Demystifying Dry Powder Inhaler Resistance with Relevance to Optimal Patient Care.

The selection of an inhaler device is a key component of respiratory disease management. However, there is a lack of clarity surrounding inhaler resistance and how it impacts inhaler selection. The most common inhaler types are dry powder inhalers (DPIs) that have internal resistance and pressurised metered dose inhalers (pMDIs) that use propellants to deliver the drug dose to the airways. Inhaler resistance varies across the DPIs available on the market, depending largely on the design geometry of the device but also partially on formulation parameters. Factors influencing inhaler choice include measures such as flow rate or pressure drop as well as inhaler technique and patient preference, both of which can lead to improved adherence and outcomes. For optimal disease outcomes, device selection should be individualised, inhaler technique optimised and patient preference considered. By addressing the common clinically relevant questions, this paper aims to demystify how DPI resistance should guide the selection of the right device for the right patient.

Selection of the right inhaler is important to ensure that patients with respiratory diseases get the most benefit from their treatment. Dry powder inhalers and pressurised metered dose inhalers are the most common inhaler types. Pressurised metered dose inhalers use propellants to deliver the drug to the lungs. In contrast, dry powder inhalers deliver the drug to the lungs by having internal resistance. This restricts the flow of air through the inhaler. As the patient inhales through the inhaler, the resistance against the air flow generates the power to separate the drug molecules and carry them to the lungs. While there are many factors to be considered for inhaler selection, there is often confusion around how resistance should guide selection of inhaler. With low-resistance devices, patients must inhale faster to generate the power to separate the drug molecules, which may be difficult in patients with poor lung function. With high-resistance devices, patients do not need to inhale as fast to separate the drug, and most patients can effectively use the inhaler. This article addresses the common clinically relevant questions to clarify how the internal resistance of the inhaler should be used to help guide the selection of the right device for the right patient.

Adapting Inhaled Medication Practice in COPD and Asthma to Avoid Funding the Tobacco Industry.

The takeover of Vectura, a healthcare company specialising in inhaled medication, by Philip Morris International raises serious ethical concerns. The European Respiratory Society notes that "health professionals will avoid prescribing drugs from any company that enriches the tobacco industry due to the ethical implications". People with chronic obstructive pulmonary disease (COPD) and asthma will also be reluctant to use medications which profit a company that is estimated to kill at least one million people every year. We discuss the practicalities involved in switching people with lung disease to inhaled medications that are not tobacco industry linked. Potential alternative inhaled medications are set out, which are likely to be equally effective for most patients. A consideration of beneficence, non-maleficence, autonomy, and distributive justice demonstrates strong ethical reasons to support switching away from the prescription of tobacco industry linked products.

Inhaler technique and training in people with chronic obstructive pulmonary disease and asthma.

Asthma and chronic obstructive pulmonary disease are both common conditions with an increasing prevalence worldwide. Inhaled therapy for these conditions has a number of advantages over systemic therapy, including reduced side effects and quicker onset of action. The effective use of inhaled therapy is critically dependent upon the nature of the drug-delivery system and the ability of the patient to use the system correctly. There are a wide number of inhaler devices on the market, each with positive and negative aspects. A crucial part of patient care is to ensure that the choice of inhaler device for the individual is an effective therapy. There are a number of interventions that can help with the choice of inhaler device and also improve the ability of the patient to use inhaled therapy. Inhaler technique training needs to be a cornerstone of the care of patients with asthma or chronic obstructive pulmonary disease to ensure optimal therapy.