Tiotropium is superior to salmeterol in reducing frequency of exacerbations: but the effect of adding tiotropium to the combination of inhaled corticosteroid and long-acting β(2)-agonist remains unclear
Tiotropium is superior to salmeterol in reducing frequency of exacerbations: but the effect of adding tiotropium to the combination of inhaled corticosteroid and long-acting β(2)-agonist remains unclear