Amiloride prevents amphotericin B related hypokalaemia in neutropenic patients.

Twenty neutropenic patients with various haematological disorders were randomised prospectively to receive either intravenous amphotericin B alone or amphotericin B and oral amiloride 5 mg twice a day for treatment of confirmed or suspected fungal infection. Patients receiving amiloride had a significantly higher plasma potassium (p less than 0.01), a significantly lower urinary potassium loss (p less than 0.01), and required significantly less potassium chloride supplementation to maintain their plasma potassium within the normal range (p less than 0.001). Amiloride was well tolerated, had no clinically important side effects, and provided effective control of plasma potassium in patients treated with amphotericin B.     

Renal impairment and amphotericin B formulations in patients with invasive fungal infections

A systematic review was performed to examine renal function in patients with invasive fungal infections, comparing the nephrotoxicity caused by conventional amphotericin B deoxycholate (c-AmB) with that induced by the use of lipid-based amphotericin B formulations. The analysis considered all comparative studies published in the literature between January 1996 and May 2007. The outcome data reviewed herein focused on renal toxicity as measured by serum creatinine (S-Cr) and the doubling or the mean difference in S-Cr levels from baseline to the end of therapy or the need for dialysis. We found that AmB lipid complex (ABLC), liposomal AmB (L-AmB) and AmB colloidal dispersion (ABCD) were significantly less nephrotoxic than c-AmB in all reported studies. ABLC and L-AmB caused low and comparable nephrotoxicity in nine studies. In one randomized study, L-AmB was significantly less nephrotoxic than ABLC. No studies compared ABCD nephrotoxicity to the other lipid formulations. Based on our review we conclude that lipid formulations of amphotericin B are an important strategy to preserve renal function and improve survival in critically ill patients who require treatment for systemic fungal infections.     

Comparative in vitro activity of LY121019 and amphotericin B against clinical isolates ofCandida species

LY121019 and amphotericin B were equally active in vitro against most clinical isolates ofCandida albicans andCandida tropicalis. Higher concentrations of LY121019 were required for inhibition ofCandida glabrata. OtherCandida species were inhibited by amphotericin B but not by LY121019.     

Guidelines for the management of deep mycosis in neutropenic patients]

Invasive fungal infections (IFIs) are a major cause of morbidity and mortality in neutropenic patients with leukemia and those undergoing hematopoietic stem cell transplant (HSCT). Two major IFIs are systemic candidiasis (including candidemia, chronic disseminated candidiasis and pneumonia) and invasive pulmonary aspergillosis. Recently, the incidence of the latter has been increasing. Three levels of diagnosis are specified in the Japanese guidelines for the diagnosis and treatment of IFIs. Proven fungal infections are diagnosed by histological/microbiological evidence of fungi at the site of infection or positive blood culture (fungemia). Clinically documented fungal infections are diagnosed by typical radiological findings such as halo sign on chest CT plus positive serological/molecular evidence of fungi such as Aspergillus galactomannan, beta-glucan or fungal DNA. Possible fungal infections are diagnosed by typical radiological findings or positive serological/molecular evidence of fungi. For patients with high risk such as those undergoing HSCT, antifungal prophylaxis using oral antifungal agents is recommended. For possible fungal infections, empiric therapy with fluconazole (FLCZ) or amphotericin B (AMPH) is recommended. For patients with proven fungal infections or clinically documented fungal infections, targeted therapy is warranted. In case of candidemia, the best choice is FLCZ (400 mg/day) or AMPH (0.5-0.7 mg/kg/day), and for invasive pulmonary aspergillosis, a higher dose of AMPH (1.0-1.5 mg/kg/day) is indicated. Micafungin (MCFG), recently licensed in Japan, is an active agent for both Candida and Aspergillus. This drug seems useful for empiric and targeted therapy of IFIs.     

Candida lusitaniae: frequency of recovery, colonization, infection, and amphotericin B resistance.

