Non-inferior relief of bronchoconstriction with salbutamol via Easyhaler dry powder inhaler compared to pressurised metered dose inhaler with spacer

<bold>Background:</bold> Salbutamol is a cornerstone for relieving acute asthma symptoms, typically administered through a pressurised metered-dose inhaler (pMDI). Dry powder inhalers (DPIs) offer an alternative, but concerns exist whether DPIs provide an effective relief during an obstructive event. <bold>Aim:</bold> The aim of the study was to show non-inferiority of Salbutamol Easyhaler (EH) DPI compared to pMDI with a spacer in treating methacholine-induced bronchoconstriction. Applicability of Budesonide-formoterol EH as a reliever was also assessed. <bold>Methods:</bold> This was a randomised, parallel-group trial in subjects sent to methacholine challenge (MC) test for asthma diagnostics. Participants with ≥20% decrease in FEV₁ were randomised to receive Salbutamol EH (2x200 mcg), Ventoline Evohaler through Volumatic spacer (4x100 mcg) or Budesonide-formoterol EH (2x160/4.5 mcg) as a reliever. Treatment was repeated if FEV₁ did not recover to ≥-10% of baseline. <bold>Results:</bold> 180 participants (69% females, mean age 46 y [range 18-80], FEV₁%pred 89.5% [62-142]) completed the trial. Salbutamol EH was non-inferior to pMDI with spacer in acute relief of bronchoconstriction with the difference of -0.083 L (95% lower confidence limit -0.146) in FEV₁ after the first dose and -0.032 L (−0.071) after the last dose. The differences in FEV₁ between Budesonide-formoterol EH and salbutamol pMDI with spacer were -0.163 L (−0.225) after the first and -0.092 L (−0.131) after the last dose. <bold>Conclusions:</bold> The study confirms non-inferiority of Salbutamol EH to Ventoline Evohaler with spacer in relieving acute bronchoconstriction, making EH a sustainable and safe reliever for MC test and asthma attacks.