Beclomethasone is used to prevent and control symptoms (wheezing and shortness of breath) caused by asthma. This medication belongs to a class of drugs known as corticosteroids. It works by reducing the swelling of the airways in the lungs to make breathing easier.This medication must be used regularly to prevent breathing problems (attacks of wheezing/shortness of breath). It does not work right away and should not be used to relieve an asthma attack. If an attack occurs, use your quick-relief inhaler as prescribed.