Fluticasone asthma drug molecule. Computer model of a molecule of the asthma drug fluticasone. Atoms are represented as spheres and are colour- coded: carbon (blue), hydrogen (white), oxygen (red), fluorine (green) and sulphur (yellow). Fluticasone belongs to a class of drugs known as corticosteroids that have anti- inflammatory properties. It is taken in aerosol form, using an inhaler, and prevents asthma attacks by relieving inflammation of the airways. It will not stop an asthma attack that has already started.