Pharmacological Management of Elderly Patients with Asthma–Chronic Obstructive Pulmonary Disease Overlap Syndrome: Room for Speculation?

Asthma and chronic obstructive pulmonary disease (COPD) are two distinct diseases that share a condition of chronic inflammation of the airways and bronchial obstruction. In clinical settings, it is not rare to come across patients who present with clinical and functional features of both diseases, posing a diagnostic dilemma. The overlap condition has been termed asthma–COPD overlap syndrome (ACOS), and mainly occurs in individuals with long-standing asthma, especially if they are also current or former smokers. Patients with ACOS have poorer health-related quality of life and a higher exacerbation rate than subjects with asthma or COPD alone. Whether ACOS is a distinct nosological entity with genetic variants or rather a condition of concomitant diseases that overlap is still a matter of debate. However, there is no doubt that extended life expectancy has increased the prevalence of asthma and COPD in older ages, and thus the probability that overlap conditions occur in clinical settings. In addition, age-associated changes of the lung create the basis for the two entities to converge on the same subject. ACOS patients may benefit from a stepwise treatment similar to that of asthma and COPD; however, the proposed therapeutic algorithms are only speculative and extrapolated from studies that are not representative of the ACOS population. Inhaled corticosteroids are the mainstay of therapy, and always in conjunction with long-acting bronchodilators. The potential heterogeneity of the overlap syndrome in terms of inflammatory features (T helper-1 vs. T helper-2 pathways) may be responsible for the different responses to treatments. The interaction between respiratory drugs and concomitant diseases should be carefully evaluated. Similarly, the effect of non-respiratory drugs, such as aspirin, statins, and β-blockers, on lung function needs to be properly assessed.