The role of vitamin B6 in the prevention of haematological toxic effects of linezolid in patients with cancer

BACKGROUND

Linezolid is the first approved synthetic oxazolidinone with activity against multidrug-resistant gram-positive pathogens. However, haematological toxic effects of linezolid frequently limit its prolonged use, especially in patients with poor marrow reserves such as those with cancer receiving chemotherapy. Previous authors have reported that administration of vitamin B6 with linezolid reversed pancytopenia in two patients.

METHODS

This is an open-label study of 31 patients with cancer who received linezolid at 600 mg twice daily and vitamin B6 at 50 mg/day for at least 2 weeks mean therapy duration and they were matched to 62 control patients who received linezolid without vitamin B6 to determine whether the concomitant use of vitamin B6 attenuates the haematological toxicity of linezolid in patients with cancer.

RESULTS

Patients were matched according to age, underlying disease, duration of therapy, creatinine level and use of chemotherapy. We found no significant differences in the rate of haematological toxic effects between the two patient groups. The rate of thrombocytopenia was 13% in the vitamin B6 group and 15% in the control group (P = 0.82). Also, the rate of leucopenia was 7% versus 5%, respectively (P = 0.75). None of the patients in the vitamin B6 group had anaemia compared with 5% in the control group.

CONCLUSIONS

Vitamin B6 given at 50 mg/day may have an impact on anaemia but did not prevent linezolid-induced thrombocytopenia or leucopenia in cancer patients.

Sources and outcome of bloodstream infections in cancer patients: the role of central venous catheters

Simultaneously drawn quantitative blood cultures are used to diagnose catheter-related bloodstream infections. We conducted this study to determine the frequency with which central venous catheters were the source of bloodstream infections detected through paired positive blood cultures drawn from cancer patients and the potential for quantitative blood cultures to help predict outcome in neutropenic and non-neutropenic patients. From September 1999 to November 2000, we identified 169 patients with bloodstream infections. Of all bloodstream infections, 56% were catheter-related bloodstream infections. Gram-positive bacteremia was found to be catheter-related in 55% and 69% of patients with hematologic malignancy and solid tumors, respectively, whereas gram-negative bacteremia was catheter-related in only 19% of patients with underlying hematologic malignancy and in 60% of patients with solid tumor (P = 0.01). By multivariate analysis, poor response was associated with critical illness and persistent neutropenia (P < 0.01). In neutropenic patients with catheter-related bloodstream infections, peripheral quantitative blood cultures of >or=100 CFU/mL was also associated with poor response (P = 0.05). Central venous catheters were the major source of bloodstream infection, particularly in patients with solid tumors. In addition to critical illness and persistent neutropenia, quantitative blood cultures might be useful in predicting outcomes for neutropenic patients with catheter-related bloodstream infections.

Bacteraemia in febrile neutropenic cancer patients

A total of 2142 patients with febrile neutropenia resulting from cancer chemotherapy were registered in two observational studies and followed prospectively in different institutions. There were 499 (23%) patients with bacteraemia who are reviewed here. The relative frequencies of Gram-positive, Gram-negative and polymicrobial bacteraemias were 57%, 34% and 10% with respective mortality rates of 5%, 18% and 13%. Mortality rates were significantly higher in bacteraemic patients than in non-bacteraemic patients; a trend for higher mortality was observed (without reaching statistical significance) in those patients in whom bacteraemia was associated with a clinical site of infection compared to bacteraemic patients without any clinical documentation. Prophylactic antibiotics but not granulopoiesis stimulating factors were associated with a lower incidence of Gram-negative bacteraemia; however, neither prophylactic approach influenced the subsequent rate of complications in the patients who developed bacteraemia. The present study also confirms that the MASCC scoring system can identify a group of bacteraemic patients with a relatively low risk of complications and death (MASCC >/=21). On the other hand, in patients with very low levels of the MASCC score (<15), and then with predicted very unfavourable risk, the rate of complications and death was dramatically high, irrespective of the microbiological nature of the bacteraemia.

blaVIM-2 and blaVIM-7 carbapenemase-producing Pseudomonas aeruginosa isolates detected in a tertiary care medical center in the United States: report from the MYSTIC program

Two Pseudomonas aeruginosa strains resistant to beta-lactams, fluoroquinolones, aminoglycosides, tetracyclines, and carbapenems and susceptible only to polymyxin B (MIC <or= 2 microg/ml) were identified as part of the Meropenem Yearly Susceptibility Test Information Collection program. Metallo-beta-lactamase screening tests were positive, PCR yielded products with blaVIM primers, and sequence analysis revealed blaVIM-7 and blaVIM-2. The isolates had distinct ribotype and pulsed-field gel electorphoresis patterns and appeared independently, remote in time and location, at the same cancer center.

Overview of systemic fungal infections

A steady increase in the frequency of invasive fungal infections has been observed in the past 2 decades, particularly in immunosuppressed patients. In recipients of bone marrow transplants, Candida albicans and Aspergillus fumigatus remain the primary pathogens. In many centers, however, Candida species other than C albicans now predominate, and many cases of aspergillosis are due to species other than A fumigatus. Additionally, heretofore unrecognized and/or uncommon fungal pathogens are beginning to emerge, including Blastoschizomyces capitatus, Fusarium species, Malassezia furfur, and Trichosporon beigelii. These opportunistic fungal pathogens are associated with various localized and disseminated clinical syndromes, and with substantial morbidity and mortality. These established, invasive mycoses, particularly in bone marrow transplant recipients, are the focus of this discussion.

