Invasive pulmonary aspergillosis is a major life-threatening complication among transplant recipients and patients receiving cancer chemotherapy. In a rat model of progressive pulmonary aspergfliosis that is characterized by hyphal bronchopneumonia, aerosol amphotericin B (aero-AmB; 1.6 mg/kg given 2 days before infection) significantly delayed mortality in rats compared with animals in a control group. The first death in the aero-AmB-treated group occurred on day 11, by which time seven of the eight control animals had died. The same dose of aero-AmB given as treatment (1.6 mg/kg given 24 h after infection and then daily for 6 days) was also effective. In this trial, eight of the ten animals treated with aero-AmB survived for 7 days, whereas only one of ten control animals survived. The most commonly encountered form of disease in these patients is pulmonary aspergillosis (7). Acute fatal sinusitis (27, 28), head and neck involvement (24), cutaneous disease (5), and catheter-related infections (3) have also been described.Invasive pulmonary aspergillosis is difficult to diagnose, even with the use of invasive techniques. Thus the standard treatment, intravenous amphotericin B (AmB), often must be given empirically, despite its severe toxicity and despite the fact that patients do not tolerate it well. Moreover, AmB is not always effective, and correction of the underlying disorder (e.g., the resolution of granulocytopenia) is usually required to achieve a favorable outcome.In a study of the distribution and activity of amphotericin B in humans, we found the highest concentrations of drug in the liver, spleen, and kidneys (6). Concentrations above 7 ,ug/g of lung tissue were seen only in patients who had received at least 1.7 g of AmB. Our data also suggested that once amphotericin B accumulated in any organ it was eliminated slowly.A reduction of the number of aspergillus spores inhaled probably reduces the risk of developing invasive aspergillus pneumonia among susceptible hosts (19,21,22,25). Since AmB is highly fungicidal against aspergillus spores (23) and has a long half-life once it reaches the lung parenchyma, it may be an ideal candidate for prophylactic use when given as an aerosol. This route of administration should limit systemic toxicity and maximize effectiveness.In evaluated whether aerosol AmB (aero-AmB) given as prophylaxis (given once, 48 h before infection) or as therapy (given 24 h after infection and then daily for 6 days) influenced survival. Other studies were done to determine the pulmonary deposition and fungicidal activity of the drug after aerosol administration.
MATERIALS AND METHODSAnimal model of pulmonary aspergiflosis. Male SpragueDawley rats (Charles River Breeding Laboratories, Wilmington, Mass.), weighing 125 to 150 g, were given cortisone acetate (100 mg/kg, given subcutaneously) three times per week throughout the experiment. They also received a low-protein diet (8% protein; ICN Biochemicals, Cleveland, Ohio) and tetracycline (250 mg dissolved in 750 ml of drinking water). ...