Pharmacologic interventions to reduce the risk of asthma exacerbations

Inhaled corticosteroids (ICS) are known to reduce the risk of asthma exacerbations and asthma fatalities. In addition, an increased dose of ICS at the onset of exacerbation can reduce the need for systemic corticosteroids, although this may require a fourfold increase in dose. The overuse of short-acting beta(2)-agonists or long-acting inhaled beta(2)-agonists, used as monotherapy, increases these risks. By contrast, the use of long-acting beta(2)-agonists together with ICS has been demonstrated to reduce the doses of ICS needed for ideal asthma control, as well as to reduce asthma exacerbations. This has been best demonstrated in the Formoterol and Corticosteroids Establishing Therapy and Oxis and Pulmicort Turbuhaler in the Management of Asthma studies, which demonstrated that the combination of inhaled budesonide and formoterol reduced the risk of asthma exacerbations over that achieved by budesonide alone. Even the "as needed" use of inhaled formoterol added to ICS reduces asthma exacerbations. The combination inhaler, Symbicort, containing both budesonide and formoterol, reduced the risk of asthma exacerbations to a similar extent as the monocomponents, given separately. Treatment with either leukotriene receptor antagonists or anti-IgE also reduces the risks of asthma exacerbations, but the magnitude of the benefit compared with the combination of ICS and long-acting beta(2)-agonists is not yet known.