The efficacy of adding budesonide/formoterol to ipratropium plus theophylline in managing severe chronic obstructive pulmonary disease: an open-label, randomized study in China

Patients diagnosed with chronic obstructive pulmonary disease (COPD) in China are commonly prescribed ipratropium plus theophylline (I+T) therapy. Studies have shown that an inhaled corticosteroid (ICS)/long-acting β