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Stereochemistry ABSOLUTE
Molecular Formula C22H24ClN3O
Molecular Weight 381.8992
Optical Activity UNSPECIFIED
Defined Stereocenters 1 / 1
E/Z Centers 0
Charge 0

Structure of AZELASTINE, (S)-






Molecular Formula C22H24ClN3O
Molecular Weight 381.8992
Charge 0
Stereochemistry ABSOLUTE
Additional Stereochemistry No
Defined Stereocenters 1 / 1
E/Z Centers 0
Optical Activity UNSPECIFIED

Azelastine (brand names AZEP, ASTEPRO, ASTELIN etc.) a phthalazine derivative, is an antihistamine and mast cell stabilizer available as a nasal spray for hay fever and as eye drops for allergic conjunctivitis. Azelastine is a potent antiallergic compound with histamine H1-receptor antagonist activity and a rapid onset and long duration of action. The major metabolite, desmethylazelastine, also exhibits H1- receptor antagonist activity. AZEP Nasal Spray is administered as a racemic mixture. The racemate, R- and S- enantiomers were equally potent at inhibiting eyelid histamine-induced oedema in rats, however the R-enantiomer was 2-fold less active at inhibiting eyeball histamine-induced oedema.

CNS Activity

Curator's Comment:: Azelastine is systemically absorbed and can cross the blood–brain barrier. In mice, azelastine showed a definite central action. In rats, a high dose of 100 mg/kg azelastine produced a slight suppression of the paradoxical sleep.

Approval Year



ConditionModalityTargetsHighest PhaseProduct

Approved Use

Astelin Nasal Spray is indicated for the treatment of the symptoms of seasonal allergic rhinitis such as rhinorrhea, sneezing, and nasal pruritus in adults and children 5 years and older, and for the treatment of the symptoms of vasomotor rhinitis, such as rhinorrhea, nasal congestion and postnasal drip in adults and children 12 years and older.