Treatment of vancomycin-resistant enterococcal infections in the immunocompromised host: quinupristin-dalfopristin in combination with minocycline

Between February 1994 and November 1998, 56 oncology patients infected with vancomycin-resistant enterococci (VRE) were treated with quinopristin-dalfopristin (Q-D) plus minocycline (MIN). Infections included bacteremia, urinary tract infection, pneumonia, and wound infection. The response rate was 68%, and the most frequent adverse event was arthralgia or myalgia (36%). Q-D-MIN is effective for VRE infection in cancer patients but is associated with a substantial frequency of arthralgia or myalgia.

Respiratory syncytial virus infections in autologous blood and marrow transplant recipients with breast cancer: combination therapy with aerosolized ribavirin and parenteral immunoglobulins

Scant data are available concerning the impact and response to therapy of respiratory syncytial virus (RSV) infections in patients undergoing autologous blood and marrow transplantation (BMT) for breast cancer. During eight winter seasons from 1992-1993 to 1999-2000, nine (4%) of 249 such patients were hospitalized with RSV infections. Six patients, including all five patients who were early post transplant in the pre-engraftment period, developed pneumonia and were treated with a combination of aerosolized ribavirin and IVIG. Among five patients with pneumonia in whom therapy was initiated prior to respiratory failure, one (20%) died. The sixth patient, in whom therapy was initiated after respiratory failure developed, also died. In total, two (1%) patients, both of whom were in the pre-engraftment period, died of progressive pneumonia. In conclusion, RSV is a significant cause of life-threatening pneumonia in autologous BMT recipients with breast cancer during the early post-transplant period, and accounted for a substantial portion of the overall transplant-related mortality, which in recent years has been minimal.

Cytomegalovirus pneumonia in adult autologous blood and marrow transplant recipients

CMV pneumonia is a major cause of morbidity and mortality among allogeneic BMT recipients. To assess the frequency, timing, risk factors and response to therapy of CMV pneumonia among autologous BMT recipients, we reviewed our experience with 795 patients. Sixteen (2%) patients were diagnosed with CMV pneumonia. The frequency was higher among patients who were seropositive than those who were seronegative (3.3% vs 0%, P = 0.008). Among seropositive patients, the frequency was higher among patients with hematological malignancies than patients with solid tumors (5.0 % vs 1.0%, P = 0.019). Eleven cases occurred <30 days, and five cases occurred >100 days post transplant. The overall CMV pneumonia-related mortality rate was 31%. Seven (78%) of nine patients treated with ganciclovir and IVIG prior to respiratory failure survived; neither of two patients treated after respiratory failure survived. Four of five (80%) untreated patients survived. In conclusion, CMV is a not infrequent cause of pneumonia among autologous BMT recipients. Risk factors include CMV seropositivity and an underlying hematological malignancy. A favorable response hinges on the prompt initiation of therapy. The survival of 25% of the patients without antiviral therapy suggests that the isolation of CMV from a BAL specimen occasionally reflects oropharyngeal contamination or that CMV pneumonia may sometimes be self-limited in more immunocompetent autologous BMT recipients.

Cytomegalovirus pneumonia in adults with leukemia: an emerging problem

Cytomegalovirus (CMV) pneumonia is reportedly unusual among adults with leukemia who have not undergone transplantation. To assess the frequency of CMV pneumonia and its outcome during the present time, we reviewed the experience of 2136 hospitalized adults with leukemia. Sixty-one patients (2.9%) had CMV pneumonia diagnosed. The frequency doubled from 1.4% in 1992--1994 to 2.8% in 1995--1997 (P<.05). Fifty-four patients (89%) had received treatment with an immunosuppressive chemotherapeutic regimen that contained fludarabine (n=37), high-dose cytoxan (n=17), or both (n=10), and 15 patients (25%) had received granulocyte transfusions that were stimulated with hematopoietic growth factors from unscreened donors. The overall CMV pneumonia--associated mortality rate was 57%. Among autopsied patients who had leukemia, the frequency of CMV pneumonia increased from 0%, 2.3%, and 0% in 1992, 1993, and 1994, respectively, to 4.6%, 6.5%, and 16% in 1995, 1996, and 1997, respectively (P<.05). CMV has emerged as an important cause of life-threatening pneumonia in adults with leukemia who have received potent immunosuppressive therapies and stimulated granulocyte transfusions from unscreened donors.

Comparison of amphotericin B lipid complex (ABLC) vs. ambisome in the treatment of suspected or documented fungal infections in patients with leukemia

Fungal infections remain a major cause of treatment failure and death in acute leukemia. New liposomal preparations of amphotericin B are now available. While less toxic, their comparative efficacy and toxicity profiles are unknown. In this study the comparative efficacy and safety of ABLC vs. AmBisome was evaluated in seventy-five patients with leukemia who developed 82 episodes of suspected or documented mycosis, and were treated (1:1) with either ABLC (n=43) or AmBisome (n=39). Both drugs were dosed accordingly from 3 to 5 mg/kg/day. Using an intent-to-treat analysis, the overall response to therapy was 27/43 (63%) for ABLC and 15/39 (39%) for AmBisome (p=0.03). Median dose and duration of treatment was 10 days at 3 mg/kg for ABLC and 15 days at 4 mg/kg for AmBisome. Acute, not dose-limiting infusion side effects were seen in 70% vs. 36% (p=0.002), ABLC vs. AmBisome. Increase of bilirubin > 1.5 times from baseline was 38% vs. 59%, ABLC vs. AmBisome (p=0.05). ABLC and AmBisome were equally effective for the treatment of suspected or documented fungal infections. While, acute infusion-toxicity was greater with ABLC, infusion toxicity requiring discontinuation was similar for both drugs. AmBisome was better tolerated than ABLC but was associated with mild abnormalities in liver function tests at the end of therapy.

