Controlled trials of double beta-lactam therapy with cefoperazone plus piperacillin in febrile granulocytopenic patients

Interactions between carbapenems and valproic acid among the patients in the intensive care units

PURPOSE

To evaluate risk factors for epileptic seizures or status epilepticus (SE) in patients concomitantly receiving valproic acid (VPA) and carbapenems.

MATERIALS AND METHODS

Adult patients in the intensive care units (ICUs) who concomitantly received VPA and carbapenems from 2007 to 2017 were included. The impacts of different carbapenems on serum concentration of VPA were compared.

RESULTS

Among 162 patients included, 104 (64.2%) and 45 (27.8%) developed epileptic seizures and SE, respectively. The risk factors for epileptic seizures were age (per year increase, adjusted odds ratio [aOR], 1.03), initial antiepileptic regimen (monotherapy and polytherapy, aOR, 0.43 and 0.18, respectively), and VPA serum concentration after concomitant carbapenem administration (per 1 μg/mL increase, aOR, 0.96). VPA serum concentration after concomitant carbapenem administration was an independent risk factor for SE (per μg/mL increase, aOR, 0.98). Concomitant imipenem/cilastatin administration did not significantly decrease VPA serum concentration compared to that by meropenem or ertapenem. The length of stay and number of days on ventilation after concomitant carbapenem administration in the ICUs were significantly more in those with epileptic seizures or SE.

CONCLUSIONS

Carbapenems decreased VPA serum concentration and increased the risk of epileptic seizures and SE, which led to increased length of ICU stay.

First Penicillin-Binding Protein Occupancy Patterns of β-Lactams and β-Lactamase Inhibitors in Klebsiella pneumoniae

Penicillin-binding proteins (PBPs) are the high-affinity target sites of all β-lactam antibiotics in bacteria. It is well known that each β-lactam covalently binds to and thereby inactivates different PBPs with various affinities. Despite β-lactams serving as the cornerstone of our therapeutic armamentarium against Klebsiella pneumoniae, PBP binding data are missing for this pathogen. We aimed to generate the first PBP binding data on 13 chemically diverse and clinically relevant β-lactams and β-lactamase inhibitors in K. pneumoniae PBP binding was determined using isolated membrane fractions from K. pneumoniae strains ATCC 43816 and ATCC 13883. Binding reactions were conducted using β-lactam concentrations from 0.0075 to 256 mg/liter (or 128 mg/liter). After β-lactam exposure, unbound PBPs were labeled by Bocillin FL. Binding affinities (50% inhibitory concentrations [IC50]) were reported as the β-lactam concentrations that half-maximally inhibited Bocillin FL binding. PBP occupancy patterns by β-lactams were consistent across both strains. Carbapenems bound to all PBPs, with PBP2 and PBP4 as the highest-affinity targets (IC50, <0.0075 mg/liter). Preferential PBP2 binding was observed by mecillinam (amdinocillin; IC50, <0.0075 mg/liter) and avibactam (IC50, 2 mg/liter). Aztreonam showed high affinity for PBP3 (IC50, 0.06 to 0.12 mg/liter). Ceftazidime bound PBP3 at low concentrations (IC50, 0.06 to 0.25 mg/liter) and PBP1a/b at higher concentrations (4 mg/liter), whereas cefepime bound PBPs 1 to 4 at more even concentrations (IC50, 0.015 to 2 mg/liter). These PBP binding data on a comprehensive set of 13 clinically relevant β-lactams and β-lactamase inhibitors in K. pneumoniae enable, for the first time, the rational design and optimization of double β-lactam and β-lactam-β-lactamase inhibitor combinations.

The risk of seizures among the carbapenems: a meta-analysis

OBJECTIVES

A consensus exists among clinicians that imipenem/cilastatin is the most epileptogenic carbapenem, despite inconsistencies in the literature.

