Azatadine

Not to be confused with azetidine.

Azatadine (Optimine) is a first-generation antihistamine and anticholinergic drug that was synthesized in 1963 by Schering-Plough, a former American pharmaceutical company.^[1][2] It is a nitrogen analog of cyproheptadine.^[3]

Azatadine

Clinical data
Trade names	Optimine
AHFS/Drugs.com	Micromedex Detailed Consumer Information
ATC code	R06AX09 (WHO)
Identifiers
IUPAC name 11-(1-Methylpiperidin-4-ylidene)-6,11-dihydro-5H-benzo[5,6]cyclohepta[1,2-b]pyridine
CAS Number	3964-81-6 Y
PubChem CID	19861
IUPHAR/BPS	7119
DrugBank	DB00719 Y
ChemSpider	18709 Y
UNII	94Z39NID6C
KEGG	D07482 Y
ChEBI	CHEBI:2946 Y
ChEMBL	ChEMBL946 Y
CompTox Dashboard (EPA)	DTXSID6022636
Chemical and physical data
Formula	C20H22N2
Molar mass	290.410 g·mol−1
3D model (JSmol)	Interactive image
SMILES n4c3\C(=C1/CCN(C)CC1)c2ccccc2CCc3ccc4
InChI InChI=1S/C20H22N2/c1-22-13-10-16(11-14-22)19-18-7-3-2-5-15(18)8-9-17-6-4-12-21-20(17)19/h2-7,12H,8-11,13-14H2,1H3 Y Key:SEBMTIQKRHYNIT-UHFFFAOYSA-N Y
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It was patented in 1967.^[4] It has been succeeded by both loratadine and desloratadine.^[5]: 53 and marketing approvals have been widely withdrawn.^{[6][7][8][9]: 290 [10]}

Pharmacology

Azatadine exhibits potent antihistamine^[11], anticholinergic, antiserotonin, and antianaphylactic properties. Its anticholinergic potency is one-third that of atropine and equivalent to that of promethazine and cyproheptadine. Azatadine is among the more potent antianaphylactic agents.^[3]

Azatadine is a first-generation antihistamine.^[12]

Field of application

The medicinal form of azatadine is the salt of maleic acid, azatadine maleate. It is described as an effective treatment for acute and chronic allergic rhinitis^[11], vasomotor rhinitis, urticaria, and certain forms of atopic and contact dermatitis. At the maximum recommended therapeutic dose of 4 mg per day, the drug markedly reduced the severity of perennial allergic rhinitis in most patients (80%) over a 7-day period and significantly decreased swelling in histamine provocation and allergen tests. It was generally well tolerated. Drowsiness was reported by 40% of patients.^[13]

Mechanism of action

Antihistamines such as azatadine compete with histamine for the histamine H1 receptor on plasma cell. This antagonism counteracts the pharmacological effects of histamine mediated through H₁ receptor activation, thereby reducing the intensity of allergic reactions and the tissue damage associated with histamine release.^[14] In addition, azatadine has been shown to downregulate leukotrienes as part of the immediate allergic response.^[12]

Synthesis

The multi-step synthesis has been described in the literature.^[15]

See also

• Azatadine/pseudoephedrine