Randomized, Multicenter, Double-Blind Study of Efficacy, Safety, And Tolerability of Intravenous Ertapenem Versus Piperacillin/Tazobactam in Treatment of Complicated Intra-Abdominal Infections in Hospitalized Adults

Estimating the Economic and Clinical Value of Introducing Ceftazidime/Avibactam into Antimicrobial Practice in Japan: A Dynamic Modelling Study

BACKGROUND

Antimicrobial resistance (AMR) is one of the most serious public health challenges worldwide, including in Japan. Globally, research and development of new antimicrobials has stalled due to unfavorable market conditions, which undervalue antimicrobials. Furthermore, Japan faces the additional challenge of delayed commercialization for a number of recently approved treatments.

OBJECTIVE

This study aims to examine the impact on AMR of introducing a new anti-infective treatment, ceftazidime/avibactam, into current treatment strategies. It reports the resulting clinical and economic outcomes from the perspective of healthcare payers in Japan.

METHODS

A previously published and validated dynamic disease transmission model was adapted to the Japanese setting. The model estimated health economic outcomes for treating three Gram-negative hospital-acquired infections, under different treatment strategies, from a healthcare payers' perspective. Outcomes were assessed over a 10-year time horizon with a willingness-to-pay threshold of ¥5,000,000 (US$45,556) per quality-adjusted life-year (QALY) gained and an annual discount rate of 2% applied to costs and benefits.

RESULTS

Introducing ceftazidime/avibactam in the framework of a diversification strategy with piperacillin/tazobactam is associated with reducing 798,640 bed days, equating to ¥21.0 billion (US$190.9 million) savings in hospitalization costs, and a gain of 363,034 life-years, or 308,641 QALYs. This translates into a monetary benefit of ¥1.56 trillion (US$14.3 billion) to Japanese healthcare payers.

DISCUSSION

Introducing a new antimicrobial agent into clinical practice is associated with considerable clinical and economic benefits. This analysis demonstrates that the approach taken to incorporate a new antimicrobial agent into clinical practice impacts on the scale of these clinical and economic benefits; greater benefits are associated with earlier use of antimicrobials as part of an antimicrobial stewardship program.

CONCLUSION

This analysis shows that changing the way in which a new antimicrobial is used within a treatment strategy has the potential for additional significant clinical and economic value.

The efficacy and safety of eravacycline compared with current clinically common antibiotics in the treatment of adults with complicated intra-abdominal infections: A Bayesian network meta-analysis

Background

Eravacycline is a novel, fully synthetic fluorocycline antibiotic for the treatment of adults with complicated intra-abdominal infections (cIAIs). However, the efficacy and safety of eravacycline compared with current clinically common antibiotics remain unknown.

Objective

This study aims to compare the efficacy and safety of eravacycline and other clinically common antibiotics in China, including tigecycline, meropenem, ertapenem, ceftazidime/avibactam+metronidazole, piperacillin/tazobactam, imipenem/cilastatin, and ceftriaxone+metronidazole, for the treatment of adults with cIAIs and to provide a reference for clinical choice.

Methods

The PubMed, Embase, Cochrane Library, and ClinicalTrials.gov databases were electronically searched to collect clinical randomized controlled studies (RCTs) comparing different antibiotics in the treatment of patients with cIAIs from inception to June 1, 2021. Two reviewers independently screened the literature, extracted data, and evaluated the risk of bias in the included studies.

Results

A total of 4050 articles were initially retrieved, and 25 RCTs were included after screening, involving eight treatment therapies and 9372 patients. The results of network meta-analysis showed that in the intention-to-treat (ITT) population, the clinically evaluable (CE) population, and the microbiologically evaluable (ME) population, the clinical response rate of eravacycline was not significantly different from that of the other 7 therapies (P > 0.05). In terms of microbiological response rate, eravacycline was significantly better than tigecycline [tigecycline vs. eravacycline: RR = 0.82, 95%CI (0.65,0.99)], and there was no significant difference between the other 6 regimens and eravacycline (P > 0.05). In terms of safety, the incidence of serious adverse events, discontinuation rate, and all-cause mortality of eravacycline were not significantly different from those of the other 7 treatment therapies (P > 0.05).

Conclusion

Based on the evidence generated by the current noninferiority clinical trial design, the efficacy and safety of eravacycline for the treatment of adults with cIAIs are not significantly different from those of the other 7 commonly used clinical antibiotics in China. In terms of microbiological response rate, eravacycline was significantly better than tigecycline. In view of the severe multidrug-resistant situation in China, existing drugs have difficulty meeting the needs of clinical treatment, and the new antibacterial drug eravacycline may be one of the preferred options for the treatment of cIAIs in adults.

