The anti-inflammatory profile of inhaled corticosteroids combined with salmeterol in asthmatic patients

Inhaled corticosteroid (ICS) therapy such as fluticasone propionate (FP) is effective in moderate-to-severe asthma, But for patients on ICS who still experience symptoms, treatment guidelines recommend either increasing the dose of ICS or adding a long-acting beta (2)-agonist such as salmeterol or formoterol. Several studies have now sown that adding salmeterol provides greater clinical benefit: than increasing the dose of ICS, raising the question of whether salmeterol has an additive or complementary anti-inflammatory effect to that of ICS. Recent studies on bronchial biopsies and bronchoalveolar lavage from asthmatic patients treated with either salmeterol, FP or placebo in addition to low-dose ICS have demonstrated that addition of salmeterol produces independent or additional reductions in several pro-inflammatory cells, cytokines and cell adhesion molecules compared with FP. Such complementary anti-inflammatory effects may explain the improved control of asthma symptoms and exacerbations observed when salmeterol is added to low-dose ICS therapy, and may help to modify the long-term sequelae of asthma. These findings also indicate, contrary to earlier speculation, that salmeterol does not have a pro-inflammatory effect or mask persistent airway inflammation. This review presents the results of recent studies and suggests possible mechanisms for the additional antiinflammatory effects of salmeterol.