scholarly journals Pharmacodynamic Activity of Amphotericin B Deoxycholate Is Associated with Peak Plasma Concentrations in a Neutropenic Murine Model of Invasive Pulmonary Aspergillosis

2006 ◽  
Vol 50 (2) ◽  
pp. 469-473 ◽  
Author(s):  
Nathan P. Wiederhold ◽  
Vincent H. Tam ◽  
Jingduan Chi ◽  
Randall A. Prince ◽  
Dimitrios P. Kontoyiannis ◽  
...  

ABSTRACT We conducted a dose fractionation study of neutropenic, corticosteroid-immunosuppressed mice to characterize the pharmacodynamic/pharmacokinetic (PK/PD) parameter most closely associated with amphotericin B (AMB) efficacy in the treatment of invasive pulmonary aspergillosis. Pharmacokinetic parameter estimates were determined by a nonparametric population pharmacokinetic analysis of plasma drug concentrations following single intraperitoneal doses (0.25, 1.0, and 3.0 mg/kg of body weight) of amphotericin B deoxycholate. Three dosage groups (0.5, 0.75, and 1.0 mg/kg) fractionated into three dosing intervals (every 8 h [q8h], q24h, or q72h) were tested to discriminate between the PK/PD parameters (the ratio of maximum concentration of drug in serum [C max]/MIC, the ratio of area under the concentration-time curve/MIC, and percentage of time above MIC) most closely associated with AMB efficacy over a range of clinically achievable exposures in humans. The efficacy of each regimen was determined by quantitative PCR and survival. Reductions in pulmonary fungal burden and improvements in survival were maximized at the highest peak plasma concentrations in each of the dosage groups. Reductions in pulmonary fungal burden and increased survival were most closely associated with C max/MIC, with maximal activity occurring as the C max/MIC approached 2.4. In our model, C max/MIC is the PK/PD parameter most closely associated with efficacy in the treatment of invasive pulmonary aspergillosis. These data predict that less frequently administered, higher dosages of AMB would optimize efficacy.

2010 ◽  
Vol 54 (8) ◽  
pp. 3432-3441 ◽  
Author(s):  
Jodi M. Lestner ◽  
Susan J. Howard ◽  
Joanne Goodwin ◽  
Lea Gregson ◽  
Jayesh Majithiya ◽  
...  

ABSTRACT The pharmacodynamic and pharmacokinetic (PK-PD) properties of amphotericin B (AmB) formulations against invasive pulmonary aspergillosis (IPA) are not well understood. We used an in vitro model of IPA to further elucidate the PK-PD of amphotericin B deoxycholate (DAmB), liposomal amphotericin B (LAmB) and amphotericin B lipid complex (ABLC). The pharmacokinetics of these formulations for endovascular fluid, endothelial cells, and alveolar cells were estimated. Pharmacodynamic relationships were defined by measuring concentrations of galactomannan in endovascular and alveolar compartments. Confocal microscopy was used to visualize fungal biomass. A mathematical model was used to calculate the area under the concentration-time curve (AUC) in each compartment and estimate the extent of drug penetration. The interaction of LAmB with host cells and hyphae was visualized using sulforhodamine B-labeled liposomes. The MICs for the pure compound and the three formulations were comparable (0.125 to 0.25 mg/liter). For all formulations, concentrations of AmB progressively declined in the endovascular fluid as the drug distributed into the cellular bilayer. Depending on the formulation, the AUCs for AmB were 10 to 300 times higher within the cells than within endovascular fluid. The concentrations producing a 50% maximal effect (EC50) in the endovascular compartment were 0.12, 1.03, and 4.41 mg/liter for DAmB, LAmB, and ABLC, respectively, whereas, the EC50 in the alveolar compartment were 0.17, 7.76, and 39.34 mg/liter, respectively. Confocal microscopy suggested that liposomes interacted directly with hyphae and host cells. The PK-PD relationships of the three most widely used formulations of AmB differ markedly within an in vitro lung model of IPA.


2015 ◽  
Vol 59 (5) ◽  
pp. 2735-2745 ◽  
Author(s):  
Zaid Al-Nakeeb ◽  
Vidmantas Petraitis ◽  
Joanne Goodwin ◽  
Ruta Petraitiene ◽  
Thomas J. Walsh ◽  
...  