Diagnosis and Management of Intraabdominal Infection: Guidelines by the Chinese Society of Surgical Infection and Intensive Care and the Chinese College of Gastrointestinal Fistula Surgeons

The Chinese guidelines for IAI presented here were developed by a panel that included experts from the fields of surgery, critical care, microbiology, infection control, pharmacology, and evidence-based medicine. All questions were structured in population, intervention, comparison, and outcomes format, and evidence profiles were generated. Recommendations were generated following the principles of the Grading of Recommendations Assessment, Development, and Evaluation system or Best Practice Statement (BPS), when applicable. The final guidelines include 45 graded recommendations and 17 BPSs, including the classification of disease severity, diagnosis, source control, antimicrobial therapy, microbiologic evaluation, nutritional therapy, other supportive therapies, diagnosis and management of specific IAIs, and recognition and management of source control failure. Recommendations on fluid resuscitation and organ support therapy could not be formulated and thus were not included. Accordingly, additional high-quality clinical studies should be performed in the future to address the clinicians' concerns.

Systematic Review and Meta-Analysis of the Efficacy of Appropriate Empiric Anti-Enterococcal Therapy for Intra-Abdominal Infection

Background: Delayed treatment of seriously infected patients results in increased mortality. However, antimicrobial therapy for the initial 24 to 48 hours is mostly empirically provided, without evidence regarding the causative pathogen. Whether empiric anti-enterococcal therapy should be administered to treat intra-abdominal infection (IAI) before obtaining culture results remains unknown. We performed a meta-analysis to explore the effects of empiric enterococci covered antibiotic therapy in IAI and the risk factors for enterococcal infection in IAI. Methods: We searched multiple databases systematically and included 23 randomized controlled trials (RCTs) and 13 observational studies. The quality of included studies was assessed, and the reporting bias was evaluated. Meta-analysis was performed using random effects or fixed effects models according to the heterogeneity. The risk ratio (RR), odds ratio (OR), and 95% confidence interval (CI) were calculated. Results: Enterococci-covered antibiotic regimens provided no improvement in treatment success compared with control regimens (RR, 0.99; 95% CI, 0.97-1.00; p = 0.15), with similar mortality and adverse effects in both arms. Basic characteristic analysis revealed that most of the enrolled patients with IAI in RCTs were young, lower risk community-acquired intra-abdominal infection (CA-IAI) patients with a relatively low APACHE II score. Interestingly, risk factor screening revealed that malignancy, corticosteroid use, operation, any antibiotic treatment, admission to intensive care unit (ICU), and indwelling urinary catheter could predispose the patients with IAI to a substantially higher risk of enterococcal infection. "Hospital acquired" itself was a risk factor (OR, 2.81; 95% CI, 2.34-3.39; p < 0.001). Conclusion: It is unnecessary to use additional agents empirically to specifically provide anti-enterococcal coverage for the management of CA-IAI in lower risk patients without evidence of causative pathogen, and risk factors can increase the risk of enterococcal infection. Thus, there is a rationale for providing empiric anti-enterococcal coverage for severely ill patients with CA-IAI with high risk factors and patients with hospital-acquired intra-abdominal infection (HA-IAI).

Carbapenems vs β-Lactam Monotherapy or Combination Therapy for the Treatment of Complicated Intra-abdominal Infections: Systematic Review and Meta-analysis of Randomized Controlled Trials

Background

Complicated intra-abdominal infections (cIAIs) result in significant morbidity, mortality, and cost. Carbapenem-resistant sepsis has increased dramatically in the last decade, resulting in infections that are difficult to treat and associated with high mortality rates. To prevent further antibacterial resistance, it is necessary to use carbapenem selectively. The objective of this study was to compare the effectiveness and safety of carbapenems vs alternative β-lactam monotherapy or combination therapy for the treatment of cIAIs.

Methods

The PubMed, Embase, Medline (via Ovid SP), and Cochrane library databases were systematically searched. We included randomized controlled trials (RCTs) comparing carbapenems vs alternative β-lactam monotherapy or combination therapy for the treatment of cIAIs.

Results

Twenty-two studies involving 7720 participants were included in the analysis. There were no differences in clinical treatment success (odds ratio [OR], 0.86; 95% confidence interval [CI], 0.71–1.05; I² = 35%), microbiological treatment success (OR, 0.88; 95% CI, 0.71–1.09; I² = 25%), adverse events (OR, 0.98; 95% CI, 0.87–1.09; I² = 17%), or mortality (OR, 0.96; 95% CI, 0.68–1.35; I² = 7%). Patients

treated with imipenem were more likely to experience clinical or microbiological failure than those treated with alternative β-lactam monotherapy or combination therapy.

Conclusions

No differences in clinical outcomes were observed between carbapenems and noncarbapenem β-lactams in cIAIs. Patients treated with imipenem were more likely to experience clinical or microbiological failure than those treated with alternative β-lactam monotherapy or combination therapy.

