MRCP UK EXAMINATIONS

Detailed explanation-1: -Montelukast and zafirlukast are cysteinyl leukotriene receptor antagonists indicated to prevent and treat chronic asthma.

Detailed explanation-2: -Leukotriene inhibitors are alternative treatments in exercise-induced asthma and can be of benefit for children when oral therapy is preferred over inhalers. Leukotriene inhibitors are effective in the treatment of allergic rhinitis but are less effective than intranasal corticosteroids.

Detailed explanation-3: -They act by preventing leukotriene release from mast cells and eosinophils or by blocking the specific leukotriene receptors on bronchial tissues, thus preventing bronchoconstriction, mucus secretion, and oedema. These drugs also reduce the influx of eosinophils, thus limiting inflammatory damage in the airway.

Detailed explanation-4: -Leukotrienes play a key role in asthma in three ways: causing inflammation, bronchoconstriction and mucus production. The cysteinyl leukotrienes (LTC 4, LTD 4 and LTE 4 ) have been shown to be the most potent bronchconstrictors in humans and are believed to play a crucial role in asthmatic airway obstruction.