Personalizing Inhaled Therapy in COPD and Asthma: Integrating Drug, Device, and Patient Factors

The management of chronic obstructive pulmonary disease (COPD) and asthma depends largely on the effective delivery of aerosolized medications to the respiratory tract. Clinical efficacy is determined not only by the active pharmaceutical ingredient but also by the interplay among drug formulation, aerosol particle size, inhaler device characteristics, dosing frequency, and patient-specific factors. This review examines the major inhaled therapeutic platforms, including soft mist inhalers (SMIs), pressurized metered-dose inhalers (pMDIs), and dry powder inhalers (DPIs), and evaluates how their characteristics influence pulmonary drug delivery. We examine the impact of particle size and extrafine formulations on peripheral deposition and small airway disease (SAD), as well as clinically relevant factors including peak inspiratory flow rate (PIFR), inhaled corticosteroid-associated pneumonia risk, dosing frequency and adherence, rescue inhaler requirements, inhaler technique, cost and accessibility, and environmental impact. By integrating inhaler characteristics with real-world clinical considerations, this article provides a structured, evidence-based framework for individualized inhaler selection in obstructive lung disease. However, the available evidence is limited by heterogeneity across devices, formulations, study populations, and assessment methods, highlighting the need for further comparative effectiveness studies and evaluation of emerging inhaler technologies.