Budesonide is a glucocorticoid steroid having a highly oxygenated pregna-1,4-diene structure. It is used mainly in the treatment of asthma and non-infectious rhinitis and for treatment and prevention of nasal polyposis. It has a role as an anti-inflammatory drug, a bronchodilator agent and a drug allergen. It is an 11beta-hydroxy steroid, a glucocorticoid, a cyclic acetal, a 20-oxo steroid, a 21-hydroxy steroid, a 3-oxo-Delta(1),Delta(4)-steroid and a primary alpha-hydroxy ketone. It derives from a hydride of a pregnane.