Piperacillin, beta-lactam inhibitor plus gentamicin as empirical therapy of a sequential regimen in febrile neutropenia of pediatric cancer patients

Evaluation of Piperacillin/Sulbactam, Piperacillin/Tazobactam and Cefoperazone/Sulbactam Dosages in Gram-Negative Bacterial Bloodstream Infections by Monte Carlo Simulation

The optimal regimens of piperacillin/sulbactam (PIS 2:1), piperacillin/tazobactam (PTZ 8:1), and cefoperazone/sulbactam (CSL 2:1) are not well defined in patients based on renal function. This study was conducted to identify optimal regimens of BLBLIs in these patients. The antimicrobial sensitivity test was performed by a two-fold agar dilution method. Monte Carlo simulation (MCS) was used to simulate the probability of target attainment (PTA) and the cumulative fraction of response (CFR) for various dosing regimens in patients with different renal functions. For strains with an MIC ≤ 8/4 mg/L, PIS 4.5 g q6h achieved 99.03%PTA in the subset of patients with creatinine clearance (CrCL) > 90 mL/min. For patients with CrCL 60-90 mL/min, PIS 4.5 g q6h achieved 81.2% CFR; for those with CrCL 40-59 mL/min, PIS 4.5 g q8h achieved 80.25% CFR. However, for patients infected by ESBL-producing Enterobacteriaceae, PIS 4.5 g q6h achieved a CFR lower than 80%. For patients infected by A. baumannii with a CrCL of 31-60 mL/min, PIS 6.0 g q8h and 4.5 g q6h achieved 81.24% and 82.42% CFR, respectively. For those infected by P. aeruginosa, PIS 4.5 g q6h reached 90% CFR. PIS and PTZ achieved a similar CFR when piperacillin was at the same dose. The CFRs of CSL were much lower than those of the other two agents in Enterobacteriaceae and P. aeruginosa infections. The antibacterial spectrum of PIS is superior to that of PTZ and CSL. Higher dosages and dosing adjustment according to renal function should be considered to treat Gram-negative bacterial BSIs.

Structure-based repurposing of FDA-approved drugs as inhibitors of NEDD8-activating enzyme

We report the discovery of an inhibitor of NEDD8-activating enzyme (NAE) by an integrated virtual screening approach. Piperacillin 1 inhibited NAE activity in cell-free and cell-based systems with high selectivity. Furthermore, piperacillin 1 was able to inhibit the degradation of the NAE downstream protein substrate p27(kip1). Our molecular modeling and kinetic studies suggested that this compound may act as a non-covalent ATP-competitive inhibitor of NAE.

Antibiotic and other lock treatments for tunnelled central venous catheter-related infections in children with cancer

BACKGROUND

The risk of developing a tunnelled central venous catheter (CVC)-related infection ranges between 0.1 and 2.3 per 1000 catheter days for children with cancer. These infections are difficult to treat with systemic antibiotics (salvage rate 24% - 66%) due to biofilm formation in the CVC. Lock treatments can achieve 100 - 1000 times higher concentrations locally without exposure to high systemic concentrations.

OBJECTIVES

Our objective was to investigate the efficacy of antibiotic and other lock treatments in the treatment of CVC-related infections in children with cancer compared to a control intervention. We also assessed adverse events of lock treatments.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, issue 3, 2011), MEDLINE/PubMed (1945 to August 2011) and EMBASE/Ovid (1980 to August 2011). In addition we searched reference lists from relevant articles and the conference proceedings of the International Society for Paediatric Oncology (SIOP) (from 2006 to 2010), American Society of Clinical Oncology (ASCO) (from 2006 to 2010), the Multinational Association of Supportive Care in Cancer (MASCC) (from 2006 to 2011), the American Society of Hematology (ASH) (from 2006 to 2010) and the International Society of Thrombosis and Haematology (ISTH) (from 2006 to 2011). We scanned the ISRCTN Register and the National Institute of Health Register for ongoing trials (www.controlled-trials.com) (August 2011).

