Abstract

Chlorofluorocarbon (CFC)-containing inhalers are gradually being phased out and replaced with hydrofluoroalkane (HFA)-based alternatives. The reformulation provided the opportunity to improve the inhalation technology and physical characteristics of corticosteroid formulations. QVAR contains HFA-beclomethasone dipropionate (HFA-BDP) with the steroid in solution rather than suspension, which, in combination with improved inhaler technology, produces an extrafine aerosol with a mass median aerodynamic diameter of 1.1 microm (smaller than the 3.5-4.0 microm found with CFC-BDP). It was predicted and demonstrated that the smaller particle size of QVAR would be deposited in the lung to a greater extent than that found with CFC-BDP, particularly in the small airway, a major site of inflammation. Increased lung deposition of QVAR permits a reduction in dosage relative to CFC-BDP. Clinical evidence confirms that adult and elderly patients required approximately half the dose of QVAR to achieve the same degree of asthma control as with CFC-BDP. In long-term assessments, patients taking CFC-BDP could be switched to QVAR at half the daily dose without exacerbation of their asthma symptoms. QVAR was associated with a low overall incidence of side effects and, at the maximum recommended dose of 640 microg/d, caused no more adrenal suppression than 672 microg/d CFC-BDP.