Application and efficacy of the multi-dose powder inhaler, Easyhaler®, in children with asthma

Abstract

With powder inhalers, optimal performance is dependent on the inspiratory flow produced by the patient through the devices. The objective of this open, non-randomized study was to evaluate the suitability of a new, multi-dose, dry powder inhaler, the Easyhaler®, for children with asthma. The peak inspiratory flow (PIF) through the Easyhaler (PIF(EH)) was measured with a pneumotachograph in 120 asthmatic children aged 4-16 yr. The bronchodilatory effect of 0.2 mg salbutamol through the Easyhaler was compared with that of 0.2 mg salbutamol through a metered dose inhaler (MDI) with a spacer, in 15 children with obstruction. The mean PIF(EH) was 56 l/min (range 22-83 l/min). The PIF(EH) correlated significantly with age, height, and absolute peak expiratory flow (PEF), but not with the level of obstruction (PEF percentage of predicted, range 45-146%). Only four children (aged 5, 6, 10, and 16 yr) had PIF(EH) values below 28 l/min, which has been shown in in vitro studies to be the threshold for effective use of the Easyhaler. In 15 children with PEF, < 85% of predicted bronchodilatory effects of 0.2 mg salbutamol through the Easyhaler and from an MDI-cum-spacer were equal. Most children aged 6-16 yr produce PIF values sufficient for the use of the Easyhaler. The gain of 0.2 mg salbutamol from the Easyhaler was equal to that from a new, unprimed, MDI with a spacer in children with asthma.