SELECTION CRITERIA

Randomised controlled trials (RCTs) and controlled clinical trials (CCTs) comparing an antibiotic lock or other lock treatment (with or without concomitant systemic antibiotics) with a control intervention (other lock treatment with or without concomitant systemic antibiotics or systemic antibiotics alone) for the treatment of CVC-related infections in children with cancer. For the description of adverse events, cohort studies were also eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies, extracted data and performed 'Risk of bias' assessments of included studies. Analyses were performed according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

Two RCTs evaluated urokinase lock treatment with concomitant systemic antibiotics (n = 56) versus systemic antibiotics alone (n = 48), and one CCT evaluated ethanol lock treatment with concomitant systemic antibiotics (n = 15) versus systemic antibiotics alone (n = 13). No RCTs or CCTs evaluating antibiotic lock treatments were identified. All studies had methodological limitations and clinical heterogeneity between studies was present. We found no evidence of significant difference between ethanol or urokinase lock treatments with concomitant systemic antibiotics and systemic antibiotics alone regarding the number of participants cured, the number of recurrent CVC-related infections, the number of days until the first negative blood culture, the number of CVCs prematurely removed, ICU admission and sepsis. Not all studies were included in all analyses. No adverse events occurred in the five publications of cohort studies (one cohort was included in two publications) assessing this outcome; CVC malfunctioning occurred in three out of five publications of cohort studies assessing this outcome.

AUTHORS' CONCLUSIONS

No significant effect of urokinase or ethanol lock in addition to systemic antibiotics was found. However, this could be due to low power or a too-short follow-up. The cohort studies identified no adverse events; some cohort studies reported CVC malfunctioning. No RCTs or CCTs were published on antibiotic lock treatment alone. More well-designed RCTs are needed to further explore the effect of antibiotic or other lock treatments in the treatment of CVC-related infections in children with cancer.

Clinical analysis of combination therapy for febrile neutropenic patients in childhood cancer

BACKGROUND

The objective of this study was to evaluate the efficacy and safety of our combination therapy in febrile neutropenic children with cancer.

METHODS

A total of 109 patients with 251 episodes of febrile neutropenia received antibiotic therapy between January 2003 and December 2008 at a single institution.

RESULTS

Blood cultures were positive in 35 episodes (14%). Gram-positive organisms predominated (23/38 organisms isolated). There were 15 gram-negative isolates and no fungal isolates. The recommended empirical first-line antibiotics (cefepime or cefozopran + piperacillin + amikacin) were used in 206 (82%), second-line antibiotics (piperacillin-tazobactam + carbapenem + amikacin + micafungin) in 73 (29%), and third-line antibiotics (meropenem + glycopeptides + micafungin) in 24 (10%) episodes. The overall response rates were 71.4%, 50.7%, and 62.5% for the first-, second-, and third-line antibiotic therapies, respectively. Granulocyte transfusion was performed in seven patients, and the response rate was 57%. Four deaths were recorded.

CONCLUSIONS

Although a significant improvement of mortality was not observed, our regimen of empirical antibiotic therapies led to a significant and clinically relevant decrease in glycopeptide use, and it is safe and well tolerated by pediatric neutropenic patients.

A meta-analysis of antipseudomonal penicillins and cephalosporins in pediatric patients with fever and neutropenia

BACKGROUND

Antipseudomonal penicillins (APP) and antipseudomonal cephalosporins (APC) play important roles in the management of pediatric patients with fever and neutropenia (FN). Our primary objective was to describe the risk of treatment failure in children treated with an APP or APC as initial empiric therapy for FN. Our secondary objectives were to compare APP with APC and third- with fourth-generation APC as initial empiric therapy in this population.

