Oral trimethoprim/sulfamethoxazole in attempt to prevent infection after induction chemotherapy for acute leukemia

Antibiotic prophylaxis for bacterial infections in afebrile neutropenic patients following chemotherapy

BACKGROUND

Bacterial infections are a major cause of morbidity and mortality in patients who are neutropenic following chemotherapy for malignancy. Trials have shown the efficacy of antibiotic prophylaxis in reducing the incidence of bacterial infections but not in reducing mortality rates. Our systematic review from 2006 also showed a reduction in mortality.

OBJECTIVES

This updated review aimed to evaluate whether there is still a benefit of reduction in mortality when compared to placebo or no intervention.

SEARCH METHODS

We searched the Cochrane Cancer Network Register of Trials (2011), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2011), MEDLINE (1966 to March 2011), EMBASE (1980 to March 2011), abstracts of conference proceedings and the references of identified studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs comparing different types of antibiotic prophylaxis with placebo or no intervention, or another antibiotic, to prevent bacterial infections in afebrile neutropenic patients.

DATA COLLECTION AND ANALYSIS

Two authors independently appraised the quality of each trial and extracted data from the included trials. Analyses were performed using RevMan 5.1 software.

MAIN RESULTS

One-hundred and nine trials (involving 13,579 patients) that were conducted between the years 1973 to 2010 met the inclusion criteria. When compared with placebo or no intervention, antibiotic prophylaxis significantly reduced the risk of death from all causes (46 trials, 5635 participants; risk ratio (RR) 0.66, 95% CI 0.55 to 0.79) and the risk of infection-related death (43 trials, 5777 participants; RR 0.61, 95% CI 0.48 to 0.77). The estimated number needed to treat (NNT) to prevent one death was 34 (all-cause mortality) and 48 (infection-related mortality).Prophylaxis also significantly reduced the occurrence of fever (54 trials, 6658 participants; RR 0.80, 95% CI 0.74 to 0.87), clinically documented infection (48 trials, 5758 participants; RR 0.65, 95% CI 0.56 to 0.76), microbiologically documented infection (53 trials, 6383 participants; RR 0.51, 95% CI 0.42 to 0.62) and other indicators of infection.There were no significant differences between quinolone prophylaxis and TMP-SMZ prophylaxis with regard to death from all causes or infection, however, quinolone prophylaxis was associated with fewer side effects leading to discontinuation (seven trials, 850 participants; RR 0.37, 95% CI 0.16 to 0.87) and less resistance to the drugs thereafter (six trials, 366 participants; RR 0.45, 95% CI 0.27 to 0.74).

AUTHORS' CONCLUSIONS

Antibiotic prophylaxis in afebrile neutropenic patients significantly reduced all-cause mortality. In our review, the most significant reduction in mortality was observed in trials assessing prophylaxis with quinolones. The benefits of antibiotic prophylaxis outweighed the harm such as adverse effects and the development of resistance since all-cause mortality was reduced. As most trials in our review were of patients with haematologic cancer, we strongly recommend antibiotic prophylaxis for these patients, preferably with a quinolone. Prophylaxis may also be considered for patients with solid tumours or lymphoma.

Antibiotic prophylaxis for bacterial infections in afebrile neutropenic patients following chemotherapy

BACKGROUND

Bacterial infections are a major cause of morbidity and mortality in neutropenic patients following chemotherapy for malignancy. Trials have shown the efficacy of antibiotic prophylaxis in decreasing the incidence of bacterial infections, but not in reducing mortality rates.

OBJECTIVES

This review aimed to evaluate whether antibiotic prophylaxis in afebrile neutropenic patients reduced mortality when compared to placebo or no intervention.

SEARCH STRATEGY

Electronic searches on The Cochrane Cancer Network Register of Trials (2004), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2004), MEDLINE (1966 to 2004) and EMBASE (1980 to 2004) and abstracts of conference proceedings; references of identified studies; the first author of each included trial was contacted.

SELECTION CRITERIA

RCTs or quasi-RCTs comparing different types of antibiotic prophylaxis with placebo or no intervention, or another antibiotic to prevent bacterial infections in afebrile neutropenic patients.

DATA COLLECTION AND ANALYSIS

Two authors independently appraised the quality of each trial and extracted data from the included trials. Relative risks (RR) or average differences, with their 95% confidence intervals (CI) were estimated.

