Epinastine

Epinastine (brand names Alesion, Elestat, Purivist, Relestat) is a second-generation antihistamine and mast cell stabilizer that is used in eye drops to treat allergic conjunctivitis. It is produced by Allergan and marketed by Inspire in the United States.^[1] It is highly selective for the H₁ receptor and does not cross the blood-brain-barrier.^[2]

Epinastine

Clinical data
Trade names	Alesion, Elestat, Purivist, Relestat
AHFS/Drugs.com	Monograph
MedlinePlus	a604011
Pregnancy category	C
Routes of administration	Eye drops
ATC code	R06AX24 (WHO) S01GX10 (WHO)
Pharmacokinetic data
Protein binding	64%
Elimination half-life	12 hours
Identifiers
IUPAC name (RS)-3-amino-9,13b-dihydro-1H-dibenz(c,f)imidazo(1,5-a)azepine
CAS Number	80012-43-7 Y
PubChem CID	3241
IUPHAR/BPS	7176
DrugBank	DB00751 Y
ChemSpider	3128 Y
UNII	Q13WX941EF
KEGG	D07900 Y
ChEBI	CHEBI:51032 Y
ChEMBL	ChEMBL1106 Y
CompTox Dashboard (EPA)	DTXSID2048371
ECHA InfoCard	100.120.187
Chemical and physical data
Formula	C16H15N3
Molar mass	249.317 g·mol−1
3D model (JSmol)	Interactive image
SMILES N\4=C(\N3c1c(cccc1)Cc2c(cccc2)C3C/4)N
InChI InChI=1S/C16H15N3/c17-16-18-10-15-13-7-3-1-5-11(13)9-12-6-2-4-8-14(12)19(15)16/h1-8,15H,9-10H2,(H2,17,18) Y Key:WHWZLSFABNNENI-UHFFFAOYSA-N Y
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It was patented in 1980 and came into medical use in 1994.^[3]

References

1. Pradhan S, Abhishek K, Mah F (September 2009). "Epinastine: topical ophthalmic second generation antihistamine without significant systemic side effects". Expert Opinion on Drug Metabolism & Toxicology. 5 (9): 1135–1140. doi:10.1517/17425250903117284. PMID 19630694. S2CID 207490591.
2. Walther G, Daniel H, Bechtel WD, Brandt K (April 1990). "New tetracyclic guanidine derivatives with H1-antihistaminic properties. Chemistry of epinastine". Arzneimittel-Forschung. 40 (4): 440–446. PMID 1972625.
3. Fischer J, Ganellin CR (2006). Analogue-based Drug Discovery. John Wiley & Sons. p. 549. ISBN 9783527607495.