METHODS

We performed electronic searches of Ovid Medline, EMBASE, and the Cochrane Central Register of Controlled Trials, limiting studies to prospective pediatric trials in FN in which at least 1 treatment arm consisted of an APP or APC antibiotic with or without an aminoglycoside. Data abstraction was conducted by 2 independent reviewers.

RESULTS

From 7281 reviewed articles, 41 studies comprising 51 treatment regimens were included in the meta-analysis. Treatment failure, including antibiotic modification, occurred in 34% and 41% of patients treated with APP and APC monotherapy, respectively, and 41% and 33% of patients treated with APP- and APC-aminoglycoside combination therapy, respectively. There were no statistically significant differences in treatment failure including modification, mortality, or adverse events when comparing APP with APC monotherapy, APP with APC combination therapy, or third- with fourth-generation APC therapy.

CONCLUSIONS

Our meta-analysis suggests that APP and APC monotherapy, as well as combination therapy with an aminoglycoside, are efficacious and safe therapeutic options for the empiric management of pediatric patients with FN. Specific antibiotic selection should be based on other important factors, such as cost, availability, and local epidemiologic and resistance patterns.

Piperacillin-tazobactam in pediatric cancer patients younger than 25 months: a retrospective multicenter survey

Piperacillin-Tazobactam (Pip-Taz) is an evidence-based empirical treatment of febrile neutropenia in adolescents and adults. No data are available in pediatric cancer patients <25 months of age. In this retrospective, multicenter data survey, the analysis focuses on safety, tolerance, and efficacy. The daily dose administered was 240 mg/kg given in three equally divided doses. Data on 156 Pip-Taz treatment courses in 69 children <25 months from five pediatric cancer treatment centers (2001-2005) were analyzed. The median duration of treatment with Pip-Taz was 5 days (range, 1-23 days; 1-12 Pip-Taz courses per patient). Pip-Taz was started on the first day of fever in 90% of all courses, in 6% in the first 72 h, and in 4% as second- or third-line agent. Forty-five percent of all patients were neutropenic. In all patients, the outcome was favorable independent whether Pip-Taz was given as monotherapy (42 courses; 27%) or in combination. Overall, Pip-Taz was well tolerated and discontinued due to adverse events in only two patients who experienced non-life-threatening allergic reactions (skin rash and wheezing). The results of this study are preliminary due to the methodological limitations of a retrospective survey. Taking this bias into consideration, Pip-Taz appears to be a safe, and feasible alternative in pediatric cancer patients with febrile neutropenia <25 months of age suggesting that the inclusion of children of all age groups in future prospective controlled studies evaluating Pip-Taz is justified.

Experience with the use of piperacillin-tazobactam in pediatric non-renal solid organ transplantation

Bacterial infection remains a major problem after solid organ transplantation (SOT), especially in children. Piperacillin-tazobactam (Pip-Tazo) is a beta-lactam-antibiotic combination with a broad spectrum of activity including gram-positive cocci as well as gram-negative rods, non-fermentative and anaerobic bacteria. The aim of this retrospective study was to critically review our experience with Pip-Tazo as perioperative prophylactic agent in pediatric non-renal SOT. Between 1993 and 2003 Pip-Tazo was used as initial perioperative prophylaxis in 45 pediatric patients who underwent a total of 49 transplants (36 liver-, seven cardiac-, two lung-, and four small bowel-) at our department. Median age of the children was 7.9 (range 0.5-18.1) years. A total of 34 rejection episodes following 27 transplants were diagnosed. During first hospitalization 44 infectious episodes were observed. Bacteria were responsible for 22 episodes including sepsis (n = 10), pneumonia (n = 5), wound infection (n = 4), urinary tract infection (n = 1), and clostridial colitis (n = 2). The isolated organisms were gram-positive cocci (n = 12), gram-negative rods (n = 3), non-fermentative bacilli (n = 4), and anaerobes (n = 3). Ten episodes were caused by Pip-Tazo resistant bacteria. Twenty-one of these infections were observed following antirejection therapy with pulse steroids. At later time points nine infectious episodes were successfully treated with a second course of Pip-Tazo. During follow up, eight patients died. Six deceased perioperatively: five from infection including aspergillosis (n = 4) and Pneumocystis jiroveci pneumonia (n = 1) and cerebrovascular bleeding (n = 1) and two children later on. At present 37 children (82%) are alive with well functioning graft after a median follow up of 39.2 (range 0.6-123.5) months. No severe side effects caused by Pip-Tazo were observed in any of the children. Pip-Tazo may be a suitable single agent for perioperative prophylaxis in pediatric non-renal solid organs recipients, however, a prospective comparative study is needed to make final conclusions.