Candida lusitaniae recovered from 58 specimens from 13 patients represented less than 1% of the yeasts isolated over a 15-month period. The majority of isolates were recovered from respiratory tract, stool, and urine specimens. Of the 13 patients, 1 had a documented infection associated with septicema. Urine isolates from that patient developed resistance to amphotericin B during therapy.     

Prospective study of 288 episodes of bacteremia in neutropenic cancer patients in a single institution

Trends in causative organisms and sources of infection were studied in a series of 288 episodes of bacteremia in neutropenic cancer patients observed in a single institution from 1986 to 1993. The incidence of bacteremia increased significantly from 20 episodes per 1000 admissions in 1986 to 50 episodes per 1000 admissions in 1993 (p=0.00001). Over the study period, a continuous increment in gram-positive bacteremia, which reached 81% of episodes in 1993 (p=0.000001), was observed. Conversely, the incidence of gram-negative bacteremia remained stable. Coagulase-negative staphylococci and viridans group streptococci were the most commonly isolated pathogens. Bacteremia caused by coagulase-negative staphylococci increased from 3 episodes per 1000 admissions to 19 episodes per 1000 admissions (p=0.0001), and viridans group streptococci bacteremia increased from 0 episodes per 1000 admissions to 19 episodes per 1000 admissions (p=0.000001). The upward trend in gram-positive bacteremia appeared to be related to a significant increase in both intravascular catheters (p=0.003) and oral mucositis (p=0.003) as sources of infection. Specific strategies to prevent chemotherapy-induced mucositis and catheter-related bacteremia merit further investigations.     

Tolerance and efficacy of amphotericin B inhalations for prevention of invasive pulmonary aspergillosis in haematological patients

The tolerance of aerosolised amphotericin B as prophylaxis against invasive pulmonary aspergillosis was investigated in 61 granulocytopenic periods in 42 patients treated for a haematologic malignancy. Each patient was to receive amphotericin B in doses escalating to 10 mg three times daily (t.i.d.), but only 20 (48%) patients managed to complete the scheduled regimen. One patient tolerated the full dose initially, but had to discontinue treatment when dyspnea developed as a result of pneumonia and acute respiratory distress. Another 22 patients (52%) experienced side effects, including eight (19%) who reported mild coughing and dyspnea but who tolerated the full dose and three (7%) patients whose dose was reduced to 5 mg t.i.d. Another six (14%) patients could tolerate only 5 mg t.i.d., and five (12%) others stopped treatment because of intolerance. Elderly patients (p<0.05) and those with a history of chronic pulmonary obstructive disease (p=0.09) were more likely to develop side effects during inhalation. Twelve (28%) patients developed proven or possible invasive fungal infections, but no correlation was established between infection and the total amount of amphotericin B inhaled. Inhalation of aerosolised amphotericin B is poorly tolerated and does not appear useful in preventing invasive pulmonary aspergillosis in granulocytopenic patients.     

Prospective study of infection,colonization and carriage of methicillin-resistantStaphylococcus aureus in an outbreak affecting 990 patients

In the three years between November 1989 and October 1992, an outbreak of methicillin-resistantStaphylococcus aureus (MRSA) affected 990 patients at a university hospital. The distribution of patients with carriage, colonization or infection was investigated prospectively. Nosocomial acquisition was confirmed in at least 928 patients, 525 of whom were identified from clinical specimens as being infected (n=418) or colonized (n=107) by MRSA. An additional 403 patients were identified from screening specimens, of whom 58 subsequently became infected and 18 colonized. Screening of the nose, throat and perineum detected 98 % of all carriers. Of the 580 infections in 476 patients, surgical wound, urinary tract and skin infections accounted for 58 % of the infections. Of the 476 infected patients, death was attributable to MRSA infection in 13 %. Colonization with MRSA was found in 127 patients and 42 % of 165 colonized sites were the skin. Auto-infection from nasal carriage or cross-infection, probably via staff hands, seemed to be the most common mode of acquisition of MRSA infections.     