Time to clinical response: an outcome of antibiotic therapy of febrile neutropenia with implications for quality and cost of care

PURPOSE

To determine whether antibiotic regimens with similar rates of response differ significantly in the speed of response and to estimate the impact of this difference on the cost of febrile neutropenia.

METHODS

The time point of clinical response was defined by comparing the sensitivity, specificity, and predictive values of alternative objective and subjective definitions. Data from 488 episodes of febrile neutropenia, treated with either of two commonly used antibiotics (coded A or B) during six clinical trials, were pooled to compare the median time to clinical response, days of antibiotic therapy and hospitalization, and estimated costs.

RESULTS

Response rates were similar; however, the median time to clinical response was significantly shorter with A-based regimens (5 days) compared with B-based regimens (7 days; P =.003). After 72 hours of therapy, 33% of patients who received A but only 18% of those who received B had responded (P =.01). These differences resulted in fewer days of antibiotic therapy and hospitalization with A-based regimens (7 and 9 days) compared with B-based regimens (9 and 12 days, respectively; P <.04) and in significantly lower estimated median costs ($8,491 v $11,133 per episode; P =.03). Early discharge at the time of clinical response should reduce the median cost from $10,752 to $8,162 (P <.001).

CONCLUSION

Despite virtually identical rates of response, time to clinical response and estimated cost of care varied significantly among regimens. An early discharge strategy based on our definition of the time point of clinical response may further reduce the cost of treating non-low-risk patients with febrile neutropenia.

The Multinational Association for Supportive Care in Cancer risk index: A multinational scoring system for identifying low-risk febrile neutropenic cancer patients

PURPOSE

Febrile neutropenia remains a potentially life-threatening complication of anticancer chemotherapy, but some patients are at low risk for serious medical complications. The purpose of this study was to develop an internationally validated scoring system to identify these patients.

MATERIALS AND METHODS

Febrile neutropenic cancer patients were observed in a prospective multinational study. Independent factors assessable at fever onset, predicting low risk of complications, on a randomly selected derivation set, were assigned integer weights to develop a risk-index score, which was subsequently tested on a validation set.

RESULTS

On the derivation set (756 patients), predictive factors were a burden of illness indicating absence of symptoms or mild symptoms (weight, 5; odds ratio [OR], 8.21; 95% confidence interval [CI], 4.15 to 16.38) or moderate symptoms (weight, 3; OR, 3.70; 95% CI, 2.18 to 6.29); absence of hypotension (weight, 5; OR, 7.62; 95% CI, 2.91 to 19.89); absence of chronic obstructive pulmonary disease (weight, 4; OR, 5. 35; 95% CI, 1.86 to 15.46); presence of solid tumor or absence of previous fungal infection in patients with hematologic malignancies (weight, 4; OR, 5.07; 95% CI, 1.97 to 12.95); outpatient status (weight, 3; OR, 3.51; 95% CI, 2.02 to 6.04); absence of dehydration (weight, 3; OR, 3.81; 95% CI, 1.89 to 7.73); and age less than 60 years (weight, 2; OR, 2.45; 95% CI, 1.51 to 4.01). On the validation set, a Multinational Association for Supportive Care in Cancer risk-index score >/= 21 identified low-risk patients with a positive predictive value of 91%, specificity of 68%, and sensitivity of 71%.

CONCLUSION

The risk index accurately identifies patients at low risk for complications and may be used to select patients for testing therapeutic strategies that may be more convenient or cost-effective.

Efficacy and safety of sibutramine in obese white and African American patients with hypertension: a 1-year, double-blind, placebo-controlled, multicenter trial

BACKGROUND

Obesity is a highly prevalent medical condition and is commonly accompanied by hypertension. This study assessed the efficacy and safety of treatment with sibutramine hydrochloride for promoting and maintaining weight loss in obese patients with controlled hypertension, including a subset analysis of African American patients.

PATIENTS AND METHODS

Obese patients with a body mass index (BMI, calculated as weight in kilograms divided by the square of height in meters) between 27 and 40 and a history of hypertension controlled with a calcium channel blocker (with or without concomitant thiazide diuretic treatment) were randomized to receive sibutramine (n = 150) or placebo (n = 74) with minimal behavioral intervention for 52 weeks. African Americans constituted 36% of enrolled patients. Efficacy assessments were body weight and related parameters (BMI and waist and hip circumferences), metabolic parameters (serum levels of triglycerides, high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], total cholesterol, glucose, and uric acid), and quality-of-life measures. Safety assessments included recording of blood pressure, pulse rate, adverse events, and reasons for discontinuation.