Restricted use of glycopeptides in paediatric cancer patients with fever and neutropenia

Until now, studies confirming the safety of glycopeptide restriction in the empirical treatment of prolonged fever and neutropenia included only nine children. In an open-label observational study, the use of teicoplanin in paediatric oncology patients was investigated. A period of unrestricted use (2001-2003) was compared with a second period (2004) following implementation of a restrictive treatment guideline. Empirical first-line treatment consisted of piperacillin/tazobactam; in 2004, fosfomycin was added after 72 h as the second-line combination instead of teicoplanin. In total, 213 episodes (n=163 in 2001-2003; n=50 in 2004) managed with teicoplanin or fosfomycin (only 2004) were eligible. Empirical treatment of fever of unknown origin with teicoplanin was reduced by 97%. In 2004, the mean length of stay was 0.4 days shorter, no infection-related death occurred and no vancomycin-resistant enterococci were detected. Restriction of empirical glycopeptides is safe in paediatric cancer patients after first-line treatment with piperacillin/tazobactam. Fosfomycin appears to offer a feasible and cost-saving alternative in second-line combination therapy.

In vitro activities of various piperacillin and sulbactam combinations against bacterial pathogens isolated from Intensive Care Units in Taiwan: SMART 2004 programme data

We investigated the in vitro activity of various piperacillin and sulbactam combinations against Gram-negative bacterial isolates from Intensive Care Units (ICUs) in Taiwan. Antimicrobial susceptibility testing of 1030 bacterial isolates recovered from ICUs of nine major teaching hospitals was performed using the agar dilution method. Sulbactam was added to piperacillin either at a fixed sulbactam concentration of 4 mg/L and 8 mg/L or at a piperacillin:sulbactam ratio of 2:1 and 4:1. Piperacillin/sulbactam at a ratio of 2:1 or a fixed 8 mg/L concentration of sulbactam had better activities against Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis and Serratia marcescens than other piperacillin/sulbactam formulations. For Pseudomonas aeruginosa, piperacillin/sulbactam (2:1 or 4:1 ratios) had MIC(90) values (minimum inhibitory concentration for 90% of the organisms) of 64 mg/L (>90% susceptibility) compared with 64 mg/L for cefoperazone/sulbactam (68% susceptibility) and 128 mg/L for piperacillin/tazobactam (82% susceptibility). For Acinetobacter baumannii, both piperacillin/sulbactam (either 2:1 ratio or a fixed 8 mg/L sulbactam) and cefoperazone/sulbactam were the most potent agents. Adding sulbactam to piperacillin resulted in increased susceptibility rates among piperacillin-resistant P. aeruginosa (53-57% in either 2:1 or 4:1 ratios) and A. baumannii (38-46% in either 2:1 ratio or a fixed 8 mg/L concentration of sulbactam) isolates. Results of susceptibility tests with piperacillin/sulbactam are dependent on the method used. Piperacillin/sulbactam combinations possessed better in vitro activities than piperacillin alone or piperacillin/tazobactam against P. aeruginosa and A. baumannii.

