Interventional antimicrobial therapy in febrile neutropenic patients. Study Group of the Paul Ehrlich Society for Chemotherapy

Tigecycline as salvage treatment of febrile neutropenia in patients with haematological malignancies-a retrospective single-centre analysis of 200 cases

Tigecycline has been used to treat patients with febrile neutropenia (FN). This study aims to analyse the effectiveness of tigecycline as salvage treatment of FN. Patients records from 09/2004 to 04/2019 were reviewed. Cases were eligible if fever persisted/recurred (p/r-FN) after 3 days of second-line treatment with a carbapenem, and were divided into three groups: switch to tigecycline (TGC group), switch to other antibiotics (OAB group), and no switch (W&W group). The primary endpoint was response rate (defervescence for ≥ 7 days or at least until discharge); the key secondary endpoint was 30-day mortality rate. Two hundred cases from 176 patients (median 59 years; 53.5% men) treated were included, mostly acute myeloid leukaemias (61.0%). 45.5% of cases were in the TGC group (in combination with an anti-pseudomonal antibiotic, mostly ceftazidime [95.6%]); 35.5% were in the OAB and 19.0% in the W&W group. There was no significant difference in response rates (TGC, 73.6%; OAB, 62.0%; W&W, 78.9%; p = 0.12) or 30-day mortality rates (TGC, 7.7%; OAB, 7.0%; W&W, 5.3%; p = 0.94). Tigecycline plus an anti-pseudomonal antibiotic does not improve response or 30-day mortality rate compared to other antibiotics in patients with p/r-FN. Also, in some cases, no switch in antibiotics may be necessary at all.

Antimicrobial Stewardship on Patients with Neutropenia: A Narrative Review Commissioned by Microorganisms

The emergence of antibiotic resistance poses a global health threat. High-risk patients such as those with neutropenia are particularly vulnerable to opportunistic infections, sepsis, and multidrug-resistant infections, and clinical outcomes remain the primary concern. Antimicrobial stewardship (AMS) programs should mainly focus on optimizing antibiotic use, decreasing adverse effects, and improving patient outcomes. There is a limited number of published studies assessing the impact of AMS programs on patients with neutropenia, where early appropriate antibiotic choice can be the difference between life and death. This narrative review updates the current advances in strategies of AMS for bacterial infections among high-risk patients with neutropenia. Diagnosis, drug, dose, duration, and de-escalation (5D) are the core variables among AMS strategies. Altered volumes of distribution can make standard dose regimens inadequate, and developing skills towards a personalized approach represents a major advance in therapy. Intensivists should partner antibiotic stewardship programs to improve patient care. Assembling multidisciplinary teams with trained and dedicated professionals for AMS is a priority.

De-escalation of empiric broad spectrum antibiotics in hematopoietic stem cell transplant recipients with febrile neutropenia

Febrile neutropenia (FN) is a common serious complication in patients undergoing hematopoietic stem cell transplantation (HSCT) requiring urgent evaluation and initiation of empiric broad spectrum antibiotics (BSA). The appropriate duration of BSA for FN in patients with negative cultures and no identifiable infection remains undefined. We retrospectively analyzed allogenic and autologous HSCT patients with FN and negative infectious work-up at our facility from 2012 to 2018. The early de-escalation group (EDG) included those who had BSA de-escalation to fluoroquinolone prophylaxis at least 24 h prior to absolute neutrophil count (ANC) recovery after the patient was fever-free for at least 48 h. Among 297 patients undergoing their first HSCT who experienced FN with negative infectious work-up, 83 patients were de-escalated early with the remaining 214 in the standard of care group (SCG) whose BSA were continued until ANC was > 500. Duration of broad-spectrum antibiotics was shorter in EDG compared to SCG (3.86 days vs. 4.62 days, p = 0.03). Rates of mortality, new infections, and clinical decompensation requiring intensive care unit transfer and/or pressor use within 30 days were all similar between the two groups (0% vs. 0.4% p = 1.00, 0% vs. 1.4% p = 0.56, 13.2% vs. 8.4% p = 0.27). This indicates that it is safe to de-escalate antibiotics prior to ANC recovery, leading to less BSA exposure.

Management of febrile neutropenia in the perspective of antimicrobial de-escalation and discontinuation

Introduction: Infections are among the most frequent complications in patients with hematological and oncological diseases. They might be classified as fever of unknown origin and microbiologically or clinically documented infections. Optimal duration of antimicrobial treatment is still unclear in these patients.Areas covered: We provide an overview on the management of febrile neutropenia in the perspective of antimicrobial de-escalation and discontinuation.Expert opinion: Patients with febrile high-risk neutropenia should be treated empirically with an anti-pseudomonal agent such as piperacillin/tazobactam. Several clinical studies support the assumption that the primary antibiotic regimen might be safely discontinued prior to neutrophil reconstitution if the patient is afebrile for several days and all infection-related symptoms have been resolved. Primary empirical treatment with carbapenems or antibiotic combinations should commonly only be considered in selected patient subgroups, such as patients with severe neutropenic sepsis or colonization with multidrug-resistant bacteria. Preemptive antifungal treatment guided by lung imaging and other parameters (e.g. serial Aspergillus galactomannan antigen screening) might reduce the consumption of antifungals compared to the classical empirical approach.Multidrug-resistant pathogens are emerging, and novel anti-infective agents under development are scarce. Therefore, a rational use of antimicrobials based on the principles of antibiotic stewardship is crucial.

Discontinuation of antimicrobial therapy in adult neutropenic haematology patients: A prospective cohort

OBJECTIVES

Antibiotics for febrile neutropenia (FN) in acute myeloid leukaemia (AML) patients undergoing intensive chemotherapy are usually maintained until neutropenia resolution, because of the risk of uncontrolled sepsis in this vulnerable population. This leads to unnecessarily prolonged antimicrobial therapy.

METHODS

Based on ECIL-4 recommendations, we modified our management strategy and discontinued antibiotics after a pre-established duration in patients treated for a first episode of FN between August 2014 and October 2017.

