Therapeutic and Medicinal Approaches in Asthma Treatment: An Overview of Routine and Novel Drugs

The discovery and introduction of novel anti-asthma drugs have been very limited in the past decades. In fact, leukotrienes has been the only approved new class of anti-asthma drugs in last three decades. However, with the help of recent advances in molecular investigations, the research on new therapeutic compounds has been accelerated. Researches on novel drugs and re-design of old drugs with new formulations and less sideeffects are very important because asthma is a chronic and prolonged illness which burdens heavy economic costs to the national health system. Severe uncontrolled asthma and chronic obstructive pulmonary disease are such the high-cost diseases affect both the patients and national health system. These cause an inappropriate quality of life and health problems of considerable proportion of people. In addition, some new health and respiratory problems caused by air pollution and urbanization have been emerged recently that result in more occurrence of respiratory diseases. On the other hand, current antiasthma medications possess some pharmacologic and physiologic advantages and disadvantages. The present anti-asthma medications are administered in inhaler forms, however, they still have their main disadvantage which is systemic distribution in whole body via the absorption by the mucosal epithelial cells of the airways. Therefore, long-term corticosteroid therapy causes some complications such as osteoporosis and immunosuppression. The immunosuppression may lead to exacerbation of the clinical manifestations of asthma and susceptibility to the other infectious diseases such as opportunistic fungal infections. Moreover, fungal colonization of the airways may have no clinical symptoms but possibly be a cause of asthma exacerbation.