Diagnosis and treatment of catheter-related infections in paediatric oncology: an update

Otherwise unexplained clinical signs of infection in patients with long-term tunnelled or totally implanted central venous access devices (CVADs) are suspected to be CVAD-associated. Diagnostic methods include catheter swabs, blood cultures and cultures of the catheter tip or port reservoir. In the case of a suspected CVAD-related bloodstream infection in paediatric oncology patients, in-situ treatment without prompt removal of the device can be attempted. Removal of the CVAD should be considered if bacteraemia persists or relapses > or = 72 h after the initiation of (in-vitro effective) antibacterial therapy administered through the line. Timely removal of the device is also recommended if the patient suffers from a complicated infection, or if Staphylococcus aureus, Pseudomonas aeruginosa, multiresistant Acinetobacter baumannii or Candida spp. are isolated from blood cultures. Duration of therapy depends on the immunological recovery of the patient, the pathogen isolated and the presence of related complications, such as thrombosis, pneumonia, endocarditis and osteomyelitis. Antibiotic lock techniques in addition to systemic treatment are beneficial for Gram-positive infections. Although prospectively controlled studies are lacking, the concomitant use of urokinase locks and taurolidine secondary prophylaxis seem to favour catheter salvage.

Monotherapy with piperacillin/tazobactam versus cefepime as empirical therapy for febrile neutropenia in pediatric cancer patients: a randomized comparison

The purpose of this study was to compare the efficacy, safety, and cost of piperacillin/tazobactam with cefepime monotherapy in children with febrile neutropenia. A prospective randomized study in children and adolescent with cancer was conducted. Patients were randomly assigned to receive either 80 mg/kg piperacillin/10 mg/kg tazobactam every 6 h (maximum 4.5 g/dose) or cefepime 50 mg/kg every 8 h (maximum 2 g/dose). Treatment modification was defined as all the changes in the empirical antimicrobials after the first 96 h. Overall treatment success was defined as cure of febrile episode with or without modification. Cost of hospitalization, antimicrobial drugs, and supportive therapy were calculated. Fifty febrile neutropenic episodes (25 in the piperacillin/tazobactam group, 25 in the cefepime group) in 27 pediatric cancer patients were evaluated. The groups were comparable in terms of age, gender, body weight, primary diagnosis, disease status, initial neutrophil count, and duration of neutropenia. Microbiologically and clinically documented infection rate was 46%. There was no infection-related mortality in the study period. The treatment success of initial empirical therapy without modification was not different in the 2 groups (56% in piperacillin/tazobactam group and 48% in cefepime group). Anti-anaerobic drugs were added more frequently in the cefepime group. Duration of fever, neutropenia, treatment, and cost of therapy were not different in the treatment groups. Piperacillin/tazobactam monotherapy is as effective as cefepime monotherapy in febrile neutropenia of pediatric cancer patients.

Prospective audit of treatment of paediatric febrile neutropenia in Australasia

OBJECTIVES

Febrile neutropenia post-chemotherapy continues to impose a burden of morbidity and mortality on patients and families affected by childhood cancer, whereas these unplanned hospital admissions increase the financial cost of treating paediatric malignancies. There are currently no published national guidelines. This study comprises the first audit of current therapeutic practice in Australasia.

METHODS

Information was sought prospectively from the 12 paediatric oncology tertiary referral centres in Australia and New Zealand regarding treatment of febrile neutropenia episodes commencing between 11 March and 10 May 2002.

RESULTS

Data were returned on 127 episodes by nine centres. The median length of stay was 6 days and 18 different antibiotic regimens were implemented as first-line therapy. The median neutrophil count at the beginning and end of the febrile neutropenic episode was 0.0 x 10(9)/L (range 0.0 to 2.3 x 10(9)/L) and 0.7 x 10(9)/L (range 0.0 to 25.4 x 10(9)/L), respectively. Thirty per cent of episodes had positive blood cultures. Of these, 81% occurred in patients with tunnelled central venous catheters. The initial antimicrobial combination was changed in 61% of episodes. Outpatient antibiotics were used in 21% episodes after initial intravenous antimicrobial therapy.