RESULTS

Antibiotics were stopped during 62 FN episodes, and maintained in the control group (n = 13). Median age of patients was 54 years. A total of 39 (63%) patients received induction and 23 (37%) consolidation chemotherapy; 36 (58%) patients had fever of unknown origin. Median neutropenia length was 26 days (IQR 24-30). Antibiotics were started at day 9 (IQR 5-13). Most patients received piperacillin-tazobactam (56%) or cefepime (32%). Antimicrobial therapy was longer in the control group than in the policy compliant group, 10 (IQR 7-16) vs. 19 days (IQR 15-23), P = 0.0001. After antibiotics discontinuation, 20% patients experienced fever recurrence, within 5.5 days (IQR 3-7.5). None of these febrile episodes were severe and 80% patients remained afebrile, with neutrophil recovery occurring within 5 days (IQR 2-8.5). Overall, 287 antibiotics days were spared; this represents 49% of all days with antibiotics. No patient had died at day 30 from intervention; six died during late follow-up, two from graft-versus-host disease and four from relapsed or refractory leukaemia.

CONCLUSIONS

Discontinuing antibiotics in neutropenic AML patients treated for a first episode of FN is safe, and results in significant antibiotic sparing.

Lenograstim and filgrastim in the febrile neutropenia prophylaxis of hospitalized patients: efficacy and cost of the prophylaxis in a retrospective survey

Purpose

We conducted a retrospective study to evaluate the efficacy and related costs of using two different molecules of granulocyte-colony stimulating factor (G-CSF) (lenograstim - LENO or filgrastim - FIL) as primary prophylaxis of chemotherapy-induced neutropenia in a hematological inpatient setting.

Methods

The primary endpoints of the analysis were the efficacy of the two G-CSFs in terms of the level of white blood cells, hemoglobin and platelets at the end of the treatment and the per capita direct medical costs related to G-CSF prophylaxis.

Results

Two hundred twelve patients (96 LENO, 116 FIL) have been evaluated. The following statistically significant differences have been observed between FIL and LENO: the use of a higher number of vials (11 vs 7; P<0.03) to fully recover bone marrow, a higher grade 3-4 neutropenia at the time of G-CSF discontinuation (29.3% vs 16.7%; P=0.031) and an increased number of days of hospitalization (8 vs 5; P<0.005). A longer hospital stay before discharge was necessary (12 vs 10), which reflects the higher final costs per patient (median treatment cost per cycle 10.706 € for LENO, compared to 12.623 € for FIL).

Conclusion

The use of LENO has been associated with a lower number of days of hospitalization, number of vials and less incidence of grade 3-4 neutropenia at the time of G-CSF discontinuation. LENO seems to be cost-saving when compared with FIL (-15.2%).

Diagnosis and empirical treatment of fever of unknown origin (FUO) in adult neutropenic patients: guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

Fever may be the only clinical symptom at the onset of infection in neutropenic cancer patients undergoing myelosuppressive chemotherapy. A prompt and evidence-based diagnostic and therapeutic approach is mandatory. A systematic search of current literature was conducted, including only full papers and excluding allogeneic hematopoietic stem cell transplant recipients. Recommendations for diagnosis and therapy were developed by an expert panel and approved after plenary discussion by the AGIHO. Randomized clinical trials were mainly available for therapeutic decisions, and new diagnostic procedures have been introduced into clinical practice in the past decade. Stratification into a high-risk versus low-risk patient population is recommended. In high-risk patients, initial empirical antimicrobial therapy should be active against pathogens most commonly involved in microbiologically documented and most threatening infections, including Pseudomonas aeruginosa, but excluding coagulase-negative staphylococci. In patients whose expected duration of neutropenia is more than 7 days and who do not respond to first-line antibacterial treatment, specifically in the absence of mold-active antifungal prophylaxis, further therapy should be directed also against fungi, in particular Aspergillus species. With regard to antimicrobial stewardship, treatment duration after defervescence in persistently neutropenic patients must be critically reconsidered and the choice of anti-infective agents adjusted to local epidemiology. This guideline updates recommendations for diagnosis and empirical therapy of fever of unknown origin in adult neutropenic cancer patients in light of the challenges of antimicrobial stewardship.

Empirical antibiotics targeting gram-positive bacteria for the treatment of febrile neutropenic patients with cancer

BACKGROUND

The pattern of infections among neutropenic patients with cancer has shifted in the last decades to a predominance of gram-positive infections. Some of these gram-positive bacteria are increasingly resistant to beta-lactams and necessitate specific antibiotic treatment.

OBJECTIVES

To assess the effectiveness of empirical anti-gram-positive (antiGP) antibiotic treatment for febrile neutropenic patients with cancer in terms of mortality and treatment failure. To assess the rate of resistance development, further infections and adverse events associated with additional antiGP treatment.

SEARCH METHODS

For the review update we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2017, Issue 2), MEDLINE (May 2012 to 2017), Embase (May 2012 to 2017), LILACS (2012 to 2017), conference proceedings, ClinicalTrials.gov trial registry, and the references of the included studies. We contacted the first authors of all included and potentially relevant trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing one antibiotic regimen versus the same regimen with the addition of an antiGP antibiotic for the treatment of febrile neutropenic patients with cancer.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial eligibility and risk of bias, and extracted all data. Risk ratios (RR) with 95% confidence intervals (CIs) were calculated. A random-effects model was used for all comparisons showing substantial heterogeneity (I2 > 50%). Outcomes were extracted by intention-to-treat and the analysis was patient-based whenever possible.

MAIN RESULTS

Fourteen trials and 2782 patients or episodes were included. Empirical antiGP antibiotics were tested at the onset of treatment in 12 studies, and for persistent fever in two studies. The antiGP treatment was a glycopeptide in nine trials. Eight studies were assessed in the overall mortality comparison and no significant difference was seen between the comparator arms, RR of 0.90 (95% CI 0.64 to 1.25; 8 studies, 1242 patients; moderate-quality data). Eleven trials assessed failure, including modifications as failures, while seven assessed overall failure disregarding treatment modifications. Failure with modifications was reduced, RR of 0.72 (95% CI 0.65 to 0.79; 11 studies, 2169 patients; very low-quality data), while overall failure was the same, RR of 1.00 (95% CI 0.79 to 1.27; 7 studies, 943 patients; low-quality data). Sensitivity analysis for allocation concealment and incomplete outcome data did not change the results. Failure among patients with gram-positive infections was reduced with antiGP treatment, RR of 0.56 (95% CI 0.38 to 0.84, 5 studies, 175 patients), although, mortality among these patients was not changed.Data regarding other patient subgroups likely to benefit from antiGP treatment were not available. Glycopeptides did not increase fungal superinfection rates and were associated with a reduction in documented gram-positive superinfections. Resistant colonisation was not documented in the studies.

AUTHORS' CONCLUSIONS

Based on very low- or low-quality evidence using the GRADE approach and overall low risk of bias, the current evidence shows that the empirical routine addition of antiGP treatment, namely glycopeptides, does not improve the outcomes of febrile neutropenic patients with cancer.

