Review: Differences in the pharmacodynamics of budesonide/formoterol and salmeterol/fluticasone reflect differences in their therapeutic usefulness in asthma

Although the available inhaled corticosteroid (ICS)/long-acting β 2-agonist (LABA) combinations principally work in a similar fashion, they differ in several important ways, leading to different efficacy. The ICS/LABA combination product budesonide/formoterol can be used as both maintenance and reliever therapy, providing a fixed maintenance dose, which does not change, and replacing short-acting β2-agonists as relievers thereby allowing intervention to address the underlying inflammation at the earliest sign of symptomatic worsening. This approach is not suitable for other combination products such as salmeterol/fluticasone. Here we review the pharmacological differences of budesonide/ formoterol and salmeterol/fluticasone that permit the use of budesonide/formoterol as both maintenance and reliever therapy.