A patient suffering from an endobronchial infection is treated by administering to the patient for inhalation a dose of less than about 4.0 ml of a nebulized aerosol formulation comprising from about 60 to about 200 mg/ml of an aminoglycoside antibiotic, such as tobramycin, in a physiologically acceptable carrier in a time period of less than about 10 minutes. Unit dose devices for storage and delivery of the aminoglycoside antibiotic formulations are also provided.