Clinical significance of pre-transplant circulating CD3+ CD4+ CD161+ cell frequency on the occurrence of neutropenic infections after allogeneic stem cell transplantation

BACKGROUND

Few studies have been performed to identify factors that are associated with an increased risk of infections during the neutropenic period in patients undergoing allogeneic stem cell transplantation (allo-SCT). The aim of this study was to identify the host immune cells responsible for infections before engraftment.

METHODS

A total of 282 patients who underwent allo-SCT were enrolled. Peripheral blood samples were collected before conditioning therapy. Expression of CD161-expressing T cells, natural killer cells, and immature myeloid cells was analyzed by flow cytometry. Microbially and clinically defined infections and fevers of unknown origin as proposed by the Immunocompromised Host Society were included in this study.

RESULTS

The median age was 45 years (range, 16-68 years). Patients had various hematologic disorders and were transplanted from human leukocyte antigen (HLA)-matched siblings, unrelated donors, and familial HLA-mismatched donors. In univariate analysis, younger age and a familial HLA-mismatched donor were risk factors for the occurrence of infections. After adjusting for potential variables in univariate analysis, multivariate analyses revealed that a lower frequency of CD3⁺ CD4⁺ CD161⁺ cells was significantly associated with the occurrence of neutropenic infections. An age of 35 years or younger and allografting from familial HLA-mismatched donors showed a trend toward higher infection rates.

CONCLUSION

Our data indicated that a lower frequency of CD3⁺ CD4⁺ CD161⁺ T cells in peripheral blood before conditioning therapy was associated with a higher incidence of infection during the neutropenic period. These results suggest that recipient innate T cells with expression of C-type lectin CD161 can guard against infections before engraftment.

European guidelines for empirical antibacterial therapy for febrile neutropenic patients in the era of growing resistance: summary of the 2011 4th European Conference on Infections in Leukemia

Owing to increasing resistance and the limited arsenal of new antibiotics, especially against Gram-negative pathogens, carefully designed antibiotic regimens are obligatory for febrile neutropenic patients, along with effective infection control. The Expert Group of the 4(th) European Conference on Infections in Leukemia has developed guidelines for initial empirical therapy in febrile neutropenic patients, based on: i) the local resistance epidemiology; and ii) the patient's risk factors for resistant bacteria and for a complicated clinical course. An 'escalation' approach, avoiding empirical carbapenems and combinations, should be employed in patients without particular risk factors. A 'de-escalation' approach, with initial broad-spectrum antibiotics or combinations, should be used only in those patients with: i) known prior colonization or infection with resistant pathogens; or ii) complicated presentation; or iii) in centers where resistant pathogens are prevalent at the onset of febrile neutropenia. In the latter case, infection control and antibiotic stewardship also need urgent review. Modification of the initial regimen at 72-96 h should be based on the patient's clinical course and the microbiological results. Discontinuation of antibiotics after 72 h or later should be considered in neutropenic patients with fever of unknown origin who are hemodynamically stable since presentation and afebrile for at least 48 h, irrespective of neutrophil count and expected duration of neutropenia. This strategy aims to minimize the collateral damage associated with antibiotic overuse, and the further selection of resistance.

Empirical antibiotics targeting Gram-positive bacteria for the treatment of febrile neutropenic patients with cancer

BACKGROUND

The pattern of infections among neutropenic cancer patients has shifted in the last decades to a predominance of Gram-positive infections. Some of these Gram-positive bacteria are increasingly resistant to beta-lactams and necessitate specific antibiotic treatment.

OBJECTIVES

To assess the effectiveness of empirical antiGram-positive (antiGP) antibiotic treatment for febrile neutropenic cancer patients in terms of mortality and treatment failure. To assess the rate of resistance development, further infections and adverse events associated with additional antiGP treatment.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 7), MEDLINE (1966 to 2013), EMBASE (1982 to 2013), LILACS (1982 to 2013), conference proceedings, and the references of the included studies. First authors of all included and potentially relevant trials were contacted.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing one antibiotic regimen to the same regimen with the addition of an antiGP antibiotic for the treatment of febrile neutropenic cancer patients.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial eligibility and risk of bias, and extracted all data. Risk ratios (RR) with 95% confidence intervals (CI) were calculated. A random-effects model was used for all comparisons showing substantial heterogeneity (I(2) > 50%). Outcomes were extracted by intention to treat and the analysis was patient-based whenever possible.

MAIN RESULTS

Thirteen trials and 2392 patients or episodes were included. Empirical antiGP antibiotics were tested at the onset of treatment in 11 studies, and for persistent fever in two studies. The antiGP treatment was a glycopeptide in nine trials. Seven studies were assessed in the overall mortality comparison and no significant difference was seen between the comparator arms, RR of 0.82 (95% CI 0.56 to 1.20, 852 patients). Ten trials assessed failure, including modifications as failures, while six assessed overall failure disregarding treatment modifications. Failure with modifications was significantly reduced, RR of 0.76 (95% CI 0.68 to 0.85, 1779 patients) while overall failure was the same, RR of 1.00 (95% CI 0.79 to 1.27, 943 patients). Sensitivity analysis for allocation concealment and incomplete outcome data did not change the results. Both mortality and failure did not differ significantly among patients with Gram-positive infections, but the number of studies in the comparisons was small. Data regarding other patient subgroups likely to benefit from antiGP treatment were not available. Glycopeptides did not increase fungal superinfection rates and were associated with a reduction in documented Gram-positive superinfections. Resistant colonisation was not documented in the studies.

AUTHORS' CONCLUSIONS

Current evidence shows that the empirical routine addition of antiGP treatment, namely glycopeptides, does not improve the outcomes of febrile neutropenic patients with cancer.

Supportive therapy in medical therapy of head and neck tumors

Fever during neutropenia may be a symptom of severe life threatening infection, which must be treated immediately with antibiotics. If signs of infection persist, therapy must be modified. Diagnostic measures should not delay treatment. If the risk of febrile neutropenia after chemotherapy is ≥20%, then prophylactic therapy with G-CSF is standard of care. After protocols with a risk of febrile neutropenia of 10–20%, G-CSF is necessary, in patients older than 65 years or with severe comorbidity, open wounds, reduced general condition. Anemia in cancer patients must be diagnosed carefully, even preoperatively. Transfusions of red blood cells are indicated in Hb levels below 7–8 g/dl. Erythropoiesis stimulating agents (ESA) are recommended after chemotherapy only when hemoglobin levels are below 11 g/dl. The Hb-level must not be increased above 12 g/dl. Anemia with functional iron deficiency (transferrin saturation <20%) should be treated with intravenous iron, as oral iron is ineffective being not absorbed. Nausea or emesis following chemotherapy can be classified as minimal, low, moderate and high. The antiemetic prophylaxis should be escalated accordingly. In chemotherapy with low emetogenic potential steroids are sufficient, in the moderate level 5-HT3 receptor antagonists (setrons) are added, and in the highest level Aprepitant as third drug.

