A total of 15 studies was included in the review (n=856, range 12 to 112): 12 in acute asthma (eight double-blind randomised studies comprised six in adults and two in children); two open-label studies (one in adults and one in children) and two investigational (methacholine challenge) studies); and three in acute COPD (one double-blind and randomised, one single-blind and randomised and one open-label).
For patients with acute COPD exacerbations, comparable improvements in lung function were achieved for increasing doses of formoterol Turbuhaler and salbutamol pMDI (one study) and budesonide/formoterol Turbuhaler and salbutamol pMDI and spacer (one study). In adults with acute asthma after four hours the increase in FEV1 was significantly greater with formoterol via Turbuhaler compared with salbutamol via pMDI (43% versus 28%, p=0.03; one study), although a similar comparison of treatments found no significant difference at 15 or 45 minutes following administration (one study). For adults and children with acute asthma Turbuhaler was found to be as effective as either pMDIs (with or without a spacer; four studies) or a nebulizer (three studies). For children with acute asthma, drugs administered by Turbuhaler, pMDI or nebulizers yielded comparable improvements in lung function (two studies), which suggested that children from as young as six years of age can be effectively treated through use of dry powder inhalers. When bronchoconstriction was induced by methacholine challenge, investigational studies (two studies) found that either salbutamol, administered by either a DPI or pMDI, or formoterol, administered by Turbuhaler, were effective and fast-acting.