Kraft Monica
Duke Asthma, Allergy, and Airway Center, Duke University, Durham, NC 27710, USA.
Curr Med Res Opin. 2007 Sep;23 Suppl 3:S21-7. doi: 10.1185/030079907X226177.
Accumulating evidence suggests that the airway inflammation and remodeling characteristic of asthma occur not only in the central airways, but also in the distal lung and the lung parenchyma. The distal airways are increasingly being recognized as important sites of airflow obstruction. Research indicates that distal inflammation may play a crucial role in airway hyperresponsiveness, nocturnal asthma, and spontaneous exacerbations of asthma symptoms. Although the effectiveness of inhaled corticosteroids in improving asthmatic symptoms and preventing exacerbations is well established, the ability of conventional formulations to reach the distal airways is limited. The impaired ability of these formulations to reach the distal airways may contribute to the observation that inhaled corticosteroids do not always provide adequate control of asthma symptoms. Newer formulations of inhaled corticosteroids that use hydrofluoroalkane (HFA) propellants in solution have greater access to the distal airways and produce beneficial changes in lung function. Due to their highly targeted delivery systems, newer HFA-based formulations have the potential to effectively treat asthma at reduced doses.
越来越多的证据表明，哮喘所特有的气道炎症和重塑不仅发生在中央气道，也发生在远端肺和肺实质。远端气道越来越被认为是气流阻塞的重要部位。研究表明，远端炎症可能在气道高反应性、夜间哮喘和哮喘症状的自发加重中起关键作用。尽管吸入性糖皮质激素在改善哮喘症状和预防发作方面的有效性已得到充分证实，但传统制剂到达远端气道的能力有限。这些制剂到达远端气道的能力受损可能导致观察到吸入性糖皮质激素并不总是能充分控制哮喘症状。使用氢氟烷烃（HFA）推进剂的新型吸入性糖皮质激素溶液制剂能更好地到达远端气道，并对肺功能产生有益变化。由于其高度靶向的给药系统，新型基于HFA的制剂有可能以较低剂量有效治疗哮喘。