METHODS

We conducted a meta-analysis of all randomized controlled trials comparing carbapenems with each other or with non-carbapenem antibiotics to assess the risk of seizures for imipenem, meropenem, ertapenem and doripenem.

RESULTS

In the risk difference (RD) analysis, there were increased patients with seizure (2 per 1000 persons, 95% CI 0.001, 0.004) among recipients of carbapenems versus non-carbapenem antibiotics. This difference was largely attributed to imipenem as its use was associated with an additional 4 patients per 1000 with seizure (95% CI 0.002, 0.007) compared with non-carbapenem antibiotics, whereas none of the other carbapenems was associated with increased seizure. Similarly, in the pooled OR analysis, carbapenems were associated with a significant increase in the risk of seizures relative to non-carbapenem comparator antibiotics (OR 1.87, 95% CI 1.35, 2.59). The ORs for risk of seizures from imipenem, meropenem, ertapenem and doripenem compared with other antibiotics were 3.50 (95% CI 2.23, 5.49), 1.04 (95% CI 0.61, 1.77), 1.32 (95% CI 0.22, 7.74) and 0.44 (95% CI 0.13, 1.53), respectively. In studies directly comparing imipenem and meropenem, there was no difference in epileptogenicity in either RD or pooled OR analyses.

CONCLUSIONS

The absolute risk of seizures with carbapenems was low, albeit higher than with non-carbapenem antibiotics. Although imipenem was more epileptogenic than non-carbapenem antibiotics, there was no statistically significant difference in the imipenem versus meropenem head-to-head comparison.

Adverse events associated with meropenem versus imipenem/cilastatin therapy in a large retrospective cohort of hospitalized infants

BACKGROUND

Carbapenems are commonly used in hospitalized infants despite a lack of complete safety data and associations with seizures in older children. We compared the incidence of adverse events in hospitalized infants receiving meropenem versus imipenem/cilastatin.

METHODS

We conducted a retrospective cohort study of 5566 infants treated with meropenem or imipenem/cilastatin in neonatal intensive care units managed by the Pediatrix Medical Group between 1997 and 2010. Multivariable conditional logistic regression was performed to evaluate the association between carbapenem therapy and adverse events, controlling for infant factors and severity of illness.

RESULTS

Adverse events were more common with use of meropenem compared with imipenem/cilastatin (62.8/1000 infant days versus 40.7/1000 infant days, P < 0.001). There was no difference in seizures with meropenem versus imipenem/cilastatin (adjusted odds ratio 0.96; 95% confidence interval: 0.68, 1.32). The incidence of death, as well as the combined outcome of death or seizure, was lower with meropenem use-odds ratio 0.68 (0.50, 0.88) and odds ratio 0.77 (0.62, 0.95), respectively.

CONCLUSION

In this cohort of infants, meropenem was associated with more frequent but less severe adverse events when compared with imipenem/cilastatin.

Epileptogenic potential of carbapenem agents: mechanism of action, seizure rates, and clinical considerations

Antimicrobials are the most frequently implicated class of drugs in drug-induced seizure, with β-lactams being the class of antimicrobials most often implicated. The seizure-inducing potential of the carbapenem subclass may be directly related to their β-lactam ring structure. Data on individual carbapenems and seizure activity are scarce. To evaluate the available evidence on the association between carbapenem agents and seizure activity, we conducted a literature search of the MEDLINE (1966-May 2010), EMBASE (1974-May 2010), and International Pharmaceutical Abstracts (1970-May 2010) databases. Reference citations from the retrieved articles were also reviewed. Mechanistically, seizure propensity of the β-lactams is related to their binding to γ-aminobutyric acid (GABA) receptors. There are numerous reports of seizure activity associated with imipenem-cilastatin, with seizure rates ranging from 3-33%. For meropenem, doripenem, and ertapenem, the seizure rate for each agent is reported as less than 1%. However, as their use increases and expands into new patient populations, the rate of seizures with these agents may increase. High-dose therapy, especially in patients with renal dysfunction, preexisting central nervous system abnormalities, or a seizure history increases the likelihood of seizure activity. Although specific studies have not been conducted, data indicate that carbapenem-associated seizure is best managed with benzodiazepines, followed by other agents that enhance GABA transmission. Due to the drug interaction between carbapenems and valproic acid, resulting in clinically significant declines in valproic acid serum concentrations, the combination should be avoided whenever possible. Clinicians should be vigilant regarding the possibility of carbapenem-induced seizures when selecting and dosing antimicrobial therapy.

