Combination eravacycline therapy for ventilator-associated pneumonia due to carbapenem-resistant Acinetobacter baumannii in patients with COVID-19: A case series

BACKGROUND

Carbapenem-resistant Acinetobacter baumannii (CRAB) pneumonia is associated with poor clinical outcomes and increased mortality. Clinical data regarding the optimal treatment of CRAB is limited, and combination therapy is often preferred. Eravacycline has demonstrated in-vitro activity against A. baumannii and has been considered for the treatment of pulmonary infections caused by CRAB.

OBJECTIVE

The objective of this case series was to describe clinical outcomes associated with eravacycline when utilized as part of a combination regimen for the treatment of CRAB pneumonia at a county hospital.

METHODS

A retrospective chart review was conducted from April 1, 2020, to October 1, 2020, which included hospitalized patients ≥18 years of age, diagnosed with coronavirus disease 2019 (COVID-19), with a sputum culture positive for CRAB, and receipt of at least one dose of eravacycline. The primary outcome studied was clinical resolution of CRAB pneumonia. A key secondary outcome was microbiological resolution.

RESULTS

A total of 24 patients received combination eravacycline therapy for a median of 10.5 days. Overall, 17 (71%) patients demonstrated clinical resolution of CRAB pneumonia. Repeat sputum cultures post-treatment were collected in 17 (71%) patients, of which 12 (71%) achieved microbiological resolution. No adverse events attributable to eravacycline were identified.

CONCLUSION

With limited viable salvage treatment options, combination eravacycline therapy showed favorable microbiological and clinical outcomes in patients with CRAB pneumonia. In light of this, eravacycline could be considered as a potential treatment option when designing CRAB pneumonia salvage therapy regimens.

Oral Tebipenem Pivoxil Hydrobromide in Complicated Urinary Tract Infection

BACKGROUND

There is a need for oral antibiotic agents that are effective against multidrug-resistant gram-negative uropathogens. Tebipenem pivoxil hydrobromide is an orally bioavailable carbapenem with activity against uropathogenic Enterobacterales, including extended-spectrum beta-lactamase-producing and fluoroquinolone-resistant strains.

METHODS

In this phase 3, international, double-blind, double-dummy trial, we evaluated the efficacy and safety of orally administered tebipenem pivoxil hydrobromide as compared with intravenous ertapenem in patients with complicated urinary tract infection or acute pyelonephritis. Patients were randomly assigned, in a 1:1 ratio, to receive oral tebipenem pivoxil hydrobromide (at a dose of 600 mg every 8 hours) or intravenous ertapenem (at a dose of 1 g every 24 hours) for 7 to 10 days (or up to 14 days in patients with bacteremia). The primary efficacy end point was overall response (a composite of clinical cure and favorable microbiologic response) at a test-of-cure visit (on day 19, within a ±2-day window) in the microbiologic intention-to-treat population. The noninferiority margin was 12.5%.

RESULTS

A total of 1372 hospitalized adult patients were enrolled; 868 patients (63.3%) were included in the microbiologic intention-to-treat population (50.8% of whom had complicated urinary tract infections and 49.2% of whom had pyelonephritis). An overall response was seen in 264 of 449 patients (58.8%) who received tebipenem pivoxil hydrobromide, as compared with 258 of 419 patients (61.6%) who received ertapenem (weighted difference, -3.3 percentage points; 95% confidence interval [CI], -9.7 to 3.2). Clinical cure at the test-of-cure visit was observed in 93.1% of the patients in the microbiologic intention-to-treat population who received tebipenem pivoxil hydrobromide and 93.6% of patients who received ertapenem (weighted difference, -0.6 percentage point; 95% CI, -4.0 to 2.8); the majority of patients with microbiologic response failures at the test-of-cure visit were asymptomatic patients with recurrent bacteriuria. Secondary and subgroup analyses were supportive of the primary analysis. Adverse events were observed in 25.7% of patients who received tebipenem pivoxil hydrobromide and in 25.6% of patients who received ertapenem; the most common adverse events were mild diarrhea and headache.

CONCLUSIONS

Oral tebipenem pivoxil hydrobromide was noninferior to intravenous ertapenem in the treatment of complicated urinary tract infection and acute pyelonephritis and had a similar safety profile. (Funded by Spero Therapeutics and the Department of Health and Human Services; ADAPT-PO ClinicalTrials.gov number, NCT03788967.).

Risk Factors and Impact of Perioperative Prophylaxis on the Risk of Extended-spectrum β-Lactamase-producing Enterobacteriaceae-related Infection Among Carriers Following Liver Transplantation

BACKGROUND

Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) carriage is frequent among liver transplant (LT) recipients, thereby fostering a large empirical carbapenem prescription. However, ESBL-E infections occur in only 10%-25% of critically ill patients with rectal colonization. Our aim was to identify risk factors for post-LT ESBL-E infection in colonized patients. The effect of perioperative antimicrobial prophylaxis (AP) was also analyzed in patients with prophylaxis lasting <48 hours and without proven intraoperative infection.

METHODS

Retrospective study from a prospective database including patients with a positive ESBL-E rectal screening transplanted between 2010 and 2016.

RESULTS

Among the 749 patients transplanted, 100 (13.3%) were colonized with an ESBL-E strain. Thirty-nine (39%) patients developed an infection related to the same ESBL-E (10 pulmonary, 11 surgical site, 13 urinary, 5 bloodstream) within 11 postoperative days in median. Klebsiella pneumoniae carriage, model for end-stage liver disease ≥25, preoperative spontaneous bacterial peritonitis prophylaxis, and antimicrobial exposure during the previous month were independent predictors of ESBL-E infection. We propose a colonization to infection risk score built on these variables. The prevalence of infection for colonization to infection score of 0, 1, 2, and ≥3 were 7.4%, 26.3%, 61.9%, and 91.3%, respectively. Of note, the incidence of post-LT ESBL-E infection was lower in case of perioperative AP targeting colonizing ESBL-E (P = 0.04).

CONCLUSIONS

Thirty-nine percentage of ESBL-E carriers develop a related infection after LT. We identified predictors for ESBL-E infection in carriers that may help in rationalizing carbapenem prescription. Perioperative AP targeting colonizing ESBL-E may be associated with a reduced risk of post-LT ESBL-E infections.

Factors associated with successful completion of outpatient parenteral antibiotic therapy in an area with a high prevalence of multidrug-resistant bacteria: 30-day hospital admission and mortality rates

Objectives

To identify factors associated with hospital admission and mortality within the first 30 days after enrolment in an outpatient parenteral antimicrobial therapy (OPAT) program, also analysing adequacy of the treatment regimen and clinical outcomes.

Patients and methods

This was a retrospective cohort study conducted between October 2016 and June 2017 in the state of São Paulo, Brazil. Variables related to hospital admission and mortality were subjected to bivariate analysis, and those with a P<0.05 were subjected to multivariate analysis as risk factors.

Results

We evaluated 276 patients, of whom 80.5% were ≥60 years of age and 69.9% had more than one comorbidity. Of the patients evaluated, 41.3% had pneumonia and 35.1% had a urinary tract infection. The most common etiological agent, isolated in 18 (31.6%) cases, was Klebsiella pneumoniae, and 13 (72,2%) strains were carbapenem resistant. The OPAT was in accordance with the culture results in 76.6% of the cases and with the institutional protocols in 76.4%. The majority (64.5%) of the patients were not admitted, and a cure or clinical improvement was achieved in 78.6%. Multivariate analysis showed that, within the first 30 days after enrolment, the absence of a physician office visit was a predictor of hospital admission (P<0.001) and mortality (P = 0.006).

Conclusions

This study demonstrated the viability of OPAT in elderly patients with pulmonary or urinary tract infections in an area with a high prevalence of multidrug-resistant bacteria and that a post-discharge physician office visit is protective against hospital admission and mortality.

