Bronchodilator responses to salbutamol using diskhaler versus metered-dose inhaler

Abstract

In adults inhaling salbutamol via metered-dose inhalers (MDIs) 200 μg doses are recommended, but with diskhalers the manufacturer advocates 400 rather than 200 μg doses. To assess this advice, a partially double-blind, placebo-controlled salbutamol dose response, crossover study (also incorporating MDI doses) was conducted in 12 mild/moderate asthmatics. After active treatment, mean peak expiratory flow rate (PEFR) increments yielded no clinically or statistically significant differences; compared to placebo, respective median differences in PEFR increments (95% Cls) were 10 (-10, 50), 20 (0, 50), and 15 (0, 30) following 400 and 200 μg via diskhalers and 200 μg via MDIs. Diskhalers are a suitable alternative for patients with poor MDI technique, but the use of 400 rather than 200 μg salbutamol doses is not supported by evidence.