RESULTS

For patients receiving sibutramine, weight loss occurred during the first 6 months of the trial and was maintained to the end of the 12-month treatment period. Among patients receiving sibutramine, 40.1% lost 5% or more of body weight (5% responders) and 13.4% lost 10% or more of body weight (10% responders) compared with 8.7% and 4.3% of patients in the placebo group, respectively (P<.05). Changes in body weight were similar among African Americans and whites. Sibutramine-induced weight loss was associated with significant improvements in serum levels of triglycerides, HDL-C, glucose, and uric acid. Waist circumference and quality-of-life measures also improved significantly in patients receiving sibutramine. Sibutramine-treated patients had small but statistically significant mean increases in diastolic blood pressure (2.0 mm Hg) and pulse rate (4.9 beats/min) compared with placebo-treated patients (-1.3 mm Hg and 0.0 beats/min; P<.05); these changes were similar among African Americans and whites. Most adverse events were mild to moderate in severity and transient. The most common adverse event resulting in discontinuation among patients receiving sibutramine was hypertension (5.3% of patients receiving sibutramine vs 1.4% of patients receiving placebo).

CONCLUSIONS

In obese patients with controlled hypertension, sibutramine was an effective and well-tolerated treatment for weight loss and maintenance. Sibutramine-induced weight loss resulted in improvements in serum levels of triglycerides, HDL-C, uric acid, and glucose, and in waist circumference and quality-of-life measures. Blood pressure and heart rate increased by a small amount. Efficacy and safety profiles for sibutramine among African American and white obese patients with controlled hypertension were similar.

Respiratory syncytial virus upper respiratory tract illnesses in adult blood and marrow transplant recipients: combination therapy with aerosolized ribavirin and intravenous immunoglobulin

Respiratory syncytial virus (RSV) is an important cause of serious respiratory illness in blood and marrow transplant (BMT) recipients. In some subsets of these immunocompromised patients, RSV upper respiratory illnesses frequently progress to fatal viral pneumonia. The frequency of progression to pneumonia is higher during the pre-engraftment than during the post-engraftment period. Once pneumonia develops, the overall mortality is 60-80%, regardless of the treatment strategy. We performed a pilot trial of therapy of RSV upper respiratory illnesses using aerosolized ribavirin and IVIG (500 mg/kg every other day), with the goal of preventing progression to pneumonia and death. Two dosages of ribavirin were used: a conventional regimen (6 g/day at 20 mg/ml for 18 h/day) and a high-dose short-duration regimen (6 g/day at 60 mg/ml for 2 h every 8 h). Fourteen patients were treated for a mean of 13 days (range: 7-23 days). In 10 (71%) patients, the upper respiratory illness resolved. The other four (29%) patients, three of whom were in the pre-engraftment period, developed pneumonia, which was fatal in two. The most common adverse effect was psychological distress at being isolated within a scavenging tent. In conclusion, prompt therapy of RSV upper respiratory illnesses in BMT recipients with a combination of aerosolized ribavirin and IVIG was a safe and promising approach to prevent progression to pneumonia and death.

Susceptibility surveillance among gram-negative bacilli at a cancer center

We conducted a survey of susceptibility among 758 gram-negative bacilli (GNB; collected from cancer patients over a 3-month period) to commonly used antibiotics. The overall resistance among GNB was least for piperacillin/tazobactam and meropenem (5 and 6%, respectively) followed by cefepime (8%), imipenem (9%), amikacin (12%), ofloxacin (13%), ciprofloxacin, ceftazidime and ticarcillin/clavulanate (14% each), aztreonam (18%) and tobramycin (24%). In comparison to data on antibiotic resistance to ceftazidime, imipenem, ciprofloxacin and aztreonam in similar studies in 1985 and 1994, resistance has significantly increased to all four antibiotic classes. Based on our current study, meropenem, cefepime, imipenem and piperacillin/tazobactam would be the most appropriate choices in our institution for empiric therapy of GNB infections in febrile neutropenic patients.

Late cytomegalovirus pneumonia in adult allogeneic blood and marrow transplant recipients

To assess the impact of antiviral prophylaxis during the first 3 months after transplantation on the frequency, timing, and outcome of cytomegalovirus (CMV) pneumonia during the first year, 541 adult allogeneic blood and marrow transplant recipients were evaluated. Thirty-four patients (6.3%) developed 35 episodes of CMV pneumonia at a mean of 188 days after transplantation, with an associated mortality rate of 76%. Twenty-six episodes (74%) occurred late (after day 100). Of the patients with late CMV pneumonia almost all (92%) had chronic graft vs. host disease or had received T cell-depleted transplants. Fourteen late CMV pneumonias (54%) were associated with serious concurrent infections, and 100% of these episodes were fatal. In conclusion, although the frequency of CMV pneumonia in the early posttransplantation period may be substantially reduced by prophylaxis, CMV continues to be a major cause of morbidity and mortality in the late period. Some subsets of patients need more prolonged surveillance and prophylaxis and/or preemptive therapy.