Carbapenems versus alternative β-lactams monotherapy or in combination for febrile neutropenia: Systematic review and meta-analysis of randomized controlled trial

BACKGROUND

Febrile neutropenia (FN) in cancer patients can be life threatening and require the timely antimicrobial agents treatment.

METHODS

To compare the effectiveness and safety of carbapenems versus β-lactams for FN. PubMed, Medline (Ovid SP), Cochrane CENTRAL, and Embase were searched up to March 2019. FN in patients due to undergoing chemotherapy and treated with carbapenems and β-lactams were included. Odds ratio (OR) and 95% confidence interval (CI) were estimated.

RESULTS

Fifty randomized controlled trials (RCTs) studies involving 10,995 participants were included. Carbapenems were more likely to experience treatment success without modification (OR = 1.34, 95% CI = 1.24-1.46) compared with β-lactams. Meropenem (OR = 1.36, 95% CI = 1.18-1.56; OR = 1.24, 95% CI = 1.01-1.53), imipenem/cilastatin (OR = 1.40, 95% CI = 1.19-1.65; OR = 1.31, 95% CI = 1.04-1.67) showed higher effectiveness from that by β-lactams monotherapy or in combination with aminoglycoside, respectively. Carbapenems-aminoglycoside combination therapy does not provide an advantage over carbapenems alone. Meropenem showed similar risk of adverse events (AEs) versus β-lactams. Imipenem/cilastatin was related to higher risk of AEs compared with β-lactams. There was no significant difference between carbapenems and β-lactams monotherapy or in combination.

CONCLUSION

Meropenem and imipenem/cilastatin monotherapy appears to be available treatment for FN compared with β-lactams. Imipenem/cilastatin was related to higher risk of AEs. Balancing the evidence for drug efficacy and side effects, meropenem monotherapy appears to be available treatment for FN. Individual centers should select the best matching therapy regimens according to local epidemiology and susceptibility patterns.

Development of the predicted and standardized carbapenem usage metric: Analysis of the Japanese Diagnosis Procedure Combination payment system data

This study aimed to develop a metric for standardized and predicted carbapenem consumption using the Diagnosis Procedure Combination payment system database and patients' characteristics. Based on Diagnosis Procedure Combination data analysis, the developed metric will provide useful benchmarks that stewardship programs can use to help drive improvements.

Antibiotic Consumption and Resistance during a 3-Year Period in Sicily, Southern Italy

Antimicrobial resistance (AMR) is one of the biggest issues facing global public health. In 2017, Italy adopted its first National Action Plan on Antimicrobial Resistance 2017–2020, which works through the synergy between national, regional, and local levels. In the framework of a Regional Action Plan on healthcare-associated infections and AMR prevention, the Sicilian Health Authority of the Sicilian Region, Southern Italy, has implemented a surveillance system of antibiotic consumption in hospitals, in the community, and of resistance rates (RRs) in hospital settings. Data on antibiotic consumption and on antibiotic RRs have been collected from 2015 to 2017 from pharmacies and laboratories of participating hospitals and from community, respectively. Data on antibiotic consumption showed that the most consumed antibiotics in hospitals were fluoroquinolones in 2015, penicillin in 2016, and beta-lactams in 2017. From 2015 to 2017, data on Klebsiella pneumoniae showed significant increasing RRs to all antibiotic classes, except to carbapenems. RRs of third-generation cephalosporins and carbapenems Escherichia coli showed significant decreasing trends. RRs of the other microorganisms did not change significantly during the study period. The results from the present study show that in Sicily, the use of antibiotics and RRs for selected microorganisms are at a high level. Immediate strategies are needed to decrease the inappropriate usage of antibiotics and control the spread of AMR.

Genome-Wide Screening for Enteric Colonization Factors in Carbapenem-Resistant ST258 Klebsiella pneumoniae

A diverse, antibiotic-naive microbiota prevents highly antibiotic-resistant microbes, including carbapenem-resistant Klebsiella pneumoniae (CR-Kp), from achieving dense colonization of the intestinal lumen. Antibiotic-mediated destruction of the microbiota leads to expansion of CR-Kp in the gut, markedly increasing the risk of bacteremia in vulnerable patients. While preventing dense colonization represents a rational approach to reduce intra- and interpatient dissemination of CR-Kp, little is known about pathogen-associated factors that enable dense growth and persistence in the intestinal lumen. To identify genetic factors essential for dense colonization of the gut by CR-Kp, we constructed a highly saturated transposon mutant library with >150,000 unique mutations in an ST258 strain of CR-Kp and screened for in vitro growth and in vivo intestinal colonization in antibiotic-treated mice. Stochastic and partially reversible fluctuations in the representation of different mutations during dense colonization revealed the dynamic nature of intestinal microbial populations. We identified genes that are crucial for early and late stages of dense gut colonization and confirmed their role by testing isogenic mutants in in vivo competition assays with wild-type CR-Kp Screening of the transposon library also identified mutations that enhanced in vivo CR-Kp growth. These newly identified colonization factors may provide novel therapeutic opportunities to reduce intestinal colonization by CR-KpIMPORTANCEKlebsiella pneumoniae is a common cause of bloodstream infections in immunocompromised and hospitalized patients, and over the last 2 decades, some strains have acquired resistance to nearly all available antibiotics, including broad-spectrum carbapenems. The U.S. Centers for Disease Control and Prevention has listed carbapenem-resistant K. pneumoniae (CR-Kp) as an urgent public health threat. Dense colonization of the intestine by CR-Kp and other antibiotic-resistant bacteria is associated with an increased risk of bacteremia. Reducing the density of gut colonization by CR-Kp is likely to reduce their transmission from patient to patient in health care facilities as well as systemic infections. How CR-Kp expands and persists in the gut lumen, however, is poorly understood. Herein, we generated a highly saturated mutant library in a multidrug-resistant K. pneumoniae strain and identified genetic factors that are associated with dense gut colonization by K. pneumoniae This study sheds light on host colonization by K. pneumoniae and identifies potential colonization factors that contribute to high-density persistence of K. pneumoniae in the intestine.

Using local clinical and microbiological data to develop an institution specific carbapenem-sparing strategy in sepsis: a nested case-control study

Background

From a stewardship perspective it is recommended that antibiotic guidelines are adjusted to the local setting, accounting for the local epidemiology of pathogens. In many settings the prevalence of Gram-negative pathogens with resistance to empiric sepsis therapy is increasing. How and when to escalate standard sepsis therapy to a reserve antimicrobial agent, is a recurrent dilemma. The study objective was to develop decision strategies for empiric sepsis therapy based on local microbiological and clinical data, and estimate the number needed to treat with a carbapenem to avoid mismatch of empiric therapy in one patient (NNTC).

Methods

We performed a nested case control study in patients (> 18 years) with Gram-negative bacteremia in 2013-2016. Cases were defined as patients with Gram-negative bacteremia with in vitro resistance to the combination 2nd generation cephalosporin AND aminoglycoside (C-2GC + AG). Control patients had Gram-negative bacteremia with in vitro susceptibility to cefuroxime AND/OR gentamicin, 1:2 ratio. Univariate and multivariable analysis was performed for demographic and clinical predictors of resistance. The adequacy rates of empiric therapy and the NNTC were estimated for different strategies.

Results

The cohort consisted of 486 episodes of Gram-negative bacteremia in 450 patients. Median age was 66 years (IQR 56-74). In vitro resistance to C-2GC + AG was present in 44 patients (8.8%). Independent predictors for resistance to empiric sepsis therapy were hematologic malignancy (adjusted OR 4.09, 95%CI 1.43-11.62, p < 0.01), previously cultured drug resistant pathogen (adjusted OR 3.72. 95%CI 1.72-8.03, p < 0.01) and antibiotic therapy during the preceding 2 months (adjusted OR 12.5 4.08-38.48, p < 0.01). With risk-based strategies, an adequacy rate of empiric therapy of 95.2-99.3% could be achieved. Compared to treating all patients with a carbapenem, the NNTC could be reduced by 82.8% (95%CI 78.5-87.5%) using the targeted approaches.

