Nebulized amphotericin B combined with intravenous amphotericin B in rats with severe invasive pulmonary aspergillosis

Nebulized amphotericin B (AMB) combined with intravenous AMB was studied in persistently leukopenic rats with invasive pulmonary aspergillosis. Pulmonary concentrations of AMB after aerosol treatment were substantially higher than after intravenous liposomal AMB. Nebulized liposomal AMB in addition to intravenous AMB resulted in significantly prolonged survival compared to controls.     

Activity of micafungin (FK463) against an itraconazole-resistant strain of Aspergillus fumigatus and a strain of Aspergillus terreus demonstrating in vivo resistance to amphotericin B

We compared the activity of four doses of micafungin (FK463) with that of amphotericin B, liposomal amphotericin B and itraconazole in a murine model of disseminated aspergillosis. Temporarily neutropenic mice were infected with a lethal dose of either an itraconazole-resistant Aspergillus fumigatus isolate or Aspergillus terreus, a species that is less susceptible to amphotericin B. Treatment was started 24 h after infection and lasted for 7 days. Mice were treated with either amphotericin B (0.5 or 5 mg/kg), liposomal amphotericin (5 or 25 mg/kg), itraconazole (25 or 75 mg/kg) or FK463 (either 1, 2, 5 or 10 mg/kg). Treatment of the A. fumigatus model with either amphotericin B, liposomal amphotericin or FK463 prolonged survival. Doses of FK463 5 and 10 mg/kg had a 100% survival. Treatment of A. terreus infection with either itraconazole or FK463, but not amphotericin B, also prolonged survival. Doses of liposomal amphotericin of 5 and 25 mg/kg were ineffective against A. terreus infection. No treatment regime was able to totally clear the liver or kidneys in either model. The data indicate that FK463 may have a clinical role in the treatment of life-threatening invasive aspergillosis.     

Efficacy of nebulized liposomal amphotericin B in treatment of experimental pulmonary aspergillosis

The efficacy of therapeutic aerosolized amphotericin B (AMB) was studied in a steroid-immunosuppressed murine model of invasive pulmonary aspergillosis. Nebulized liposomal AMB can be a valid approach to the treatment of this infection, with subjects showing significantly improved survival relative to that of subjects given intravenous deoxycholate AMB, as well as lower lung weights and pulmonary glucosamine levels.     

Efficacy of liposomal amphotericin B with prolonged circulation in blood in treatment of severe pulmonary aspergillosis in leukopenic rats

The therapeutic efficacy of long-circulating polyethylene glycol-coated liposomal amphotericin B (AMB) (PEG-AMB-LIP) was compared with that of AMB desoxycholate (Fungizone) in a model of severe invasive pulmonary aspergillosis in persistently leukopenic rats as well as in temporarily leukopenic rats. PEG-AMB-LIP treatment (intravenous administration) consisted of a single, or double (every 72 h), or triple (every 72 h) dose of 10 mg of AMB/kg of body weight, a double dose (every 72 h) of 14 mg of AMB/kg, or a 5-day treatment (every 24 h) with 6 mg/kg/dose. AMB desoxycholate was administered for 10 consecutive days at 1 mg of AMB/kg/dose. Treatment was started 30 h after fungal inoculation, at which time mycelial growth was firmly established. Both persistently and temporarily leukopenic rats died between 4 and 9 days after Aspergillus fumigatus inoculation when they were left untreated or after treatment with a placebo. In persistently leukopenic rats, a single dose of PEG-AMB-LIP (10 mg/kg) was as effective as the 10-day treatment with AMB desoxycholate (at 1 mg/kg/dose) in significantly prolonging the survival of rats infected with A. fumigatus and in reducing the dissemination of A. fumigatus to the liver. Prolongation of PEG-AMB-LIP treatment (double or triple dose or 5-day treatment) did not further improve efficacy. For temporarily leukopenic rats no major advances in efficacy were achieved compared to those for persistently leukopenic rats, probably because the leukocyte numbers in blood were restored too late in the course of infection.     

Efficacy of escalating doses of liposomal amphotericin B (AmBisome) against hematogenous Candida lusitaniae and Candida krusei infection in neutropenic mice.