Profile of infections and outcome in high-risk febrile neutropenia: experience from a tertiary care cancer center in India

Objective of the present study was to describe the profile of infections in febrile neutropenia (FN) in acute leukemia and hematopoietic stem cell transplant (HSCT) with emphasis on response to therapy and outcome. In a prospective, observational single-institutional study, consecutive episodes of high-risk FN were enrolled over a 1½-year period. Uniform antibiotic policy and response criteria were used. Of the 200 episodes enrolled, acute leukemia induction comprised 40.5%, consolidation with high-dose cytarabine 22.5%, HSCT 29% (auto-HSCT 84%), and others 8% of the episodes, respectively. Microbiologically documented infections comprised 30% episodes, while bacteremia was documented in 26% episodes. Gram-negative isolates were more common (55.7%). Cefoperazone-sulbactam had the highest in vitro efficacy against Gram-negative rods. Carbapenem resistance was most prevalent among Acinetobacter spp. (80%) and Pseudomonas aeruginosa (50%). All Gram-positive cocci other than enterococci were susceptible to vancomycin, while 2/8 enterococci were resistant to it. Cefoperazone-sulbactam and amikacin were used as first-line antibiotics. Overall mortality was 8%. On multivariate analysis, mortality was associated with a nadir leukocyte count < 200/μl and an abnormal chest radiograph. Among high-risk FN patients, inspite of a high-level of resistance to antibiotics, a frontline regime containing cefoperazone-sulbactam could restrict the use of imipenem and resulted in an acceptable mortality of 8%.

Cefoperazone/sulbactam versus cefoperazone plus mezlocillin: empiric therapy for febrile, neutropenic bone marrow transplant patients

We conducted a prospective, randomized trial in 132 patients undergoing bone marrow transplantation comparing cefoperazone in combination with sulbactam (S), N = 66, vs. cefoperazone plus mezlocillin (CM), N = 66, as empiric antibiotic therapy for fever and neutropenia. Overall duration of neutropenia was 3-55 (median, 13) days. Forty-one patients had positive initial cultures (S = 22 and CM = 19). Twelve of these 41 patients responded to initial study antibacterial agent treatment (S = 6 and CM = 6). Twenty-nine of 41 patients were withdrawn from study because of clinical deterioration, continued fever, or persistently positive cultures (S = 16 and CM = 13). Of the 90 patients who had culture-negative fever (S = 44 and CM = 46), 44 subjects responded with or without the addition of amphotericin B (S = 21 and CM = 23). Thirty-seven of 90 patients were withdrawn from study due to continued fever or clinical deterioration (S = 17 and CM = 20). Nine patients were withdrawn as a result of rash or diarrhea (S = 6 and CM = 3). We conclude that in patients undergoing bone marrow transplantation, there was no difference in efficacy between cefoperazone/sulbactam and the combination of cefoperazone plus mezlocillin in the empiric treatment of the febrile neutropenic patient. Since the majority of initial infections were due to gram positive bacteria, consideration should be given to broadening initial empiric antibacterial agent therapy with drugs that possess potent activity against these organisms.

