Clinical Consequences of Inhaler Non-Adherence in Asthma and COPD

For any therapy to be effective it needs to be taken (conversely, adverse events attributable to the drug can only be manifest if the drug is actually taken). In all therapeutic areas, poor compliance with the recommended regimen is common for a variety of reasons. In asthma and chronic obstructive pulmonary disease (COPD), the consequences of poor compliance range from a minor persistence of symptoms, such as an itchy nose during the hay fever season, to significant morbidity and premature death. There is some, but not overwhelming, data to suggest that regimen compliance may be worse when using inhalers compared to oral medication. The inhaled route adds an extra level of complexity because failure of drug delivery leading to excessive morbidity and mortality may also be due to poor device compliance – that is, the patient does not have the competence to use their inhaler effectively (either because they have not received instruction, have been given a device they cannot master, or have forgotten), or alternatively, they know how to use it effectively but choose to use an ineffective technique. The result is similar to that associated with regimen compliance – excessive morbidity and mortality.