Immunosuppressed CF1 mice were infected intravenously with two strains of Candida krusei and four strains of Candida lusitaniae (two of which were resistant to amphotericin B). Mice were treated with 1 or 2 mg of amphotericin B desoxycholate per kg of body weight per day or escalating doses of liposomal amphotericin B (8 to 30 mg/kg/day) or were left untreated. Higher doses of liposomal amphotericin B were as effective as standard dose of amphotericin B desoxycholate in prolonging survival but were significantly more effective in reducing the fungal burden in the kidneys of animals infected with both C. krusei strains and the C. lusitaniae strains that were susceptible to amphotericin B desoxycholate. This advantage of liposomal amphotericin B therapy could not be demonstrated in mice infected with the C. lusitaniae strains that were resistant to amphotericin B desoxycholate.     

Efficacy of prophylactic aerosol amphotericin B lipid complex in a rat model of pulmonary aspergillosis.

Invasive pulmonary aspergillosis remains an important cause of morbidity and mortality among transplant recipients and patients receiving cancer chemotherapy. The lipid-associated formulation of amphotericin B (AmB), AmB lipid complex (ABLC), was evaluated for its prophylactic efficacy when it was administered as an aerosol in a rat model of pulmonary aspergillosis. Aerosol ABLC (aero-ABLC), in doses from 0.4 to 1.6 mg/kg of body weight given 2 days before infection, significantly delayed mortality compared to the mortality of rats given placebo (P < 0.001). At day 10 postinfection, 50% of rats in the 0.4-mg/kg group and 75% of rats in the 1.6-mg/kg group were alive, while all control animals had died. In a second trial aero-ABLC was more effective than an equivalent dose of aerosol AmB (aero-AmB) in prolonging survival, with 100% survival at day 14 postinfection in the ABLC group, compared to 62.5% survival in the AmB group. Mean concentrations of AmB in lungs were 3.7 times higher at day 1 (P < 0.002) and almost six times higher at day 7 (P < 0.001) after treatment with aero-ABLC than after treatment with a similar dose of aero-AmB. We conclude that aero-ABLC provided higher and more prolonged levels of the parent compound in the lungs than aero-AmB and was more effective in delaying mortality from aspergillosis in this model.     

Economic evaluation of targeted treatments of invasive aspergillosis in adult haematopoietic stem cell transplant recipients in the Netherlands: a modelling approach

OBJECTIVES: The aim of this study was to assess the cost-effectiveness of a targeted treatment model of antifungal treatment strategies for adult haematopoietic stem cell transplant (HSCT) recipients in the Netherlands from a hospital perspective, using a decision analytic modelling approach. METHODS: The economic evaluation of desoxycholate amphotericin B, liposomal amphotericin B, voriconazole and caspofungin was undertaken. These drugs could be used alone, in various combinations or sequentially. In our model, first-line therapy consisted of either voriconazole or liposomal amphotericin B. If necessary, treatment was switched to a second-line treatment, including combination antifungal therapy. The theoretical population in this model consisted of adult HSCT recipients with proven or probable invasive aspergillosis (IA). Long-term survival was extrapolated from survival after 12 weeks of treatment and life expectancy. RESULTS: First-line antifungal treatment strategies with voriconazole were both more effective and less costly over first-line strategies employing liposomal amphotericin B at a dosage of 4 mg/kg/day. The strategy of voriconazole followed by caspofungin (voriconazole/caspofungin) was dominant over the strategies of voriconazole followed by liposomal amphotericin B (voriconazole/liposomal amphotericin B) or desoxycholate amphotericin B (voriconazole/desoxycholate amphotericin B). However, the voriconazole followed by the combination of liposomal amphotericin B and caspofungin strategy (voriconazole/liposomal amphotericin B+caspofungin) was more effective though more expensive than the voriconazole/caspofungin strategy resulting in an incremental cost-effectiveness ratio (ICER) of about euro107,000 for a life-year saved. At a dosage of 1 mg/kg/day of liposomal amphotericin B, the voriconazole/caspofungin strategy was more effective but more costly than the voriconazole/desoxycholate amphotericin B strategy with an ICER of euro10,000 for each extra life-year saved. Between the voriconazole/liposomal amphotericin B+caspofungin and the voriconazole/caspofungin strategies, the ICER was euro40,000. CONCLUSIONS: Probabilistic analyses on net monetary benefit showed that the voriconazole/caspofungin strategy had the highest probability of being the most cost-effective strategy.     