Acute Myelogenous Leukemia and Febrile Neutropenia

Aggressive chemotherapy has a deleterious effect on all components of the defense system of the human body. The resulting neutropenia as well as injury to the pulmonary and gastrointestinal mucosa allow pathogenic micro-organisms easy access to the body. The symptoms of an incipient infection are usually subtle and limited to unexplained fever due to the absence of granulocytes. This is the reason why prompt administration of antimicrobial agents while waiting for the results of the blood cultures, the so-called empirical approach, became an undisputed standard of care. Gram-negative pathogens remain the principal concern because their virulence accounts for serious morbidity and a high early mortality rate. Three basic intravenous antibiotic regimens have evolved: initial therapy with a single antipseudomonal β-lactam, the so-called monotherapy; a combination of two drugs: a β-lactam with an aminoglycoside, a second β-lactam or a quinolone; and, thirdly, a glycopeptide in addition to β-lactam monotherapy or combination. As there is no single consistently superior empirical regimen, one should consider the local antibiotic susceptibility of bacterial isolates in the selection of the initial antibiotic regimen. Not all febrile neutropenic patients carry the same risk as those with fever only generally respond rapidly, whereas those with a clinically or microbiologically documented infection show a much slower reaction and less favorable response rate.

Once an empirical antibiotic therapy has been started, the patient must be monitored continuously for nonresponse, emergence of secondary infections, adverse effects, and the development of drug-resistant organisms. The averageduration of fever in serious infections in eventually successfully treated neutropenic patients is 4–5 days. Adaptations of an antibiotic regimen in a patient who is clearly not responding is relatively straightforward when a micro-organism has been isolated; the results of the cultures, supplemented by susceptibility testing, will assist in selecting the proper antibiotics. The management of febrile patients with pulmonary infiltrates is complex. Bronchoscopy and a high resolution computer-assisted tomographic scan represent the cornerstones of all diagnostic procedures, supplemented by serological tests for relevant viral pathogens and for aspergillosis. Fungi have been found to be responsible for two thirds of all superinfections that may surface during broad-spectrum antibiotic treatment of neutropenic patients. Antibiotic treatment is usually continued for a minimum of 7 days or until culture results indicate that the causative organism has been eradicated and the patient is free of major signs and symptoms. If a persistently neutropenic patient has no complaints and displays no evidence of infection, early watchful cessation of antibiotic therapy or a change to the oral regimen should be considered.

Clinical review: balancing the therapeutic, safety, and economic issues underlying effective antipseudomonal carbapenem use

Antipseudomonal carbapenems have played a useful role in our antimicrobial armamentarium for 20 years. However, a review of their use during that period creates concern that their clinical effectiveness is critically dependent on attainment of an appropriate dosing range. Unfortunately, adequate carbapenem dosing is missed for many reasons, including benefit/risk misconceptions, a narrow therapeutic window for imipenem and meropenem (due to an increased rate of seizures at higher doses), increasingly resistant pathogens requiring higher doses than are typically given, and cost containment issues that may limit their use. To improve the use of carbapenems, several initiatives should be considered: increase awareness about appropriate treatment with carbapenems across hospital departments; determine optimal dosing regimens for settings where multidrug resistant organisms are more likely encountered; use of, or combination with, an alternative antimicrobial agent having more favorable pharmacokinetic, pharmacodynamic, or adverse event profile; and administer a newer carbapenem with lower propensity for resistance development (for example, reduced expression of efflux pumps or greater stability against carbapenemases).

Infections in neutropenic patients. II: Management

Improvement in supportive care including the introduction of new antibiotics, antiviral and antifungal agents and haematopoietic growth factors have all contributed to a decreased chemotherapy-related mortality and morbidity in cancer patients. However, infection during neutropenia is still a major complication and a great concern for the clinician responsible for the patient. Management of infectious complications in the neutropenic patient is reviewed.

