Inspiratory Profiles Through Easyhaler Dry Powder Inhaler During Acute Bronchoconstriction.

Background

Dry powder inhalers (DPIs) are passive devices, which rely on a patient's inspiratory effort for drug dispersion and delivery. The aim of this study was to assess how acute bronchoconstriction affects the ability to use Easyhaler DPI in adults.

Methods

This study was conducted as part of a parallel-group clinical trial assessing use of Salbutamol Easyhaler, Budesonide-formoterol Easyhaler and salbutamol pMDI with spacer during a methacholine challenge (MC) test. The inhalations through both Easyhaler variants, the inhaler for the single active substance product (EH-mono) and the inhaler for the combination product (EH-combi), were recorded at baseline and during bronchoconstriction. Peak inspiratory flow (PIF), flow rate acceleration and inhalation volume after PIF were compared to the criteria for successful inhalation.

Results

The study population consisted of 120 adult subjects indicated for MC as a diagnostic test for asthma, with 60 subjects in both Easyhaler arms. With EH-combi 98.3% and 91.4% passed the criteria (PIF ≥30 L/min, inhalation acceleration ≥0.7 L/s2, and inhalation volume ≥500 mL after PIF) for successful inhalation at baseline and during bronchoconstriction, respectively. With EH-mono, success rates were 95.0% and 88.1% at baseline and during bronchoconstriction, respectively. The most common reason for not passing the criteria was slow inhalation acceleration. Aside from two subjects using EH-mono during bronchoconstriction, all subjects were able to generate PIF ≥ 30 L/min.

Conclusions

During an acute obstructive event, the vast majority of patients have no difficulty in achieving sufficient PIF, inhalation acceleration, and volume after PIF when using an Easyhaler DPI.