Efficacy of high doses of liposomal amphotericin B in the treatment of experimental aspergillosis

OBJECTIVE: Differences in efficacy between deoxycholate amphotericin B (d-AmB) and escalating doses of liposomal amphotericin B (L-AmB) were evaluated in a model of invasive pulmonary aspergillosis in persistently steroid-immunosuppressed rats. METHODS: Animals were infected intratracheally with a conidial suspension of a clinical isolate of Aspergillus fumigatus and randomized to receive intravenously 5% dextrose, 1 mg/kg/day of d-AmB or 3, 5 or 10 mg/kg/day of L-AmB. RESULTS: All the antifungal treatments improved survival, although no differences were found among the groups, perhaps because of treatment-related toxicity. In animals surviving long enough to receive at least five doses of antifungal treatment, there were significant reductions in paired lung weight in the 5 and 10 mg/kg/day L-AmB groups as compared with the controls (P=0.004 and 0.001, respectively) and with the 3 mg/kg/day L-AmB group (P=0.007 and 0.002, respectively). Significant decreases in fungal biomass, measured indirectly by chitin quantification, were found only in the 10 mg/kg/day L-AmB group as compared with controls (P=0.003), d-AmB (P=0.007) and 3 mg/kg/day L-AmB (P=0.001). CONCLUSION: Infusion of L-AmB doses as high as 10 mg/kg/day may be a good therapeutic option for the management of invasive pulmonary aspergillosis developing in the context of steroid immunosuppression, although further studies are needed to assess this approach.     

Efficacy of single-dose liposomal amphotericin B or micafungin prophylaxis in a neutropenic murine model of invasive pulmonary aspergillosis

In a neutropenic murine model of invasive pulmonary aspergillosis, prophylaxis with single doses of liposomal amphotericin B or micafungin at ≥5 mg/kg of body weight improved animal survival and suppressed the lung fungal burden for up to 7 days after infection, demonstrating the potential utility of infrequent dosing with these antifungals.     

In-vitro antifungal activity of liposomal nystatin in comparison with nystatin, amphotericin B cholesteryl sulphate, liposomal amphotericin B, amphotericin B lipid complex, amphotericin B desoxycholate, fluconazole and itraconazole.

The in-vitro susceptibilities of 120 clinical isolates of yeasts to liposomal nystatin were compared with those to amphotericin B lipid complex (ABLC), liposomal amphotericin B (LAB), amphotericin B cholesteryl sulphate (ABCD), amphotericin B desoxycholate, nystatin, fluconazole and itraconazole. Yeast isolates examined included strains of Candida albicans, Candida parapsilosis, Candida glabrata, Candida krusei, Candida guilliermondii, Candida tropicalis, Candida kefyr, Candida viswanathii, Candida famata, Candida rugosa, Rhodotorula rubra, Trichosporon spp., Cryptococcus laurentii and Cryptococcus neoformans. The mean MICs for all strains examined were: liposomal nystatin 0.96 mg/L; nystatin 0.54 mg/L; ABLC 0.65 mg/L; LAB 1.07 mg/L; ABCD 0.75 mg/L; amphotericin B 0.43 mg/L; fluconazole 5.53 mg/L; and itraconazole 0.33 mg/L. No significant differences were seen between the activity of liposomal nystatin and the polyene drugs or itraconazole, but liposomal nystatin was more active than fluconazole. MICs were lower than the reported blood concentrations following therapeutic doses of this drug, indicating the potential for a therapeutic use of liposomal nystatin in humans. These results indicate good activity in vitro against medically important yeasts, which compares favourably with the activities of other currently available antifungal drugs. Liposomal nystatin may have a role in the treatment of disseminated and systemic mycoses.     

Efficacy of SPK-843, a novel polyene antifungal, in comparison with amphotericin B, liposomal amphotericin B, and micafungin against murine pulmonary aspergillosis

SPK-843, a new polyene antifungal, exhibited dose-dependent efficacy on murine pulmonary aspergillosis models. SPK-843 doses of higher than 1.0 mg/kg of body weight exhibited no renal toxicities and a tendency toward better survival prolongation than the estimated maximum tolerated doses of amphotericin B (Fungizone) (1.0 mg/kg) and liposomal amphotericin B (AmBisome) (8.0 mg/kg).     