The Role of Ertapenem for the Treatment of Complicated Intra-abdominal Infections With a Positive Culture for Enterococcus faecalis

Controversy remains as to whether Enterococcus faecalis recovered from intra-abdominal infections (IAIs) requires targeted therapy. In a multicenter study comparing patients with IAIs from which E. faecalis was identified in intra-abdominal cultures, no difference in clinical outcomes was observed between patients receiving ertapenem vs those receiving piperacillin/tazobactam.

Moxifloxacin in Pediatric Patients With Complicated Intra-abdominal Infections: Results of the MOXIPEDIA Randomized Controlled Study

BACKGROUND

This study was designed to evaluate primarily the safety and also the efficacy of moxifloxacin (MXF) in children with complicated intra-abdominal infections (cIAIs).

METHODS

In this multicenter, randomized, double-blind, controlled study, 451 pediatric patients aged 3 months to 17 years with cIAIs were treated with intravenous/oral MXF (N = 301) or comparator (COMP, intravenous ertapenem followed by oral amoxicillin/clavulanate; N = 150) for 5 to 14 days. Doses of MXF were selected based on the results of a Phase 1 study in pediatric patients (NCT01049022). The primary endpoint was safety, with particular focus on cardiac and musculoskeletal safety; clinical and bacteriologic efficacy at test of cure was also investigated.

RESULTS

The proportion of patients with adverse events (AEs) was comparable between the 2 treatment arms (MXF: 58.1% and COMP: 54.7%). The incidence of drug-related AEs was higher in the MXF arm than in the COMP arm (14.3% and 6.7%, respectively). No cases of QTc interval prolongation-related morbidity or mortality were observed. The proportion of patients with musculoskeletal AEs was comparable between treatment arms; no drug-related events were reported. Clinical cure rates were 84.6% and 95.5% in the MXF and COMP arms, respectively, in patients with confirmed pathogen(s) at baseline.

CONCLUSIONS

MXF treatment was well tolerated in children with cIAIs. However, a lower clinical cure rate was observed with MXF treatment compared with COMP. This study does not support a recommendation of MXF for children with cIAIs when alternative more efficacious antibiotics with better safety profile are available.

The Surgical Infection Society Revised Guidelines on the Management of Intra-Abdominal Infection

BACKGROUND

Previous evidence-based guidelines on the management of intra-abdominal infection (IAI) were published by the Surgical Infection Society (SIS) in 1992, 2002, and 2010. At the time the most recent guideline was released, the plan was to update the guideline every five years to ensure the timeliness and appropriateness of the recommendations.

METHODS

Based on the previous guidelines, the task force outlined a number of topics related to the treatment of patients with IAI and then developed key questions on these various topics. All questions were approached using general and specific literature searches, focusing on articles and other information published since 2008. These publications and additional materials published before 2008 were reviewed by the task force as a whole or by individual subgroups as to relevance to individual questions. Recommendations were developed by a process of iterative consensus, with all task force members voting to accept or reject each recommendation. Grading was based on the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) system; the quality of the evidence was graded as high, moderate, or weak, and the strength of the recommendation was graded as strong or weak. Review of the document was performed by members of the SIS who were not on the task force. After responses were made to all critiques, the document was approved as an official guideline of the SIS by the Executive Council.

RESULTS

This guideline summarizes the current recommendations developed by the task force on the treatment of patients who have IAI. Evidence-based recommendations have been made regarding risk assessment in individual patients; source control; the timing, selection, and duration of antimicrobial therapy; and suggested approaches to patients who fail initial therapy. Additional recommendations related to the treatment of pediatric patients with IAI have been included.

SUMMARY

The current recommendations of the SIS regarding the treatment of patients with IAI are provided in this guideline.

Evaluation of Tigecycline Efficacy and Post-Discharge Outcomes in a Clinical Practice Population with Complicated Intra-Abdominal Infection: A Propensity Score-Matched Analysis

Background: The utility of tigecycline as compared with other antibiotic therapies in the treatment of patients with complicated intra-abdominal infection (cIAI) and the short- and long-term outcomes of a large cohort of severely ill patients were examined. We provide the first published data on post-discharge events for these patients.

Methods: Retrospective data for the cIAI cohort were obtained from a large clinical database. Patients aged ≥18 y were selected for inclusion based on hospitalization with a relevant diagnosis code and procedure code, and guideline-compliant antimicrobial therapy. Propensity scoring was used to reduce treatment-selection bias introduced by the use of observational data. Tigecycline patients were placed into quintiles based on propensity score and were matched 1:3.

Results: The final model based on propensity score matching included 2,424 patients: Tigecycline (n = 606) and other antibiotic therapy (n = 1,818). Treatment was successful in 426 (70.3%) tigecycline-treated patients and in 1,294 (71.2%) patients receiving other antibiotics. Similar treatment success occurred across all infection sites. Among survivors, treatment failure was associated with a greater need for all-cause re-hospitalization at 30 d and 180 d. No differences in cIAI-related re-hospitalization and discharge status were observed.

