DIFFERENCES IN OUTPUT FROM CORTICOSTEROID INHALERS USED WITH A VOLUMATIC SPACER

Corticosteroid inhaler therapy using a spacer device is commonly used as an important part of asthma management. Increasingly, generic corti costeroid inhalers are being used with spacer devices, We have therefo re tested whether these generic inhalers yield equivalence in dose whe n compared to the established inhalers. We measured the in vitro outpu t, discharged into a Volumatic spacer from beclomethasone dipropionate inhalers (250 mu g . puff(-1)) made by three manufacturers, Allen & H anburys, 3M and Baker Norton. The output from 20 of each type of inhal er was sampled, in random order, by a computer driven pump system, Bec lomethasone was absorbed onto a coded filter, which was analysed indep endently for drug content. The output per puff differed significantly between the inhalers of each manufacturer, with a 36% difference betwe en the highest output from the Allen & Hanburys device and the lowest output device. We conclude that there are important differences in out put from these inhalers when used with a spacer, and that substitution of one device with another will not necessarily give equivalent thera py to the patient.