Effects of inhaled corticosteroids (ICS) on lung microbiota and local immune response in long-term treatment of chronic obstructive pulmonary disease (COPD): utility of titration and therapeutic index.

Administration of inhaled corticosteroids (ICS) is one of the most controversial issues in the treatment of stable chronic obstructive pulmonary disease (COPD). Associations between these drugs and increased incidence of severe pneumonia and other respiratory infections have already been reported in literature, as well as effects on the immune system and on the lung microbiota. ICS vary in their pharmacodynamic and pharmacokinetic properties, despite being widely considered therapeutically similar. The use of ICS requires, therefore, a deep knowledge of their pharmacokinetics and pharmacodynamics to obtain the maximum benefit and the least side effects. Defining new phenotypes-endotypes of COPD may lead to novel pharmacological and therapeutic scenarios while define the correct indications for prescription of ICS. Titration is certainly an important means by which these objectives can be achieved.