Conclusions: Using propensity scores to match populations, similar outcomes were demonstrated between treatment with tigecycline and other antibiotics as expressed by treatment success, the need for re-admission, similar 30-d discharge status, and the need for re-admission at 180 d.

Impact of a Dynamic Microbiological Environment on the Clinical Efficacy of Ertapenem and Piperacillin/Tazobactam in the Treatment of Complicated Community-Acquired Intra-Abdominal Infection in Spain: A Cost-Consequence Analysis

BACKGROUND AND OBJECTIVE

The microbial susceptibility of many antibiotics has been affected by prescribing patterns and their extensive use. The purpose of this evaluation was to assess how these changes could affect the initial efficacy of ertapenem and piperacillin/tazobactam in the treatment of complicated intra-abdominal infections (IAIs) acquired in the community and the potential consequences this may have in healthcare costs in Spain.

METHODS

The Initial efficacy of ertapenem and piperacillin/tazobactam for patients with APACHE (Acute Physiology and Chronic Health Evaluation) II scores <10 was extracted from a multicenter randomized study and were combined with the current microbial susceptibilities obtained from the SMART study, a multinational surveillance program. Country-specific pathogens distribution was extracted from a national study in patients with community-acquired IAI. The estimated effectiveness was used in a decision-analytic model to compare total costs between ertapenem and piperacillin/tazobactam in the treatment of complicated IAI. The model performs extensive one-way and probabilistic sensitivity analyses.

RESULTS

The model suggested a savings of €209 (year 2012 values) per patient when complicated IAIs acquired in the community (APACHE II <10) were treated with ertapenem instead of piperacillin/tazobactam. One-way sensitivity analyses showed length of stay as the key driver parameter. Further analysis of this parameter and probabilistic sensitivity analysis confirmed the robustness of our evaluation, with a 58% likelihood of ertapenem being dominant.

CONCLUSIONS

Ertapenem appears to be a cost-saving strategy over piperacillin/tazobactam for the treatment of patients with complicated IAIs acquired in the community in Spain.

β-Lactam/β-lactamase inhibitors versus carbapenems for the treatment of sepsis: systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Data on the relative efficacy of β-lactam/β-lactamase inhibitors (BL/BLIs) versus carbapenems are scant.

METHODS

This is a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing any BL/BLI versus any carbapenem for the treatment of sepsis. The primary outcome was all-cause mortality. A broad search was conducted with no restrictions on language, publication status or date. Two reviewers independently applied the inclusion criteria and extracted the data. Assessment of risk of bias was performed using the domain-based approach. Subgroup analyses were used to investigate heterogeneity and focus on patient groups more likely to harbour ESBL-positive bacteria. Risk ratios (RRs) with 95% CIs were calculated and pooled.

RESULTS

Thirty-one RCTs were included. There was no difference between BL/BLIs and carbapenems in terms of mortality (RR 0.98, 95% CI 0.79-1.20), without heterogeneity. No differences were observed with regard to clinical or microbiological failure and bacterial superinfections. The results were not affected by risk of bias. No differences were detected in the subgroups of patients with nosocomial infections, Gram-negative infections and neutropenic fever. Adverse events requiring discontinuation were more common with BL/BLIs, on account of an increased incidence of diarrhoea. However, Clostridium difficile-associated diarrhoea (RR 0.29, 95% CI 0.10-0.87) was more frequent with carbapenems and seizures were more frequent with imipenem (RR 0.21, 95% CI 0.05-0.93).

CONCLUSIONS

No differences in efficacy between BL/BLIs and carbapenems exist in RCTs including patient populations with a certain, albeit unknown, rate of ESBL-positive bacteria causing infections.

The risk of seizures among the carbapenems: a meta-analysis

OBJECTIVES

A consensus exists among clinicians that imipenem/cilastatin is the most epileptogenic carbapenem, despite inconsistencies in the literature.

METHODS

We conducted a meta-analysis of all randomized controlled trials comparing carbapenems with each other or with non-carbapenem antibiotics to assess the risk of seizures for imipenem, meropenem, ertapenem and doripenem.

RESULTS

In the risk difference (RD) analysis, there were increased patients with seizure (2 per 1000 persons, 95% CI 0.001, 0.004) among recipients of carbapenems versus non-carbapenem antibiotics. This difference was largely attributed to imipenem as its use was associated with an additional 4 patients per 1000 with seizure (95% CI 0.002, 0.007) compared with non-carbapenem antibiotics, whereas none of the other carbapenems was associated with increased seizure. Similarly, in the pooled OR analysis, carbapenems were associated with a significant increase in the risk of seizures relative to non-carbapenem comparator antibiotics (OR 1.87, 95% CI 1.35, 2.59). The ORs for risk of seizures from imipenem, meropenem, ertapenem and doripenem compared with other antibiotics were 3.50 (95% CI 2.23, 5.49), 1.04 (95% CI 0.61, 1.77), 1.32 (95% CI 0.22, 7.74) and 0.44 (95% CI 0.13, 1.53), respectively. In studies directly comparing imipenem and meropenem, there was no difference in epileptogenicity in either RD or pooled OR analyses.

