Low resistance aerosol exhalation filters, and methods of their use are provided. The exhalation filters provided herein are used in conjunction with a nebulizer in the treatment of a pulmonary infection in a patient in need thereof. In one method, an antiinfective formulation is administered to a patient in need of treatment of a pulmonary infection, with a nebulizer comprising a low resistance aerosol exhalation filter of the invention. The pulmonary infection, in one embodiment, is a Pseudomonas or mycobacterial (e.g., NTM) infection.