Imipenem resistance of Pseudomonas in pneumonia: a systematic literature review

Background

Pneumonia, and particularly nosocomial (NP) and ventilator-associated pneumonias (VAP), results in high morbidity and costs. NPs in particular are likely to be caused by Pseudomonas aeruginosa (PA), ~20% of which in observational studies are resistant to imipenem. We sought to identify the burden of PA imipenem resistance in pneumonia.

Methods

We conducted a systematic literature review of randomized controlled trials (RCT) of imipenem treatment for pneumonia published in English between 1993 and 2008. We extracted study, population and treatment characteristics, and proportions caused by PA. Endpoints of interest were: PA resistance to initial antimicrobial treatment, clinical success, microbiologic eradication and on-treatment emergence of resistance of PA.

Results

Of the 46 studies identified, 20 (N = 4,310) included patients with pneumonia (imipenem 1,667, PA 251; comparator 1,661, PA 270). Seven were double blind, and 7 included US data. Comparator arms included a β-lactam (17, [penicillin 6, carbapenem 4, cephalosporin 7, monobactam 1]), aminoglycoside 2, vancomycin 1, and a fluoroquinolone 5; 5 employed double coverage. Thirteen focused exclusively on pneumonia and 7 included pneumonia and other diagnoses. Initial resistance was present in 14.6% (range 4.2-24.0%) of PA isolates in imipenem and 2.5% (range 0.0-7.4%) in comparator groups. Pooled clinical success rates for PA were 45.2% (range 0.0-72.0%) for imipenem and 74.9% (range 0.0-100.0%) for comparator regimens. Microbiologic eradication was achieved in 47.6% (range 0.0%-100.0%) of isolates in the imipenem and 52.8% (range 0.0%-100.0%) in the comparator groups. Resistance emerged in 38.7% (range 5.6-77.8%) PA isolates in imipenem and 21.9% (range 4.8-56.5%) in comparator groups.

Conclusions

In the 15 years of RCTs of imipenem for pneumonia, PA imipenem resistance rates are high, and PA clinical success and microbiologic eradication rates are directionally lower for imipenem than for comparators. Conversely, initial and treatment-emergent resistance is more likely with the imipenem than the comparator regimens.

Comparison of infectious complications during induction/consolidation chemotherapy versus allogeneic hematopoietic stem cell transplantation

Induction/consolidation chemotherapy and allogeneic hematopoietic stem cell transplantation (HSCT) for hematological malignancies are associated with treatment-related risks such as infections. The predominant types of infections are blood stream infections (BSIs) and respiratory tract infections. We prospectively compared infectious complications after induction/consolidation chemotherapy versus allogeneic HSCT in a directly comparable setting with both groups being hospitalized on the same ward. From July 2003 until June 2008, 492 hospitalizations of 321 patients took place; 237 chemotherapies and 255 HSCTs were performed. We observed 49 (20.7%) BSIs, 70 (29.5%) pneumonias and 11 (4.6%) probable or proven invasive mould infections in the chemotherapy group. In the HSCT group we detected 70 (27.5%) BSIs, 71 (27.8%) pneumonias and 14 (5.4%) probable or proven invasive mould infections. There was a trend toward more transfers to the intensive care unit (OR 1.61; 95%CI 0.95-2.72; P=0.074) and BSIs (OR 1.45; 95%CI 0.95-2.22; P=0.079) after HSCT; 44 (13.7%) patients died. In-hospital mortality was significantly higher in the HSCT group (OR 2.39; 95%CI 1.22-4.68; P=0.010). We conclude that the risk of pneumonia and invasive mould infection is comparable after induction/consolidation chemotherapy and allogeneic HSCT. However, there was a trend for more BSIs and intensive care unit stays and a higher mortality in the latter.

Clostridium difficile-associated diarrhoea, a frequent complication in patients with acute myeloid leukaemia

Diarrhoea occurs frequently in neutropenic patients with acute leukaemia receiving chemotherapy and may be caused by either infection- or drug-induced cytotoxicity. Since Clostridium difficile is the most common cause of nosocomial infectious diarrhoea in non-haematologic patients, we were interested in its incidence in patients with acute myeloid leukaemia (AML). In this retrospective study, we analysed 134 patients with AML receiving a total of 301 chemotherapy courses. Diarrhoea occurred during 33% of all courses in 58 patients. C. difficile-associated diarrhoea (CDAD) occurred in 18% of all patients and 9% of all treatment courses. Almost one third of diarrhoea episodes were caused by C. difficile. CDAD was associated with older age (58 vs. 50 years), number of antibiotics administered (2 vs. 1), duration of antibiotic therapy (7 vs. 4 days), ceftazidime as the antibiotic of choice (75% vs. 54%) and duration of neutropenia (12 vs. 7 days) prior to onset of diarrhoea. An increased risk for CDAD was seen for prolonged neutropenia. CDAD responded well to oral metronidazole and/or vancomycin and no patient died of this complication. In conclusion, CDAD is common in patients with AML receiving chemotherapy. C. difficile enterotoxin testing of stool specimens should be included in all symptomatic patients.

