Proair HFA is an inhaler used to stop wheezing and shortness of breath which arise from conditions such as asthma. Proair HFA works by relaxing the airway muscles to increase airflow to the lungs. It achieves this by enhancing its activity at beta-2 receptors which are located on the lungs.Proair Hfa belongs to leukotriene receptor antagonists and comes in different forms of tablets; chewable, flash and granules which can be taken by mouth. Proair Hfa is a CysLT1 antagonist is usually taken once daily with or without food. Proair Hfa is used in preventing the shortness and wheezing of breath caused by asthma and reduce the number of asthma attacks. Proair Hfa is used before exercise to prevent breathing problems during exercise. Proair Hfa can help in reducing the number of times you will need to use your rescue inhaler. Proair Hfa is also used in relieving symptoms of allergic rhinitis and hayfever such as sneezing and itchy nose. Proair Hfa works by blocking the action of the leukotriene D4 on the leukotriene receptor CysLT1 in the bronchial and lungs tubes by binding to it. Thus decreasing the bronchoconstriction caused by the leukotriene and results in less inflammation. Proair Hfa will not work immediately and should not be used in the treatment of sudden asthma attacks or other breathing problems.