Aerosol therapy in tuberculosis: Is it useful and is it feasible

Aims: To present new developments in antibiotic aerosol therapy in the treatment of tuberculosis (TB). The purpose and potential advantages of aerosol treatment will be discussed. Finally, technical developments will be discussed in the light of the clinical objective and requirements from the antibiotics and their use. Summary: The rise of multi-drug resistant tuberculosis and extensively-drug resistant tuberculosis strains are a threat to global health. Since the lungs are the main port of entry for the mycobacterium tuberculosis, pulmonary administration of antibioticsseemsanattractive therapeutic option. Potential advantages of pulmonary drug administration in TB encompass: a reduced change of transmission of the disease; a high local exposure, related to an increased therapeutic efficacy; a decreased systemic exposure, which may reduce side effects; the prevention of the development of new drug resistant strains of mycobacteria; and compared to parenteral administration, inhalation does not require medically trained personnel, is free from the injec- tionassociated infection risks and cheaper. So far, only limited information is available from human studies. The increasing lung surface leads to the question whether the drug concentrations attained upon inhalation are sufficient to obtain the antimicrobial effect in the deeper lung. This may shift the purpose of the aerosol therapy to the prevention of transmission. Pulmonary administration of anti-TB drugs is associated with several challenges for the drug delivery system (formulation and inhalation device). These challenges are related to aspects such as: a high dose, prevention of re-infection via the device and world-wide availability. Conclusions: Aerosol therapy of antibiotics offers a number of potential advantages. However, the prevention of transmission may be a more important objective than treatment of the patient. The development of adequate inhalation devices for TB antibiotics is challenging