Clinical and radiological features of pulmonary disease caused by rapidly growing mycobacteria in cancer patients

The role of rapidly growing mycobacteria in the pathogenesis of pulmonary disease is being increasingly recognized; however, the clinical significance of these mycobacteria in patients with underlying malignancy has not been well studied. Over a 6-year period, 37 cancer patients with rapidly growing mycobacteria isolated from respiratory specimens were identified at our center. Mycobacterium chelonae group was isolated in 24 cases and Mycobacterium fortuitum in 13 cases. Of the 24 cases with cultures yielding Mycobacterium chelonae group, eight met the study criteria for infection and were determined to be clinically significant, whereas only one of the Mycobacterium fortuitum isolates was determined to represent infection. An average of two antimicrobial agents were used for treatment, most commonly clarithromycin, ciprofloxacin, and trimethoprim/sulfamethoxazole. Although the isolation of rapidly growing mycobacteria represents colonization in most cases, these bacteria, especially the Mycobacterium chelonae group, may cause pulmonary disease in cancer patients. The clinical and radiological findings are usually non-specific in this population, and patients with respiratory cultures yielding rapidly growing mycobacteria should be assessed carefully to distinguish infection from colonization. Effective therapy can be provided with oral regimens that include at least two antibiotics to which the organism is susceptible.

Staphylococcus epidermidis: emerging resistance and need for alternative agents

Previously, Staphylococcus epidermidis and other coagulase-negative staphylococci isolated from the blood of hospitalized patients were often considered contaminants. Now, coagulase-negative staphylococci are among the leading causes of nosocomial blood infections. Multidrug resistance could predict a true nosocomial infection rather than a blood culture contaminant. Recent studies indicated the emergence of resistance to the quinolones, particularly to ciprofloxacin. Tolerance and occasional resistance to vancomycin have been reported recently. In addition, several reports indicated that vancomycin and other glycopeptide antibiotics lose their effectiveness against S. epidermidis organisms embedded in the biofilm environment on the surface of medical devices. Alternative agents have been proposed in the prevention and treatment of device-related and glycopeptide-tolerant S. epidermidis infections. These agents include minocycline, rifampin, and, more recently, quinupristin/dalfopristin and the oxazolidinones.

Influenza among hospitalized adults with leukemia

Influenza is one of the most important respiratory diseases of mankind, yet scant data exist concerning the frequency and clinical course of influenza in severely immunocompromised adults. From October 1993 to September 1994, we cultured the respiratory secretions of all adults with leukemia who were hospitalized with an acute respiratory illness at The University of Texas M.D. Anderson Cancer Center in Houston. During a 9-week period from 29 November 1993 to 29 January 1994, influenza virus type A (H3N2) was isolated from 15 (33%) of these 45 hospitalized adults. Twelve (80%) of the cases of influenza were associated with pneumonia, and four patients (33%) with pneumonia died. Patients who died tended to have received chemotherapy more recently and to be more myelosuppressed. Autopsy examination in two cases revealed histopathologic changes consistent with viral pneumonia. During community outbreaks, influenza is a frequent cause of serious respiratory disease in hospitalized adults with leukemia. Effective prophylactic and therapeutic regimens need to be defined for immunocompromised patients.

Respiratory disease due to parainfluenza virus in adult bone marrow transplant recipients

We reviewed the frequency and clinical course of parainfluenza virus (PIV) infections in 1,173 adult bone marrow transplant (BMT) recipients cared for at The University of Texas M.D. Anderson Cancer Center (Houston). Between January 1991 and September 1994, PIV was isolated from the respiratory secretions of 61 (5.2%) of these patients. Thirty-four (56%) of the 61 patients had uncomplicated upper respiratory tract illnesses and survived. The remaining 27 patients (44%) developed pneumonia, and the associated mortality was 37% (10 of 27 patients). Twenty-three (85%) of the patients with pneumonia had had preceding upper respiratory illnesses. Of the 10 patients who died, nine died within 100 days after transplantation. Histopathologic examination of lung tissue from seven patients revealed intracytoplasmic viral inclusions in six, a finding consistent with invasive PIV pneumonia, and viral changes in the seventh patient. Seven of the 10 patients who died had other serious concurrent infections. Of 42 patients who developed PIV infection early after transplantation (i.e., < 100 days), the frequency of pneumonia was higher among the 18 allogeneic BMT recipients (61%) than among the 24 autologous BMT recipients (42%), and the associated mortality was also higher (55% vs. 30%, respectively). PIVs are an important cause of life-threatening pneumonia in adult BMT recipients, particularly patients who have recently undergone allogeneic bone marrow transplantation.

Imipenem or cefoperazone-sulbactam combined with vancomycin for therapy of presumed or proven infection in neutropenic cancer patients

The purpose of this prospective randomized study was to compare the efficacy and safety of imipenem and cefoperazone-sulbactam combined with vancomycin for the treatment of fever in neutropenic cancer patients. Patients were assigned to either imipenem 500 mg/m2 (500 mg for bone marrow transplant recipients) every 6 h or cefoperazone (2 g)-sulbactam (1 g) every 8 h All patients received vancomycin 1 g every 12 h. A total of 457 febrile or infectious episodes occurring in 407 patients were entered in the study. The response rate was 73% for imipenem plus vancomycin and 74% for cefoperazone-sulbactam plus vancomycin among the 369 episodes that could be evaluated. Response rates were comparable for the two regimens with regard to infecting organism, administration of antimicrobial prophylaxis, and neutrophil count and trend. The frequency of side-effects was significantly higher for imipenem plus vancomycin (11% vs.5%, p = 0.02), due to therapy-associated nausea and vomiting (5.3% vs. 0%, p = 0.0004). The overall frequency of superinfections was similar with both regimens, but Clostridium difficile colitis occurred significantly more often in patients receiving imipenem plus vancomycin (5 vs. 0, p = 0.02). In this study cefoperazone-sulbactam plus vancomycin was an effective alternative to imipenem plus vancomycin for initial therapy of fever in neutropenic patients.