Lipid formulations of amphotericin B in the management of invasive fungal infections

Three lipid formulations of amphotericin B have been developed: amphotericin B colloidal dispersion, amphotericin B lipid complex, and liposomal amphotericin B. These three compounds differ by their lipid composition and therefore by their physical characteristics, their pharmacokinetics, and their safety and efficacy profile. There is a consensus to accept reduced toxicity of these formulations, especially reduced, but not absence of, renal toxicity as compared to amphotericin B deoxycholate. Few well-designed studies have been conducted and none of them demonstrated convincingly superiority in term of efficacy of any of the lipid preparations over amphotericin B deoxycholate. Recently a double blind randomized study compared a standard dose of 3 mg/kg/d of liposomal amphotericin B and a loading dose (10 mg/kg/d for 14 days and then the standard dose) in primary therapy of invasive filamentous fungal infections, mainly aspergillosis. Response rate at end of randomized therapy as well as survival at 12 weeks was numerically superior in the standard dose arm but this difference was not statistically significant. Lack of benefit of high dose liposomal amphotericin B in aspergillosis cannot yet be extrapolated to other filamentous fungal infections. Nephrotoxicity was substantially higher in the loading dose arm and this contraindicates its use in clinical practice.     

Long-Circulating Immunoliposomal Amphotericin B against Invasive Pulmonary Aspergillosis in Mice

We investigated the efficacy of long-circulating immunoliposomal amphotericin B (AmB) against invasive pulmonary aspergillosis in mice using three types of liposomal AmB: conventional liposomal AmB (AmBisome), a long-circulating liposomal AmB and prepared by coating the liposome surface with polyethylene glycol (PEG; PEG-L-AmB), long-circulating immunoliposomal AmB (34A-PEG-L-AmB). The survival rates for mice with invasive pulmonary aspergillosis treated with an intravenous dose of 2 mg of AmBisome, PEG-L-AmB, or 34A-PEG-L-AmB per kg of body weight were 16.7, 83.3, and 100%, respectively. Treatment with 34A-PEG-L-AmB produced a marked reduction in the number of Aspergillus fumigatus organisms in the lungs. Pharmacokinetic studies showed the presence of high AmB concentrations in the plasma of mice treated with PEG-L-AmB (40.8 μg/ml) and in the lungs of mice treated with 34A-PEG-L-AmB (42.3 μg/g). We conclude that 34A-PEG-L-AmB, a long-circulating immunoliposomal AmB, is a promising form of AmB against invasive pulmonary aspergillosis.     

Chronic necrotizing pulmonary aspergillosis treated by endobronchial amphotericin B

Chronic necrotizing pulmonary aspergillosis is an indolent, locally invasive form of Aspergillus infection. Treatment options are limited and controversial. Resection is often curative if the patient has sufficient ventilatory reserve. Even though intravenous amphotericin B is effective in a few patients, toxicity limits its use. Aerosolized amphotericin B has proven ineffective. Anecdotal reports of intracavitary and endobronchial antifungal therapy show limited success. Our patient had unresectable chronic necrotizing pulmonary aspergillosis treated successfully with intracavitary instillation of amphotericin B, delivered via the flexible fiberoptic bronchoscope.     

Dose-dependent antifungal activity and nephrotoxicity of amphotericin B colloidal dispersion in experimental pulmonary aspergillosis.