CONCLUSIONS

The current practice in Australasia is consistent with international guidelines, although changes are made more frequently to first-line therapy than in previous published studies. The central venous catheters are associated with a much higher risk of bacteraemia and consideration should be given to increased use of implanted port systems.

Piperacillin–sulbactam versus piperacillin–tazobactam: a multicentre, randomised, single-blind, controlled clinical trial

The objective of this study was to compare the efficacy and safety of piperacillin-sulbactam (PIP-SBT) and piperacillin-tazobactam (PIP-TAZ) in the treatment of bacterial respiratory and urinary tract infections. A randomised, single-blind, controlled clinical trial was performed. Differences in clinical efficacy, bacteriology and safety between the two groups were subjected to statistical analysis, including intent-to-treat (ITT) analysis. A total of 215 cases were enrolled, with 203 complete cases (99 PIP-SBT, 104 PIP-TAZ). A total of 209 cases (103 PIP-SBT, 106 PIP-TAZ) were included in the ITT analysis and a total of 212 cases (104 PIP-SBT, 108 PIP-TAZ) were included in the safety analysis. Overall efficacy rates of PIP-SBT and PIP-TAZ were 93.2% and 93.4%, respectively. Overall bacterial eradication rates of the two groups were 95% and 97.59%, respectively. Among the PIP-SBT group, eight patients (7.69%) had adverse events, including four probable drug-related events. Among the PIP-TAZ group, nine patients (8.33%) had adverse events, including one definitely drug-related and four probable drug-related events. All differences between the two groups were insignificant. PIP-SBT could be a suitable replacement for PIP-TAZ in the therapy of community-acquired respiratory and urinary tract infections caused by beta-lactamase-producing bacterial isolates.

[Treatment of febrile neutropenia episodes in children, with a piperacillin-tazobactam and netilmicin combination]

OBJECTIVES

The authors had for aim to assess the effectiveness and toxicity of a piperacillin-tazobactam-netilmicin combination, and the possibility of avoiding using glycopeptide, in children with febrile neutropenic episodes induced by chemotherapy.

METHODS

A retrospective study was made, including children treated for a febrile neutropenic episode (absolute neutrophile count < 0.5 x 10(9)/l) by a piperacillin-tazobactam-netilmicin combination. If fever persisted 48 hours after the beginning of antibiotic therapy, a glycopeptide could be added. The responses to the treatment were defined as follows: 1) total success (no fever or documented infection) at 48 hours and at 72 hours following the beginning of treatment; 2) partial success (apyrexia beyond 72 hours without any therapeutic change); 3) failure (persistent infectious signs 48 hours after the introduction of glycopeptide).

RESULTS

Sixty-nine episodes were assessable, corresponding to 41 patients, treated for a solid tumour (29), an acute leukaemia in remission (11), or a metabolic disease (1). The febrile episodes were divided into fever of unknown origin (71%), microbiologically documented fever (12%), and clinically documented fever (17%). No death occurred, no toxicity was reported. With this antibiotic therapy, total success at 72 hours was observed in 72% in case of fever of unknown origin and 45% in case of documented infections. The success rate reached 84% when a glycopeptide was added (30% of the cases).

CONCLUSION

The piperacillin-tazobactam-netilmicin combination is very effective and well tolerated in probabilistic treatment of febrile neutropenia induced by chemotherapy, but does not allow to decreasing the frequency of glycopeptide administration.

Tobramycin Pharmacokinetics in Children with Febrile Neutropenia Undergoing Stem Cell Transplantation: Once-Daily versus Thrice-Daily Administration

STUDY OBJECTIVE

To describe the pharmacokinetic disposition of tobramycin in children undergoing stem cell transplantation (SCT) after intravenous administration either every 24 hours or every 8 hours, and to use this information to create initial dosing guidelines for administration every 24 hours in this patient population.

DESIGN

Pharmacokinetic analysis of a randomized controlled trial.