ABSTRACTAmphotericin B is a first-line agent for the treatment of invasive aspergillosis. However, relatively little is known about the pharmacodynamics of amphotericin B for invasive pulmonary aspergillosis. We studied the pharmacokinetics (PK) and pharmacodynamics (PD) of amphotericin B deoxycholate (DAMB), amphotericin B lipid complex (ABLC), and liposomal amphotericin B (LAMB) by using a neutropenic-rabbit model of invasive pulmonary aspergillosis. The study endpoints were lung weight, infarct score, and levels of circulating galactomannan and (1→3)-β-d-glucan. Mathematical models were used to describe PK-PD relationships. The experimental findings were bridged to humans by Monte Carlo simulation. Each amphotericin B formulation induced a dose-dependent decline in study endpoints. Near-maximal antifungal activity was evident with DAMB at 1 mg/kg/day and ABLC and LAMB at 5 mg/kg/day. The bridging study suggested that the “average” patient receiving LAMB at 3 mg/kg/day was predicted to have complete suppression of galactomannan and (1→3)-β-d-glucan levels, but 20 to 30% of the patients still had a galactomannan index of >1 and (1→3)-β-d-glucan levels of >60 pg/ml. All formulations of amphotericin B induce a dose-dependent reduction in markers of lung injury and circulating fungus-related biomarkers. A clinical dosage of liposomal amphotericin B of 3 mg/kg/day is predicted to cause complete suppression of galactomannan and (1→3)-β-d-glucan levels in the majority of patients.


2015 ◽  
Vol 59 (5) ◽  
pp. 2875-2881 ◽  
Author(s):  
Nathan P. Wiederhold ◽  
Laura K. Najvar ◽  
Satoru Matsumoto ◽  
Rosie A. Bocanegra ◽  
Monica L. Herrera ◽  
...  

ABSTRACTASP9726 is an investigational echinocandin within vitroactivity againstAspergillusspecies. We evaluated the pharmacokinetics and efficacy of this agent in an established guinea pig model of invasive pulmonary aspergillosis. ASP9726 plasma concentrations were measured in guinea pigs administered either a single dose or multiple doses of this agent at 2.5, 5, and 10 mg/kg of body weight/day by subcutaneous injection. Immunosuppressed guinea pigs were inoculated withA. fumigatusAF293, and ASP9726 (2.5, 5, and 10 mg/kg/day), voriconazole (10 mg/kg by oral gavage twice daily), or caspofungin (3 mg/kg/day by intraperitoneal injection) was administered for 8 days. Changes in fungal burden were measured by enumerating CFU and by quantitative PCR of specimens from within the lungs, as well as by analysis of serum (1→3)-β-d-glucan and galactomannan. Lung histopathology was also evaluated. ASP9726 plasma concentrations increased in a dose-proportional manner, and the drug was well tolerated at each dose. Each dose of ASP9726, voriconazole, and caspofungin significantly reduced pulmonary fungal burden as measured by quantitative PCR and by determining (1→3)-β-d-glucan and galactomannan levels, but only voriconazole significantly reduced numbers of CFU. ASP9726 at 5 mg/kg also significantly improved survival. Histopathology demonstrated morphological changes in hyphae in animals exposed to ASP9726 and caspofungin, consistent with the activities of the echinocandins. These results suggest that ASP9726 may be efficacious for the treatment of invasive pulmonary aspergillosis.


2008 ◽  
Vol 52 (11) ◽  
pp. 4178-4180 ◽  
Author(s):  
Russell E. Lewis ◽  
Nathaniel D. Albert ◽  
Dimitrios P. Kontoyiannis

ABSTRACT 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.


2006 ◽  
Vol 51 (3) ◽  
pp. 1078-1081 ◽  
Author(s):  
Russell E. Lewis ◽  
Georgios Chamilos ◽  
Randall A. Prince ◽  
Dimitrios P. Kontoyiannis

ABSTRACT In a nonneutropenic murine model of invasive pulmonary aspergillosis, pretreatment with empty liposomes (E-lipo) was nearly as effective as 10 mg/kg of body weight liposomal amphotericin B and superior to 1 mg/kg amphotericin B deoxycholate. The beneficial immunomodulatory properties of E-lipo appear to compensate for their lack of direct antifungal activity.


2007 ◽  
Vol 51 (4) ◽  
pp. 1253-1258 ◽  
Author(s):  
Russell E. Lewis ◽  
Guangling Liao ◽  
Jinggou Hou ◽  
Georgios Chamilos ◽  
Randall A. Prince ◽  
...  

