Most guidelines recommend long-acting bronchodilators over short-acting bronchodilators for patients with chronic obstructive pulmonary disease (COPD). The available evidence for the guidelines was based on dry powder or pressurized metered dose inhalers, but not nebulizations. Nevertheless, there is considerable, poorly evidenced based, use of short acting nebulized bronchodilators.

This was an investigator initiated, randomized, active controlled, cross-over, double-blind and double-dummy single centre study in patients with stable COPD. The active comparators were indacaterol/glycopyrronium 110/50 μg as Ultibro® via Breezhaler® (IND/GLY) and salbutamol/ipratropium 2,5/0,5 mg via air driven nebulization (SAL/IPR), both given as a single dose on separate days. The primary end point was the area under the FEV₁ curve from baseline till 6 h. Secondary end points included change in Borg dyspnoea score, adverse events and change in hyperinflation measured by the inspiratory capacity.

A total of 33 COPD patients completed the trial and were evaluable, most of them were ex-smokers. The difference between the tested regimens for the primary endpoint, FEV₁ AUC 0–6 h, 2965 ± 1544 mL (mean ± SD) for IND/GLY versus 3513 ± 1762 mL for SAL/IPR, was not significant (P = 0.08). The peak in FEV1 was higher and was reached faster with SAL/IPR compared to IND/GLY. No other significant differences were detected for the secondary endpoints including the Borg score, or adverse events.

Among patients with stable COPD, dry powder long-acting single inhalation of a LABA and a LAMA (IND/GLY) was not superior compared to nebulized short-acting salbutamol plus ipratropium (SAL/IPR) in its bronchodilating effects over 6 h.The effects of the nebulization kicked in faster and peaked higher. The observed differences may be caused by the difference in dosing between the two regimens. The improvement in Borg dyspnoea score did not favour the nebulization. Long-term outcomes were not assessed in this study.