CONCLUSIONS

The absolute risk of seizures with carbapenems was low, albeit higher than with non-carbapenem antibiotics. Although imipenem was more epileptogenic than non-carbapenem antibiotics, there was no statistically significant difference in the imipenem versus meropenem head-to-head comparison.

Phase 2, randomized, double-blind study of the efficacy and safety of two dose regimens of eravacycline versus ertapenem for adult community-acquired complicated intra-abdominal infections

Eravacycline is a novel fluorocycline, highly active against Gram-positive and Gram-negative pathogens in vitro, including those with tetracycline and multidrug resistance. This phase 2, randomized, double-blind study was conducted to evaluate the efficacy and safety of two dose regimens of eravacycline compared with ertapenem in adult hospitalized patients with complicated intra-abdominal infections (cIAIs). Patients with confirmed cIAI requiring surgical or percutaneous intervention and antibacterial therapy were randomized (2:2:1) to receive eravacycline at 1.5 mg/kg of body weight every 24 h (q24h), eravacycline at 1.0 mg/kg every 12 h (q12h), or ertapenem at 1 g (q24h) for a minimum of 4 days and a maximum of 14 days. The primary efficacy endpoint was the clinical response in microbiologically evaluable (ME) patients at the test-of-cure (TOC) visit 10 to 14 days after the last dose of study drug therapy. Overall, 53 patients received eravacycline at 1.5 mg/kg q24h, 56 received eravacycline at 1.0 mg/kg q12h, and 30 received ertapenem. For the ME population, the clinical success rate at the TOC visit was 92.9% (39/42) in the group receiving eravacycline at 1.5 mg/kg q24h, 100% (41/41) in the group receiving eravacycline at 1.0 mg/kg q12h, and 92.3% (24/26) in the ertapenem group. The incidences of treatment-emergent adverse events were 35.8%, 28.6%, and 26.7%, respectively. Incidence rates of nausea and vomiting were low in both eravacycline groups. Both dose regimens of eravacycline were as efficacious as the comparator, ertapenem, in patients with cIAI and were well tolerated. These results support the continued development of eravacycline for the treatment of serious infections, including those caused by drug-resistant Gram-negative pathogens. (This study has been registered at ClinicalTrials.gov under registration no. NCT01265784.).

Source control review in clinical trials of anti-infective agents in complicated intra-abdominal infections

In clinical trials of complicated intra-abdominal infections, assessment of adequacy of the initial surgical approach to the management of the infection is of considerable importance in determining outcome. Antibiotic therapy would not be expected to adequately treat the infection if the surgical procedure was inadequate with respect to source control. Inclusion of such cases in an efficacy analysis of a particular therapeutic antibiotic may confound the results. We analyzed the source control review process used in double-blind clinical trials of antibiotics in complicated intra-abdominal infections identified through systematic review. We searched MEDLINE (PubMed) and ClinicalTrials.gov databases to identify relevant articles reporting results from double-blind clinical trials that used a source control review process. Eight prospective, randomized, double-blind, multicenter, clinical trials of 5 anti-infective agents in complicated intra-abdominal infections used a source control review process. We provide recommendations for an independent, adjudicated source control review process applicable to future clinical trials.

Clinical experience with ertapenem in the treatment of infections of the biliary tract in daily practice in five Spanish hospitals

Efficacy of ertapenem in biliary tract infections in daily practice was retrospectively analyzed. Records of patients admitted to five Spanish hospitals (January 2007/February 2011) with biliary infections (cholecystitis/cholangitis) treated with ertapenem for ≥72 hours were reviewed. A total of 187 patients (mean 63.8±19.3 years, 52.9% males) were identified. Up to 96 (51.3%) were operated, with cholecystectomy (97.9%) and primary laparoscopy approach (75%) as most frequent intervention. Non-operated patients presented higher age (71.0±17.5 vs 56.9±18.5 years; P<0.001), heart insufficiency (11.0 vs 3.1%; P = 0.044) and the Mortality in Emergency Department Sepsis score (2.99±2.26 vs 1.94±2.34; P<0.001); and longer length of stay (10.3±6.6 vs 9.1±7.0; P = 0.005). Mean duration of treatment was 6.89±3.38 days. Overall favourable response was 87.7% (95% CI = 83.0-92.4) at the end of treatment. In the multivariate analysis (P<0.001, R² Cox = 0.10), non-favourable response was associated with Charlson index≥5 (OR = 18.71; 95% CI: 1.26-278.55; P = 0.034), pericholecystic abscess (OR = 5.30; 95% CI: 1.26-22.37; P = 0.023) and >3 days from symptoms start to admission (OR = 3.02; 95% CI: 1.13-8.04; P = 0.027).

