A comparative study of cefepime and ceftazidime in the treatment of community-acquired lower respiratory tract infections

Ceftazidime for respiratory infections

INTRODUCTION

Ceftazidime is a third-generation cephalosporin that has activity against Gram-negative bacilli, including Pseudomonas aeruginosa. The increasing prevalence of antimicrobial resistance and the limited number of antimicrobial agents in development have necessitated a review of the current status of treatments involving ceftazidime.

AREAS COVERED

This review focuses on studies examining the in vitro antibacterial activity of ceftazidime against recent clinical isolates and recent randomized controlled trials studying the clinical efficacy of ceftazidime, and discusses strategies for the optimal use of ceftazidime for treating respiratory tract infections, mainly hospital-acquired pneumonia (HAP).

EXPERT OPINION

Although ceftazidime remains an important option for HAP treatment, its role as an effective antimicrobial agent has been compromised by the sharp increase in resistance rates over the last decade, especially in P. aeruginosa and Acinetobacter baumannii. To maintain or improve the clinical use of ceftazidime in patients with severe HAP, it will be essential to gain a thorough understanding of local resistance patterns, reserve ceftazidime use when pathogens are susceptible to other third-generation cephalosporins, optimize ceftazidime therapy using prolonged or continuous infusion, determine the effectiveness of the combination of ceftazidime with inhibitors of broad-spectrum β-lactamases and role of combination therapy for P. aeruginosa infections, and judiciously use antimicrobial agents through individualization of antimicrobial therapy for HAP.

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.

Comparative study of the disposition of levofloxacin, netilmicin and cefepime in the isolated rat lung

An experimental model of artificially perfused and mechanically ventilated lung has been applied to compare the kinetic behaviour of levofloxacin, cefepime and netilmicin in this body tissue. The study has been performed to explore the usefulness of the isolated lung technique in the pharmacokinetic field, particularly to study the disposition of antibiotics in pulmonary tissue. The lung was perfused with Krebs-Henseleit medium containing 3% bovine albumin at a flow rate of 5 mL min−1. It was ventilated at 60 respirations/min with a 2-mL tidal volume of air previously humidified and warmed to 37°C. The concentrations of the above antibiotics were determined by HPLC techniques and the outflow curves were analysed by stochastic, as well as by model-dependent, methods. The results show pharmacokinetic differences among these antibiotics, which are in accordance with previously reported data, levofloxacin being the drug with the highest distribution coefficient in this tissue (1.25 ± 0.14 vs 0.39 ± 0.07 and 0.41 ± 0.06 mL g−1 for netilmicin and cefepime, respectively). Accordingly, the isolated lung of the rat, under the experimental conditions used here, constitutes an alternative model to be incorporated to pharmacokinetic studies with a great potential use for those drugs that show a pharmacological or toxicological action depending on the kinetic profile in the lung tissue.

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 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.

Community-acquired pneumonia: causes of treatment failure in patients enrolled in clinical trials

In order to determine the causes of treatment failure in community-acquired pneumonia (CAP) clinical trials, a MEDLINE search for all CAP studies published between 1990 and 1997 was performed. Prospective, randomized studies comparing the efficacy of two or more antibiotics in CAP were selected. Treatment failure was defined as persistent fever, deterioration of patient's condition, or a change in the prescribed antibiotic regimen. In 16% of the cases included in the clinical trials, the treatment of CAP is unsuccessful. A significant number of identified failure cases were owing to antibiotic side-effects. Resistant pathogens are an unusual cause of failure whatever the antibiotic used.

Steady-state plasma and intrapulmonary concentrations of cefepime administered in continuous infusion in critically ill patients with severe nosocomial pneumonia

OBJECTIVE

To determine the steady-state plasma and epithelial lining fluid concentrations of cefepime administered in continuous infusion in critically ill patients with severe bacterial pneumonia.

DESIGN

Prospective, open-label study.

SETTING

An intensive care unit and research ward in a university hospital.

PATIENTS

Twenty adult patients with severe nosocomial bacterial pneumonia on mechanical ventilation were enrolled.

INTERVENTIONS

All subjects received a 30-min intravenous infusion of cefepime 2 g followed by a continuous infusion of 4 g over 24 hrs. The concentrations of cefepime in plasma and epithelial lining fluid were determined at steady state after 48 hrs of therapy with high performance liquid chromatography.

MEASUREMENTS AND MAIN RESULTS

The mean +/- sd steady-state plasma and epithelial lining fluid concentrations of cefepime 4 g in continuous infusion were 13.5 +/- 3.3 microg/mL and 14.1 +/- 2.8 microg/mL, respectively, with a mean percentage penetration of cefepime into epithelial lining fluid of about 100%.

