The ADMIT series--issues in inhalation therapy. 3) Mild persistent asthma: the case for inhaled corticosteroid therapy.

Mild persistent asthma should be treated with continuous inhaled corticosteroids (ICS), which reduces exacerbations of disease, controls symptoms and reduces bronchial mucosal inflammation. Most patients can be controlled with low dosage ICS (<or= 500 mcg/day beclometasone or equivalent) and there is limited benefit from further escalating dosages. There is some evidence of additional benefit of early treatment in terms of better longer term control of symptoms, but not alteration of the natural history of the disease. Withdrawal of ICS therapy results in rapid relapse of symptoms. Although some studies have suggested that intermittent therapy with ICS is not detrimental to asthma control, in the absence of any studies investigating the long term clinical, functional and pathophysiological differences between regular and intermittent therapy, the former continues to be recommended in guidelines. In patients well controlled on low/moderate dosages of ICS there is little benefit of adding any other medication and no rationale for commencing combination therapy routinely as first line controller therapy. There is no evidence that ICS or any other medication prevents the occurrence of asthma, and scanty evidence that the decline in lung function associated with asthma is arrested to any significant degree by ICS therapy. ICS has variable effects on features of airways remodelling but the long term physiological consequences of these effects, if any, are as yet unknown.