Predictive factors of septic shock and mortality in neutropenic patients

Neutropenia is a major risk factor for developing a serious infection. Bacteremia still causes significant mortality among neutropenic patients with cancer. The purpose of this study was to identify risk factors for septic shock and for mortality in neutropenic patients with leukemia and bacteremia. Consecutive samples from 20 patients with acute myeloid leukemia and bacteremia were studied during a 1 year period (January-December 2003). All patients received empirical antibiotic therapies for febrile episodes using ceftazidime plus amikacin. About 110 neutropenic febrile episodes were noted: clinically documented 14.54%, microbiologically documented 16.36% and fever of unknown origin 69.09%. Gram-negative organism caused eight febrile episodes: Pseudomonas (5), Klebsiella (3). Gram-positive organism caused 10 episodes: Staphylococcus (6), Streptococci (2), Enterococci (2). Pulmonary infection accounted for 25% of clinically documented infections. About 14 of the 110 febrile episodes were associated with septic shock causing mortality in 7 patients. In a univariate analysis variables associated with septic shock were: pulmonary infection (OR = 17, p = 0.001), serum bicarbonate < 17 mmol/l (OR = 68, p < 0.001) and serum lactate >3 mmol/l (OR = 62, p < 0.001). Variables associated with mortality were: pulmonary infection (OR = 83, p < 0.001) and serum bicarbonate < 17 mmol/l (OR = 61, p < 0.001). In a multivariate analysis two variables were associated with septic shock: pulmonary infection (OR = 5, p = 0.043) and serum lactate >3 mmol/l (OR = 10, p = 0.003). An elevated serum lactate (>3 mmol/l) and low serum bicarbonate ( < 17 mmol/l) at the onset of bacteremia are useful biomarkers in predicting septic shock and mortality in neutropenic patients.

Diagnostic yield of bronchoscopy with bronchoalveolar lavage in febrile patients with hematologic malignancies and pulmonary infiltrates

Infectious complications are a major cause of morbidity and mortality in immunosuppressed patients. Febrile patients with hematologic malignancies and pulmonary infiltrates have high mortality rates, especially if mechanical ventilation is required. The diagnostic value of fiberoptic bronchoscopy (FOB) with bronchoalveolar lavage (BAL) in these patients is controversial. We retrospectively analyzed the microbiological results of BAL samples obtained during 249 FOB examinations from 199 febrile patients with hematologic malignancies and pulmonary infiltrates (underlying diseases: acute leukemia 103 patients, lymphoma 84 patients, other malignancies 12 patients). Two hundred forty-six examinations could be evaluated. Seventy-three out of 246 BAL samples were sterile; 55 samples showed microbiological findings classified as contamination or colonization. One hundred eighteen samples showed positive microbiological results of bacteria and/or fungi classified as causative pathogens. Thereof, in 70 samples, only bacterial pathogens were detectable (Gram-positive, 35; Gram-negative, 30; mixed Gram-positive and Gram-negative, 5). Thirteen samples showed both fungi and bacterial pathogens. In 33 samples, only fungi were detectable, thereof, in 15 samples Aspergillus species, in 16 samples Candida species, and in 2 both. In two samples, a viral pathogen could be detected. Three nonlethal complications (bleeding, arrhythmia) occurred that required early termination of FOB. In 94 (38.2%) patient episodes, antibiotic treatment was modified as a result of microbiological findings in BAL samples. Our results show that FOB with BAL is a valuable diagnostic tool with low complication rates in high-risk febrile patients with hematologic malignancies and pulmonary infiltrates, contributing crucial results for the individual case, and also improving epidemiologic knowledge.

IgMA-enriched immunoglobulin in neutropenic patients with sepsis syndrome and septic shock: A randomized, controlled, multiple-center trial*

OBJECTIVE

To evaluate the effect of intravenous IgMA-enriched immunoglobulin (ivIGMA) therapy on mortality in neutropenic patients with hematologic malignancies and sepsis syndrome or septic shock.

DESIGN

Multiple-center, prospective randomized, controlled study.

SETTING

Six university hospitals in Germany.

PATIENTS

Patients were 211 neutropenic patients with sepsis syndrome or septic shock after chemotherapy for severe hematologic disorders between 1992 and 1999.

INTERVENTIONS

Patients received 1300 mL of ivIGMA (7.8 g IgM, 7.8 g IgA, and 49.4 g IgG) infused intravenously within a period of 72 hrs or human albumin according to the same schedule as ivIGMA.

MEASUREMENTS AND MAIN RESULTS

All-cause mortality at 28 days, sepsis-related mortality at 28 days, all-cause mortality at 60 days, mortality from septic shock, and mortality from microbiologically proven Gram-negative sepsis and septic shock were recorded. Immunoglobulin had no benefit over human albumin. The 28-day mortality rate was 26.2% and 28.2% in the ivIGMA and control patients, respectively (difference, 2.0% [95% confidence interval, -10.2 to 14.2 percentage points]). Likewise, the 60-day mortality rate did not differ between both arms (29.6% vs. 34.7% in the ivIGMA and control patients, respectively). Mortality rates in patients with sepsis syndrome (17.1% vs. 16.7%) and septic shock (51.9% vs. 54.8%) were also found to be similar between both groups.

CONCLUSIONS

Intravenous ivIGMA had no beneficial effects in neutropenic patients with hematologic malignancies and sepsis syndrome and septic shock.

Management of sepsis in neutropenia: guidelines of the infectious diseases working party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

These guidelines from the infectious diseases working party (AGIHO) of the German Society of Hematology and Oncology (DGHO) give recommendations for the management of adults with neutropenia and the diagnosis of sepsis. The guidelines are written for clinicians and focus on pathophysiology, diagnosis, and treatment of sepsis. The manuscript contains evidence-based recommendations for the assessment of the quality and strength of the data.

Empirical antifungal therapy in patients with neutropenia and persistent or recurrent fever of unknown origin

Persistent or recurrent fever of unexplained origin (PFUO) in neutropenic patients receiving antibiotic therapy is commonly treated with empirical antifungal therapy (EAFT). EAFT was established as an adequate management of PFUO around 20 years ago with conventional amphotericin B deoxycholate (c-AmB), despite its high rate of infusional and systemic toxicities. In recent years, EAFT trials for PFUO have used less toxic agents, such as the lipid formulations of AmB, the new azoles, and the echinocandin, caspofungin. In clinical trials, the lipid formulations of AmB [especially liposomal AmB (L-AmB)] provided similar efficacy with lower toxicity but at a much higher cost. Although rarely used in clinical practice, fluconazole is equivalent to c-AmB, provided patients at high risk of Aspergillus infections are excluded. Intravenous itraconazole was shown to be equivalent to c-AmB, with a lower toxicity. Voriconazole did not meet non-inferiority criteria when compared with L-AmB. Caspofungin was shown to be non-inferior to L-AmB and more effective in treating baseline invasive fungal infections. To date, alternatives to AmB have shown less toxicity, but improved efficacy is less clear. This is probably because of the weakness of the indication and to the consequent difficulty in establishing objective and reproducible endpoints for comparisons. The new challenge for physicians in this field is probably presumptive antifungal therapy, an approach based on patient risk-group stratification for developing invasive candidiasis or aspergillosis and/or the use of new diagnostic techniques to identify patients at a very early stage of infection.