Conclusions

A risk-based approach in empiric sepsis therapy has the potential to better target the use of reserve antimicrobial agents aimed at multi-resistant Gram-negative pathogens. A structured evaluation of the expected antimicrobial consumption and antibiotic adequacy rates is essential to be able to weigh the costs and benefits of potential antibiotic strategies and select the most appropriate approach.

Modeling Ertapenem: the impact of body mass index on distribution of the antibiotic in the body

Ertapenem is an antibiotic commonly used to treat a broad spectrum of infections and is part of a broader class of antibiotics called carbapenems. Unlike other carbapenems, ertapenem has a longer half-life and thus only has to be administered once a day. Previously, a physiologically-based pharmacokinetic (PBPK) model was developed to investigate the uptake, distribution, and elimination of ertapenem following a single one gram dose in normal height, normal weight males. Due to the absorption properties of ertapenem, the amount of fat in the body can influence how the drug binds, how quickly the drug passes through the body, and thus how effective the drug might be. Thus, we have revised the model so that it is applicable to males and females of differing body mass index (BMI). Simulations were performed to consider the distribution of the antibiotic in males and females with varying body mass indexes. These results could help to determine if there is a need for altered dosing regimens in the future.

Evaluation of carbapenem use in a tertiary hospital: antimicrobial stewardship urgently needed

Background

China launched a 3-year rectification scheme for the clinical use of antibiotics in 2011, and a specific scheme for carbapenem use in 2017. The aim of this study was to investigate the effects of government policies on carbapenem use, and their correlation with carbapenem-resistant Pseudomonas aeruginosa (CRPA).

Methods

The study was divided into four stages: preintervention (2010), antimicrobial programme (2011-2013), post-antimicrobial programme (2014-2016) and carbapenem programme (2017). A point-score system was proposed for evaluating the rationality of carbapenem use, and evaluated based on the indications, microbial culture, single dose, interval, and duration. Any prescription without a global score of 10 points was judged as irrational. The trend was analyzed by regression analysis, and Spearman correlation analysis was used for testing the correlation.

Findings

The rate of rational use of carbapenems was 29.7% in 2010, and increased by 55.5, 45.2, and 51.5% during the subsequent three stages. The rationality declined slightly during the post-antimicrobial programme (2014-2016) while the consumption of carbapenems was markedly increased. These two parameters improved slightly in 2017. Moreover, the prevalence of CRPA was significantly negatively correlated with the rate of rational carbapenem use (Coefficient = - 0.553, P < 0.05), and not with the consumption of carbapenems (P > 0.05).

Conclusions

The rational application of carbapenems was related to government policies in this study, with irrational carbapenem use possibly related to the development of CRPA. The current point-score system could be a useful tool for performing assessments.

Considerations for Systemic and Topical Treatment of Morganella morganii Septicemia Arising from Maggot Infestation

INTRODUCTION

Live maggot infestation (myiasis) of wounds can present a host of ailments. Loosely associated with maggot excreta, Morganella morganii is a widespread, gram-negative rod bacterium commonly found in the intestinal tracts of humans. M morganii has been observed as being pathogenic, particularly in nosocomial and postoperative environments, as well as in immunosuppressed and elderly populations.

CASE REPORT

Herein, the authors present a rare, previously unreported case of M morganii septicemia (as confirmed by positive blood culture), secondary to myiasis of the lower extremities. The patient was successfully treated with both systemic and topical interventions. Posttreatment examination revealed resolution of myiasis and negative blood cultures.

CONCLUSIONS

Myiasis can be invasive, leading to severe systemic infection. In these cases, a broad-spectrum antibiotic combined with systemic and topical antiparasitic therapy should be considered.

"Double carbapenem" and oral fosfomycin for the treatment of complicated urinary tract infections caused by blaNDM -harboring Enterobacteriaceae in kidney transplantation

Infections with carbapenemase-producing carbapenem-resistant Enterobacteriaceae represent an emergent problem worldwide. Treatment of infections caused by New Delhi metallo-beta-lactamase (NDM)-harboring Enterobacteriaceae is particularly challenging as it frequently involves the use of nephrotoxic agents, which is problematic in kidney transplant recipients and non-renal transplant patients with marginal kidney function. We present two cases of urinary tract infections caused by NDM-harboring Enterobacteriaceae successfully treated with a combination of "double carbapenem" and oral fosfomycin.

Trends and relationship between antimicrobial resistance and antibiotic use in Xinjiang Uyghur Autonomous Region, China: Based on a 3 year surveillance data, 2014-2016

PURPOSES

The objective of the study was to identify the trends and relations between antimicrobial resistance (AMR) and antibiotic use in the Xinjiang Uyghur Autonomous Region in Western China from 2014 to 2016.

METHODS

A retrospective, descriptive analysis of AMR prevalence, and trends and relations between AMR and antibiotic use during the 3-year period was performed.

RESULTS

Third-generation cephalosporin-resistant Escherichia coli was the most prevalent resistant pathogen in terms of both resistance density and resistance proportion. A significant correlation was found between resistance density of third-generation cephalosporin-resistant Klebsiella pneumoniae and the use of beta-lactam-beta-lactamase inhibitor combinations (cc=0.63, p=0.03), quinolones (cc=0.60, p=0.04), and carbapenems (cc=0.76, p=0.004), among which only beta-lactam-beta-lactamase inhibitor combinations showed a significant correlation with third-generation cephalosporin-resistant E. coli (cc=0.63, p=0.03). For carbapenem-resistant Pseudomonas aeruginosa, not only carbapenem use (cc=0.65, p=0.02) but also penicillin (cc=0.76, p=0.004) and quinolone (cc=0.69, p=0.01) use showed significant correlation. A strong correlation was observed between the resistant proportion of third-generation cephalosporin-resistant E. coli and only the use of beta-lactam-beta-lactamase inhibitor combinations (cc=0.61, p=0.03).

CONCLUSION

The association between antibiotic use and AMR, especially the implication of the difference in resistance density and resistance proportion, is crucial for local physicians and decision-makers to better use of antibiotics and allocate healthcare resources more effectively, as well as to better implement antimicrobial stewardship and effective infection control strategies.

Evaluation of antimicrobial stewardship (AS) for appropriate use of antimicrobial agents

We implemented an antimicrobial stewardship (AS) program whereby pharmacists sought appropriate use of antimicrobial agents in January 2012. At that time, we targeted anti-methicillin-resistant Staphylococcus aureus (MRSA) agents and carbapenems; however, in January 2014, we added tazobactam/piperacillin (TAZ/PIPC). We evaluated outcomes using multilateral analyses. The average one-day dosage of carbapenems increased; however, the duration of administration and number of recipient patients decreased significantly (P < 0.01). Moreover, the percentage of patients receiving meropenem (MEPM), for whom the time above minimal inhibitory concentration (MIC) was 40% or higher increased (P < 0.01). In contrast, patient utilization of TAZ/PIPC increased significantly after targeting of carbapenems as specific antibacterial agents. However, after TAZ/PIPC was targeted as a specific antibacterial agent, the number of TAZ/PIPC administrations decreased significantly (P < 0.01). The duration of hospitalization and mortality rate in patients receiving specific antibacterial agents significantly decreased after implementation of the AS program (P < 0.01). In conclusion, pharmacist's interventions to provide AS and patient follow-up reduced improper use and promoted proper administration of antibacterial agents. Furthermore, AS was effective in improving patient prognoses and suppressing drug-resistant strains, as well as promoting effective treatment.

