Review of therapeutically equivalent alternatives to short acting beta(2) adrenoceptor agonists delivered via chlorofluorocarbon-containing inhalers

Background-To study the transition from metered dose inhalers using chlorof luorocarbons as propellants (CFC-MDIs) to non-CFC containing devices, a sys tematic review was conducted of clinical trials which compared the delivery of salbutamol and terbutaline via CFC-MDIs and non-CFC devices. Methods-Papers were selected by searching electronic databases (Medline, Co chrane, and BIDS) and further information and studies were sought from phar maceutical companies. The studies were assessed for their methodological qu ality. Results-Fifty three relevant trials were identified. Most were scientifical ly flawed in terms of study design, comparison of inappropriate doses, and insuffcient power for the determination of therapeutic equivalence. Differe nces between inhaler devices were categorised according to efficacy and pot ency. Most trials claimed to show therapeutic equivalence, usually for the same doses from the different devices. Two commercially available salbutamo l metered dose inhalers using a novel hydrofluorocarbon HFC-134a as propell ant were equally as potent and efficacious as conventional CFC-MDIs, as wer e the Rotahaler and Clickhaler dry powder inhalers (DPIs). Evidence suggest s that a dose of 200 mu g salbutamol via CFC-MDI may be substituted with 20 0 mu g and 400 mu g of salbutamol via Accuhaler and Diskhaler DPIs, respect ively. Terbutaline delivered via a Turbohaler DPI is equally as potent and efficacious as terbutaline delivered via a conventional CFC-MDI. Conclusions-When substituting non-CFC containing inhalers for CFC-MDIs, att ention must be given to differences in inhaler characteristics which may re sult in variations in pulmonary function.