Achieving asthma control.

The number of people with asthma continues to grow around the world. However, despite the availability of highly effective medication it remains a poorly controlled disease. Reasons for this poor control include non-implementation and inherent limitations of the asthma management guidelines, poor compliance with asthma therapy, incorrect use of inhaler devices and insufficient treatment of peripheral airway inflammation. Guidelines may not be efficiently implemented as they may be complicated and difficult to understand. In addition, the scientific evidence upon which they are based, although the best available at the present time, is flawed. Patient non-compliance with therapy is a major reason for poor asthma control. Patients fail to comply with their asthma regimen for a wide variety of reasons, but incorrect use of inhaler devices is amongst the most common. Most patients derive incomplete benefit from pressurised metered dose inhalers (pMDIs) as they are unable to use them correctly. Dry powder inhalers (DPIs) have several advantages over pMDIs; they are breath-activated (avoiding coordination difficulties between actuation and inhalation), easy and convenient to use, and environmentally friendly. Although there are many treatments for asthma currently in development, it is unlikely that significant improvements in inhaled medication will occur within the next 15 years. Therefore, improvement in asthma management will be facilitated by improvements in inhaler technology. When choosing an inhaler device it is essential that it is easy to use correctly, dosing is consistent, adequate drug is deposited in the lungs (both central and peripheral airways) and that drug deposition is independent of airflow.