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Stereochemistry ABSOLUTE
Molecular Formula C22H24ClN3O
Molecular Weight 381.898
Optical Activity UNSPECIFIED
Defined Stereocenters 1 / 1
E/Z Centers 0
Charge 0

Structure of AZELASTINE, (S)-






Molecular Formula C22H24ClN3O
Molecular Weight 381.898
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



Safety of antihistamines in children.
Efficacy of azelastine nasal spray in the treatment of vasomotor (perennial nonallergic) rhinitis.
2001 Jan
Update on nonallergic rhinitis.
2001 May
Azelastine is more potent than olopatadine n inhibiting interleukin-6 and tryptase release from human umbilical cord blood-derived cultured mast cells.
2002 May
Intranasal corticosteroids versus topical H1 receptor antagonists for the treatment of allergic rhinitis: a systematic review with meta-analysis.
2002 Nov
Topical azelastine in perennial allergic conjunctivitis.
[In vitro effects of antiallergic eyedrops on complement activation induced by particulate matter].
2003 Apr
Efficacy of azelastine nasal spray in patients with an unsatisfactory response to loratadine.
2003 Aug
Effects of TAK-427 on acute nasal symptoms and nasal obstruction in guinea pig model of experimental allergic rhinitis.
2003 Aug 29
[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
Efficacy of azelastine nasal spray in seasonal allergic rhinitis patients who remain symptomatic after treatment with fexofenadine.
2004 Aug
Antiallergic activity of hesperidin is activated by intestinal microflora.
2004 Aug
Intradermal nociceptin elicits itch-associated responses through leukotriene B(4) in mice.
2004 Jul
Evidence-based strategies for treatment of allergic rhinitis.
2004 Nov
Efficacy and tolerability of newer antihistamines in the treatment of allergic conjunctivitis.
Prediction of genotoxicity of chemical compounds by statistical learning methods.
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
Synergistic effects of the anti-cholinergic R,R-glycopyrrolate with anti-inflammatory drugs.
2006 Dec 15
[Comparison of clinical efficacy and cost-quality of antihistamines in early treatment for Japanese cedar pollinosis].
2006 May
Impact of azelastine nasal spray on symptoms and quality of life compared with cetirizine oral tablets in patients with seasonal allergic rhinitis.
2006 Sep
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
Inhibition of IgE-mediated phosphorylation of FcepsilonRIgamma protein by antiallergic drugs in rat basophilic leukemia (RBL-2H3) cells: a novel action of antiallergic drugs.
2007 Jul
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
Azelastine hydrochloride: a review of pharmacology, pharmacokinetics, clinical efficacy and tolerability.
2007 Oct

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 Thu Jul 06 14:31:26 UTC 2023
by admin
on Thu Jul 06 14:31:26 UTC 2023
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Created by admin on Thu Jul 06 14:31:26 UTC 2023 , Edited by admin on Thu Jul 06 14:31:26 UTC 2023
Created by admin on Thu Jul 06 14:31:26 UTC 2023 , Edited by admin on Thu Jul 06 14:31:26 UTC 2023
Created by admin on Thu Jul 06 14:31:26 UTC 2023 , Edited by admin on Thu Jul 06 14:31:26 UTC 2023
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