Clinical equivalence between salbutamol hydrofluoroalkane pMDI and salbutamol Turbuhaler TM at the same cumulative microgram doses in paediatric patients

Abstract

This study aimed to demonstrate equivalent efficacy and safety between salbutamol delivered via the HFA134a pMDI (Hydrofluoroalkane 134a pressurised Metered Dose Inhaler) and the Turbuhaler™ dry powder inhaler in asthmatic children. This was a randomised, double-blind, double-dummy, placebo-controlled, crossover study in 10 asthmatic children aged 6–15 years who demonstrated at least 10% reversibility of FEV 1 after inhaling 400 μg of salbutamol. On 5 single study days subjects received either placebo or cumulative doses of 100, 200, 400 and 800 μg of salbutamol at 30 minute intervals. Both devices were placebo on one study day, while each device was active on two study days. FEV 1 was measured before and 20 minutes after each dose. Heart rate was measured before spirometry. Mean FEV 1 and heart rate at each time point and the area under the dose response time curve (AUC) were analysed using ANOVA. FEV 1 increased similarly after cumulative doses of salbutamol on each of the study days, irrespective of device. Mean treatment difference in AUC was 0.01L.min (95%CI –0.05 to 0.08L). Heart did not differ at any dose. It is concluded that salbutamol delivery from a HFA pMDI and Turbuhaler™ is equivalent on a microgram basis in asthmatic children for efficacy and safety.