Septic intramuscular embolism in a neutropenic patient with myelodysplastic syndrome accompanied by asymptomatic septic pulmonary emboli

Septic embolisms are rare disorders which are associated with increased mortality and morbidity. We describe a rare case of septic intramuscular embolism accompanied by asymptomatic pulmonary embolism in a neutropenic patient. Methicillin-sensitive Staphylococcus aureus (S. aureus) was detected and multiple nodules were revealed in both thighs and lung. Although he was treated with sensitive antibiotics to .S. aureus, the symptoms remained unchanged during the neutropenic period. Fever subsided rapidly and his thigh pain disappeared after neutropenia resolved. A prompt diagnosis and optimal therapeutic decisions are critical for the reduction of mortality.

Additional anti-Gram-positive antibiotic treatment for febrile neutropenic cancer patients

BACKGROUND

The pattern of infections among neutropenic cancer patients has shifted in the last decades to a predominance of Gram-positive infections. Some of these Gram-positive bacteria are increasingly resistant to beta-lactams and necessitate specific antibiotic treatment.

OBJECTIVES

To assess the effectiveness of empirical anti-Gram-positive (antiGP) antibiotic treatment for febrile neutropenic cancer patients in terms of mortality and treatment failure. To assess the rate of resistance development, further infections and adverse events associated with additional antiGP treatment.

SEARCH STRATEGY

We searched The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2004), MEDLINE (1966 to 2004), EMBASE (January 1980 to 2004), LILACS (1982 to 2004), conference proceedings, and all references of included studies. First authors of all included and potentially relevant trials were contacted.

SELECTION CRITERIA

Randomised controlled trials comparing one antibiotic regimen to the same regimen with the addition of an antiGP antibiotic for the treatment of febrile neutropenic cancer patients.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial eligibility, methodological quality and extracted all data. Relative risks (RR) with 95% confidence intervals (CI) were calculated. A random effects model was used for all comparisons showing substantial heterogeneity (I(2 )> 50%). Outcomes were extracted by intention-to-treat and the analysis was patient-based whenever possible.

MAIN RESULTS

Thirteen trials and 2392 patients or episodes were included. Empirical antiGP antibiotics were tested at the onset of treatment in eleven studies and for persistent fever in two studies. The antiGP treatment was a glycopeptide in nine trials. Seven studies were assessed in the overall mortality comparison and no significant difference between the comparator arms was seen, RR 0.82 (95% CI 0.56 to 1.20, 852 patients). Ten trials assessed failure including modifications as failures, while six assessed overall failure, disregarding treatment modifications. Failure with modifications was significantly reduced, RR 0.76 (95% CI 0.68 to 0.85, 1779 patients) while overall failure was equal, RR 1.00, 95% CI (0.79 to 1.27, 943 patients). Both mortality and failure did not differ significantly among patients with Gram-positive infections, but comparisons were small. Data regarding other patient subgroups likely to benefit from antiGP treatment were not available. Glycopeptides did not increase fungal superinfection rates, and were associated with a reduction in documented Gram-positive superinfections. Resistant colonisation was not documented in the studies.

AUTHORS' CONCLUSIONS

Current evidence shows that the addition of antiGP treatment, namely glycopeptides, prior to documentation of a Gram-positive infection does not improve outcomes.

Neutropenic enterocolitis in adults: systematic analysis of evidence quality

OBJECTIVE

Neutropenic enterocolitis is a life-threatening complication occurring most frequently after intensive chemotherapy in acute leukaemias. The literature is heterogeneous and a systematic review is lacking.

METHODS

Following a systematic search we categorised all relevant reports according to their quality and extracted evidence to answer the questions: Which diagnostic criteria are appropriate? What is the incidence of neutropenic enterocolitis? Are there good quality studies supporting specific interventions: Which empiric antimicrobial therapy is recommendable? Is neutropenic enterocolitis without surgical emergency complications an indication for bowel resection?

RESULTS

We found and analysed 145 articles of these reports: 64 were reports of single cases, 30 papers reported of two or three cases, 13 were narrative reviews, 34 were retrospective case series of more than three cases and four were prospective diagnostic studies. There were no prospective trials or case control studies on the therapy of neutropenic enterocolitis. There was no consensus on diagnostic criteria. We discuss the difficulty to define diagnostic criteria without having a disease definition. Histology is mostly not available in the living patients. We suggest applying a combination of clinical and radiological criteria: fever, abdominal pain and any bowel wall thickening >4 mm detected by ultrasonography (US) or computed tomography. We calculated a pooled incidence rate from 21 studies of 5.3% (266/5058; 95% CI: 4.7%-5.9%) in patients hospitalised for haematological malignancies, for high-dose chemotherapy in solid tumours or for aplastic anaemia.

CONCLUSIONS

This systematic review provides diagnostic criteria for neutropenic enterocolitis, presents a quantitative synthesis on its incidence and discusses its treatment recommendations. Prospective studies are clearly warranted.

Empirical antibiotics against Gram-positive infections for febrile neutropenia: systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

To assess the value of empirical anti-Gram-positive antibiotics for the treatment of febrile neutropenia.

METHODS

Systematic review and meta-analysis of randomized controlled trials comparing antibiotics with anti-Gram-positive spectrum to control or placebo, in addition to the same baseline antibiotic regimen in both arms. We searched MEDLINE, EMBASE, LILACS, the Cochrane Library, conference proceedings, and references. No restrictions on inclusion were imposed. Two reviewers independently applied selection criteria, carried out quality assessment, and extracted the data. Relative risks with 95% confidence intervals were pooled using the fixed effect model. The primary outcome assessed was all-cause mortality.

RESULTS

Thirteen studies met inclusion criteria, including 2392 participants. Glycopeptides were assessed in nine trials. Empirical anti-Gram-positive antibiotics were assessed for the initial treatment in 11 studies, and for persistent fever in two. No significant difference in all-cause mortality was seen [RR 0.86 (0.58-1.26), seven studies, 852 participants]. Overall failure at end of therapy occurred equally [RR 1.00 (0.79-1.27), six studies, 943 participants]. Failure associated with treatment modifications was more frequent in the control arm when empirical initial glycopeptides were assessed [RR 0.70 (0.61-0.80), five studies, 1178 participants]. Bacterial superinfections, mainly Gram-positive, were detected less frequently in the intervention arm. Adverse events were significantly more common with the additional antibiotic, and nephrotoxicity was significantly more common with additional glycopeptides [RR 1.88 (1.10-3.22), six studies, 1282 participants]. No significant heterogeneity was present in these comparisons.