Epileptogenic potential of carbapenem agents: mechanism of action, seizure rates, and clinical considerations

Antimicrobials are the most frequently implicated class of drugs in drug-induced seizure, with β-lactams being the class of antimicrobials most often implicated. The seizure-inducing potential of the carbapenem subclass may be directly related to their β-lactam ring structure. Data on individual carbapenems and seizure activity are scarce. To evaluate the available evidence on the association between carbapenem agents and seizure activity, we conducted a literature search of the MEDLINE (1966-May 2010), EMBASE (1974-May 2010), and International Pharmaceutical Abstracts (1970-May 2010) databases. Reference citations from the retrieved articles were also reviewed. Mechanistically, seizure propensity of the β-lactams is related to their binding to γ-aminobutyric acid (GABA) receptors. There are numerous reports of seizure activity associated with imipenem-cilastatin, with seizure rates ranging from 3-33%. For meropenem, doripenem, and ertapenem, the seizure rate for each agent is reported as less than 1%. However, as their use increases and expands into new patient populations, the rate of seizures with these agents may increase. High-dose therapy, especially in patients with renal dysfunction, preexisting central nervous system abnormalities, or a seizure history increases the likelihood of seizure activity. Although specific studies have not been conducted, data indicate that carbapenem-associated seizure is best managed with benzodiazepines, followed by other agents that enhance GABA transmission. Due to the drug interaction between carbapenems and valproic acid, resulting in clinically significant declines in valproic acid serum concentrations, the combination should be avoided whenever possible. Clinicians should be vigilant regarding the possibility of carbapenem-induced seizures when selecting and dosing antimicrobial therapy.

[What should and should not be covered in intraabdominal infection]

Despite improvements in our knowledge of the physiopathology of severe infection, diagnostic methods, antibiotic therapy, postoperative care and surgical techniques, a substantial number of patients with intraabdominal infection (IAI) will develop advanced stages of septic insult requiring admission to the intensive care unit. The success of treatment of IAI is multifactorial and the best antibiotic protocol may be insufficient unless adequate control of the focus of infection has been achieved. The present article discusses the appropriacy of empirical antibiotic therapy and the main pathogens associated with treatment failure. We also analyze the patients at risk of infection with microorganisms requiring broad-spectrum antimicrobial coverage. However, excessive antibiotic treatment, in terms of either spectrum or duration, could jeopardize future patients in an environment already threatened by the scarcity of research and development into new molecules required for the emergence of pathogens resistant to current antibiotics.

Diagnosis and management of complicated intra-abdominal infection in adults and children: guidelines by the Surgical Infection Society and the Infectious Diseases Society of America

Evidence-based guidelines for managing patients with intra-abdominal infection were prepared by an Expert Panel of the Surgical Infection Society and the Infectious Diseases Society of America. These updated guidelines replace those previously published in 2002 and 2003. The guidelines are intended for treating patients who either have these infections or may be at risk for them. New information, based on publications from the period 2003-2008, is incorporated into this guideline document. The panel has also added recommendations for managing intra-abdominal infection in children, particularly where such management differs from that of adults; for appendicitis in patients of all ages; and for necrotizing enterocolitis in neonates.

Diagnosis and Management of Complicated Intra-abdominal Infection in Adults and Children: Guidelines by the Surgical Infection Society and the Infectious Diseases Society of America

Evidence-based guidelines for managing patients with intra-abdominal infection were prepared by an Expert Panel of the Surgical Infection Society and the Infectious Diseases Society of America. These updated guidelines replace those previously published in 2002 and 2003. The guidelines are intended for treating patients who either have these infections or may be at risk for them. New information, based on publications from the period 2003–2008, is incorporated into this guideline document. The panel has also added recommendations for managing intra-abdominal infection in children, particularly where such management differs from that of adults; for appendicitis in patients of all ages; and for necrotizing enterocolitis in neonates.

Ertapenem versus piperacillin/tazobactam for the treatment of complicated infections: a meta-analysis of randomized controlled trials

Background

Ertapenem, a new carbapenem with a favorable pharmacokinetic profile, has been approved for the treatment of complicated intra-abdominal Infections (cIAIs), acute pelvic infections (APIs) and complicated skin and skin-structure infections (cSSSIs). The aim of this study is to compare the efficacy and safety of ertapenem with piperacillin/tazobactam, which has been reported to possess good efficacy for the treatment of these complicated infections.

