Therapeutic approaches of asthma and COPD overlap

Asthma and COPD overlap (ACO) is an important clinical phenotype, due to the low-health-related quality of life (QOL), rapid decline in lung function, frequent exacerbation, and high economic burden. However, no large-scaled therapeutic trials of ACO have been conducted. At present, ACO is treated according to asthma/COPD guidelines. The goals of ACO treatment are to relieve symptoms and improve QOL and lung functions. Treatment must also prevent disease progression, airway remodeling, exacerbation, complications, and comorbidities. To achieve these goals, ACO needs first to be assessed based on pathophysiological findings. Comprehensive long-term management includes medication, reduction of risk factors, environmental improvement, patient education, rehabilitation, and vaccination. Drug treatment for ACO employs a combination of inhaled corticosteroids (ICSs) and long-acting bronchodilators; long-acting muscarinic antagonists and/or long-acting β₂-agonists. The dose of ICS is determined according to ACO severity. Leukotriene receptor antagonists and theophylline are used as add-on drugs. Macrolides and expectorants are recommended for reduction of mucus hypersecretion. Anti-IgE and anti-IL-5 antibodies, oral corticosteroids, and oxygen therapy are additional treatments for the most severe ACO. The therapeutic effects are evaluated using lung function tests, eosinophil counts in sputum and blood, FeNO, and symptom questionnaires. ACO exacerbation is treated by inhalation of short-acting β₂-agonist and systemic corticosteroids. The doses of corticosteroids are determined based on the asthma/COPD component of the exacerbation. Administration of antibiotics is recommended if sputum is purulent. Referral to specialists is necessary in cases of inability to control symptoms by medication, uncertain diagnosis with atypical features, or severe complications and comorbidities.