MAIN RESULTS

One hundred trials (10,274 patients) performed between the years 1973 to 2004 met inclusion criteria. Antibiotic prophylaxis significantly decreased the risk for death when compared with placebo or no intervention (RR, 0.66 [95% CI 0.54 to 0.81]). The authors estimated the number needed to treat (NNT) in order to prevent 1 death from all causes as 60 (95% CI 34 to 268). Prophylaxis resulted in a significant decrease in the risk of infection-related death, RR 0.58 (95% CI 0.45 to 0.74) and in the occurrence of fever, RR 0.78 (95% CI 0.75 to 0.82). A reduction in mortality was also evident when the more recently conducted quinolone trials were analysed separately. Quinolone prophylaxis reduced the risk for all-cause mortality, RR 0.52 (95% CI, 0.37 to 0.84).

AUTHORS' CONCLUSIONS

Our review demonstrated that prophylaxis significantly reduced all-cause mortality. The most significant reduction in mortality was observed in trials assessing prophylaxis with quinolones. The benefit demonstrated in our review outweighs harm, such as adverse effects, and development of resistance, since all-cause mortality is reduced. Since most trials in our review were of patients with haematologic cancer, prophylaxis, preferably with a quinolone, should be considered for these patients.

Bacteremia due to viridans streptococci in neutropenic patients: a review

Viridans streptococci have long been considered, with the exception of the ability to cause endocarditis, as minor pathogenic agents. More recently, however, these bacteria have become a major concern in neutropenic patients undergoing a chemotherapeutic treatment. In this high-risk population, they can be responsible for up to 39% of bacteremia cases and are the most frequent cause of this type of infection. The most frequently isolated species in blood cultures are Streptococcus mitis and Streptococcus sanguis II. Viridans streptococcus bacteremia can be accompanied by serious complications, like adult respiratory distress syndrome (ARDS) (3% to 33%), shock (7% to 18%) or endocarditis (7% to 8%). Mortality rates range from 6% to 30%. Case-control studies have identified the following risk factors: severe neutropenia (< 100 neutrophils/mm3), prophylactic antibiotic treatments with quinolone or co-trimoxazole, absence of intravenous antibiotics at the time of bacteremia, high doses of cytosine arabinoside, oropharyngeal mucositis, and heavy colonization by viridans streptococci. The introduction of penicillin in prophylactic antibiotic treatments has reduced the incidence of these infections, but the long-term use of penicillin could be compromised by the emergence of resistant strains.

Use of selective decontamination in the prevention of infection after accidental irradiation. A review

Exposure to radiation induces a reduction in the number of gastrointestinal, anaerobic bacterial flora, and an increase in the number of Enterobacteriaceae that are associated with sepsis and mortality. Antimicrobials that suppress anaerobic flora have a deleterious effect on survival by promoting earlier enterobacterial sepsis. In contrast, in studies of animals and immunosuppressed patients, antimicrobials that inhibit gram-negative enteric bacteria and preserve the anaerobic flora have shown a beneficial effect by preventing bacterial translocation and fatal sepsis. The quinolone antimicrobials hold potential for therapy of endogenous and exogenous infection after irradiation.

Selective decontamination in neutropenic patients

It is well known that severe neutropenia, as usually seen in patients with acute leukaemia, aplastic anaemia or secondary to aggressive chemotherapy, predisposes to infections with Gram-negative enteric bacilli,Pseudomonas aeruginosa, Staphylococcus aureus, and to fungal infections. Infection with anaerobes, in contrast, is rare in patients with haematologic malignancy [1]. The spectrum of bacterial pathogens in this patient population has recently broadened, and now includes coagulase-negative staphylococci, viridans group streptococci, and, occasionally, coryneforms and other rather unusual opportunistic organisms. All these microorganisms originate either from the patient's own microflora, especially from the digestive tract, or from the hospital environment after having colonized the patient during the hospital stay [2]. Studies have shown that the incidence of fever during periods of severe neutropenia approaches 100%, and most of these fever episodes actually represent bacterial infection. For more than 20 years, methods for the prevention of bacterial and fungal infections have been under investigation in patients with profound neutropenia. These included decontamination trails, oral or systemic antimicrobial prophylaxis, strict reverse isolation and maintenance of germ-free conditions [3–8], prophylactic granulocyte transfusions [9], and, more recently, the application of haemopoietic growth factors [10, 11]. The method which remains the most widely used is oral antimicrobial prophylaxis, especially with agents for so-called selective decontamination of the intestinal tract.