Application of Bacteriophage-containing Aerosol against Nosocomial Transmission of Carbapenem-Resistant Acinetobacter baumannii in an Intensive Care Unit

BACKGROUND

Carbapenem-resistant Acinetobacter baumannii (CRAB) is associated with nosocomial infections worldwide. Here, we used phage as a potential agent to evaluate the efficacy of daily cleaning practices combined with a bacteriophage-containing aerosol against CRAB.

METHODS

A two-phase prospective intervention study was performed at a 945-bed public teaching hospital. From March to December 2013, we performed terminal cleaning using standard procedures plus an aerosol with active bacteriophage in the intensive care units to evaluate the impact on nosocomial incidence density, carbapenem-resistance rates and antimicrobial drug consumption amounts. Patients with culture proven CRAB infection were transferred to the isolation room when the phage aerosol cleaning had been completed.

RESULTS

A total of 264 new acquisitions of CRAB were identified in the intensive care units (191 in the pre-intervention period and 73 in the intervention period). The rates of new acquisitions of CRAB in the intensive care units decreased from 8.57 per 1000 patient-days in the pre-intervention period to 5.11 per 1000 patient-days in the intervention period (p = 0.0029). The mean percentage of resistant isolates CRAB decreased from 87.76% to 46.07% in the intensive care units (p = 0.001). All of the antimicrobials showed a significant reduction in consumption except imipenem.

CONCLUSIONS

The bacteriophage was successful in decreasing the rates of infection caused by CRAB across intensive care units in a large teaching hospital.

Characterization of Multidrug Resistant Extended-Spectrum Beta-Lactamase-Producing Escherichia coli among Uropathogens of Pediatrics in North of Iran

Escherichia coli remains as one of the most important bacteria causing infections in pediatrics and producing extended-spectrum beta-lactamases (ESBLs) making them resistant to beta-lactam antibiotics. In this study we aimed to genotype ESBL-producing E. coli isolates from pediatric patients for ESBL genes and determine their association with antimicrobial resistance. One hundred of the E. coli isolates were initially considered ESBL producing based on their MIC results. These isolates were then tested by polymerase chain reaction (PCR) for the presence or absence of CTX, TEM, SHV, GES, and VEB beta-lactamase genes. About 30.5% of isolated E. coli was ESBL-producing strain. The TEM gene was the most prevalent (49%) followed by SHV (44%), CTX (28%), VEB (8%), and GES (0%) genes. The ESBL-producing E. coli isolates were susceptible to carbapenems (66%) and amikacin (58%) and showed high resistance to cefixime (99%), colistin (82%), and ciprofloxacin (76%). In conclusion, carbapenems were the most effective antibiotics against ESBl-producing E. coli in urinary tract infection in North of Iran. The most prevalent gene is the TEM-type, but the other resistant genes and their antimicrobial resistance are on the rise.

Pharmacological interaction between valproic acid and carbapenem: what about levels in pediatrics?

Valproic acid (VPA) is the most commonly used antiepileptic drug in pediatric patients, but its major drawback is its multiple pharmacological interactions.

OBJECTIVE

To study children who had been simultaneously treated with carbapenems and valproic acid, considering drug levels, pharmacological interactions and clinical follow-up.

MATERIAL AND METHODS

Retrospective study of children who simultaneously received treatment with VPA and carbapenems between January 2003 and December 2011. Demographic variables, indication of treatment, dose, VPA plasma levels, interactions, clinical manifestations and medical management were analyzed.

RESULTS

28 children with concomitant treatment with both drugs were included in the study. 64.3% were males. 78.6% of the interactions were observed in the Intensive Care Unit. 60.7% of children had been previously treated VPA and its major indication were generalized seizures. Basal plasma levels of VPA were recorded in 53% and at 24 h after admittance in 60%. "40% of basal VPA levels were below therapeutic range prior to the administration of carbapenem. After the introduction of carbapenem 88% of level determinations were below therapeutic range". 54.5% of the patients that were chronically receiving VPA and had good control of epilepsy before admission had seizures during the coadministration. One patient that was on VPA before admission but with bad control of epilepsy worsened, and one patient that acutely received VPA did not achieve seizure freedom. In these cases it was necessary to either increase VPA dose or change to a different antiepileptic drug.

CONCLUSIONS

Little is known about the mechanism of pharmacologic interactions between carbapenems and VPA, but it leads to a reduction in plasma levels that may cause a loss of seizure control, so simultaneous use of both drugs should be avoided when possible. If not, VPA levels should be monitored.

Antimicrobial efficacy of doripenem and its combinations with sulbactam, amikacin, colistin, tigecycline in experimental sepsis of carbapenem-resistant Acinetobacter baumannii

Acinetobacter baumannii is the most common species to have developed resistance to antibiotics. Due to increasing levels of drug resistance, the available therapeutic options are insufficient in A. baumannii infections. This study investigated the efficacy of doripenem monotherapy versus doripenem combination therapy with sulbactam, amikacin, colistin and tigecycline in experimental sepsis. A carbapenem-resistant A. baumannii was used to develop a sepsis model in 8-10-week-old Balb/c mice by intraperitoneal injection. Antibiotic therapies were initiated two hours after injection of bacterial suspension. Necropsy was performed at 24, 48 and 72 hours and cultures were made from heart, lung, liver and spleen samples. Bacterial loads of lung and liver were calculated as CFU/g. Combination therapies with doripenem were more effective than monotherapy at 24 and 48 hours of infection but no differences between groups were detected at 72 hours. The combination of doripenem with tigecycline and amikacin began to eradicate the bacterial load of lung and liver after 48 hours of infection, whereas doripenem+sulbactam and doripenem+colistin were started to eradication at 72 hours. The results of the study showed that combination therapies with doripenem are more effective than monotherapy and the combination of doripenem with tigeycline or amikacin has more rapid bactericidal effect than that with sulbactam or colistin.

[Pharmacokinetics study of injected doripenemin healthy volunteers]

OBJECTIVE

To study the pharmacokinetics of injected doripenem in Chinese healthy volunteers, in order to optimize dosages for patients.

METHODS

Twelve healthy volunteers were recruited in the threecross Latin square designed study. Participants received intravenous infusions of 0.25, 0.5 and 1.0 g doripenem sequentially in three periods at a random order. Plasma and urine doripenem were measured by HPLC-UV, using an internal standard method with meropenem for plasma samples and an external standard method for urine samples, respectively. Phoenix WinNonlin 6.1 pharmacokinetic software was used to calculate non-compartment pharmacokinetics parameters. SPSS 19.0 software was used for statistical analysis.

RESULTS

A single dose infusion of 0.25, 0.5 and 1.0 g doripenemin 60 min produced the following respective parameters: Cmax (11.81 +/- 1.52), (22.80 +/- 3.80) and (47.26 +/- 8.38) microg/mL, Tmax (60.42 +/- 1.44), (58.33 +/- 5.77) and (60.00 +/- 0) min, t(1/2) (63.48 +/- 10.51), (69.12 +/- 16.72) and (69.30 +/- 11.71) min, AUC(0-1), (1100.86 +/- 150.04), (2111.50 +/- 359.58) and (4359.50 +/- 789.38) microg/(mL x min). Linear Regression and Confidence Interval analyses suggested a linear kinetic characteristic. Doripenem was mainly excreted through kidneys, with 24 h cumulative urine excretion rates ranging from 70% to 75% for the three doses of infusions. It was safe to administer doripenem through infusion in healthy volunteers. Adverse reactions occurred in 19.44% cases of infusions, although all were mild reactions. Tinnitus happened in two cases (8.33%) of infusions, which required close observations.

CONCLUSION

Doripenem infusion possesses a linear kinetics. There is no need to adjust the regimenpatients.