Subcutaneous Nocardia asteroides abscess in a bone marrow transplant recipient

We describe a case of cutaneous Nocardia asteroides infection in a 13-year-old Venezuelan boy with aplastic anemia, following allogeneic BMT. He was receiving immunosuppressive therapy with corticosteroids for GVHD and trimethoprim/sulfamethoxazole (TMP/SMX) for prophylaxis against Pneumocystis carinii pneumonia (PCP). He was not neutropenic and gave no history of cutaneous inoculation or trauma. He developed an abscess on the plantar surface of his right big toe from which Nocardia asteroides was isolated. He was successfully treated with a combination of TMP/SMX and minocycline. Despite prolonged immunosuppressive therapy for GVHD, the infection responded and did not recur. TMP/SMX prophylaxis for PCP in BMT recipients with GVHD does not always prevent nocardial infection but may prevent or delay the development of dissemination.

Outpatient management of febrile episodes in neutropenic cancer patients

Febrile neutropenic patients have traditionally received hospital-based parenteral antibiotic therapy because of the risk of serious complications and associated mortality. Recently a low-risk subset among febrile neutropenic patients has been identified. Several alternatives to hospital-based therapy have been evaluated in such patients. These include early discharge to home antibiotic therapy after initial stabilization in the hospital, or treatment of the entire febrile episode with intravenous and/or oral antibiotics in an ambulatory setting. A multidisciplinary approach involving the physician and other health-care providers, the patients, and their families, ensures the success of this therapeutic modality. Careful patient selection, daily follow-up, close monitoring for the development of complications and/or adverse reactions, and informed consent along with detailed instructions to patients, minimize the risk of the development of serious complications. Outpatient antibiotic therapy for febrile episodes in low-risk neutropenic patients should now be considered an acceptable alternative to hospital-based therapy.

A changing pattern of susceptibility of Xanthomonas maltophilia to antimicrobial agents: implications for therapy

The in vitro susceptibilities of 130 Xanthomonas maltophilia isolates to 12 antibiotics--trimethoprim-sulfamethoxazole, minocycline, ticarcillin-clavulanate, ceftazidime, cefoperazone, cefoperazone-sulbactam, imipenem, ciprofloxacin, and the investigational quinolones PD 117558, PD 117596, PD 127391, and sparfloxacin--were determined by a microtiter broth dilution technique. Other than the investigational quinolones, the most active antibiotics were minocycline, trimethoprim-sulfamethoxazole, and ticarcillin-clavulanate, in order. However, the first two were not bactericidal, while about half of the isolates exhibited intermediate susceptibility to ticarcillin-clavulanate. Patterns of susceptibility to trimethoprim-sulfamethoxazole and ciprofloxacin relative to the years of isolation of these strains reflected the development of resistance to the antibiotic prophylaxis practices in the hospital. We recommend that a combination of antibiotics, such as trimethoprim-sulfamethoxazole, minocycline, and ticarcillin-clavulanate, at or close to the maximum tolerated doses be in the treatment of serious X. maltophilia infections.

In vitro susceptibilities of rapidly growing mycobacteria to newer antimicrobial agents

The in vitro antimicrobial susceptibilities of 42 isolates of rapidly growing mycobacteria (Mycobacterium fortuitum, M. chelonae, and Mycobacterium species [other than M. fortuitum and M. chelonae]) to nine quinolones, including newer agents, two new aminoglycosides, and an aminocyclitol (trospectomycin) were determined by a broth microdilution method. The new quinolones, PD 117596, PD 127391, and PD 117558, showed excellent in vitro activities against M. fortuitum (MICs for 90% of isolates [MIC90s], 0.06, 0.06, and 0.12 microgram/ml, respectively). The MIC90 of ciprofloxacin for M. fortuitum was 0.5 microgram/ml. Only 14 to 28% of isolates of M. chelonae were susceptible to various quinolones. Most isolates of all three species were susceptible to the new aminoglycosides SCH 21420 and SCH 22591. The MIC90s of trospectomycin were 8 micrograms/ml for M. chelonae, 32 micrograms/ml for Mycobacterium species, and > 64 micrograms/ml for M. fortuitum.

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.

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.

In vitro antimicrobial susceptibilities of Nocardia species

The in vitro activities of various quinolones, two new aminoglycosides, a new cephamycin analog (cefmetazole) and a new spectinomycin analog (trospectomycin), imipenem, and trimethoprim-sulfamethoxazole against 26 isolates of Nocardia asteroides, 7 isolates of N. brasiliensis, and 6 isolates of N. caviae were determined by a broth microdilution method. The three new quinolones, PD 117558, PD 117596 and PD 112739, inhibited 90% of N. asteroides at 1 to 2 micrograms/ml, and two new aminoglycosides, SCH 21420 and SCH 22591, inhibited 90% of N. asteroides at 2 to 4 micrograms/ml. Among the beta-lactams, cefmetazole was more active than imipenem. N. brasiliensis and N. caviae isolates were also very susceptible to the three quinolones (MICs for 50% of the isolates, 0.25 to 1 microgram/ml) and the two aminoglycosides (MICs for 50% of the isolates, 1 to 2 micrograms/ml). Cefmetazole was moderately active against N. brasiliensis, whereas imipenem showed poor activity against both of these species.