ABSTRACT The reformulation of amphotericin B (AMB) into a lipid complex (AMB lipid complex [ABLC]) or liposomal carrier (liposomal AMB [L-AMB]) changes the rate and extent of drug distribution to the lung. The importance of pharmacokinetic differences among the various lipid AMB formulations in the treatment of invasive pulmonary aspergillosis (IPA) remains unknown. We compared the kinetics of AMB lung accumulation and fungal clearance of ABLC- and L-AMB-treated mice with acute IPA. BALB/c mice were immunosuppressed with cyclophosphamide and cortisone before intranasal inoculation with 1.5 × 106 Aspergillus fumigatus 293 conidia. ABLC or L-AMB was administered in daily intravenous doses (1, 5, or 10 mg/kg of body weight), starting 12 h after infection and continuing until day 5. At predetermined times (0, 24, 72, and 120 h), mice were euthanized, and lungs were harvested for determinations of lung fungal burdens (quantitative PCR) and total AMB lung tissue concentrations. Both ABLC and L-AMB were effective at reducing lung fungal burdens at doses of ≥5 mg/kg/day. Clearance of A. fumigatus during the first 24 h was associated with AMB tissue concentrations of >4 μg/g. At 5 mg/kg/day, ABLC produced a more rapid fungal clearance than did L-AMB, but at the end of therapy, fungal burden reductions were similar for both formulations and were not improved with higher dosages. These data suggest that ABLC delivers active AMB to the lung more rapidly than does L-AMB, resulting in faster Aspergillus clearance in an experimental model of IPA. However, pharmacodynamic differences between the two formulations were less apparent when mice were dosed at 10 mg/kg/day.


2009 ◽  
Vol 53 (6) ◽  
pp. 2613-2615 ◽  
Author(s):  
Justin A. Tolman ◽  
Nathan P. Wiederhold ◽  
Jason T. McConville ◽  
Laura K. Najvar ◽  
Rosie Bocanegra ◽  
...  

ABSTRACT Targeted airway delivery of antifungals as prophylaxis against invasive aspergillosis may lead to high lung drug concentrations while avoiding toxicities associated with systemically administered agents. We evaluated the effectiveness of aerosolizing the intravenous formulation of voriconazole as prophylaxis against invasive pulmonary aspergillosis caused by Aspergillus fumigatus in an established murine model. Inhaled voriconazole significantly improved survival and limited the extent of invasive disease, as assessed by histopathology, compared to control and amphotericin B treatments.


2005 ◽  
Vol 49 (4) ◽  
pp. 1642-1645 ◽  
Author(s):  
Vidmantas Petraitis ◽  
Ruta Petraitiene ◽  
Pengxin Lin ◽  
Karim Calis ◽  
Amy M. Kelaher ◽  
...  

ABSTRACT The recent shortage of the brand name drug Fungizone has necessitated a change to generic formulations of amphotericin B deoxycholate. Clinical trials cannot be conducted in a timely manner to provide data on the safety and efficacy of these formulations. We therefore compared generic amphotericin B and Fungizone for activity and safety in the treatment of experimental invasive pulmonary aspergillosis (IPA) in persistently neutropenic rabbits. Fungizone and generic amphotericin B are similar in efficacy, pharmacokinetics, and safety in the treatment of experimental IPA.


2010 ◽  
Vol 21 (4) ◽  
pp. e116-e121 ◽  
Author(s):  
UD Allen

Traditionally, the mainstay of systemic antifungal therapy has been amphotericin B deoxycholate (conventional amphotericin B). Newer agents have been developed to fulfill special niches and to compete with conventional amphotericin B by virtue of having more favourable toxicity profiles. Some agents have displaced conventional amphotericin B for the treatment of specific fungal diseases. For example, voriconazole has emerged as the preferred treatment for invasive pulmonary aspergillosis. This notwithstanding, conventional amphotericin B remains a useful agent for the treatment of paediatric fungal infections. Knowledge of the characteristics of the newer agents is important, given the increasing numbers of patients who are being treated with these drugs. Efforts need to be directed at research aimed at generating paediatric data where these are lacking. The antifungal agents herein described are most often used as monotherapy regimens because there is no uniform consensus on the value of combination therapy, except for specific scenarios.


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