[Pharmacotherapy of severe asthma]

Severe asthma affects 5-10% of the asthma population. Exact pathophysiology of severe asthma mechanisams is complex and not fully understood. Cellular inflammation of the airways with neutrophils is a characteristic feature and is considered relevant to the pathogenesis of the disease, but all components of the airway wall have been reported to be thickened in severe asthma with or without cellular inflammation. Clinically it usually involves women with severe non-allergic asthma, late onset of asthma patients and aspirin induced asthma. Severe asthma rarely affects allergic asthma patients. Although majority of adults with mild or moderate asthma can be treated by inhaled glucocorticoids either alone or in combination with beta 2 agonists bronchodilators, patients with severe asthma require high doses of inhaled glucocorticoids or continuous oral use of glucocorticoids. Treatment of severe asthma should be started with high doses of inhaled steroids, 2000 microg of beclomethasone or its equivalents in addition to long acting beta 2 agonists, leukotriene receptor antagonists, theophylline and long acting anticholinergic drugs. Due to significant short-term and longterm oral glucocorticoids side effects it is essential to emphasize the importance of alternative therapies in severe asthma: treatment with omalizumab, macrolide antibiotics, tumor necrosis factor alpha inhibitors, cytokine receptors inhibitors and bronchial thermoplasty. Although there is a significant improvement in the treatment of severe asthma, the challenge remains to determine therapeutic strategy for appropriate phenotype in view of the heterogeneity of severe asthma.