CONCLUSIONS

The use of glycopeptides can be safely deferred until the documentation of a resistant Gram-positive infection.

Management of infections in critically ill neutropenic cancer patients

Because of improving antineoplastic treatment options with increasing cure rates, prolonging survival, and improving quality of life, the reluctance to admit patients with malignant disease to an intensive care unit is not justified; thus, the number of patients with malignancies treated in intensive care units rises. The use of more aggressive anticancer regimens leads to an increase of attendant infections, which are the most frequent and often life-threatening complications in cancer patients. A multidisciplinary practical approach to evaluation and treatment is needed to optimize treatment results and to meet the various diagnostic and therapeutic challenges in this subset of patients on an intensive care unit.

ANCA-associated renal vasculitis at the end of the twentieth century--a disease of older patients

OBJECTIVE

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides are increasingly recognized in older patients. However, it is unknown whether disease presentation and response to treatment differs from younger patients. We aimed to examine the presentation, response to treatment and outcome of patients over 65 yr of age compared with a younger cohort.

METHODS

This retrospective, single centre, sequential cohort study reports presenting features and outcome of 233 consecutive new patients with ANCA-associated vasculitis between 1990 and 2000.

RESULTS

The median age of all patients was 65 yr (range 16-90 yr). Older patients (>65 yr) presented with more severe renal involvement at presentation (P < 0.001). Older patients were as likely to respond to treatment or undergo relapse as the younger patients. Older patients receiving immunosuppression had an increased risk of infection (P = 0.0027). Survival was worse in the older group (P = 0.016) and death occurred early. Mortality was associated with poor renal function (creatinine >400 micromol/l), infection and low serum albumin. Leucopenia was associated with severe renal impairment (P = 0.0048) and increased risk of infection (P = 0.0006). Multivariate analysis determined that serum creatinine >400 micromol/l and age were independent risk factors for poor prognosis.

CONCLUSION

ANCA-associated vasculitis occurs frequently in older patients and physicians should maintain a high index of suspicion. Older patients have a poorer prognosis due to more severe renal involvement and increased sensitivity to adverse effects of treatment. This study highlights the importance of careful dosing of cyclophosphamide: in those aged over 65 yr a 25% dose reduction is safe and reduces the risk of leucopenia. This study further highlights the importance of renal function on prognosis and the need for less toxic treatment regimens.

Responsiveness to G-CSF before leukopenia predicts defense to infection in high-dose chemotherapy recipients

An active assessment of the host capacity to prevent infection during myelosuppression should be beneficial in patients receiving high-dose chemotherapy. A single dose of granulocyte colony-stimulating factor (G-CSF) (5 μg/kg) was given to 57 patients with multiple myeloma early after the completion of 85 high-dose chemotherapy (melphalan 200 mg/m2) courses. This provoked a highly variable white blood cell (WBC) peak after 12 to 14 hours. The median WBC count was 21 000/μL (range, 6400-60 600/μL) after a first high-dose therapy (n = 50) and 13 500/μL (range, 4700-24 800/μL) after a second high-dose therapy (n = 35). The responsiveness to single G-CSF was associated with the risk of infection during subsequent cytopenia (P = .003). This association was significant after adjustment for neutropenia duration. Notably, the result of testing G-CSF responsiveness was opportunely available before the onset of leukopenia, and G-CSF responsiveness was more informative than neutropenia duration regarding the risk of infection. Furthermore, there was an association between the responsiveness to G-CSF and stem cell engraftment (P &lt; .005), which remained significant after adjustment for the number of transplanted CD34+ cells. Our results show for the first time that G-CSF potentially could be used for an early in vivo assessment of defense to infection in recipients of high-dose chemotherapy.

Diagnosis and treatment of documented infections in neutropenic patients--recommendations of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

Approximately 85% of patients with acute leukemia undergoing intensive antileukemic treatment develop infections and/or fever during neutropenic phases; in about 50% of these patients clinical, microbiological or clinical and microbiological evidence of infections can be obtained. The response rate is significantly lower in documented infections than in fever of unknown origin (FUO). Evidence-based recommendations for diagnosis and treatment procedures are presented, reflecting study results and expert opinions.

Serial granulocytapheresisunder daily administration of rHuG-CSF: effects on peripheral blood counts, collection efficiency, and yield

BACKGROUND

An option for treatment of severe infections in neutropenic patients is the transfusion of granulocytes from donors stimulated with rHuG-CSF. The schedule of rHuG-CSF-stimulated granulocyte donations and the quality of the components remain controversial. This study was done with the intention of ensuring daily granulocyte support with therapeutic cell numbers, while keeping the patients' allogeneic exposure as low as possible.

STUDY DESIGN AND METHODS

Granulocyte collection with multiple consecutive leukapheresis procedures under daily rHuG-CSF administration and with hydroxyethyl starch as sedimenting agent were prospectively studied. Complete blood counts of the donors, collection yield, and efficiency were analyzed.

RESULTS

Products (n = 259) from 76 donors were examined. The median peripheral blood WBC and neutrophil counts were 28.1 g per L and 24.1 g per L, respectively, and they were significantly higher on Day 5 of collections than on Days 1 to 3. Platelet counts and Hb levels decreased steadily. Collection yields increased over time from 4.9 to 6.7 x 10(10) neutrophils. Side effects of cytokines and aphereses did not exceed World Health Organization grade II status.

CONCLUSION

Repetitive daily rHuG-CSF administration-even under daily leukapheresis procedures-results in a continuing increase in WBC and neutrophil levels and thus leads to increased collection yields. Side effects are tolerable, although Hb and platelet levels should be monitored closely.

National guidelines for the judicious use of glycopeptides in Belgium

OBJECTIVE

The 'HICPAC guidelines', published in the USA in 1995 stressed the crucial role of restrictive usage of glycopeptides in the strategy to limit the emergence and spread of resistant enterococci. Because controversy still remains in Belgium on the necessity and feasability of restricting glycopeptide usage, the infectious diseases advisory board (IDAB) developed a consensus statement on the judicious use of glycopeptides in Belgium.

METHODS

The literature on the indications for glycopeptide treatment was reviewed, categorized and discussed by a working party of the IDAB.Consequently, the IDAB reached consensus on the warranted indications for glycopeptide use in Belgium.

RESULTS

The opinion of the IDAB-members is reported in a consensus statement specifying the indications for treatment and for prophylaxis with glycopeptide antimicrobials, as well as the situations where glycopeptides should not be used, taking into account the specific epidemiology of bacterial resistance, the availability of antibiotics and the common prescribing practices in Belgium.

