Comparison of two schedules of cefoperazone plus aztreonam in the treatment of neutropenic patients with fever

Monobactams: A Unique Natural Scaffold of Four-Membered Ring Skeleton, Recent Development to Clinically Overcome Infections by Multidrug- Resistant Microbes

Background:

Monobactam antibiotics have been testified to demonstrate significant antibacterial activity especially the treatment of infections by superbug microbes. Recently, research has been focused on the structural modifications, and new generation of this privileged natural scaffold.

Objective:

Efforts have been made to discover the structure-antibacterial relationship of monbactams in order to avoid the aimless work involving the ongoing generated analogues. This review aims to summarize the current knowledge and development of monobactams as a broad-spectrum antibacterial scaffolds. The recent structural modifications that expand the activity, especially in the infections by resistant-strains, combinational therapies and dosing, as well as the possibility of crosshypersensitivity/ reactivity/tolerability with penicillins and cephalosporins will also be summarized and inferred. Different approaches will be covered with emphasis on chemical methods and Structure- Activity Relationship (SAR), in addition to the proposed mechanisms of action. Clinical investigation of monobactams tackling various aspects will not be missed in this review.

Conclusion:

The conclusion includes the novels approaches, that could be followed to design new research projects and reduce the pitfalls in the future development of monobactams.

Balanoposthitis caused by Pseudomonas aeruginosa co-producing metallo-beta-lactamase and 16S rRNA methylase in children with hematological malignancies

Balanoposthitis is defined as the inflammation of the glans penis and its foreskin. In the presence of other underlying medical conditions, this localized infection may spread systemically, serving as a source of fever and bacteremia in neutropenic males. Two rare cases of balanoposthitis caused by a clonally related Pseudomonas aeruginosa isolate co-producing the SPM-1 metallo-beta-lactamase and the novel 16S rRNA methylase RmtD are described. Four multidrug-resistant (MDR) P. aeruginosa isolates were successively recovered from glans/foreskin swabs and urine cultures from two uncircumcised pediatric patients, one with Burkitt's non-Hodgkin's lymphoma and one with acute lymphoblastic leukemia. Clinically, preputial colonization by MDR P. aeruginosa evolved to severe balanoposthitis with glans/foreskin lesions as a source of fever. Combination therapy of ciprofloxacin and/or aztreonam (systemic) plus polymyxin B (topical) was effective once reversion of the neutropenic condition was achieved. Although P. aeruginosa remains an unusual cause of balanoposthitis, these cases should alert the physician to the potential pathogenicity of this bacterium. Furthermore, co-production of metallo-beta-lactamase and 16S rRNA methylase has a potential impact on the empirical management of complicated infections caused by P. aeruginosa.

Outcomes of treatment pathways in outpatient treatment of low risk febrile neutropenic cancer patients

BACKGROUND

We treated low-risk febrile neutropenic cancer patients utilizing two standard outpatient antibiotic pathways: oral ampicillin/clavulanate (500 mg) and ciprofloxacin (500 mg) or intravenous ceftazidime (2 g) and clindamycin (600 mg) every 8 h. The objectives were to determine the success of outpatient treatment of low-risk febrile neutropenia, to identify factors predicting outpatient failure, and to determine mortality related to the febrile episode.

METHODS

Eligibility criteria included solid tumor diagnosis, stable vital signs, temperature > or =38.0 degrees C, absolute neutrophil count (ANC) of <1000/ml, patient compliance, no significant organ dysfunction, ability to tolerate oral medication and fluids for oral pathway, residence within 30 miles of the institution, 24-h caregiver, and telephone and transportation access.

RESULTS

There were 257 febrile episodes in 191 patients meeting the criteria. Patients were treated during March 1998 through February 2000. Median age was 48 (range, 17-77) years, and 60% (n = 153) had an entry ANC of <100/ml; 205 (80%) febrile episodes successfully responded to outpatient treatment, and 52 (20%) were hospitalized. Logistic regression analysis showed the following were related to hospitalization: mucositis >grade 2 (p < 0.002); Zubrod performance status > or =2 (p = 0.029); ANC <100/ml (p = 0.039), and age > or =70 years (p = 0.048).

CONCLUSIONS

Outpatient treatment of low-risk febrile neutropenic cancer patients utilizing standard treatment pathways is associated with minimal morbidity and mortality and should be considered an acceptable standard of care with appropriate infrastructure available to provide strict and careful follow-up while on treatment. Certain factors are associated with higher risk of hospitalization and should be further examined in eligible patients with low-risk febrile neutropenia.

Piperacillin plus aztreonam for treatment of neutropenic fever

BACKGROUND

A combination of beta-lactam plus an aminoglycoside is the most frequently used regimen for febrile episodes in neutropenic cancer patients. However, aminoglycoside-related toxicity occasionally makes this regimen difficult to use as the first-line drug therapy. In the present study, we chose aztreonam as the alternative to aminoglycoside in combination with piperacillin for neutropenic fever in pediatric patients and we evaluated its effectiveness.

METHODS

A total of 31 febrile episodes in 16 patients with malignant neoplasms were evaluted. Piperacillin (200 mg/kg per day) plus aztreonam (150 mg/kg per day) were administered intravenously following a routine fever work-up.

RESULTS

The overall response rate was 67%. The response rate when neutrophil count was less than 100/mm3 was 63%. The side effects were mild and rare. In three patients, all of the microbiologically documented infections were caused by alpha-streptococcus, which required a change in the regimen.

CONCLUSIONS

A combination of piperacillin and aztreonam provides an effective and non-toxic regimen for first-line therapy in febrile patients with neutropenia. In contrast, the results of the present study suggest the need for caution with regard to alpha-streptococcus infections.

Outpatient antibiotic therapy for febrile episodes in low-risk neutropenic patients with cancer

Until recently, febrile neutropenic patients were treated with intravenous antibiotics in inpatient settings. Because of work completed in the last several years by various investigators, identification of a low-risk group of febrile, neutropenic patients has allowed successful treatment with both parenteral and oral antibiotics in an ambulatory environment. This accomplishment has been facilitated by advances in broad-spectrum antibiotics with long half-lives and stabilities, the introduction of the quinolones providing oral antipseudomonal activity, home health care, improvements in vascular access devices, and technically enhanced antibiotic delivery systems. This review focuses on the rationale of risk stratification and the progress made in treating low-risk febrile neutropenic patients as outpatients.