[Usefulness of antibiotics in the treatment of bronchial asthma].

The efficacy and safety of antibiotics in the treatment of asthma are not unequivocal. Among various antibiotics, macrolides play the main role in the therapy of bronchial asthma. Macrolides are useful in the treatment of asthma not only because of their antimicrobial activity. The mechanism of action of macrolides in improving asthma and reducing airway responsiveness is evaluated especially due to their activity in non-infectious asthma. Macrolides may not only enhance the host defense system through increased cytokine synthesis, but also exhibit anti-inflammatory activity mediated by anti-inflammatory cytokines. The steroid-sparing effect of macrolide antibiotics has been postulated to contribute to their beneficial actions in the treatment of asthma. Macrolides may be useful in the treatment of patients with steroid-dependent asthma, probably because they inhibit eosinophilic inflammation. It has also been suggested that the effect of macrolides on bronchial hyperresponsiveness is mediated by their inhibitory action on superoxide production and chemotaxis of polymorphonuclear neutrophils and the mixed lymphocyte reactions. In spite of these suggestions, the mechanism of action of macrolides in asthmatic syndrome is not clear. Only well-designed and conducted clinical studies are capable of assessing the efficacy and safety of immunosuppressive macrolides in the treatment of asthma.