We investigated the safety and efficacy of amphotericin B colloidal dispersion (ABCD) for the treatment of invasive pulmonary aspergillosis in persistently granulocytopenic rabbits. Treatment groups included ABCD in dosages of 1, 5, and 10 mg/kg/day intravenously or conventional desoxycholate amphotericin B (DAmB) at 1 mg/kg/day intravenously. Antifungal activity was directly related to increasing dosage of ABCD as determined by the concentration of Aspergillus fumigatus organisms in lungs and the frequency of hemorrhagic pulmonary lesions. At 5 and 10 mg/kg/day, there was a significant reduction in the tissue burden of A. fumigatus as measured by percent culture-positive lobes and CFU per gram of tissue (P < or = 0.001), whereas at 1 mg/kg/day measured by percent culture-positive lobes and CFU per gram of tissue (P < or = 0.001), whereas at 1 mg/kg/day the tissue burden of A. fumigatus was not significantly different from that in untreated controls. Microbiological clearance was significantly greater at 1 mg of DAmB per kg per day than at 1 mg of ABCD per kg per day (P < or = 0.001). There was no difference in microbiological clearance of bronchoalveolar lavage fluid among the treatment groups as measured by CFU per milliliter. As determined by survival, ABCD at 5.0 mg/kg/day was more effective than DAmB at 1.0 mg/kg/day and ABCD at 10 mg/kg/day. ABCD at 10 mg/kg/day was more nephrotoxic than the lower dosages of ABCD and resulted in higher mortality. Impairment of glomerular filtration developed as a direct function increasing the ABCD dosage (r = 0.77; P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of amphotericin B and micafungin combination on survival, histopathology, and fungal burden in experimental aspergillosis in the p47phox-/- mouse model of chronic granulomatous disease

Chronic granulomatous disease (CGD) is an inherited disorder of the NADPH oxidase characterized by recurrent life-threatening bacterial and fungal infections. We characterized the effects of single and combination antifungal therapy on survival, histopathology, and laboratory markers of fungal burden in experimental aspergillosis in the p47phox-/- knockout mouse model of CGD. CGD mice were highly susceptible to intratracheal Aspergillus fumigatus challenge, whereas wild-type mice were resistant. CGD mice were challenged intratracheally with a lethal inoculum (1.25 x 10(4) CFU/mouse) of A. fumigatus and received one of the following regimens daily from day 0 to 4 after challenge (n = 19 to 20 per treatment group): (i) vehicle, (ii) amphotericin B (intraperitoneal; 1 mg/kg of body weight), (iii) micafungin (intravenous; 10 mg/kg), or (iv) amphotericin B plus micafungin. The rank order of therapeutic efficacy based on prolonged survival, from highest to lowest, was as follows: amphotericin B plus micafungin, amphotericin B alone, micafungin alone, and the vehicle. Lung histology showed pyogranulomatous lesions and invasive hyphae, but without hyphal angioinvasion or coagulative necrosis. Treatment with micafungin alone or combined with amphotericin B produced swelling of invasive hyphae that was not present in mice treated with the vehicle or amphotericin B alone. Assessment of lung fungal burden by quantitative PCR showed no significant difference between treatment groups. Serum galactomannan levels were at background despite documentation of invasive aspergillosis by histology. Our findings showed the superior efficacy of the amphotericin B and micafungin combination compared to either agent alone after A. fumigatus challenge and also demonstrated unique features of CGD mice as a model for experimental aspergillosis.     

Efficacy of posaconazole and amphotericin B in experimental invasive pulmonary aspergillosis in dexamethasone immunosuppressed rats

OBJECTIVES: Invasive pulmonary aspergillosis is associated with high mortality. To assess new antifungal therapy options, animal models have to be developed to assess, in an appropriate setting, the activity of new drugs. METHODS: Male albino CD rats (125-150 g) were fed with a protein-free diet and received dexamethasone thrice weekly subcutaneously during the whole experiment. After 2 weeks, an inoculum of 10(6) conidia of Aspergillus fumigatus (H11-20) was injected intratracheally. Antifungal treatment was initiated and continued for a total of 7 days. Animals were grouped in numbers of 10. One group of animals served as untreated control, whereas the others were treated with amphotericin B intraperitoneally (2 and 4 mg/kg) and posaconazole via gavage (2, 4, 10 and 20 mg/kg). Survival and log(10) cfu/g of the lungs were the endpoints. The strain H11-20 was tested for susceptibility in vitro to amphotericin B and posaconazole, respectively. Fungal burden of the lungs was expressed as log(10) cfu/g. Survival analysis was performed by the Kaplan-Meier method. Differences in fungal burden were assessed by the Mann-Whitney test. RESULTS: All untreated animals died within a week. Amphotericin B and posaconazole at 2 mg/kg demonstrated survival benefits over control (P = 0.01 and P = 0.04). Dosages of 4 mg/kg were superior to 2 mg/kg for amphotericin B (P = 0.02) and posaconazole (P < 0.05), respectively. No further survival benefits were demonstrated beyond dosages of 10 mg/kg. Rats treated with 20 mg/kg posaconazole, however, had a lower fungal burden than all the other treatment groups (P = 0.0002). CONCLUSIONS: Posaconazole and amphotericin B are effective in a dosage-dependent manner in this pulmonary aspergillosis model in immunocompromised rats.     