In vitro susceptibility of Xanthomonas (Pseudomonas) maltophilia to newer antimicrobial agents

The susceptibilities of 45 clinical and 3 environmental isolates of Xanthomonas maltophilia to 14 antimicrobial agents was determined by broth microdilution. The newer quinolones PD117596, PD117558, PD127391, A-56620, amifloxacin, and fleroxacin were the most active agents tested, with 70 to 99% of isolates being susceptible to these agents. All isolates were resistant to trospectomycin. The new aminoglycosides SCH24120 and SCH22591 were active against 12 and 1% of isolates, respectively.

Prophylaxis of candidiasis in cancer patients

Patients undergoing therapy for metastatic malignancies were randomly assigned to receive fluconazole or placebo as antifungal prophylaxis. Oropharyngeal candidiasis developed in 28% of 54 evaluable patients receiving placebo but in only 2% of 58 evaluable patients receiving fluconazole (P = .0003). Among patients receiving placebo, oropharyngeal candidiasis (thrush) occurred in 30% of those receiving antibiotic therapy and in 44% of those receiving adrenal corticosteroid therapy. Oropharyngeal candidiasis developed in 54% of the placebo patients who were colonized by Candida sp at the onset of prophylaxis. Fluconazole proved to be effective for prophylaxis of oropharyngeal candidiasis in susceptible patients and was well tolerated.

Prophylaxis of oropharyngeal candidiasis with fluconazole

A total of 112 cancer patients who could ultimately be evaluated were randomly assigned in a double-blind study to receive either fluconazole or placebo as antifungal prophylaxis during hospitalization. Thrush, defined by appropriate lesions in the oropharynx and confirmed by scrapings and cultures positive for Candida species, occurred in 2% of the 58 patients given fluconazole and in 28% of the 54 patients given placebo (P = .0003). Candida species were cultured from initial throat specimens from 29 patients given fluconazole and from 26 patients given placebo. Oropharyngeal candidiasis was detected subsequently in 3% of the former patients and 54% of the latter patients (P = .0001). Adverse reactions that were probably due to or aggravated by fluconazole occurred in only four patients and consisted of transient liver function abnormalities in three instances and nausea and vomiting in one. Oral fluconazole is an effective agent for prophylaxis of oropharyngeal candidiasis in susceptible cancer patients.

Beta-lactam regimens for the febrile neutropenic patient

A total of 535 evaluable febrile episodes in neutropenic patients were randomly assigned to treatment with ticarcillin-clavulanate plus vancomycin (TV), ceftazidime plus vancomycin (CV), or all three antibiotics (TCV). The TCV regimen was significantly more effective than TV, considering all evaluable episodes, documented infections, gram-negative infections, and infections in patients with persistent severe neutropenia (less than 100 neutrophils/mm3). The results with CV were intermediate between TV and TCV. The toxicities were similar with all three regimens and consisted primarily of skin rashes. The TCV regimen is effective for empiric therapy of fever in neutropenic patients and probably should be utilized in preference to CV or TV, although its superiority over CV in this study was inconclusive.

Comparative in-vitro activity of twenty antimicrobial agents against clinical isolates of Mycobacterium avium complex

The in-vitro susceptibility of Mycobacterium avium complex isolates, obtained from immunosuppressed patients with and without the Acquired Immunodeficiency Syndrome (AIDS), to various antimicrobial agents was determined. Amikacin, the 4-quinolone compounds--ciprofloxacin, temafloxacin and PD 117558--and the penem SCH 34343 were active against most of the isolates. In-vitro synergism using selected antimicrobial combinations could not be demonstrated. No differences in the susceptibility, depending upon the source of the isolates (AIDS or non-AIDS), were noted.

Cutaneous Rhizopus and Aspergillus infections in five patients with cancer

Primary cutaneous infection with Aspergillus species and Rhizopus species was observed in five patients between October 1986 and January 1988. All patients had an underlying hematological malignancy and were neutropenic. Four patients developed skin lesions with eschars at and around the site of intravenous catheter insertion. One patient had two lesions along the course of the intravenous line. The fifth patient developed the lesion on the left side of the lower part of the back subsequent to the appearance of a rash due to excessive perspiration. A diagnosis was made in each case by histopathological studies and cultures of skin biopsy specimens. The fungal organisms cultured were Aspergillus species in three patients and Rhizopus species in two patients. All patients were treated with amphotericin B. Three patients responded to antifungal therapy and local care without surgical débridgement. Two patients died of disseminated fungal infection. The development of cutaneous lesions due to opportunistic fungal pathogens seemed to have been related to the moist and humid conditions created by occlusive dressings or excessive perspiration.

New spectrum of fungal infections in patients with cancer

We report on 44 cancer patients who had serious infections with unusual fungal pathogens and who were cared for at our cancer center between 1974 and 1986. Twelve different fungal species accounted for these infections, including Trichosporon beigelii, Fusarium species, Geotrichum candidum, Curvularia species, Drechslera species, Penicillium species (but not Penicillium marneffei), Rhodotorula rubra, Pseudallescheria boydii, Pichia farinosa, Torulopsis pintolopesii, Saccharomyces cerevisiae, and Cunninghamella bertholletiae. Skin lesions were noted in seven patients, and sinusitis occurred in four. Twenty-four patients had disseminated infection, 12 had involvement of a single organ, and eight had fungemia alone. Features that correlated with a poor prognosis were persistent neutropenia and disseminated visceral infection but not fungemia alone. We suggest that unusual fungi have now emerged as significant pathogens in this patient population. Fungal sinusitis, previously caused by Aspergillus species and the phycomycetes, also occurs as a result of some of these newly recognized fungi. A high level of suspicion should be maintained when any of these unusual fungi are cultured from clinical specimens from immunocompromised patients.

