The anti-inflammatory effects of leukotriene-modifying drugs and their use in asthma

Asthma is a chronic inflammatory disease of the airways. Anti-inflammatory drug therapy, primarily using corticosteroids, is now considered the first-line treatment in the management of all grades of asthma severity. Although corticosteroids are believed to be the most potent anti-inflammatory agents available, they do not suppress all inflammatory mediators involved in the asthmatic response. Leukotrienes, which are lipid mediators generated from the metabolism of arachidonic acid, play an important role in the pathogenesis of asthma. They produce bronchospasm, increase bronchial hyperresponsiveness, mucus production, and mucosal edema, and enhance airway smooth muscle cell proliferation and eosinophil recruitment into the airways, and their synthesis or release is unaffected by corticosteroid administration. The use of leukotriene synthesis inhibitors or leukotriene receptor antagonists as anti-inflammatory therapies in asthma has therefore been investigated. Beneficial effects of leukotriene-modifying drugs have been demonstrated in the management of all grades of asthma severity, and there is evidence that certain patient groups (such as those with exercise-induced asthma or aspirin-induced asthma) may be particularly suitable for such therapy.