SETTING

The Hospital for Sick Children, Toronto, Ontario, Canada.

PATIENTS

Sixty children (< 18 yrs) with febrile neutropenia undergoing stem cell transplantation.

INTERVENTION

Patients were randomized to receive intravenous tobramycin either every 24 hours (29 patients) or every 8 hours (31 patients). Initially, they received either 2.5 mg/kg/dose every 8 hours or weight-based doses by age group (< 5 yrs, 9 mg/kg/dose; 5 to < 12 yrs, 8 mg/kg/dose; > or = 12 yrs, 7 mg/kg/dose) every 24 hours.

MEASUREMENTS AND MAIN RESULTS

Serum tobramycin concentrations were obtained at 2 and 8 hours after the first dose. Initial guidelines for dosing every 24 hours were derived using the parameters from all patients to achieve a maximum serum concentration (Cmax) of 20-22.5 mg/L and a drug-free interval (time during dosing interval when the tobramycin concentration was < 1 mg/L) of at least 4 hours. After the first tobramycin dose, the elimination rate constant (kel) and volume of distribution (Vd) observed in the every-8-hour group (23 patients) were 0.34 +/- 0.09 hours(-1) and 0.48 +/- 0.21 L/kg, respectively. The kel and Vd in the every-24-hour group (22 patients) were 0.43 +/- 0.12 hr(-1) and 0.43 +/- 0.26 L/kg, respectively. Tobramycin Vd varied with age. Initial doses of tobramycin every 24 hours recommended to achieve the target parameters are 10 mg/kg/dose for patients aged 6 months to less than 9 years, 8 mg/kg/dose for those aged 9 to less than 12 years, and 6 mg/kg/dose for those aged 12 years or older.

CONCLUSION

Children undergoing SCT who receive tobramycin every 24 hours should receive an initial dose based on age. Further validation of the proposed dosing guidelines is required.

Étude sur sept ans des isolats d’hémocultures dans un service d’hématologie clinique

GOAL

This study had for aim to analyze the epidemiology of strains identified in blood cultures (hôpital d'instruction des armées Percy, Clamart, France, hematology unit) to compare the rate of identified micro-organisms with literature data, and to search for a possible correlation between antibiotherapy management and evolution of resistance profiles.

MATERIAL AND METHODS

All the micro-organisms (N = 690) collected over seven years (January 1996 to December 2002), from blood cultures of hospitalized patients in conventional and sterile sector were studied.

RESULTS

Gram positive cocci rate (GPC) was 62.6% and Gram negative bacilli (GNB) 31.3%. Evolution in time showed a decrease of GPC and an increase of GNB, notably the non fermenting Gram negative bacilli, leading to an equal rate by 2001-2002. The most frequently identified species were Staphylococcus epidermidis (36.4%), Escherichia coli (8.7%), Pseudomonas aeruginosa (6.8%), and Staphylococcus aureus (4.9%). The rate of methicillin-resistant staphylococci was 63.6%. Fifty-five percent of E. coli strains had a penicillinase phenotype. Pseudomonas aeruginosa resistance was 8.5, 8.5, 6.4 and 8.5%, respectively for ceftazidime, piperacillin-tazobactam, imipenem, and amikacin.

CONCLUSION

This study showed a tendency to inversion of former bacteremia epidemiology with increasing negative Gram bacilli. It justifies the antibiotherapy protocols adopted in the hematology unit.

Randomized controlled trial of once- versus thrice-daily tobramycin in febrile neutropenic children undergoing stem cell transplantation

BACKGROUND

The benefits of aminoglycoside antibiotics, such as tobramycin, administered as a once-daily dose to manage febrile neutropenia, have been demonstrated in many patient populations. However, toxicity and safety data are lacking for pediatric stem cell transplant recipients, who are at especially high risk for aminoglycoside-related toxicity and infectious morbidity. In particular, the relative nephrotoxicity and efficacy of tobramycin administered as a single daily dose or as three daily doses among this patient population is not known.

