Zafirlukast

Zafirlukast

Clinical data
Trade names	Accolate[1]
AHFS/Drugs.com	Monograph
MedlinePlus	a697007
License data	US DailyMed: Zafirlukast
Pregnancy category	AU: B1
Routes of administration	Oral
ATC code	R03DC01 (WHO)
Legal status
Legal status	UK: POM (Prescription only)
Pharmacokinetic data
Bioavailability	Unknown
Protein binding	>99% (albumin)[1]
Metabolism	Hepatic (CYP2C9-mediated)
Metabolites	hydroxylated metabolites[1]
Elimination half-life	10 hours
Excretion	Fecal[1]
Identifiers
IUPAC name Cyclopentyl 3-{2-methoxy-4-[(o-tolylsulfonyl)carbamoyl]benzyl}-1-methyl-1H-indol-5-ylcarbamate
CAS Number	107753-78-6 Y
PubChem CID	5717
IUPHAR/BPS	3322
DrugBank	DB00549 Y
ChemSpider	5515 Y
UNII	XZ629S5L50
KEGG	D00411 Y
ChEBI	CHEBI:10100 Y
ChEMBL	ChEMBL603 Y
CompTox Dashboard (EPA)	DTXSID5023746
ECHA InfoCard	100.189.989
Chemical and physical data
Formula	C31H33N3O6S
Molar mass	575.68 g·mol−1
3D model (JSmol)	Interactive image
Melting point	138 to 140 °C (280 to 284 °F)
SMILES Cc1ccccc1S(=O)(=O)NC(=O)c2cc(OC)c(cc2)Cc3cn(C)c4ccc(cc43)NC(=O)OC5CCCC5
InChI InChI=1S/C31H33N3O6S/c1-20-8-4-7-11-29(20)41(37,38)33-30(35)22-13-12-21(28(17-22)39-3)16-23-19-34(2)27-15-14-24(18-26(23)27)32-31(36)40-25-9-5-6-10-25/h4,7-8,11-15,17-19,25H,5-6,9-10,16H2,1-3H3,(H,32,36)(H,33,35) Y Key:YEEZWCHGZNKEEK-UHFFFAOYSA-N Y
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Zafirlukast is an orally administered leukotriene receptor antagonist (LTRA) used for the chronic treatment of asthma. While zafirlukast is generally well tolerated, headaches and stomach upset often occur. Some rare side effects can occur, which can be life-threatening, such as liver failure. eosinophilic granulomatosis with polyangiitis has been associated with zafirlukast, but the relationship isn't thought to be causative. Overdoses of zafirlukast tend to be self-limiting.

Zafirlukast, like other LTRAs, works by inhibiting the immune system. Through its action on inflammatory cells in the lungs, zafirlukast reduces the production of inflammatory mediators that are implicated in the pathogenesis of asthma. Zafirlukast is extensively hepatically metabolized by an enzyme called CYP2C9. Zafirlukast inhibits the action of CYP3A4, leading to drug-drug interactions with other drugs that are metabolized by CYP3A4. Genetic differences in LTC4 synthase and CYP2C9 may predict how a person reacts to zafirlukast treatment.

Zafirlukast (brand name Accolate) was the first cysteinyl leukotriene receptor antagonist approved in the United States. It is now approved in many other countries under other brand names.