Cerebral aspergillosis in the critically ill: two cases of successful medical treatment

Objective Invasive aspergillosis is associated with a poor prognosis, especially in critically ill patients with cerebral involvement. We present two cases of cerebral invasive aspergillosis successfully treated in the intensive care unit with combination antifungal therapies and without surgery.Case presentation The first patient was a 49-year-old man with rheumatoid arthritis who received corticosteroid and cyclophosphamide treatment and developed pulmonary and cerebral invasive aspergillosis. After failure of voriconazole the patient had a successful outcome with voriconazole and liposomal amphotericin B therapy. The patient returned home after an 8-month hospital stay. The second patient was a 54-year-old woman with pulmonary neoplasia and corticosteroid treatment who developed pulmonary and cerebral invasive aspergillosis. After failure of voriconazole and liposomal amphotericin B therapy the patient had a favorable outcome with liposomal amphotericin B and caspofungin therapy. The patient died 10 months after initial diagnosis of cardiac tamponade unrelated to fungal infection.Discussions These cases illustrate the improving prognosis of invasive aspergillosis due to the availability of new treatments, especially in cases of cerebral involvement. It also demonstrates that the outcome of critically ill patients requiring mechanical ventilation for invasive aspergillosis can be favorable. The treatment of patients with invasive cerebral aspergillosis in the intensive care setting should be encouraged.     

恶性血液病伴发侵袭性肺曲霉病3例诊治分析

侵袭性肺曲霉病诊断图难，病情凶险，死亡率高。本对合并有侵袭性肺曲霉病的3例恶性血液病(2例急性白血病和l例MDS-RA)患的诊治过程进行了回顾性分析。3例患均有免疫力低下的病史，虽经过预防性抗真菌治疗，仍发生了肺曲霉菌感染，经过痰培养确诊后采用脂质体两性霉素B，伊曲康唑和氟胞嘧啶联合治疗。结果表明，联合治疗7—14天后，3例中2例痊愈，l例显效。结论：对侵袭性肺曲霉病的早期诊治很关键，脂质体两性霉素B，伊曲康硅和氟胞嘧啶联合治疗起效快，效果好。     

Liposomal nystatin in patients with invasive aspergillosis refractory to or intolerant of amphotericin B

We assessed the activity and safety of liposomal nystatin, a broad-spectrum antifungal agent, for invasive aspergillosis in patients refractory to or intolerant of amphotericin B. Thirty-three patients were enrolled, received at least one dose of the study drug, and were evaluable for safety. Twenty-six patients had confirmed probable or definite aspergillosis and were fully eligible. Most patients had a hematological malignancy (53.8%) or hematopoietic stem cell transplantation (23.0%), were neutropenic (61.5%), and were refractory to previous amphotericin B (92.3%). The median duration of previous amphotericin B treatment was 16.5 days (range, 5 to 64 days). Aspergillosis was definite in 3 cases and probable in 23 cases. Liposomal nystatin was initiated at a dose of 4 mg/kg of body weight/day. Twenty-five patients were evaluable for response: a complete response was achieved for one patient, and a partial response was achieved for six. Thus, the overall response rate is 7 of 25 (28%; 95% confidence interval, 12 to 49%). Seventeen (68.0%) of the 25 evaluable patients died during therapy or within 1 month after the end of therapy. The primary cause of death was invasive aspergillosis for nine patients and underlying malignancy for eight patients. The most frequent side effects included chills, shivering, and fever, leading to discontinuation of therapy for two patients. Grade 1 decline in renal function was seen for 10 (30.3%) patients, and hypokalemia was seen for 13 (39.4%). We conclude that liposomal nystatin can be effective for salvage therapy of invasive aspergillosis. Infusion-related adverse events have been observed frequently.