Current Approach to the Management of Neutropenia

Neutrophils have a critical role in host defense. Reduction in the absolute neutrophil count to below 1,000/μL is associated with increased susceptibility to infection. The pattern of infections depends on the severity and the duration of neutropenia and other associated defects in host defense mechanisms and exposure to antibiotics and other drugs, particularly corticosteroids and immunosuppressive agents. Breaks in the integrity of the skin or the gastrointestinal mucosal surfaces serve as the portals of entry for the majority of infecting organisms. Empiric antibiotic therapy and hospitalization are almost always required for the management of fever (temperature >38.2°C) in a neutropenic patient. A single antibiotic (e.g., ceftazidime or imipenem) or a combination of antibiotics with activity against both gram-positive and gram-negative organisms usually provides effective antimicrobial therapy. In low-risk patients, trials of out-patient therapy are ongoing. When febrile neutropenia does not respond to empiric broad-spectrum antibacterial therapy, fungal infections, particularly Candida and Aspergillus, should be considered, and antifungal therapy should be initiated. Recently, availability of the hematopoietic growth factors, particularly G-CSF and GM-CSF, have changed the approach to prevention and treatment of neutropenia. Randomized controlled studies have established that these growth factors accelerate hematopoietic recovery following chemotherapy and bone marrow transplantation. By shortening the duration of neutropenia, many of the heretofore inevitable problems with fever and infection can be avoided. The only major factor limiting the use of these agents is their cost. Despite the use of these growth factors, some patients will still experience slow hematopoietic recovery. For these patients, use of neutrophil transfusions, possibly from G-CSF-stimulated normal donors, may prove to be a useful adjunctive therapy.

Empiric therapy for infections in the febrile, neutropenic, compromised host

In the years to come, it is likely that with the advent of cytokines and even more with possibility to insert drug-resistant genes into hematopoietic stem cells, the risk of infection will be decreased because the severity and duration of neutropenia will be minimized. It is true that the ideal empiric antimicrobial regimen--a single antibiotic with a low incidence of superinfection and a low toxicity, without need for subsequent additions and readjustments--is still a wish. In the meantime and while living in the neutropenic area, physicians, for the benefit of patients, have to follow guidelines and create algorithms (see Fig. 1). Recommendations, however, should be always adjustable to the individual characteristics of the patient and the institution and to progress in antimicrobial chemotherapy. It is inevitable that research and clinical practice should go "hand in hand" in these "difficult-to-manage" and "difficult-to-treat" patients. After all, it should never be forgotten that the ultimate goal of empiric antimicrobial regimens in febrile neutropenia is to ensure patients' survival.

Infection prevention in severely myelosuppressed patients: a comparison between ciprofloxacin and a regimen of selective antibiotic modulation of the intestinal flora

PURPOSE

To study whether oral ciprofloxacin would be as effective in preventing bacterial infections in severely myelosuppressed patients as selective antibiotic modulation of the gut flora with neomycin/polymyxin B sulfate/nalidixic acid (NPN).

PATIENTS AND METHODS

One hundred and five patients undergoing allogeneic or autologous bone marrow transplant, or induction therapy for acute leukemia in 1988 and 1989 were studied. Patients were stratified according to the type of therapy, and randomized in a ratio of 2:1 to either oral ciprofloxacin 500 mg BID, or a combination of oral neomycin 250 mg QID, polymyxin-B 100 mg QID, and oral nalidixic acid 1,000 mg BID. Treatment began on admission and continued until the absolute granulocyte count was greater than 500/mm3 for 3 consecutive days.

RESULTS

The 96 evaluable patients were evenly distributed over the 3 treatment groups; 63 patients received ciprofloxacin and 33 received NPN. Fever developed in 92% of patients on ciprofloxacin and in 97% of patients on NPN. (P = 0.66), 6.6 +/- 5.8 and 7.2 +/- 5.3 days from the start of prophylaxis, respectively. Twenty-five patients on ciprofloxacin developed 29 microbiologically documented infections, fewer than the 26 infections in the 22 patients on NPN (P = 0.02). Patients on ciprofloxacin had fewer bacteremias (33%) than did the NPN patients (55%) (P = 0.05). Gram-negative bacteremias were very rare (2 cases; no Enterobacteriaceae), but streptococcal bacteremias were frequent in both arms (27 cases). Side effects were not significantly different, but compliance with ciprofloxacin was better.