Determination of amphotericin B, liposomal amphotericin B, and amphotericin B colloidal dispersion in plasma by high-performance liquid chromatography.

Amphotericin B is a potent polyene antifungal drug for intravenous treatment of severe infections. It is used as amphotericin B-deoxycholate and in order to reduce amphotericin B toxicity as lipid-formulated complex (liposomal or colloidal dispersion). A sensitive and specific analytical method is presented for the separation of lipid-complexed and plasma protein-bound amphotericin B in human heparinized plasma. This separation, which is required for pharmacokinetic studies, is achieved by solid-phase extraction (SPE) via Bond Elut C18. The protein-bound amphotericin B has a higher affinity to the SPE material and is therefore retained, whereas the lipid-complexed amphotericin B is eluted in the first step. The recovery of the SPE was >75% for high concentrations and >95% for low concentrations. Quantification was performed by reversed-phase HPLC using a LiChrosorb-RP-8 column, UV detection (lambda=405 nm) and a mixture of acetonitrile-methanol-0.010 M NaH2PO4 buffer (41:10:49, v/v) as mobile phase. The retention time for amphotericin B under the given conditions was 6.7 min. The calibration curves were found to be linear (r > or = 0.999) in two different ranges (5.0-0.50 microg/ml and 0.50-0.005 microg/ml). Intra- and inter-day precision and accuracy fulfilled the international requirements. No interference from other drugs (typical broad medication for intensive-care patients) or common plasma components was detected in >400 samples analyzed.     

Oral itraconazole plus nasal amphotericin B for prophylaxis of invasive aspergillosis in patients with hematological malignancies

The use of oral itraconazole (200 mg daily) plus nasal amphotericin B (10 mg daily) for prophylaxis of invasive aspergillosis was evaluated in 164 patients with hematological malignancies at risk due to presence of neutropenia and/or steroid therapy. This prophylactic regimen was evaluated for a period of two years. Two hundred and ninety patients with similar characteristics who were observed over the three-year period prior to the introduction of prophylaxis served as historical control group. Environmental surveillance during the study period showed constant contamination of the air withAspergillus. Prophylaxis significantly reduced the incidence of proven invasive aspergillosis from 12/290 to 0/164 (p=0.004), and reduced the mortality rate from 8/290 to 0/164. The incidence of proven plus probable aspergillosis amounted to 34/290 in the control group and 8/164 in the study group (p=0.01); the mortality rates were 11/290 (3.7 %) and 2/164 (1.2 %) respectively. All nasal cultures in the study group were negative forAspergillus. The prophylactic regimen was well tolerated. Larger studies assessing each agent alone and in combination are necessary to confirm these observations.     

PCR monitoring of response to liposomal amphotericin B treatment of systemic candidiasis in neutropenic mice.

When a diagnosis of invasive candidiasis has been made, treatment with toxic fungicidal agents is inevitable. The crucial decision of when to stop such treatment is difficult to make, because cultures are often negative despite ongoing invasive candidiasis and can therefore not be used as a reliable parameter of effective therapy. In the present study, the use of PCR in monitoring the therapeutic efficacy of antifungal treatment with liposomal amphotericin B was evaluated by using neutropenic mice with systemic candidiasis. Blood cultures of infected mice treated with different doses of liposomal amphotericin B were only positive at the early onset of the infection process and became sterile within 3 days; this was true even with mice treated with 1 mg of liposomal amphotericin B per kg of body weight that experienced a relapse of infection 14 days later. A significant correlation between presence of Candida albicans in the kidneys and PCR results obtained with blood was demonstrated. Thus, PCR results obtained with blood samples correlated well with the therapeutic efficacy of antifungal treatment.     