CONCLUSIONS

The administration of 4 g of cefepime in continuous infusion in critically ill patients with severe nosocomial pneumonia appears to optimize the pharmacodynamic profile of this beta-lactam by constantly providing concentrations in excess of minimal inhibitory concentration of most of susceptible organisms over the course of therapy in both serum and epithelial lining fluid.

A study evaluating the efficacy, safety, and tolerability of ertapenem versus ceftriaxone for the treatment of community-acquired pneumonia in adults

In a double-blind, multicenter trial, 502 patients hospitalized with community-acquired pneumonia were randomized to receive therapy with either ertapenem or ceftriaxone (for each, 1 g given intravenously once daily). After a minimum of 3 days, therapy could be switched to oral amoxicillin-clavulanate. The median duration of intravenously administered therapy for the 383 clinically evaluable patients was 4 days for both treatment groups; 345 patients (90.1%) had their treatment switched to orally administered therapy. Of the clinically evaluable patients, 168 (92.3%) in the ertapenem group and 183 (91.0%) in the ceftriaxone group had a favorable clinical response. Streptococcus pneumoniae was the most commonly isolated pathogen, and high cure rates were observed both for penicillin-susceptible and -nonsusceptible infections in the ertapenem group (28 [87.5%] of 32 patients versus 17 [100%] of 17 patients, respectively). Both treatment regimens were generally well tolerated; the most common drug-related adverse events reported were diarrhea (2.9% versus 2.7%) and nausea (0.8% versus 2.0%) in the ertapenem and ceftriaxone groups, respectively. These results suggest that ertapenem and ceftriaxone therapy have similar efficacy and safety in hospitalized patients with community-acquired pneumonia.

Empiric use of cefepime in the treatment of lower respiratory tract infections in children

BACKGROUND

These studies were designed to assess the efficacy and safety of cefepime, a fourth generation cephalosporin, for the treatment of serious infections, including lower respiratory tract infections (LRTI) in children.

METHODS

Four clinical trials of cefepime for the treatment of serious bacterial infections enrolled 259 children with LRTI. In 3 trials cefepime was compared with ceftazidime (n = 166), cefotaxime (n = 16) or cefuroxime (n = 12). One trial was noncomparative (n = 65).

RESULTS

Treatment with cefepime 50 mg/kg/ dose administered every 8 to 12 h produced a satisfactory clinical response (clinical signs of infection resolved or improved with no evidence of recurrent infection at posttreatment follow-up) in 88 to 100% of patients, comparable with comparator therapy. In children from whom a causative pathogen was identified, bacteriologic eradication was comparable between cefepime and comparator therapy. Cefepime was as safe and well-tolerated as comparator therapy. Few treatment-related clinical or laboratory adverse events were noted and were equivalent to comparator in all studies.

CONCLUSION

Cefepime is as effective, safe and well-tolerated for the empiric treatment of children with LRTI as comparator agents but offers the advantage of an enhanced spectrum of activity for Gram-positive and Gram-negative pathogens compared with second or third generation cephalosporins.

Cephalosporins, carbapenems, and monobactams

Nonpenicillin beta-lactams exhibit a variable spectrum of antimicrobial activity, have a wide range of clinical uses and a favorable safety profile. Cefepime's twice-daily dosage and increased activity against Enterobacteriaceae may offer some advantages over older cephalosporins. The carbapenems offer a broad antimicrobial spectrum, and meropenem has an improved safety profile compared with imipenem. Aztreonam is a useful alternative for patients with aerobic gram-negative infections who are allergic to penicillin. The emergence of resistant organisms, however, is an increasing problem with the frequent use of these antibiotics.

Cefepime versus ceftazidime for the treatment of serious bacterial infections

The objective of this open, comparative and randomized clinical trial was to compare the safety and efficacy of cefepime and ceftazidime in the treatment of adults with severe infections. Fifty patients were included; 25 received cefepime (1 g b.i.d.) and 25 ceftazidime (1 g t.i.d.). Demographic characteristics of the groups were similar. The drugs were well tolerated and adverse reactions were minor and comparable in both groups. Forty-four patients were evaluated (22 from each group). There was a satisfactory clinical response in 86% and 77% in the cefepime and ceftazidime groups, respectively. In patients with microbiologically documented infection 83% (15/18) treated with cefepime and 64% (9/14) treated with ceftazidime responded satisfactorily (no statistical significance). In conclusion, the data confirms that cefepime is as safe and effective as ceftazidime for the treatment of serious bacterial infections, with the advantage of being administrated only twice daily.

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.

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.