CONCLUSIONS

Ciprofloxacin is at least as effective as the combination of neomycin/polymyxin/nalidixic acid in the prophylaxis of bacterial infections in myelosuppressed patients, and is better tolerated. Additional agents to prevent streptococcal infections are needed.

Effect of induction cytarabine dose intensity on long-term survival in acute myelogenous leukemia: results of a randomized, controlled study

The optimal dose and schedule of cytarabine in induction chemotherapy of newly diagnosed acute myelogenous leukemia is not established. We compared the use of cytarabine 200 mg/m2/day by continuous infusion for seven days to an intermediate-dose of cytarabine, 500 mg/m2 every 12 hours for 12 doses. Thirty-seven of 52 patients assigned to conventional-dose cytarabine achieved complete remission (71%) and the actuarial disease-free and overall survival after achieving remission were 22 +/- 16% and 31 +/- 19% respectively. Thirty-seven of 50 patients assigned to intermediate-dose cytarabine achieved remission (74%) and the actuarial disease-free and overall survival after achieving remission were 26 +/- 16% and 39 +/- 18% respectively. There were no statistically significant differences in complete remission rate, actuarial leukemia-free survival or overall survival between the groups. The most significant predictor for survival was age. Actuarial two year leukemia-free survival and overall survival for patients age > 60 were 8 +/- 15% and 20 +/- 19% respectively compared to 36 +/- 14% and 54 +/- 15% for patients age < or = 60 (P = .058 and .01, respectively). Induction regimen did not significantly affect disease free or overall survival for patients under or over age 60. We conclude that intermediate-dose cytarabine did not substantially improve results of induction for newly diagnosed acute myeloid leukemia.

Outpatient treatment of febrile episodes in low-risk neutropenic patients with cancer

BACKGROUND

Hospitalization and intravenous (IV) broad-spectrum antibiotics are the standard of care for all febrile neutropenic patients with cancer. Recent work suggests that a low-risk population exists who might benefit from an alternate approach.

METHODS

A prospective randomized clinical trial was performed comparing oral ciprofloxacin 750 mg plus clindamycin 600 mg every 8 hours with IV aztreonam 2 g plus clindamycin 600 mg every 8 hours for the empiric outpatient treatment of febrile episodes in low-risk neutropenic patients with cancer.

RESULTS

The oral regimen cured 35 of 40 episodes (88% response rate), whereas the IV regimen cured 41 of 43 episodes (95% response rate, P = 0.19). Although the cost of the oral regimen was significantly less than that of the IV regimen (P < 0.0001), it was associated with significant renal toxicity (P < 0.05), which led to early termination of the study. Overall, combining its safety and efficacy, the IV regimen was superior (P = 0.03).

CONCLUSIONS

This prospective study suggested that outpatient antibiotic therapy for febrile episodes in low-risk neutropenic patients with cancer is safe and effective. Better oral regimens are needed.

A randomized study of intermediate versus conventional-dose cytarabine as intensive induction for acute myelogenous leukaemia

