Montair FX Tabs is a combination medication that contains two active ingredients – Montelukast and Fexofenadine. Montelukast is a leukotriene receptor antagonist that works by blocking the action of leukotrienes, which are chemicals in the body that cause allergic reactions and asthma symptoms. Fexofenadine is an antihistamine that helps to reduce the effects of histamine, a substance in the body that causes allergy symptoms. Montair FX Tabs is commonly used to treat symptoms such as sneezing, runny nose, itchy/watery eyes, and wheezing caused by allergies or asthma. It is important to follow the dosage instructions provided by your healthcare provider and to not exceed the recommended dose.