Streptococcal bacteremia in adult patients with leukemia undergoing aggressive chemotherapy. A review of 55 cases

We reviewed 55 cases of streptococcal bacteremia in adult patients who received cytotoxic chemotherapy for treatment of acute leukemia. Viridans group streptococci were the most frequent species isolated (45 isolates). Hemolytic streptococci (four isolates), pneumococci (three isolates), and enterococci (three isolates) were infrequent. Clinical features of streptococcal bacteremia included fever, upper and lower respiratory infection, respiratory distress syndrome, soft tissue infection, and septic shock. Forty patients who had only streptococci, but no other organisms isolated from their blood, were compared with 36 cases of gram-negative bacillary bacteremia that occurred during the same study period within the same population at risk. The comparison showed that patients with streptococcal bacteremia had more often received high dose cytosine arabinoside as part of their chemotherapy (17 vs. five), had a longer mean duration of fever (11 vs. seven days, p less than 0.01) needed slightly more days of antibacterial therapy (15 vs. 12 days, p = 0.07, not significant), and were more likely to have been treated with newer quinolones for infection prevention (30 vs. eight). No differences between both groups were found for age, underlying disease, remission status, duration of severe granulocytopenia, and number of superinfections. The overall mortality was 18% in streptococcal bacteremia and 17% in gram-negative bacillary bacteremia. Streptococci, especially viridans group streptococci, should now be regarded as frequent causes of serious life-threatening infections following aggressive chemotherapy in patients with hematologic malignancies.

Analysis of early infectious complications after autologous bone marrow transplantation

We reviewed the hospital course of 35 patients who underwent autologous bone marrow transplantation. Fever and profound neutropenia developed in all. Microbiologically confirmed infection developed in 22 patients, and unconfirmed but clinically evident infection developed in six. A bacterial infection developed in 21 patients (most commonly bacteremia without a detectable focus). Mucocutaneous fungal (12 patients) and viral (13 patients) infections were common, whereas invasive fungal (two patients) and viral (one patient) infections were uncommon. New pulmonary infiltrates developed in seven patients. Six deaths occurred during the initial hospitalization for transplantation, only one of which was directly attributable to infection. Stepwise logistic regression analysis retained male gender, total body irradiation, administration of trimethoprim/sulfamethoxazole, and development of mucositis or diarrhea as predictors of decreased survival, whereas higher pretreatment albumin levels and the administration of oral nonabsorbable antifungals were associated with an increased likelihood of survival. A comparison of these infectious complications with those found in allogeneic bone marrow transplant recipients shows similarities and differences with potentially important implications for patient management.

Co-trimoxazole in patients with haematological malignancies: a review of 10-years' clinical experience

Co-trimoxazole has been used in a hospital for over 10 years as a major antibacterial agent in the treatment of malignant haematological diseases. Routine selective gut decontamination with co-trimoxazole combined with colistine and an antifungal agent has led to a reduction in infections in neutropenic patients from 40% to 25% since the strategy was adopted, and this had been accompanied by a change in the most frequent pathogens, from Gram-negative to Gram-positive organisms. Co-trimoxazole has proved to be the drug of choice for Pneumocystis carinii infections. Finally, it is used as first-line therapy in febrile immunosuppressed patients who are not on selective decontamination, with an efficacy of over 90%. Apart from mild abdominal discomfort, an elevated allergy rate of 14% in patients with overt leukaemia is a major disadvantage. On the other hand, substantial prolongation of episodes of bone marrow aplasia has not been observed.

Trimethoprim-sulfamethoxazole and other sulfonamides

Trimethoprim-sulfamethoxazole continues to be a useful antibiotic for common outpatient problems such as urinary tract infections, prostatitis, acute exacerbations of chronic bronchitis, and acute otitis media as well as for serious infections of the hospitalized patient including Pneumocystis carinii pneumonia, acute pyelonephritis, and some forms of gram negative meningitis. The other sulfonamides have a limited role.

