Ventidox-M Tablet is used to treat and prevent asthma and chronic obstructive pulmonary diseases (COPD). It contains Doxofylline and Montelukast, which works by relaxing muscles and widening the airways of the lungs. It treats the airflow obstruction in the lungs, thereby relieving chest tightness, wheezing and cough to make breathing easier. Also, it blocks the leukotrienes (chemicals released in response when a body comes in contact with an allergen), thereby reducing inflammation and swelling in the nose. It also inhibits bronchoconstriction (narrowing of airways in the lungs that lead to breathing difficulties). It may cause common side effects such as fever, nausea, vomiting, stomach pain/epigastric pain, headache, insomnia (difficulty in sleeping), irritation, sore throat, increased heart rate and flu-like symptoms.