Structure and function of the tuberculous lung: Considerations for inhaled therapies

Inhaled therapies for pulmonary tuberculosis are in development and appear promising at first look. A fundamental premise of such therapy is efficient delivery of drug at high concentrations to the active disease site, while minimizing systemic delivery. This assumes that inhaled drug will actually reach the diseased lung, which while intuitive for healthy lungs, may be untrue for diseased lungs with abnormal structure or function. This review discusses the structural and functional aspects of respiratory physiology that are likely to impact local drug delivery and presents the available evidence on how this pertains to tuberculous lungs.