[OFF-LABEL DRUG USAGE IN THE TREATMENT OF URINARY TRACT INFECTION OF NEWBORNS]

Infectious pathology in the neonatal period is of the leading causes of neonatal morbidity and mortality. Urinary tract infection occurs in 23% of all infectious diseases. The treatment of infectious diseases mainly employs eradication therapy, mostly with anti-bacterial drugs. In practice, the therapy of infants frequently employs prescribing off-label drugs (cephalosporins 1 and 4 generation, macrolides, carbapenem, sulfonamides), which extends the duration of therapy on the average by 37.1% and increases the incidence of adverse reactions on the average by 11.4%. We believe that neonatologists should use drugs in accordance with prescription labeling. Elucidation of age-related restrictions, dosing, administration ways, and therapy duration must be carried out in the framework of clinical investigations. This is important for increasing the efficacy and safety of practical drug therapy.

Clinical pharmacology of carbapenems in neonates

Carbapenems are an effective tool to treat complicated bacterial infections. This review aims to summarize the available information on carbapenems in neonates to guide clinicians on drug choice and indications in neonates. Moreover, identification of knowledge gaps may stimulate researchers to design studies to further improve pharmacotherapy in neonates. To do so, a bibliographic search [infant/newborn and meropenem, imipenem, panipenem, ertapenem, doripenem or imipenem] was performed (PubMed, EMBASE) and public clinical trial registries (clinicaltrials.gov, EU registry) were searched to summarize the available information. Carbapenem clearance in neonates is low. Variability relates to maturation (weight, age) and renal function (creatinine clearance), while observations in neonates with renal failure are absent. Pharmacodynamics are almost exclusively limited to meropenem, and the available information will further increase (NeoMero-1-2, necrotizing enterocolitis, meningitis). Finally, there are also some ongoing doripenem pharmacokinetics (PK) studies in neonates. It was concluded that observations on carbapenems in neonates are limited, but studies (NeoMero, doripenem) are ongoing. Until this information becomes available, off label prescription of meropenem seems to be the most reasonable choice when a carbapenem is appropriate. Knowledge gaps relate to PK in neonates with renal failure and to the potential benefit of prolonged compared to short duration of infusion.

The minimal inhibitory concentration for sulbactam was not associated with the outcome of infections caused by carbapenem-resistant Acinetobacter sp. treated with ampicillin/sulbactam

OBJECTIVE

The objective of this study was to evaluate whether the outcomes of carbapenem-resistant Acinetobacter infections treated with ampicillin/sulbactam were associated with the in vitro susceptibility profiles.

METHODS

Twenty-two infections were treated with ampicillin/sulbactam. The median treatment duration was 14 days (range: 3-19 days), and the median daily dose was 9 g (range: 1.5-12 g). The median time between Acinetobacter isolation and treatment was 4 days (range: 0-11 days).

RESULTS

The sulbactam minimal inhibitory concentration (MIC) ranged from 2.0 to 32.0 mg/L, and the MIC was not associated with patient outcome, as 4 of 5 (80%) patients with a resistant infection (MIC≥16), 5 of 10 (50%) patients with intermediate isolates (MIC of 8) and only 1 of 7 (14%) patients with susceptible isolates (MIC ≤4) survived hospitalization.

CONCLUSION

These findings highlight the need to improve the correlation between in vitro susceptibility tests and clinical outcome.

[Pharmacokinetics of carbapenems]

Carbapenems, beta-lactam antibiotics, are ideal candidates for the treatment of serious nosocomial infections including sepsis for their exceptionally broad antibacterial spectrum and high efficiency. They are administered parenterally by intravenous infusion. Carbapenems penetrate well and rapidly into many different tissue compartments and the interstitial fluid. They are metabolized by renal dihydropeptidase-1. Therefore, imipenem must be co-administered with an inhibitor of dihydropeptidase-1. Other carbapenems registered in the Czech Republic (meropenem, ertapenem and doripenem) are more stable to this enzyme. Carbapenems are mainly eliminated via the kidneys and dose adjustment in patients with renal impairment is necessary. The elimination half-life of most carbapenems is around 1 hour with the exception of ertapenem, with 3.8-hour half-life, which allows its once-daily use. Carbapenems are a group of antibiotics with time-dependent effect. Their typical pharmaceutical property is a limited stability in solution after dilution. Administration in the prolonged infusion appears to be a convenient strategy to achieve higher efficiency. Pharmacokinetic parameters of carbapenems may vary individually, especially in critically ill patients and those treated by renal replacement therapy. Therefore, individualization of dosing regimens based on knowledge of pharmacokinetic parameters of individual patients may be useful.

Mortality attributable to carbapenem-resistant nosocomial Acinetobacter baumannii infections in a Turkish university hospital

This study was performed to compare the mortality associated with carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem-sensitive A. baumannii (CSAB) infections, to identify potential risk factors for CRAB infections, and to investigate the effects of potential risk factors on mortality in CRAB and CSAB patients. This retrospective case-control study was conducted in a university hospital between January 1, 2005 and December 30, 2006. One hundred and ten patients with CRAB and 55 patients with CSAB infection were identified during the study period. The mortality rate was 61.8% and 52.7% in CRAB and CSAB cases, respectively (P = 0.341). In CRAB cases, the risk factors for mortality were identified as intubation (odds ratio [OR], 3.3; 95% confidence interval [CI], 1.0-10.1; P = 0.042) and high APACHE II score (OR, 1.2; 95% CI, 1.1-1.3; P = 0.000), by multivariate analysis. Previous use of carbapenem (OR, 6.1; 95% CI, 2.2-17.1; P = 0.001) or aminopenicillin (OR, 2.5; 95% CI, 1.2-5.1; P = 0.013) were independently associated with carbapenem resistance. Although the mortality rate was higher among patients with CRAB infections, this difference was not found to be statistically significant. Previous use of carbapenem and aminopenicillin were found to be independent risk factors for infections with CRAB.

[Clinical efficacy of tebipenem pivoxil treatment in children with pneumonia, who had no relief despite having administered oral beta-lactam antibiotics]

We assessed the clinical efficacy of tebipenem pivoxil (TBPM-PI) in 30 children with pneumonia who, despite having received oral administration of beta-lactam antibiotics at the standard dose for at least 3 days, had no relief of symptoms and showed an abnormal shadow on the chest X-ray and elevated serum CRP levels of 3.0 mg/dl or more between December 2009 and November 2010. TBPM-PI was administered at a single dose of 4 mg/kg twice a day for 3 days. The children ranged in age from 8 months to 5 years. The serum CRP level ranged from 3.05 to 12.9 mg/dl. In 28 of the 30 children, either Streptococcus pneumoniae or Haemophilus influenzae or both were detected. Of the 28 children, 7 carried penicillin resistant S. pneumoniae; 9 carried beta-lactamase nonproducing ampicillin resistant H. influenzae; and 3 carried both. In all children, defervescence was observed within 48 hours of the start of TBPM-PI administration, and the severity of coughing/wheezing reduced significantly by the 3rd to 5th day. Thus, TBPM-PI was determined to be effective. Diarrhea or loose stool was observed as an adverse reaction in 4 children (13.3%).