Methods

We performed a meta-analysis of randomized controlled trials identified in PubMed, Cochrane library and Embase that compared the efficacy and safety of ertapenem with piperacillin/tazobactam for the treatment of complicated infections including cIAIs, APIs, cSSSIs. The primary efficacy outcome was clinical treatment success assessed at the test-of-cure visit. The primary safety outcome was drug related clinical and laboratory adverse events occurred during the treatment and the post-treatment period.

Result

Six RCTs, involving 3161 patients, were included in our meta-analysis. Ertapenem was associated similar clinical treatment success with piperacillin/tazobactam for complicated infections treatment (clinically evaluable population, 1937 patients, odds ratios: 1.15, 95% confidence intervals: 0.89-1.49; modified intention to treat population, 2855 patients, odds ratios: 1.03, 95% confidence intervals: 0.87-1.22). All of secondary efficacy outcomes analysis obtained similar findings with clinical treatment success. No difference was found about the incidence of drug related adverse events between ertapenem and piperacillin/tazobactam groups.

Conclusion

This meta-analysis provides evidence that ertapenem 1 g once a day can be used as effectively and safely as recommended dose of piperacillin/tazobactam, for the treatment of complicated infections, particularly of mild to moderate severity. It is an appealing option for the treatment of these complicated infections.

Pharmacokinetics of ertapenem following intravenous and subcutaneous infusions in patients

Steady-state pharmacokinetics of ertapenem were compared in patients after 1-g intravenous and subcutaneous (s.c.) infusions. Bioavailability was 99%+/-18% after s.c. administration, but peaks were reduced by about (43+/-29 versus 115+/-28 microg/ml) and times to peak were delayed. Simulations based on unbound concentrations show that time over the MIC should always be longer than 30% to 40% of the dosing interval, suggesting that s.c. infusion could be an alternative in patients with reduced vascular access.

Cost-effectiveness evaluation of ertapenem versus piperacillin/tazobactam in the treatment of complicated intraabdominal infections accounting for antibiotic resistance

OBJECTIVE

To evaluate the cost-effectiveness of ertapenem versus piperacillin/tazobactam in the treatment of community-acquired complicated intraabdominal infections accounting for development of antibiotic resistance in the Dutch setting.

METHODS

A decision tree was developed to estimate cost-effectiveness of ertapenem versus piperacillin/tazobactam at different time points after introduction of treatment. Development of resistance was incorporated using a compartment model. Resistance was a function of the eradication rate of pathogens and antibiotic prescription. Model outcomes included quality-adjusted life years (QALYs), direct costs and cost per QALY saved. Microbiological eradication rate, clinical success, and costs were derived from literature. The analyses included pathogens with intrinsic or acquired resistance.

RESULTS

The model suggested overall savings of euro355 (95% uncertainty interval euro480; euro1205) per patient when abdominal infections are treated with ertapenem instead of piperacillin/tazobactam. Probabilistic sensitivity analysis found a 94% probability of the incremental cost per QALY saved being within the generally accepted threshold for cost-effectiveness (euro20,000). After 5 years, it is expected that antibiotic resistance with piperacillin/tazobactam has increased with a greater rate compared to ertapenem, and cost-savings with ertapenem are expected to increase to euro672 (euro-232; euro1617). Ertapenem will, in addition, result in greater success rates and in QALY savings (0.17; 0.07-0.30). Alternative scenarios, with lower levels of initial resistance confirm the cost savings with ertapenem.

CONCLUSION

Given the underlying assumptions and data used, this evaluation demonstrated that ertapenem is a cost saving and possibly an economically dominant therapy over piperacillin/tazobactam for the treatment of community-acquired intraabdominal infections in The Netherlands.

Carbapenems versus other beta-lactams in the treatment of hospitalised patients with infection: a mixed treatment comparison

OBJECTIVE

To compare the effectiveness of meropenem with cefepime and piperacillin/tazobactam in the absence of direct comparisons in randomised controlled trials.

DATA SOURCES

Two previously conducted systematic reviews, one comparing the carbapenems (ertapenem and imipenem/cilastatin) versus 4th-generation cephalosporins (cefepime) or antipseudomonal penicillins (piperacillin/tazobactam), and the other comparing the carbapenems (imipenem/cilastatin versus meropenem), were updated to provide the basis for this mixed treatment comparison. Searching was completed in April 2007. No restriction was placed on language of publication.

STUDY SELECTION AND DATA EXTRACTION

Randomised controlled trials of adult patients hospitalised with infection and treated with a carbapenem or cefepime or piperacillin/tazobactam. Two reviewers independently assessed the papers against the inclusion/exclusion criteria and for methodological quality with any differences in opinion adjudicated by a third party. Two reviewers independently extracted data on clinical response, bacteriological response, mortality, and adverse events.