CONCLUSIONS

The IDAB concludes that restrictive usage of glycopeptides must also be a priority in Belgium. Guidelines on the judicious use of these antibiotics adapted to the national situations must contribute to this objective.

Leucocyte transfusions from rhG-CSF or prednisolone stimulated donors for treatment of severe infections in immunocompromised neutropenic patients

Sepsis in profound neutropenia after chemotherapy is associated with high mortality despite appropriate antibacterial or antifungal treatment. In a prospective phase I/II study we evaluated the feasability and efficacy of leucocyte transfusions (LT) in patients with malignancies or haematological disorders who were suffering from severe bacterial or fungal infection during therapy-related bone marrow aplasia. 30 patients with severe neutropenia and clinical signs of life-threatening sepsis not responding to adequate treatment, received LT from rhG-CSF-stimulated family donors or from prednisolone-primed volunteers. A total of 301 LT were administered. The median number of LT per patient was seven (range three to 65), the median duration of LT treatment was 8 d (range 2-35). The white cell count (WBC), absolute neutrophil count (ANC) and lymphocyte count of the concentrates from rhG-CSF-stimulated donors were significantly higher than those from prednisolone-primed volunteers (P = 0.0001). Despite the critical condition of the patients, LT were generally well tolerated. Only 39 (12.9%) LT were associated with adverse reactions. The transfusion of leucocytes collected by continuous flow leukapheresis from both rhG-CSF and prednisolone stimulated donors resulted in a measurable increment of the peripheral leucocyte and ANC counts in our patients. On day 100 after the first LT, 20/30 patients were alive with complete clearance of the infection.

Imipenem-cilastatin versus sulbactam-cefoperazone plus amikacin in the initial treatment of febrile neutropenic cancer patients

The treatment of infectious complications in cancer patients has evolved as a consequence of the developments in the chemotherapy of cancer patients. In this prospective, randomized study, we compared imipenem-cilastatin and sulbactam-cefoperazone with amikacin in the empiric therapy of febrile neutropenic (< 1000/mm3) patients with liquids and solid tumours. Of 30 evaluable episodes, 15 were treated with imipenem-cilastatin and 15 were treated with sulbactam-cefoperazone plus amikacin. 73% of episodes were culture-positive: gram-positive pathogens accounted for 62% of the isolates. Bacteremia was the most frequent site of infection. The initial clinical response rate for both regimens was 60% (p > 0.05). No major adverse effects occurred. This study demonstrated that imipenem-cilastatin monotherapy and combination therapy of sulbactam-cefoperazone plus amikacin were equally effective empiric therapy for febrile granulocytopenic cancer patients.

Interventional antimicrobial therapy in febrile neutropenic patients

In febrile neutropenic patients, prompt empiric antimicrobial intervention is mandatory. Numerous studies have demonstrated the benefit of broad-spectrum beta-lactams active against Gram-negative aerobes as well as against streptococci and Staphylococcus aureus in this setting. With this interventional strategy, a reduction of infection-related mortality to < or = 10% of patients undergoing intensive remission induction or consolidation chemotherapy could be obtained. Thereby, subgroups of patients have been identified who require an empiric modification of antimicrobial treatment, e.g., patients with catheter-related infections, with pulmonary infiltrates, or with unexplained fever (FUO) not responding to first-line antibacterials. In two consecutive, prospectively randomized trials conducted by the German Paul Ehrlich Society it could be shown that empiric antifungal therapy is beneficial for second-line treatment in patients with persistent FUO and improves first-line treatment results in patients with lung infiltrates. The addition of glycopeptides, however, should be restricted to patients with catheter-related infections due to coagulase-negative staphylococci or with infections due to multiresistant Gram-positive pathogens.

Clinical outcome and economic impact of aminoglycoside peak concentrations in febrile immunocompromised patients with hematologic malignancies

The aim of this study was to investigate the clinical and economic significance of aminoglycoside peak concentrations in febrile neutropenic patients with hematologic malignancies. Sixty-one patients were treated according to protocol II of the Paul-Ehrlich-Gesellschaft: initial application of gentamicin or tobramycin in combination with a cephalosporin or ureidopenicillin and, after 3 days, a potential change of antibiosis to be decided in case of nonresponse. At the same time, samples were collected by an independent controller. We found a significant dependence of clinical outcome on aminoglycoside peak concentrations (P = 0.004). Twelve of 17 patients with peak concentrations &gt;4.8 mg/L, but only 13 of 44 patients with concentrations ≤4.8 mg/L, responded to initial therapy. Average infection-related costs per patient with peak values &gt;4.8 mg/L were US$1429, $1790, and $1701 for nursing, diagnostics, and therapeutics, respectively (total $4920). Expenses for patients with peak concentrations ≤4.8 mg/L were ∼1.8-fold higher (average total $8718). If all 61 patients had achieved peaks &gt;4.8 mg/L, the potential savings would have totalled $167 112. We conclude that neutropenic patients form a target group for successful pharmacokinetic intervention and cost saving.

Imipenem/cilastatin: an update of its antibacterial activity, pharmacokinetics and therapeutic efficacy in the treatment of serious infections

The prototype carbapenem antibacterial agent imipenem has a very broad spectrum of antibacterial activity, encompassing most Gram-negative and Gram-positive aerobes and anaerobes, including most beta-lactamase-producing species. It is coadministered with a renal dehydropeptidase inhibitor, cilastatin, in order to prevent its renal metabolism in clinical use. Extensive clinical experience gained with imipenem/cilastatin has shown it to provide effective monotherapy for septicaemia, neutropenic fever, and intra-abdominal, lower respiratory tract, genitourinary, gynaecological, skin and soft tissues, and bone and joint infections. In these indications, imipenem/cilastatin generally exhibits similar efficacy to broad-spectrum cephalosporins and other carbapenems and is at least equivalent to standard aminoglycoside-based and other combination regimens. Imipenem/cilastatin is generally well tolerated by adults and children, with local injection site events, gastrointestinal disturbances and dermatological reactions being the most common adverse events. Seizures have also been reported, occurring mostly in patients with impaired renal function or CNS pathology, or with excessive dosage. Although it is no longer a unique compound, as newer carbapenems such as meropenem are becoming available, imipenem/cilastatin nevertheless remains an important agent with established efficacy as monotherapy for moderate to severe bacterial infections. Its particular niche is in treating infections known or suspected to be caused by multiresistant pathogens.