The optimal dose of cytarabine for induction chemotherapy is unknown. Most studies have utilized doses of 100-200 mg/m2/d, although higher doses have been proposed to increase the concentration of the active metabolite ara-CTP within leukaemia cells. To address this question 101 adults with newly diagnosed acute myeloid leukaemia were randomized to receive treatment with daunorubicin and either conventional-dose cytarabine (200 mg/m2/d by continuous infusion) or an intermediate-dose of cytarabine (500 mg/m2 every 12 h). 36/51 (71%) patients assigned to conventional-dose cytarabine achieved complete remission compared to 37/50 (74%) who achieved remission with intermediate-dose cytarabine (P = 0.9). Patient age significantly affected remission rate. 8/17 patients age greater than 60 assigned to conventional-dose cytarabine and 10/17 assigned to intermediate-dose cytarabine achieved complete remission compared to 27/33 patients under age 60 assigned to the conventional dose and 28/34 patients assigned to the intermediate dose arm (P = 0.004). Actuarial 4-year disease-free survival for patients assigned to conventional-dose cytarabine was 20 +/- 16% versus 28 +/- 17% for patients assigned to intermediate-dose cytarabine (P = 0.9). We conclude that intermediate dose cytarabine did not substantially improve results of induction chemotherapy for acute myeloid leukaemia.

Empiric Antimicrobial Therapy in the Febrile Granulocytopenic Patient

In the normal individual, about 100 billion polymorphonuclear leukocytes (neutrophils) enter the bloodstream daily from the bone marrow. About half of the intravascular neutrophils are adherent (marginated) to the endothelium of small vessels and the remainder are circulating. Without unusual disturbances, the half-life of the intravascular neutrophil is about six hours. Although the number of circulating neutrophils seems enormous, it represents only 5% of the total body content of these cells, the major portion residing in the bone marrow.

It is remarkable that quantitation of polymorphonuclear leukocytes in a drop of peripheral blood can be highly predictive of an individual's resistance and response to infectious diseases, especially those caused by bacteria. Neutrophil activity is complex and its role in host defense is dependent upon factors other than quantity. Nevertheless, when the absolute neutrophil count is maintained at values less than 1000/cu mm, increased susceptibility to infection occurs and is at a rate that is inversely proportional to the neutrophil count. When the count is decreased to values of 500 neutrophils/cu mm or less, the frequency of serious bacterial infection reaches a point where special attention must be directed to the patient at the earliest sign of infection.

Ofloxacin versus vancomycin/polymyxin for prevention of infections in granulocytopenic patients

INTRODUCTION

The efficacy and safety of oral ofloxacin were compared with those of vancomycin/polymyxin for prophylaxis of bacterial infections in granulocytopenic patients undergoing chemotherapy for hematologic malignancy.

PATIENTS AND METHODS

Antimicrobial prophylaxis was begun at the time of initiation of chemotherapy. Thirty patients received ofloxacin tablets (300 mg orally every 12 hours) plus a nystatin suspension. Thirty-two patients received vancomycin capsules (500 mg orally every eight hours) and polymyxin capsules (100 mg orally every eight hours) plus a nystatin suspension.

RESULTS

In the group of patients receiving ofloxacin, there were a lower number of acquired gram-negative bacillary organisms per patient (0.13 versus 1.37, p less than 0.00005), fewer patients with documented infection (11 of 30 versus 21 of 32, p = 0.04), and fewer cases of gram-negative septicemia (zero of 30 versus five of 32, p = 0.05). Ofloxacin was also better tolerated (24 of 30 versus 10 of 32 patients highly compliant, p = 0.01) and associated with fewer gastrointestinal side effects (one of 30 versus nine of 32 patients with gastrointestinal side effects, p = 0.01) than vancomycin/polymyxin. However, except for a reduction of Staphylococcus aureus colonization and infection by ofloxacin, neither ofloxacin nor vancomycin/polymyxin was effective in eliminating colonization or infection with viridans group streptococci, coagulase-negative staphylococci, or other gram-positive organisms. Only three isolates of ofloxacin-resistant gram-negative bacteria (Pseudomonas fluorescens, Pseudomonas putida, and Enterobacter aerogenes) were isolated from surveillance cultures, but none caused infection.

CONCLUSION

These results suggest that oral ofloxacin is a more tolerable and efficacious alternative to vancomycin/polymyxin for prevention of serious gram-negative bacillary infections in granulocytopenic patients. More effective prophylaxis of gram-positive infections, however, is still needed.