|Trade names||Aerobid, Nasalide, Nasarel, others|
|Other names||6α-Fluoro-11β,16α,17,21-tetrahydroxypregna-1,4-diene-3,20-dione acetone cyclic 16,17-acetal|
|Protein binding||40% after inhalation|
|Elimination half-life||1.8 hours|
|CompTox Dashboard (EPA)|
|Chemical and physical data|
|Molar mass||434.504 g·mol−1|
|3D model (JSmol)|
|(what is this?)|
Flunisolide (marketed as AeroBid among others) is a corticosteroid often prescribed as treatment for allergic rhinitis. Intranasal corticosteroids are the most effective medication for controlling symptoms. 
The principal mechanism of action of flunisolide is to activate glucocorticoid receptors, meaning it has an anti-inflammatory action. The effects of topical corticosteroids is not immediate and requires regular use and at least a few days to start experiencing noticeable symptom relief. As-needed use has been shown to be not as effective as regular recommended use.  Flunisolide should not be used in the presence of nasal infection. It should not be continued if there is no relief of symptoms after regular use over two to three weeks. 
It was patented in 1958 and approved for medical use in 1978. It is on the World Health Organization's List of Essential Medicines.
Temporary nose and throat dryness, irritation, bleeding or unpleasant taste or smell may occur. Nasal septum perforation is rarely reported. Rare, but localized infections of the nose and pharynx with Candida albicans have been reported and long-term use may raise the chance of cataracts or glaucoma.
Flunisolide nasal spray is absorbed into the circulatory system (blood). Corticosteroid nasal sprays may affect the hypothalamic-pituitary-adrenal axis function in humans. After the desired clinical effect is obtained, the maintenance dose should be reduced to the smallest amount necessary to control symptoms, which can be as low as 1 spray in each nostril a day. Utilizing the minimum effective dose will reduce possibility of side effects. Recommended amounts of intranasal corticosteroids are generally not associated with systemic side effects.
Corticosteroids inhibit wound healing. Therefore, use of corticosteroid nasal sprays in patients who have experienced recent nasal septal ulcers, recurrent epistaxis, nasal surgery or trauma, a nasal corticosteroid should be used with caution until healing has occurred. In pregnancy, recommended doses of intranasal corticosteroids are safe and effective.
- "Flunisolide". DrugBank.
- Wallace DV, Dykewicz MS, Bernstein DI, Blessing-Moore J, Cox L, Khan DA, et al. (August 2008). "The diagnosis and management of rhinitis: an updated practice parameter". The Journal of Allergy and Clinical Immunology. 122 (2 Suppl): S1-84. doi:10.1016/j.jaci.2008.06.003. PMID 18662584.
- "Flunisolide Nasal Solution". DailyMed. U.S. National Library of Medicine.
- Fischer J, Ganellin CR (2006). Analogue-based Drug Discovery. John Wiley & Sons. p. 486. ISBN 9783527607495.
- World Health Organization (2021). World Health Organization model list of essential medicines: 22nd list (2021). Geneva: World Health Organization. hdl:10665/345533. WHO/MHP/HPS/EML/2021.02.
- "FLUNISOLIDE - NASAL (Nasalide, Nasarel) side effects, medical uses, and drug interactions". MedicineNet.
- "Nasalide (Flunisolide (Nasal Spray)) Drug Information: Clinical Pharmacology - Prescribing Information". RxList.