Influence of continuous venovenous hemofiltration and continuous venovenous hemodiafiltration on the disposition of doripenem

The pharmacokinetics, safety, and tolerability of a single 1-hour, 500-mg intravenous infusion of doripenem were assessed in dialysis-dependent subjects with stage 5 chronic kidney disease undergoing continuous renal replacement therapy (CRRT) via 12-hour continuous venovenous hemofiltration (CVVH) (n = 6) or continuous venovenous hemodiafiltration (CVVHDF) (n = 5). Healthy volunteers were also assessed (n = 12). Concentrations of doripenem and the primary metabolite doripenem-M-1 were measured in plasma and ultrafiltrate or ultrafiltrate/dialysate by a validated liquid chromatography-tandem mass spectrometry method. In dialysis-dependent subjects, levels of systemic exposure to doripenem and doripenem-M-1 were approximately 3- and 5-fold greater, respectively, than those in healthy subjects: for doripenem, 98 μg·h/ml for CVVH and 77 μg·h/ml for CVVHDF versus 32 μg·h/ml for healthy subjects, and for doripenem-M-1, 24 μg·h/ml for CVVH and 22 μg·h/ml for CVVHDF versus 4.7 μg·h/ml for healthy subjects. The mean sieving coefficients and saturation coefficients were >0.67 for both doripenem and doripenem-M-1. During CVVH and CVVHDF, respectively, the percentages of administered doripenem dose removed were 38% and 29%, and clearances of doripenem were 22 and 25 ml/min. Both CVVH and CVVHDF efficiently removed doripenem and doripenem-M-1. Despite significant removal of drug by CVVH and CVVHDF, a single 1-hour, 500-mg doripenem infusion produced significantly higher plasma concentrations of doripenem, higher systemic exposure (area under the plasma concentration-time curve from time zero to 12 h after the start of infusion [AUC(0-12)]), and longer half-life (t(1/2)) in subjects receiving CVVH or CVVHDF than in healthy volunteers. The recovery of drug in ultrafiltrate and ultrafiltrate/dialysate and the enhanced rate of reduction of plasma concentrations indicate that CVVH and CVVHDF significantly augmented residual total body clearance of doripenem in subjects receiving CRRT. Doripenem dosage regimens for patients receiving CRRT thus need to be adjusted.

Urinary tract infection caused by carbapenem-resistant K. pneumoniae and P. aeruginosa

There has been an increase in recent years of antimicrobial resistance of Gram negative bacilli (GNB). Carbapenems, the mainstay for the treatment of multidrug resistant GNB infections, are no longer always effective leaving treatment options limited. We present the case of patient with recurrent, complicated urinary tract infections. The current episode was caused by carbapenem-resistant K. pneumoniae and P. aeruginosa and carbapenem-susceptible, but MDR E. cloacae. Resistance to carbapenems of K. pneumoniae was conferred by the production of the class B metallo-beta-lactamase, VIM1. Infection control measures were implemented and following a 2-week course of treatment with colistin, the infection resolved and the patient was discharged. We discuss the changes in the epidemiology, the mechanisms involved and the means of detecting carbapenem resistance in GNB. We would also like to stress the role of infection control measures in limiting patient-to-patient spread of MDR organisms which, are of paramount importance in cases when few treatment options are left available.

[A hospital-wide intervention program to optimize the utilization quality of carbapenems and glycopeptides]

OBJECTIVE

To investigate the impact of intervention program upon improvement of utilization quality of carbapenems and glycopeptides.

METHODS

Multifaceted intervention program of carbapenems and glycopeptides was conducted at our hospital. It involved written justification forms, expert consultation committee meetings, audit, feedback and re-feedback. From November 1, 2007 until October 31, 2008, retrospective audit and feedback were performed on all patients dosed with carbapenems or glycopeptides. Case reports were reviewed and data of ratio of appropriate antibiotic use, length of hospital stay, total cost, mortality and rate of vancomycin-resistant Enterococci (VRE) were collected and compared between the first and second half year of antibiotic intervention program.

RESULTS

A total of 397 cases were reviewed, 75 cases discussed at expert committee meetings and 58 feedback letters delivered to responsible doctors. The consumption of both carbapenems and glycopeptides decreased. The appropriate use of carbapenems and glycopeptides increased from 37.8% (45/119) to 53.5% (48/127, P < 0.05) and from 45.6% (36/79) to 63.9% (46/72, P < 0.05) respectively. The total cost and mortality of patients dosed with glycopeptides decreased from a median of RMB 65,700 (30,300 - 146,900) yuan to 55,700 (36,700 - 90,900) yuan, and from 39.2% to 26.4% respectively. The rate of VRE decreased from 5.63% in 2007 to 3.80% during the second half year of 2008.

CONCLUSION

Antibiotic intervention program of carbapenems and glycopeptides is effective in decreasing the inappropriate antibiotic use.

[Convulsive liability of an oral carbapenem antibiotic, tebipenem pivoxil]

Tebipenem pivoxil (TBPM-PI), the first oral carbapenem antibiotic both in Japan and abroad, was examined on its convulsive liability. We used ICR male mice and Sprague-Dawley male rats to examine the pro-convulsive effect and anticonvulsive effect of TBPM-PI and its active metabolite, TBPM. (1) When mice were treated with TBPM-PI (30-1000 mg/kg, p.o.) or TBPM (10-300 mg/kg, i.v.), no convulsion was noted at any dose level. When rats were treated with TBPM (300 mg/kg, i.v.), no convulsant effects were noted in electroencephalography or behavioral observation. In intraventricular injection of TBPM in mice, clonic convulsion was observed in 7/10 animals at 100 microg but no effect at 30 microg. On the other hand, the administration of 10/10 microg imipenem/cilastatin (IPM/CS) resulted in clonic convulsion in all animals and tonic convulsion in 3/10 animals, and 4/10 animals died. The administration of 100 microg meropenem did not cause any effects. (2) When mice were co-administered with pentylenetetrazole (45 mg/kg: maximum dose level at which no convulsion is induced) and TBPM-PI (30-300 mg/kg, p.o.) or TBPM (300 mg/kg, i.v.), convulsion enhancing effect was not noted. On the other hand, the co-administration of pentylenetetrazole with IPM/CS (300/300 mg/kg, i.v.) enhanced a convulsive effect of pentylenetetrazole. (3) When mice were treated with TBPM-PI (30-300 mg/kg, p.o.) or TBPM (100 mg/kg, i.v.), inhibitory effect was not noted on convulsions induced by electrostimulation, pentylenetetrazole or strychinine. In conclusion, there were no pro-convulsive effects or anticonvulsive effect in the oral administration of TBPM-PI or intravenous administration of TBPM. Pro-convulsive effect was observed in the intraventricular injection of TBPM as in the case of other carbapenem antibiotics, but such action was weaker than that in IPM/CS administration. Accordingly, the risk of occurrence of convulsion related to TBPM-PI administration was low compared to IPM/CS administration, and TBPM-PI was considered to be less potential to induce convulsions in clinical use.

[Pharmacokinetics of tebipenem pivoxil, a novel oral carbapenem antibiotic, in experimental animals]

Pharmacokinetics of tebipenem pivoxil (TBPM-PI), a novel oral carbapenem antibiotic, were known in various laboratory animal. (1) In mouse, rat, dog and monkey, TBPM-PI were absorbed quickly, and the bioavailability was (71.4, 59.1, 34.8 and 44.9%, respectively. (2) TBPM-PI was quickly converted to tebipenem (TBPM), an active form of TBPM-PI. Through blood circulation, TBPM was distributed into the kidney at a high concentration and eliminated quickly. There was no other tissue than the kidney, in which TBPM was highly distributed and remained for a long time. In addition, low penetration to the central nervous system was confirmed. The penetration ratio of TBPM to ELF, that is the ratio of ELF concentration to plasma concentration of TBPM, was 21.8 +/- 14.7%. (3) Serum protein bindings of TBPM in the range of 0.1-100 microg/ml were 90.4-98.3% for mouse, 78.5-90.0% for rat, 15.7-18.7% for dog, 35.3-39.3% for monkey and 59.7-73.9% for human. (4) In vitro metabolism was investigated in plasma, liver S9 fractions and small intestinal S9 fractions derived from infant and adult animals. TBPM-PI was transformed into TBPM quickly in any matrices. It was confirmed that absorbed TBPM-PI was quickly transformed into TBPM or LJC 11,562 (opened ring TBPM) in the plasma after oral administration of 14C-TBPM-PI to infant or adult rat and monkey. TBPM-PI and opened ring TBPM-PI was not detected in plasma and urine samples. In rat and monkey, the oral absorption, distribution, metabolite and excretion of TBPM-PI were not so much different between infant and adult animals. (5) Liver metabolic enzyme system was little affected by 7-days repeated administration of 1-100 mg/kg TBPM-PI. IC50 values of TBPM-PI and TBPM for human CYP isoforms were estimated to be 100 microg/ml or higher. (6) After single oral administration of 10 mg/kg 14C-TBPM-PI to rat, 36.9-42.7% and 58.3-62.2% of radioactivity was excreted to urine and feces, respectively, by 120 hours after administration. The majority of dosage was excreted out of body by 48 hours after administration. After single intravenous administration of 10 mg/kg 14C-TBPM, 87.4% and 11.4% of radioactivity was excreted in urine and bile, respectively, by 24 hours after administration. The majority of dosage was excreted out of body by 4 hours after administration.