In vitro activity of trospectomycin (U-63366F), a novel spectinomycin analog, against gram-positive isolates from cancer patients

The in vitro activity of trospectomycin was compared to that of amikacin, cephalothin and vancomycin against gram-positive organisms, mostly isolated from cancer patients. Trospectomycin was considerably more active than amikacin against most isolates tested, particularly species of Staphylococcus and Streptococcus. Overall, vancomycin was the most active agent tested.

Cefoperazone plus mezlocillin for empiric therapy of febrile cancer patients

Two dosing regimens of cefoperazone plus mezlocillin were compared in a prospective, randomized trial for therapy of febrile cancer patients. The two regimens were 5 g mezlocillin plus 2 g cefoperazone intravenously every four hours (higher dose) or 3 g mezlocillin plus 1 g cefoperazone intravenously every four hours (lower dose). Although the overall response rate was higher with the higher dose regimen (78 percent versus 66 percent, p = 0.04), the two regimens were comparable in patients with documented infections (72 percent versus 68 percent). Likewise, the two regimens were equally effective against those infections in which the pathogen could be determined (82 percent versus 82 percent). Serum bactericidal titers of at least 1:32 against a known pathogen were associated with a higher response rate than were titers of less than 1:32, but the higher dose regimen did not result in higher serum bactericidal titers. Hypoprothrombinemia was a side effect, especially with the higher dose regimen, before prophylactic vitamin K was routinely administered to patients. Since there were no major benefits with the use of the higher dose regimen of mezlocillin plus cefoperazone, the lower dose regimen is more appropriate for routine usage.

In vitro susceptibilities of Nocardia species to newer antimicrobial agents

The in vitro activities of various quinolones, two newer cephalosporins, and imipenem against 23 strains of Nocardia asteroides, 4 strains of Nocardia brasiliensis, and 4 strains of Nocardia caviae were determined by an agar dilution method. PD-117558, a newer carboxyquinolone, and imipenem were the most active agents tested, inhibiting 90% of N. asteroides isolates at an MIC of 2 micrograms/ml. Of the 23 strains of N. asteroides, 15 were susceptible to cefpirome and 10 were susceptible to ciprofloxacin. The N. brasiliensis and N. caviae strains were very susceptible to PD-117558 (MIC, less than or equal to 1 microgram/ml), moderately susceptible to ciprofloxacin, and resistant to most of the other tested drugs.

The emerging role of Fusarium infections in patients with cancer

Infection due to Fusarium species is an increasing cause of serious potentially fatal disease in patients with cancer. We described 9 patients with infection caused by Fusarium species during a 4-year period at the M. D. Anderson Hospital. The spectrum of infections included disseminated disease in 4 patients, skin or soft-tissue infections in 3, pneumonia in 1, and fungemia in 1. All 4 patients with disseminated infection had culture- and biopsy-proven skin lesions caused by Fusarium species and the blood cultures yielded the organism in 3 of these 4 patients. Maxillary sinusitis was the presenting manifestation of Fusarium infection in 2 of these 4 patients, suggesting that paranasal sinuses are potential portals of entry for the infection. Eight patients had a hematological malignancy and 7 were neutropenic at the onset of their infection. Patients with deep-seated infections remained neutropenic and died from infection despite treatment with amphotericin B. All 5 isolates tested in vitro showed resistance to ketoconazole and miconazole, whereas 3 were susceptible to amphotericin B. Fusarium species could play a role in producing myelosuppression and fungal cultures are required to differentiate it from the more commonly encountered Aspergillus species. Fusarium species are emerging as a serious, potentially fatal, pathogen in patients with cancer.

Randomized trial of beta-lactam regimens in febrile neutropenic cancer patients

A three-arm prospective randomized trial was designed to compare the efficacies of piperacillin plus vancomycin, ceftazidime plus vancomycin, or all three drugs as initial therapy for fever in neutropenic cancer patients. The objectives were to determine whether a broad-spectrum penicillin was as effective as a broad-spectrum cephalosporin and whether two beta-lactam antibiotics were more effective than one. Four hundred and seventy of the 519 febrile episodes entered in the study could be evaluated for response. Ceftazidime plus vancomycin was significantly more effective than piperacillin plus vancomycin, considering all febrile episodes (79 percent versus 61 percent, p = 0.001), documented infections (79 percent versus 57 percent, p = 0.004), gram-negative infections (88 percent versus 47 percent, p = 0.001), and bacteremias (81 percent versus 51 percent, p = 0.01). The addition of piperacillin to ceftazidime (piperacillin plus ceftazidime and vancomycin versus ceftazidime plus vancomycin) did not improve the response rate and was associated with a significantly higher incidence of skin rash. Vancomycin plus ceftazidime provides adequate antibiotic coverage for initial treatment of fever in neutropenic patients. This combination was equally effective, less expensive, and less toxic than the double beta-lactam combination used in this study.