Weekly liposomal amphotericin B as secondary prophylaxis for invasive fungal infections in patients with hematological malignancies

There have been no published studies evaluating the efficacy and safety of weekly liposomal amphotericin B as secondary prophylaxis in leukemic patients with invasive fungal infections (IFIs). We found in a retrospective review of our experience with 14 such patients admitted from 2003-2009 that the use of this approach was associated with frequent relapse of IFIs (36%) and kidney injury (36%).     

Differentiation of intestinal candidial colonization from invasive candidiasis by measuring serum level of D-arabinitol in combination with oral administration of low dose amphotericin B

The measurement of D-arabinitol in serum has been reported to be useful for the diagnosis of invasive candidiasis. However, excessive proliferation of Candida species in intestinal tract often leads false positive result of serum D-arabinitol. Based on the evidence that amphotericin B (AMPH) is scarcely absorbed from intestinal tract and inhibits the proliferation of Candida species only in intestinal tract, we have developed a simple differentiation method of intestinal candida colonization from invasive candidiasis by measuring serum level of D-arabinitol in combination with oral administration of low dose AMPH. AMPH, 600 mg/day for 2 days was orally administered to five patients with hematological malignancies who showed more than 1.7 mumol/mg of D-arabinitol/creatinine ratio (D/C ratio) in serum without any evidence of invasive candidiasis. D/C ratios were markedly decreased and normalized after the oral administration of low dose AMPH. While, in a patient with invasive candidiasis in whom Candida species was detected by blood cultures, D/C ratio remained unchanged in spite of oral administration of AMPH. These observations suggest that this method is a simple and reliable diagnostic method to distinguish intestinal candida colonization from true invasive candidiasis.     

Clinical utility and prognostic value of galactomannan in neutropenic patients with invasive aspergillosis

Invasive aspergillosis (IA) is a major cause of morbidity and mortality in profoundly neutropenic patients. Delayed diagnosis and therapy may lead to poor outcomes.AimsThe objective of this study was to assess the performance characteristics of the galactomannan (GM) assay in serum and bronchoalveolar lavage specimens for the diagnosis of IA in neutropenic patients with hematological malignancies. We also evaluated the prognostic outcome.Patients and methodsA total of 1198 serum samples and 42 BAL from 235 neutropenic patients were tested with a GM elisa platelia test. We used Cox modeling of time to 6- and 12-week mortality for GM level at the time of diagnosis (GM0) and GM decay in the week following diagnosis in proven and probable IA patients with more than two GM values.ResultsThere were three proven, 55 probable, and four possible cases of IA. The sensitivity and specificity of the GM test were 96.8% and 82.4% respectively. In BAL samples, sensitivity was 86% and the specificity 93%. BAL GM was more sensitive than microscopy (22.2%) and BAL culture (38.9%). Among patients with proven/probable IA, serum and BAL GM were in agreement for 92.8% of paired samples. The hazard ratio (HR) of GM0 and 1-week GM decay per unit increase in Aspergillus enzyme immunoassay (EIA) was 1.044 (95% CI, 0.738 to 1.476) and 0.709 (95% CI, 0.236 to 2.130) respectively.ConclusionWe found good correlation between the GM0 and GM decay combination and outcome of IA patients. The GM is a useful tool for diagnosis and monitoring of IA.     

Prospective, randomised, multicentre study of meropenem versus imipenem/cilastatin as empiric monotherapy in severe nosocomial infections

