Chapter 24: Asthma & COPD – Pharmacologic Management

The management of chronic respiratory conditions, specifically asthma and Chronic Obstructive Pulmonary Disease (COPD), relies on distinct yet related evidence-based strategies informed by global guidelines such as the Global Initiative for Asthma (GINA) and the Global Initiative for Chronic Obstructive Lung Disease (GOLD). The chapter thoroughly delineates the differences in etiology, noting asthma's complex interaction of genetics and environment (including the Hygiene, Old Friends, and Biodiversity hypotheses) versus COPD's strong links to tobacco smoke, air pollution, and infections. Pathophysiological understanding is guided by precision medicine concepts like endotype (underlying molecular mechanisms), phenotype (observable characteristics), theratype (response to therapy), and measurable biomarkers (such as eosinophil counts and Immunoglobulin E levels). Diagnosis for both requires spirometry: asthma is characterized by variable, reversible airflow limitation, while COPD presents with persistent, irreversible obstruction, graded using GOLD stages based on forced expiratory volume in 1 second (FEV1) and assessment groups (A, B, C, D) defined by symptoms and exacerbation history. Pharmacologic intervention must be individualized, starting with quick-reliever therapies (short-acting beta2-agonists [SABA] or short-acting muscarinic antagonists [SAMA]) for acute symptoms. Long-term controller therapy includes inhaled corticosteroids (ICS), which are foundational for asthma, often combined with long-acting beta2-agonists (LABA) or long-acting muscarinic antagonists (LAMA) for maintenance in both diseases. Other specialized agents covered include leukotriene modifier drugs (LMDs), phosphodiesterase 4 (PDE-4) inhibitors like roflumilast (used for severe chronic bronchitis COPD), methylxanthines, and monoclonal antibodies (mABs) targeting specific inflammatory markers (such as IL-4R, IL-5/5R, and IgE) for severe asthma phenotypes. The text emphasizes essential patient education on proper drug delivery device usage (MDI, DPI, nebulizer techniques), self-monitoring with written action plans, and lifestyle modifications like smoking cessation, alongside specific management considerations for pediatric, geriatric, and pregnant populations, and the required use of immunizations and supplemental oxygen in appropriate cases.