The frequency of oral candidiasis secondary to the use of inhaled corticosteroids delivered by Turbuhaler is low and similar to that seen with current pMDIs attached to a large volume spacer . Oral candidiasis can be prevented almost completely by thorough mouth rinsing and gargling after use and by bid dosing as opposed to qid. Delivery of the inhaled corticosteroid budesonide to the airway with the Tur-buhaler is twice that obtained using a conventional pMDI and equivalent to the amount deposited in the lower airway using the pMDI with a large volume spacer . Increasing inspiratory flow from 30 L/s (the usual inspiratory flow recommended for pMDIs) to 60 L/s doubles lung deposition and may permit a substantial reduction in the dose of inhaled corticosteroid required to maintain symptom control .
This may in turn result in substantial cost savings. (A flow of approximately 60 L/min can be obtained by asking patients to breathe in rapidly).
The bronchodilator effect of the beta-agonist terbutaline delivered by Turbuhaler is adequate at inspiratory flows as low as 15 L/s and has been used effectively in the treatment of acute severe asthma in the emergency room . The therapeutic effect obtained is equivalent to that seen with wet nebuliza-tion or with a pMDI attached to a large volume spacer.