in patients with reversible airflow obstruction. Thorax

re: Lung deposition of budesonide from Turbuhaler is twice that from a pressurized metered-dose inhaler (P-MDI). Thorsson, et al. Eur Respir J 1994 7: 1839–1844. Therefore, any differences in lung deposition need to be supported by clinical data to determine whether they are clinically relevant. Indeed, there are data which show no difference, in terms of improvements in lung function, between the MDI and Turbuhaler in multiple-dose studies with ipatropium bromide [3], terbutaline [4, 5] and bud-esonide [6] as well as single-dose and cumulative dose studies with terbutaline [7, 8]. It is clear, therefore, that caution has to be taken in the interpretation of the clinical relevance of lung deposition studies, both in terms of extrapolation to other drugs in the same device and also different drugs and devices