Beta-blocker prescription in elderly patients with asthma

The impact of regular bisoprolol on the response to salbutamol in asthma: A double-blind randomized placebo-controlled crossover trial

BACKGROUND AND OBJECTIVE

Non-selective beta-blockers impair the bronchodilator response to beta₂ -agonists. Cardio-selective beta₁ -blockers are less likely to cause this effect, yet they remain relatively contraindicated in asthma. We investigated whether the response to salbutamol is impaired during cardio-selective beta₁ -blocker treatment in people with asthma.

METHODS

A random-order, double-blind, placebo-controlled, non-inferiority, crossover study was conducted comparing up to 5 mg bisoprolol daily for 2 weeks with matching placebo, with an open-label extension of up to 10 mg bisoprolol daily. After each treatment period, mannitol was inhaled to induce bronchoconstriction with a 15% fall in forced expiratory volume in 1 s (FEV₁ ). Immediately after mannitol challenge, salbutamol (100, 100 and 200 μg) was administered via spacer at 5-min intervals with repeated FEV₁ measures. The FEV₁ recovery with salbutamol was measured as an area under recovery curve (AUC). Based on earlier research, a clinically relevant non-inferiority limit of a 30% reduction in the AUC was set.

RESULTS

A total of 19 adults with mild asthma and positive inhaled mannitol challenge completed the study. Adjusting for the FEV₁ fall induced by mannitol and treatment sequence, the mean AUC response to salbutamol after bisoprolol was 5% lower than after placebo, with a one-sided 95% confidence interval (CI) of 26% lower. Thirteen participants completed the open-label extension up to 10 mg bisoprolol daily with mean AUC 11% higher after bisoprolol with a 95% CI of 5% lower.

CONCLUSION

The bronchodilator response to rescue salbutamol after mannitol-induced bronchoconstriction is non-inferior during regular treatment with the cardio-selective beta₁ -blocker, bisoprolol, compared to placebo.

CLINICAL TRIAL REGISTRATION

ACTRN12618000306213 at https://www.anzctr.org.au.

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.

Challenges in the pharmacological treatment of geriatric asthma

Asthma in older populations is characterized by frequent comorbid conditions, which increase the risk of side effects and of detrimental interactions between respiratory and non-respiratory drugs. These observations lead to the need to manage asthma in older populations by applying a multidimensional assessment and a multidisciplinary treatment; therefore, we favor the use of the 'geriatric' term to define asthma in the elderly. Geriatric asthma is a complex disease, which may not necessarily imply that it is also complicated, although the two conditions may often coexist. On this basis, the switch from an organ-driven management to the holistic approach may be the key factor to attain optimal control of the disease in this age range. The current review discusses the age-related factors affecting asthma treatment in the oldest individuals, such as the comorbid conditions, and age-related changes of metabolism and excretion that can impair the efficacy and safety of drugs.