Launch Date



Poor sleep and daytime somnolence in allergic rhinitis: significance of nasal congestion.
Mechanism of the antitussive effect of azelastine in guinea pigs.
Effects of antihistamines on leukotriene and cytokine release from dispersed nasal polyp cells.
24-hour efficacy of once-daily desloratadine therapy in patients with seasonal allergic rhinitis [ISRCTN32042139].
2002 Aug 5
Inhibition of allergic dermal inflammation by the novel imidazopyridazine derivative TAK-427 in a guinea pig experimental model of eczema.
2002 Dec
Antiproliferative effects of the antiallergic agent azelastine on human aortic smooth-muscle cells: an in vitro study.
2002 May
Safety and tolerability profiles of intranasal antihistamines and intranasal corticosteroids in the treatment of allergic rhinitis.
Azelastine eye drops in the treatment of perennial allergic conjunctivitis.
Rapid anti-inflammatory action of azelastine eyedrops for ongoing allergic reactions.
2003 Apr
Efficacy of azelastine nasal spray in patients with an unsatisfactory response to loratadine.
2003 Aug
Simultaneous enantioselective separation of azelastine and three of its metabolites for the investigation of the enantiomeric metabolism in rats. I. Liquid chromatography-ionspray tandem mass spectrometry and electrokinetic capillary chromatography.
2003 Aug 15
Interactions of olopatadine and selected antihistamines with model and natural membranes.
2003 Dec
[Mechanism of production and release of tumor necrosis factor implicated in inflammatory diseases].
2003 Mar
Acute stress results in skin corticotropin-releasing hormone secretion, mast cell activation and vascular permeability, an effect mimicked by intradermal corticotropin-releasing hormone and inhibited by histamine-1 receptor antagonists.
2003 Mar
Azelastine inhibits secretion of IL-6, TNF-alpha and IL-8 as well as NF-kappaB activation and intracellular calcium ion levels in normal human mast cells.
2003 Nov
Epinastine inhibits eosinophil chemotaxis and adhesion molecules in atopic dermatitis.
2003 Nov-Dec
Effects of fexofenadine and other antihistamines on components of the allergic response: adhesion molecules.
2003 Oct
Histamine skin test reactivity following single and multiple doses of azelastine nasal spray in patients with seasonal allergic rhinitis.
2003 Sep
Treatment of nonallergic perennial rhinitis.
Antiallergic activity of hesperidin is activated by intestinal microflora.
2004 Aug
[Topical H1 antihistaminics in the therapy of acute conjunctival allergic reactions].
2004 Jan
[Respiratory allergies in the child and the adult].
2004 Jan 31
Ocular allergy treatment comparisons: azelastine and olopatadine.
2004 Jul
Vasomotor rhinitis update.
2004 Jun
Cutaneous drug eruption from cetirizine and hydroxyzine.
2004 Jun
Influences of allergic rhinitis on sleep.
2004 May
Evidence-based strategies for treatment of allergic rhinitis.
2004 Nov
Open-label evaluation of azelastine nasal spray in patients with seasonal allergic rhinitis and nonallergic vasomotor rhinitis.
2005 Apr
Passive cutaneous anaphylaxis-inhibitory activity of flavanones from Citrus unshiu and Poncirus trifoliata.
2005 Jan
Prediction of genotoxicity of chemical compounds by statistical learning methods.
2005 Jun
Protein kinase C-alpha mediates TNF release process in RBL-2H3 mast cells.
2005 Jun
A Japanese patient with familial Mediterranean fever associated with compound heterozygosity for pyrin variant E148Q/M694I.
2005 Mar
Effectiveness of azelastine nasal spray compared with oral cetirizine in patients with seasonal allergic rhinitis.
2005 May
Nasal obstruction, the airway, and the athlete.
2005 Oct
[Azelastine hydrochloride in the treatment of allergic rhinitis].
2005 Sep
The role of antihistamines in asthma management.
Expression of urocortin in rat lung and its effect on pulmonary vascular permeability.
2006 Apr
Long QT syndrome in a patient with allergic rhinoconjunctivitis and auto-immune diabetes: focus on the choice of anti-H1 drugs.
2006 Dec
Azelastine nasal spray and desloratadine tablets in pollen-induced seasonal allergic rhinitis: a pharmacodynamic study of onset of action and efficacy.
2006 Jan
[Comparison of clinical efficacy and cost-quality of antihistamines in early treatment for Japanese cedar pollinosis].
2006 May
Allergic rhinitis: evidence for impact on asthma.
2006 Nov 30
Antiallergic drugs, azelastine hydrochloride and epinastine hydrochloride, inhibit ongoing IgE secretion of rat IgE-producing hybridoma FE-3 cells.
2006 Oct 10
Review of azelastine nasal spray in the treatment of allergic and non-allergic rhinitis.
2007 Apr
Duration of action of topical antiallergy drugs in a Guinea pig model of histamine-induced conjunctival vascular permeability.
2007 Aug
Nasal azelastine for self-medication: modest symptomatic relief from rhinitis.
2007 Aug
Onset of action of azelastine nasal spray compared with mometasone nasal spray and placebo in subjects with seasonal allergic rhinitis evaluated in an environmental exposure chamber.
2007 Jul-Aug
Antianaphylactic properties of 7-epiclusianone, a tetraprenylated benzophenone isolated from Garcinia brasiliensis.
2007 Jun
Meta-analysis of azelastine nasal spray for the treatment of allergic rhinitis.
2007 Jun
Comparative efficacy of steroid nasal spray versus antihistamine nasal spray in allergic rhinitis.
2007 Mar
Efficacy and safety of azelastine nasal spray at a dose of 1 spray per nostril twice daily.
2007 Sep

Sample Use Guides

In Vivo Use Guide
Curator's Comment:: To male Wistar rats one single dose of 50 mg/kg AZELASTINE, (S)- was applied orally (by oral gavage): https://www.ncbi.nlm.nih.gov/pubmed/12906914
Adults and children aged 5 years and over: Each spray contains 125 ug of azelastine (as hydrochloride). One spray into each nostril twice daily as necessary (equivalent to a daily dose of 0.50 mg azelastine
Route of Administration: Nasal
In Vitro Use Guide
Curator's Comment:: Sensitized cultured human mast cells (CHMCs) were pretreated with various concentrations of azelastine or olopatadine for 5 minutes. Then, CHMCs were challenged with anti-immunoglobulin E (IgE) and the released mediators were quantitated.
The greatest inhibition of mediator release was seen when cultured human mast cells (CHMCs) were pretreated with 24 uM of azelastine.
Substance Class Chemical
by admin
on Sat Jun 26 08:24:41 UTC 2021
by admin
on Sat Jun 26 08:24:41 UTC 2021
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Created by admin on Sat Jun 26 08:24:41 UTC 2021 , Edited by admin on Sat Jun 26 08:24:41 UTC 2021
Created by admin on Sat Jun 26 08:24:41 UTC 2021 , Edited by admin on Sat Jun 26 08:24:41 UTC 2021
Created by admin on Sat Jun 26 08:24:41 UTC 2021 , Edited by admin on Sat Jun 26 08:24:41 UTC 2021
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