The clinical and bacteriological efficacy and the tolerability of meropenem versus imipenem/cilastatin (both 1 g t.i.d.) in severe nosocomial infections were compared in a multicentre, randomised, nonblinded study. A total of 151 patients were recruited; 133 (66 meropenem, 67 imipenem/cilastatin) were clinically evaluable and 84 (42 meropenem, 42 imipenem/cilastatin) bacteriologically evaluable. Most clinically evaluable patients (90%) were in intensive care units, required mechanical ventilation (72%), and had received previous antibiotic therapy (62%). The mean (±SD) APACHE II score was 15.2 (±6.6) in the meropenem group and 17.8 (±6.8) in the imipenem/cilastatin group. The primary infections were nosocomial lower respiratory tract infections (56% of patients), intra-abdominal infections (15%), septicaemia (21%), skin/skin structure infections (5%), and complicated urinary tract infections (3%); 35% of the patients had two or more infections. There was no significant difference between the meropenem and imipenem/cilastatin groups in the rates of satisfactory clinical (weighted percentage 87% vs. 74%) or bacteriological (weighted percentage 79% vs. 71%) response. There was a slightly higher rate of clinical success with meropenem against primary or secondary lower respiratory tract infection (89% vs. 76%). Drug-related adverse events occurred in 17% and 15% of meropenem and imipenem/cilastatin patients, respectively. Meropenem (1 g t.i.d.) was as efficacious as the same dose of imipenem/cilastatin in this setting, and both drugs were well tolerated.     

Differential effects of amphotericin B and liposomal amphotericin B on inflammatory cells in vitro

OBJECTIVE AND DESIGN: To understand whether the pseudo-allergic reactions to amphotericin B (AmB) administration are due to AmB or to the solubilizing vehicles, a study was designed to evaluate the effects of AmB, liposomal AmB, (L-AmB), AmB-deoxycholate micellar complex (AmB-DC) and deoxycholate (DC) on the responses of rat serosal mast cells (RSMC) and of human basophils (HB), in vitro. MATERIALS AND METHODS: Serosal mast cells were obtained by density gradient centrifugations from male Wistar albino rats. Partially purified HB were obtained from healthy donors. The cells were exposed to AmB, L-AmB, AmB-DC and DC. Histamine release was measured fluorometrically, and the release of lactic dehydrogenase (LDH) was measured spectrophotometrically. HB activation was evaluated cytofluorimetrically by CD63 expression. RESULTS: AmB and L-AmB did not evoke histamine or LDH release from either RSMC or HB. CD63 expression was not induced in HB challenged with AmB and L-AMB. On the other hand, AmB-DC and DC produced a cytotoxic histamine release from both RSMC and HB, and a sustained increase of CD63 expression on HB. CONCLUSIONS: Only AmB-DC was able to induce the release of inflammatory mediators from RSMC and HB. Conceivably, the cytotoxic effect is accounted for by the micellar complexes with DC, which has been confirmed as a powerful histamine releaser, and held responsible for the pseudo-allergic reactions after AmB-DC administration. The data lend support to a better safety profile of L-AmB.     

Assessment of nephrotoxicity in patients receiving amphotericin B lipid complex: a pharmacosurveillance study in Spain

This study assessed the risk of haematological, renal and hepatic toxicity associated with amphotericin B lipid complex (ABLC; Abelcet) in a multicentre, open-label, non-comparative study of 93 patients from 17 different hospitals who received ABLC because of proven or suspected systemic fungal infection or leishmaniasis. Most (66%) patients had onco-haematological diseases. Optimum treatment with ABLC comprised a slow (2-h) infusion dose of 5 mg/kg/day for a minimum period of 14 days. Biochemical and haematological parameters were measured pre-, during and post-treatment. In the overall patient group, the mean serum creatinine concentration was similar pre- and post-study (1.00 +/- 1.14 mg/dL vs. 1.20 +/- 1.19 mg/dL; p > 0.05). There were no significant changes pre- and post-treatment in concentrations of haemoglobin, potassium, transaminases and bilirubin. There was no significant correlation between the dose administered and the concentrations of serum creatinine (Spearmann 0.22). There was no greater nephrotoxicity in the patients with previous renal failure, or in those who had received amphotericin B previously. There were serious adverse events in five patients, but other alternative causes that could explain these events were present in three of these patients. Fevers or chills were experienced by 23% of the patients during the ABLC infusion, but only in one case did this necessitate the suspension of treatment. It was concluded that ABLC is a drug with low nephrotoxicity, even when administered to patients with pre-existing renal insufficiency. Adverse events were generally slight or moderate, and were managed easily with appropriate pre-medication.