[Pharmacokinetics analysis of tebipenem pivoxil in a phase II clinical trial in otolaryngological infections]

In a phase IIb clinical study (dose-finding test, 450 mg dosing group: 150 mg t.i.d., 500 mg dosing group: 250 mg b.i.d., 900 mg dosing group: 300 mg t.i.d.) of tebipenem pivoxil (TBPM-PI) for treatment of otolaryngological infections in adults, TBPM concentrations in the patient plasma were quantified. The primary pharmacokinetic parameters such as ka, kel, Vd/F and Tlag were estimated by the Bayesian method and then the secondary pharmacokinetic parameters such as tmax, Cmax, t1/2 and AUC were calculated. As for the patients whose primary parameters were not properly estimated by the Bayesian method, the secondary parameters were calculated by the trapezoidal method. The primary pharmacokinetic parameters obtained by the Bayesian method in 450 mg dosing group (150 mg t.i.d.), 500 mg dosing group (250 mg b.i.d.), and 900 mg dosing group (300 mg t.i.d.) were 5.64 +/- 2.76, 5.11 +/- 3.06 and 2.51 +/- 1.13 hr(-1) for ka, 1.75 +/- 0.25, 2.03 +/- 0.10 and 1.34 +/- 0.27 hr(-1) for kel, 17.62 +/- 5.09, 15.83 +/- 6.14 and 19.34 +/- 8.80 L for Vd/F, and 0.48 +/- 0.11, 0.38 +/- 0.03 and 0.39 +/- 0.26 hr for Tlag, respectively. The secondary parameters obtained by the Bayesian method and the trapezoidal method were 0.85 +/- 0.29, 0.81 +/- 0.33 and 1.18 +/- 1.53 hr for tmax, 5.08 +/- 2.05, 7.92 +/- 4.02 and 8.69 +/- 4.01 microg/ml for Cmax, 0.40 +/- 0.06, 0.34 +/- 0.01 and 0.54 +/- 0.10 hr for t1/2, 5.22 +/- 1.90, 7.93 +/- 4.04 and 13.62 +/- 6.29 microg x hr/ml for AUC after each dosing (AUC(0-8h) or AUC(0-12h)) and 15.65 +/- 5.70, 15.85 +/- 8.08 and 40.87+/- 18.87 microg x hr/ml for AUC(0-24h), respectively. As shown in the above, Cmax and AUC after each dosing were increased with a rise in the dose level, and AUC(0-24h) was increased with a rise in the total dose level per day. Regardless of the dosage, tmax was about 0.8-1.2 hr and t1/2 was about 0.3-0.5 hr, showing almost constant values. Changes in the regimen and dosage did not influence the pharmacokinetic properties of TBPM-PI. Pharmacokinetics of TBPM-PI in adult patients with otolaryngological infection were similar to those in healthy subjects.

[Tissue and aural discharge distribution of tebipenem pivoxil]

Tebipenem pivoxil (TBPM-PI) is a novel oral carbapenem antibiotic. It has been developed as a prodrug of tebipenem (TBPM), to increase absorption. We assessed the distribution of TBPM to aural discharge and tissues after administration of TBPM-PI to adult patients who underwent otolaryngological surgical tissue resection and pediatric patients with acute otitis media or acute sinusitis. Following the administration of single oral doses of 150 and 250 mg (potency) of TBPM-PI to adult patients who underwent otolaryngological surgical tissue resection, tissue TBPM concentrations for the respective doses were 0.38 to 1.76 microg/g and 0.17 to 0.91 microg/g in mucous membranes of the maxillary sinus, 0.26 to 0.94 microg/g and 0.14 to 0.45 microg/g in mucous membranes of the ethmoid sinus, and 0.12 to 0.13 microg/g and 0.14 to 0.47 microg/g in palatine tonsil tissues, as well as 0.29 microg/g in mucous membranes of the middle ear for the dose of 250 mg. The percentages of these tissue concentrations to plasma concentrations for the respective doses were 14.3% to 61.0% and 18.4% to 54.6% in mucous membranes of the maxillary sinus, 34.3% to 52.1% and 9.9% to 54.6% in mucous membranes of the ethmoid sinus, and 10.3% to 15.0% and 6.5% to 17.4% in palatine tonsil tissues, as well as 16.8% in mucous membranes of the middle ear for the dose of 250 mg. Following the administration of TBPM-PI at doses of 4 mg (potency)/kg and 6 mg (potency)/kg twice daily to pediatric patients with acute otitis media or acute sinusitis, TBPM concentrations in the aural discharge for these doses were 0.03 to 2.00 microg/g and 1.07 or 1.18 microg/g, respectively. The percentage of aural discharge concentrations to plasma concentrations for these doses was 0.3% to 86.1% and 40.5% or 83.6%, respectively. These results indicate a favorable distribution profile of TBPM to tissues affected by otitis media or sinusitis after the administration of TBPM-PI and can support the high efficacy of TBPM-PI.

[Carbapenem restriction reduce the incidence of multidrug-resistant Acinetobacter baumannii in ventilator associated pneumonia]

OBJECTIVE

To determine the relation of carbapenem restriction with the incidence of multidrug-resistant (MDR) Acinetobacter baumannii in ventilator associated pneumonia (VAP).

METHODS

Twenty-six patients admitted to the intensive care unit, West China Hospital, Sichuan University, from June to December in 2007, with confirmed VAP were randomized to two groups: conventional group (14 cases) and carbapenem restriction group (12 cases). All sputum samples were collected throughout the trial. The correlation between the incidence of MDR Acinetobacter baumannii and the consumption of carbapenem was analyzed.

RESULTS

The incidence of MDR Acinetobacter baumannii (10.7%, 7/65) and consumption of carbapenem (61 g) in carbapenem restriction group were significantly lower than conventional group (17.8%, 13/73, 188 g, both P<0.05). The result implied that the decreased incidence of MDR Acinetobacter baumannii was attributable to the reduction of carbapenem consumption.

CONCLUSION

Carbapenem constraint could reduce the incidence of MDR Acinetobacter baumannii in VAP.

[Clinical efficacy, safety and PK-PD analysis of tebipenem pivoxil in a phase II clinical trial in otolaryngological infections]

We conducted a double-blind intergroup comparative study investigating the efficacy, safety and PK-PD analysis of the new oral carbapenem antibacterial drug tebipenem pivoxil (TBPM-PI) for the treatment of otolaryngological infections in adults to establish the recommended clinical dosage. The primary endpoint was the clinical effect of a 7-day oral administration of TBPM-PI to subjects with confirmed cases of infection by any of the 5 major bacterial species causative for otolaryngological infections (Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, Moraxella catarrhalis, and Haemophilus influenzae) assigned to three groups set according to the TBPM-PI dosage, namely, a 450 mg group (150 mg t.i.d), a 500 mg group (250 mg b.i.d), and a 900 mg group (300 mg t.i.d). 1. Clinical efficacy: At the end of administration or at discontinuation, the efficacy rate for the 112 subjects in the efficacy analysis set was 72.1% (31/43 subjects) in the 450 mg group, 88.6% (31/35 subjects) in the 500 mg group, and 85.3% (29/34 subjects) in the 900 mg group. Both the 500 mg and 900 mg groups showed a high efficacy rate of over 80%. 2. Bacteriological efficacy: The disappearance rate of the pre-administration causative bacteria (5 major bacterial species) at the end of administration (at discontinuation), it was 92.2% (47/51 strains) in the 450 mg group, 94.7% (36/38 strains) in the 500 mg group, and 91.7% (33/36 strains) in the 900 mg group. All the groups showed a high disappearance rate, with no large differences among them. All strains of S. pneumoniae, including PRSP, as well as those of S. pyogenes and M. catarrhalis disappeared. The overall disappearance rate of H. influenzae was 78.6%, namely, 76.9% in the 450 mg group, 100% in the 500 mg group, and 66.7% in the 900 mg group, showing differences among the groups. 3. PK-PD: The PK-PD analysis was executed in 124 strains isolated from 111 subjects in which the plasma TBPM concentration and the MIC of causative organism were measured. The target value of the PK-PD parameter was examined from the relation between PK-PD parameter and bacteriological efficacy. The presumed target value of AUCf/MIC was 10-20, Cmaxf/MIC was 4. On the other hand, a clear relation was not found between T>MIC and the bacteriological efficacy. 4.

