Dose-response relationship for inhaled corticosteroids and the add-on effect of long-acting β₂-adrenergic receptor agonists in adult chronic asthmatics

Abstract

Therapy with inhaled corticosteroids (ICS) has been regarded as first-line treatment for persistent asthma because of its highly potent anti-inflammatory effects. However, the limitations of such therapy are also well known. Although the anti-inflammatory effects of ICS are initially dose dependent, a plateau of response is reached at medium doses and a further increase of the dose is not associated with any significant additional therapeutic benefit. In contrast, it has been reported that a proportion of patients with severe asthma may benefit from prolonged treatment with higher doses of ICS in terms of a reduction in the frequency of severe acute exacerbations. Inhaled corticosteroids also exhibit a dose-response relationship for systemic adverse effects, which are most pronounced in patients receiving high doses of ICS. Thus, the long-term systemic burden of steroids should be minimized by always attempting to reduce the dose of ICS to the minimum required to maintain acceptable control of asthma symptoms and instituting, where required, add-on therapy with other controller agents, such as inhaled long-acting β₂-adrenergic receptor agonists and leukotriene receptor antagonists.