How to achieve good compliance with inhaled asthma therapy.

Inability to use inhaler devices correctly is a major source of non-compliance in patients with asthma. The problem of coordinating dose release with inspiration seen with pressurised metered dose inhalers (pMDIs) is overcome by dry powder inhalers (DPIs), since they use inspiratory flow energy to carry the drug dose to the respiratory tract. The first DPIs were not popular because they were single dose devices and inconvenient to use. The introduction of multiple dose DPIs improved the image of the dry powder systems in the eyes of both the clinician and the patient. The continued development of DPIs has led to inhaler devices which include dose counters, are easy to use, are refillable and provide feedback to the patient on a correct inhalation. Criteria that may improve patient compliance with an inhaler include: correct use of the device by most patients; ease and convenience of device use; dose release even at low inspiratory flow rates; feedback of drug release which could instill confidence that the dose has been inhaled; cartridge refills and overall confidence in the device. The Novolizer has all the desirable features listed above and is expected to improve compliance if prescribed for the large number of patients who cannot use the conventional pMDI or less efficient DPSs.