SAFETY

The incidence of adverse reactions related to symptoms and signs was 28.8% (21/73 subjects) in the 450 mg group, 35.8% (24/67 subjects) in the 500mg group, and 30.6% (22/72 subjects) in the 900 mg group. The incidence of abnormal changes in laboratory test values was 8.2% (6/73 subjects) in the 450 mg group, 9.2% (6/65 subjects) in the 500 mg group, and 9.9% (7/71 subjects) in the 900 mg group. There were no differences in either of these categories among the groups, and the incidence was considered not to be correlated with dose. Based on the above, we considered that TBPM-PI at doses of 250 mg b.i.d (500 mg/day) promises high clinical usefulness for the treatment of otolaryngological infections in adults.

[Use of systemic antibacterial agents at a university emergency clinic in Bucharest, in the year 2008]

OBJECTIVE

use of ATC/DDD (Anatomic Therapeutic Classification/Daily Defined Dose) methodology promoted by World Health Organization for calculating and analysis of systemic antimicrobial agents' annual rates of usage among the adult patients hospitalized in Bucharest municipality.

METHODS

descriptive retrospective study conducted in the main university clinic for medical emergencies from Bucharest municipality. Consumption of systemic antimicrobial agents, taken from the clinic pharmacy's records, regarding the 2008 year, has been transformed in defined daily doses and aggregated by ATC subgroups. The number of patient days from 2008 was obtained from clinic administrative service. Antimicrobial agents' usage was expressed as consumption density rate by dividing the defined daily doses counts to the correspondent number of patient days. Analysis of consumption rates has been performed both by whole clinic and also stratified by departments of medical specialties: surgery, internal medicine and intensive care.

RESULTS

In the year 2008, the patients carried in the clinic totalized 255,600 days of hospitalization; during the respective time in clinic there were used 36 of individual antibacterial agents that made up 184,857 defined daily doses. At the level of entire clinic the consumption rate of all systemic antimicrobial agents was 72.6 defined daily doses per 100 de patient days (DDD/PD); by medical specialties the indicator's values were 61.2 DDD/100 PD in the department of internal medicine specialties, 62.8 DDD/100 PD in the departament of surgical specialties and 126 DDD/100 PD in the medical/surgical intensive care unit, respectively. Almost 70% of the defined daily doses' total included five antimicrobial agents: co-amoxiclav, cefuroxim, cefoperazone + sulbactam, ciprofloxacine si metronidazol. By ATC subgroups, the top three consumption rates included penicillin plus beta-lactamase inhibitors, 2nd generation cefalosporines and fluorochinolons, respectively. Comparing the own rate with the distributions of NNIS (National Nosocomial Infection Surveillance) system form USA, demonstrated that the usage was into the expected limits for the majority of antimicrobial agents groups considered, excess usage being detected only in the case of 2nd generation cefalosporins (in non-intensive care sector) and in the case of carbapenems in the intensive care units, respectively.

CONCLUSIONS

At the whole clinic level, the study detected a rate of systemic antimicrobial agents' usage similar with the correspondent values recently reported even from the South European states or form USA. Excessive usage (against the NNIS standard) might be mitigated through augmentation of the compliance with guidelines for prudent utilization of antimicrobial agents.

[Clinical examination of doripenem for infectious diseases in gynecological and associated fields]

We examined the efficacy of doripenem (DRPM), a carbapenem antimicrobial agent, against infectious diseases in gynecological and associated fields, as well as its safety. The following results were obtained: 1) The subjects were 20 patients with infection in the absence of pregnancy and 4 patients with pregnancy/puerperal infection. Intravenous drip of DRPM at 0.25 g x 2/day was performed for 3 to 8 days. The total doses ranged from 1.5 to 4.0 g. 2) Concerning its clinical efficacy, a complete response was achieved in 4 (16.7%) of the 24 patients, and a partial response in 18 (75.0%). The response rate was 91.7% (22/24). In 6 patients who did not respond to the previous agent, the response rate was 100% (6/6). 3) Concerning its clinical efficacy with respect to clinically isolated bacteria, a complete response was achieved in 3 (10.0%) of the 30 strains, and a partial response in 26 (86.7%). Bacteria disappeared in 29 (96.7%) of the 30 strains. 4) There were no side effects nor abnormalities in the laboratory data related to this agent. These results suggest the usefulness of DRPM in the treatment of gynecological infectious diseases.

Pharmacodynamics of the antibacterial effect and emergence of resistance to tomopenem, formerly RO4908463/CS-023, in an in vitro pharmacokinetic model of Staphylococcus aureus infection

The antibacterial effects (ABE) of tomopenem (formerly RO4908463/CS-023) against seven Staphylococcus aureus strains (methicillin-resistant S. aureus [MRSA] strain tomopenem MICs, 0.5 to 16 mg/liter; methicillin-sensitive S. aureus [MSSA] strain tomopenem MIC, 0.06 mg/liter) were studied in an in vitro pharmacokinetic model. Initially, two human doses were simulated, 750 mg every 8 hours (8hly) and 1,500 mg 8hly intravenously, using S. aureus at a standard inoculum of 10(6) CFU/ml. There was a rapid clearance of bacteria from the model by 12 h after drug exposure with most strains. Clearance was not related to the tomopenem MIC. The ABE of these two tomopenem dose regimens were also tested at a high inoculum, 10(8) CFU/ml; in all simulations, there was a >4-log drop in viable count at 24 h. Strains were not cleared from the model at 10(8) CFU/ml, in contrast to what was seen for the standard inoculum. When the ABE of tomopenem at 750 mg 8hly was compared to those of vancomycin, tomopenem was seen to have a superior effect, as measured by the area under the bacterial kill curve at 24 h (AUBKC24) and 48 h (P < 0.05). Dose ranging studies were performed to provide time-above-MIC (T>MIC) drug exposures of 0 to 100% (8 to 10 doses per strain) with five MRSA/MSSA strains. The T>MIC for a 24-h bacteriostatic effect was 8% +/- 5% (range, 1.3% to 15.4%); the T>MIC for a 4-log drop in viable count was 32% +/- 18% (range, 12.8% to 36.2%). The T>MIC for a 90% maximum response using AUBKC24 as ABE was 24.9% +/- 15.7%. Inoculum had little impact on T>MIC exposures for ABE. There was emergence of resistance to tomopenem in the dose ranging studies, with increased growth of subpopulations on plates containing tomopenem at 2x and 4x the MIC compared to what was seen for preexposure population analysis at T>MICs of <20%. The pharmacodynamics of tomopenem against S. aureus is similar to those of other members of the carbapenem class, with the exception that MRSA is included. These data indicate that tomopenem will have clinically useful activity against MRSA at T>MICs achievable in humans.