Selective gut decontamination with nalidixic acid or trimethoprim-sulfamethoxazole for infection prophylaxis in neutropenic cancer patients: relationship of efficacy to antimicrobial spectrum and timing of administration

Eighty-four cancer patients at risk of infection because of neutropenia were randomized to receive nalidixic acid as an alternative to trimethoprim-sulfamethoxazole (TMP-SMX) for infection prophylaxis. Infections were documented significantly earlier and more often among patients who entered the trial with neutrophil counts of less than 0.1 X 10(9)/liter. TMP-SMX recipients experienced fewer microbiologically documented infections and bacteremias and were free of infection for a higher proportion of days with severe neutropenia (less than 0.1 X 10(9)/liter) than nalidixic acid recipients. Gram-negative bacillary and Staphylococcus aureus infections accounted for the major differences. Although the majority of aerobic gram-negative bacilli were eliminated from the feces after 1 week of prophylaxis with either agent, TMP-SMX was proved superior to nalidixic acid in this regard and was associated with acquired drug resistance by gram-negative bacilli less frequently. Both agents selected for colonization and subsequent infection by gram-positive cocci. Our data suggest that prophylaxis is most likely to be effective if administered to patients for at least 1 week before they become severely neutropenic. Nalidixic acid used as a single agent in doses of 4 g daily, however, cannot be recommended as an alternative to TMP-SMX for infection prophylaxis in neutropenic cancer patients.

Antimicrobial prophylaxis in immunocompromised patients

The results of a randomised, prospective trial to investigate the efficacy of prophylactic treatment with ofloxacin during granulocytopenia after cytostatic treatment are presented. 42 patients with metastasised testicular germ-cell tumours entered the study. Cytostatic treatment consisted of at least 4 courses, 2 of which were succeeded by prophylactic treatment with ofloxacin. Three patients undergoing prophylactic treatment developed fever. Fever occurred in 16 patients during control phases (no ofloxacin prophylaxis) of cytostatic treatment. Seven of the 19 infections could be documented microbiologically. No side effects that related to ofloxacin were noted. In conclusion, ofloxacin was highly effective in the prevention of infection and, therefore, should be given prophylactically to patients with granulocytopenia.

Autologous bone marrow transplantation following high dose chemotherapy for the treatment of adult patients with acute myeloid leukaemia

24 adult patients with acute myeloid leukaemia (AML) were treated with intensive chemotherapy followed by autologous marrow rescue. The procedure was repeated twice in eight patients. 11 of 16 patients treated in first remission continue in first unmaintained remission (9-54 months, median 17 months). Eight patients treated at relapse or second remission have relapsed again and died within 14 months of their first autologous bone marrow transplant (ABMT). This form of intensification therapy would appear valuable for adult AML patients in first remission.

Prevention of infection in acute leukemia: a prospective randomized study on the efficacy of two different drug regimens for antimicrobial prophylaxis

In a prospective study patients with acute leukemia undergoing remission induction therapy were randomized to receive either a regimen of non-absorbable antimicrobial drugs (colistin and neomycin) or of absorbable and non-absorbable drugs (trimethoprim-sulfamethoxazole [TMP-SMZ] and colistin) for antibacterial prophylaxis. For antifungal prophylaxis patients in both groups were given oral amphotericin B. The proportion of patients without acquired infections and the median of study time to the first acquired infection did not differ significantly between the two treatment groups (p greater than 0.05). Septicemias occurred in nine out of 49 recipients of colistin and neomycin and in one out of 56 patients receiving TMP-SMZ and colistin (p = 0.03). Localized infections and fever episodes without proven infections were equally distributed between the two groups. The incidence of febrile days and of days on parenteral antibiotic therapy was significantly lower in the group given TMP-SMZ and colistin (p less than 0.05). The duration of severe granulocytopenia and thrombocytopenia did not differ significantly between the two groups (p greater than 0.05).

Problems of intensive therapy in childhood cancer

Tremendous progress has been made in the treatment of childhood cancers. Certain hematologic malignancies have an impressive cure rate with the current intensive antineoplastic treatment regimens. There is optimism that the treatment of children who have advanced stage solid tumors with intensive, multimodality therapy may improve their chances for long-term survival. These treatment programs, though potentially curative, are highly toxic, with severe myelosuppression and damage to other organ systems. An awareness of these potential toxicities, an understanding of how to prevent or minimize certain problems, and the ability to treat those complications which do arise are all essential to the successful management of childhood cancer.