DATA SYNTHESIS

A mixed treatment comparison meta-analysis using Bayesian Markov Chain Monte Carlo simulation was used to perform the indirect comparison. The dataset comprised 34 trials: four comparing ertapenem versus piperacillin/tazobactam, one imipenem/cilastatin versus cefepime, 26 imipenem/cilastatin versus meropenem, three imipenem/cilastatin versus piperacillin/tazobactam. We calculated odds ratios (OR) using imipenem/cilastatin as the common comparator. Meropenem was associated with the highest probability of being the most effective treatment for clinical response (OR 1.52, 95% credible interval [CrI] 1.23-1.87) and bacteriological response (OR 1.45, 95% CrI 1.15-1.80) with a reduced risk of serious adverse events (overall: OR 0.88, 95% CrI 0.76-1.02; serious adverse events leading to withdrawal: OR 0.73, 95% CrI 0.42-1.20; and GI-related: OR 0.76, 95% CrI 0.55-1.02). There was little difference between the three carbapenems and cefepime on all-cause mortality.

CONCLUSIONS

This mixed treatment comparison suggests meropenem has substantial advantages over cefepime, ertapenem, imipenem/cilastatin and piperacillin/tazobactam in the treatment of hospitalised patients with infection.

Meta-analysis: ertapenem for complicated intra-abdominal infections

BACKGROUND

Ertapenem is a new member of the carbapenem class of antibiotics, with a favourable pharmacokinetic profile, but a narrower spectrum of antimicrobial activity, compared with older representatives of this class.

AIM

To evaluate the effectiveness and safety of ertapenem for treatment of complicated intra-abdominal infections.

METHODS

We performed a meta-analysis of randomized-controlled trials identified in PubMed, Cochrane and Scopus that compared ertapenem with other antimicrobial regimens, in patients of all ages, with complicated intra-abdominal infections. The primary outcomes evaluated were clinical success (cure or improvement) in the modified intention-to-treat population and clinical adverse events.

RESULTS

Six randomized-controlled trials involving patients with complicated intra-abdominal infections, mainly of mild-to-moderate severity (three with a double-blind design; one performed in children) that compared ertapenem treatment (once daily) against piperacillin/tazobactam, ceftriaxone plus metronidazole and ticarcillin/clavulanic acid (in three, two and one randomized-controlled trials respectively) were included. No difference was found between adult patients with complicated intra-abdominal infections treated with ertapenem vs. comparators, regarding clinical success (five randomized-controlled trials, 2002 patients, fixed-effect model, odds ratio: 1.11, 95% confidence interval (CI): 0.89-1.39); clinical adverse events (four randomized-controlled trials, 1530 patients, fixed-effect model, OR: 0.86, 95% CI: 0.61-1.20); microbiological success; mortality and withdrawals because of adverse events. Ertapenem was associated with more laboratory adverse events (four randomized-controlled trials, 1530 patients, fixed-effect model, OR: 1.73, 95% CI: 1.14-2.61), but none was reported as serious.

CONCLUSION

This meta-analysis provides additional evidence that ertapenem can be used as effectively and safely, as other recommended antimicrobial regimens, for the treatment of complicated intra-abdominal infections, particularly of mild-to-moderate severity.

Carbapenems versus other beta-lactams in treating severe infections in intensive care: a systematic review of randomised controlled trials

Carbapenems have not been comprehensively compared in clinical trials with fourth-generation cephalosporins (4GC) and antipseudomonal penicillins (APP) in the treatment of severe infections (SI) and febrile neutropenia (FN). A systematic review of CENTRAL, EMBASE, MEDLINE and JICST-EPlus for randomised controlled trials was conducted to establish the currently available evidence. Database searching was supplemented by hand searching and contacting conference organisers. Searching was completed in November 2006 and no restriction was placed on the language of publication. Data were extracted on clinical response, bacteriologic response, all-cause mortality and adverse events. Of the 265 papers identified, 12 were appropriate for meta-analysis (four 4GC and eight APP). The results showed that carbapenems are associated with a significant reduction in all-cause mortality (relative risk 0.62, 95% confidence interval: 0.41 to 0.95; p=0.03) compared to APP in the treatment of SI, and withdrawals due to adverse events (RR 0.65, 95% CI: 0.45 to 0.96; p=0.03) are also less common. When compared in the treatment of FN, carbapenems are associated with a significant increase in clinical response during the initial 72 h of treatment (RR 1.37, 95% CI: 1.09 to 1.74; p=0.008) and bacteriologic response (RR 1.73, 95% CI: 1.03 to 2.89; p=0.04). For all other outcomes, including all comparisons with 4GC, there were no significant differences between treatments. The use of carbapenems rather than APP could reduce mortality and, by simplifying treatment decisions, reduce the time before patients receive appropriate antibiotic treatment. The currently available evidence is insufficient for distinguishing between carbapenems and 4GC.