Budesonide is an inhaled corticosteroid commonly used as a controller medication for the long-term management of asthma. It works by reducing inflammation and swelling in the airways, helping to prevent asthma symptoms such as wheezing, coughing, and shortness of breath.

Budesonide is effective as monotherapy for mild to moderate persistent asthma and is also available in combination with a long-acting beta agonist (e.g., formoterol) for more severe cases. It comes in inhaler and nebulizer forms, making it suitable for both adults and children. Regular use can significantly reduce the frequency of asthma exacerbations and improve overall lung function.