate-to-severe pneumonia (including cases associated with concurrent bacteremia), complicated and uncomplicated urinary tract infections (also including cases associated with concurrent bacteremia), and skin and skin-structure infections. Clinical response rates are > or = 75% for most infections and have been comparable to ceftazidime in comparative trials. In addition, pretreatment susceptibility testing indicates that >94% of organisms isolated in patients enrolled in clinical trials were susceptible to cefepime.

A new therapeutic option for the treatment of pneumonia

Patients with bacterial pneumonia often are treated empirically with parenteral broad-spectrum antimicrobials intended to cover potential gram-negative and gram-positive pathogens. However, beta-lactamase-mediated resistance has developed to many of these antimicrobials, particularly third-generation cephalosporins, and has led to the development of fourth-generation agents that are relatively beta-lactamase stable. The purpose of these studies was to compare the efficacy and safety of the fourth-generation agent, cefepime, with that of the third-generation agent, ceftazidime, in the treatment of hospitalized patients with moderate-to-severe bacterial pneumonia. A total of 336 (97 evaluable) patients were enrolled in an open-label study, and 99 (23 evaluable) patients were enrolled in a blinded study of patients with lower respiratory tract infections (LRTI) including pneumonia. Patients were randomized to receive either cefepime 1 g every 12 hours or ceftazidime 1 g every 8 hours given as an intravenous infusion over 30 minutes. Efficacy analysis included the evaluable patients while the safety analysis included all patients. The results in the open-label study were as follows: In patients with pneumonia, clinical response was satisfactory in 58 (85%) of 68 patients in the cefepime group and 21 (72%) of 29 patients in the ceftazidime group. Bacteriologic eradication occurred for 75 (93%) of 81 pathogens and 30 (94%) of 32 pathogens isolated from the 68 cefepime-treated patients and 29 ceftazidime-treated patients, respectively. The results in the blinded study were as follows: In patients with pneumonia, clinical response was satisfactory in 12 (80%) of 15 cefepime patients and in 7 (88%) of 8 ceftazidime patients, and the bacteriologic eradication rates were 85% (17/20 pathogens) and 73% (8/11 pathogens) isolated from the 15 cefepime-treated patients and the eight ceftazidime-treated patients, respectively. Among the most frequent adverse events in both groups were nausea, diarrhea, vomiting, and abdominal pain. Similar adverse events were noted in the 99 patients in the blinded study. These studies indicate that the efficacy and safety of cefepime administered at 1 g twice daily is comparable to that of ceftazidime administered at 1 g three times daily for treatment of hospitalized patients with pneumonia caused by susceptible pathogens.

Safety of cefepime: a new extended-spectrum parenteral cephalosporin

The purpose of this study was to compare the safety profile of cefepime, a new extended-spectrum, fourth-generation cephalosporin used to treat mild-to-severe bacterial infections, with that of ceftazidime. A total of 2,032 patients enrolled in North American and European cefepime trials were analyzed. The study population spanned adolescence to the elderly (15-100 years); the median age was 62 years. Cefepime was compared with ceftazidime (1,456 patients), a third-generation cephalosporin. Cefepime dosing was 1-4 g/day (0.5-2.0 g twice daily) for adults; ceftazidime dosing was 1-6 g/day (0.5 g every 12 hours to 2.0 g every 8 hours). A limited number of cefepime-treated patients received 2 g every 8 hours. The median length of dosing for both cefepime and ceftazidime was 7 days. In randomized trials in which cefepime (2,032 patients) was compared with ceftazidime (1,456 patients), analysis of comparative data indicated that adverse events of probable or unknown relation to study drugs were observed in 13.8% of cefepime patients and 15.6% of ceftazidime patients. The most commonly observed adverse event for cefepime was headache (2.4%), followed by nausea (1.8%), rash (1.8%), and diarrhea (1.7%). For ceftazidime, the most commonly observed adverse event was diarrhea (3.2%), followed by headache (2.5%), nausea (2.1%), rash (1.9%), and constipation (1.5%). The incidence of positive Coombs' test was higher in high-dose cefepime recipients than in ceftazidime recipients (14.5% vs 8.7%; p = 0.043), although there was no evidence of hemolysis in either treatment group. Coadministration of analgesics, diuretics, and anticoagulants did not increase incidence of adverse events associated with study-drug therapy. Adverse renal and hematologic events, as well as anaphylaxis and death, were rare in both groups. In the comparative trials with cefepime, anaphylaxis was reported in no patients receiving cefepime and in one patient receiving ceftazidime. None of the three seizures reported in patients receiving cefepime and one of six seizures in patients receiving ceftazidime were of probable or possible relationship to the study drugs. None of the 12 cases of gastrointestinal hemorrhage reported in cefepime patients or five cases reported in ceftazidime patients were judged to be related to treatment drug. Tolerance for intravenous administration in both treatment groups was similar. Cefepime did not effect any significant or unusual allergic, hematologic, gastrointestinal, neurologic, or renal toxicity when administered to patients with mild-to-severe infections, including those receiving concomitant medications. The safety profile of cefepime is excellent and comparable to that of ceftazidime and those reported for other cephalosporins.

Cefepime

Because of the popularity of some third-generation cephalosporins, emergence of resistant organisms (e.g., selected Enterobacteriaceae) that produce inducible and extended-spectrum beta-lactamases has been a problem. Cefepime's twice-a-day dosage schedule and enhanced activity against Enterobacteriaceae and gram-positive organisms give it several advantages over older drugs. The clinical efficacy of cefepime has been demonstrated in comparative and noncomparative trials in the United States and Europe. Cefepime with twice-daily dosing has been useful in the treatment of lower respiratory tract infections, urinary tract infections, skin and skin structure infections, and in serious infection, including those with associated bacteremia. Cefepime is comparable to ceftazidime in clinical and bacteriologic response rates when both agents are administered three times a day in febrile neutropenic patients. Cefepime is also active against organisms that show resistance to other agents. Several studies have shown that cefepime retains its activity against E. cloacae and E. coli strains resistant to other cephalosporins and against many strains of P. aeruginosa resistant to ceftazidime. Cefepime exhibits a low level of cross-resistance with third-generation cephalosporins and a low propensity for selection of resistant mutants and offers a low potential for the induction of bacterial resistance, which complicates the course of many patients treated with single-agent third-generation therapy. Cefepime should be used in place of ceftazidime based on resistance potential, activity against resistant organisms, and cost.