METHODS

We conducted a randomized, double-blind controlled study of tobramycin dosing among children 18 years or younger who had fever and neutropenia while undergoing stem cell transplantation. From October 2000 through November 2002, 60 children were randomly assigned to receive intravenous tobramycin, as either a single daily dose (n = 29) or every 8 hours (n = 31), in combination with either piperacillin or ceftazidime (intravenous). Tobramycin doses were adjusted to achieve pharmacokinetic targets. The primary outcome was nephrotoxicity, as represented by the maximal percent increase in serum creatinine concentration throughout the episode of febrile neutropenia relative to the baseline serum creatinine concentration. Efficacy was a secondary outcome and was defined as survival of the episode without modification of the antibacterial regimen. All statistical tests were two-sided.

RESULTS

In a modified intent-to-treat analysis, the mean maximal percent increase in serum creatinine concentration was 32% (N = 26) in the once daily dose group and 51% (N = 28) in the every 8 hours dose group (difference = 19%, 95% confidence interval [CI] = 0% to 38%; P =.054). Among patients evaluable for efficacy, 12 (46%) of 26 patients in the once daily dose group and five (19%) of 27 patients in the every 8 hours dose group survived the episode of febrile neutropenia without requiring antibacterial treatment modification (difference = 27%, 95% CI = 4% to 52%; P =.03). There was one death in each group.

CONCLUSIONS

In febrile neutropenic children undergoing stem cell transplantation, tobramycin may be less nephrotoxic and more efficacious when administered as a once daily dose than when administered every 8 hours.

Comparative in vitro activity of piperacillin, piperacillin–sulbactam and piperacillin-tazobactam against nosocomial pathogens isolated from intensive care patients

We investigated the antimicrobial activity of piperacillin-tazobactam versus piperacillin-sulbactam against common nosocomial pathogens (n = 565) isolated from intensive care patients. For Gram-positive bacteria, antimicrobial susceptibilities to the two piperacillin-beta-lactamase inhibitor combinations were almost identical. For Gram-negative bacteria, piperacillin-tazobactam exhibited greater activity against Escherichia coli and Proteus vulgaris than piperacillin-sulbactam. Both combinations, however, were equally effective against the other Enterobacteriaceae and Pseudomonas aeruginosa isolates. Piperacillin-sulbactam exhibited better antimicrobial activity against Acinetobacter baumannii. Our findings might prove important for the appropriate choice of antibiotic therapy with beta-lactam-beta-lactamase inhibitor combinations.

Treatment of febrile neutropenia: what is new?

PURPOSE OF THE REVIEW

To identify the more recent challenges in the treatment of patients with febrile neutropenia following antineoplastic chemotherapy or bone marrow transplant published in the English language in the period late 2000-early 2002 regarding: changes in etiology of bacteremia in neutropenic patients; new options for initial empirical antibacterial therapy; factors associated with the risk of developing infection in cancer patients; prediction of prognosis in febrile neutropenia; oral therapy; need for a specific anti-Gram-positive coverage in persistently febrile and neutropenic patients.

RECENT FINDINGS

Findings may be summarized according with the identified topics as follows: many centers are reporting an increase in the incidence of Gram-negative bacteremias; piperacillin-tazobactam could be safely administered as monotherapy of febrile neutropenia; congenital factors and intensity of chemotherapy and other medical interventions, such as antifungal prophylaxis, are recognized as of increasing importance in the determination of infectious risk; it is now possible to identify patients with a good prognosis (low risk) by means of validated scoring systems; oral therapy is feasible in low risk patients; the empirical addition of a glycopeptide in persistently febrile neutropenic patients is not indicated.

SUMMARY

Many of the identified points may have a great impact in the daily management of febrile granulocytopenic patients. However, all recent epidemiological and therapeutical studies underline the absoloute need for the knowledge of the pattern of infecting organisms in each center.