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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.
Safety and tolerability profiles of intranasal antihistamines and intranasal corticosteroids in the treatment of allergic rhinitis.
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
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
Suplatast tosilate inhibits eosinophil production and recruitment into the skin in murine contact sensitivity.
2003 Sep
Treatment of nonallergic perennial rhinitis.
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
Synthesis and potential anti-inflammatory activity of some tetrahydrophthalazinones.
2004 Dec
In vitro effects of astaxanthin combined with ginkgolide B on T lymphocyte activation in peripheral blood mononuclear cells from asthmatic subjects.
2004 Feb
[Respiratory allergies in the child and the adult].
2004 Jan 31
Nasal saline: placebo or drug?
2004 Jul
Intradermal nociceptin elicits itch-associated responses through leukotriene B(4) in mice.
2004 Jul
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
Pharmacokinetic interactions between Japanese traditional medicine (kampo) and modern medicine (III). Effect of Sho-seiryu-to on the pharmacokinetics of azelastine hydrochloride in rats.
2004 May
Evidence-based strategies for treatment of allergic rhinitis.
2004 Nov
Efficacy and tolerability of newer antihistamines in the treatment of allergic conjunctivitis.
Open-label evaluation of azelastine nasal spray in patients with seasonal allergic rhinitis and nonallergic vasomotor rhinitis.
2005 Apr
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
Antipruritic effect of ginsenoside rb1 and compound k in scratching behavior mouse models.
2005 Sep
The role of antihistamines in asthma management.
Synergistic effects of the anti-cholinergic R,R-glycopyrrolate with anti-inflammatory drugs.
2006 Dec 15
Azelastine nasal spray and desloratadine tablets in pollen-induced seasonal allergic rhinitis: a pharmacodynamic study of onset of action and efficacy.
2006 Jan
Pharmacotherapy of allergic eye disease.
2006 Jun
[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
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
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
Azelastine hydrochloride: a review of pharmacology, pharmacokinetics, clinical efficacy and tolerability.
2007 Oct
Efficacy and safety of azelastine nasal spray at a dose of 1 spray per nostril twice daily.
2007 Sep
Effect of azelastine, montelukast, and their combination on allergen-induced bronchoconstriction in asthma.

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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