Zafirlukast  

Zafirlukast
Systematic (IUPAC) name
cyclopentyl {3-[2-methoxy-4-({[(2-methylphenyl)sulfonyl]amino}carbonyl)benzyl]-1-methyl-1H-indol-5-yl}carbamate
Identifiers
CAS number	107753-78-6
ATC code	R03DC01
PubChem	5717
DrugBank	APRD00377
Chemical data
Formula	C31H33N3O6S
Mol. mass	575.676 g/mol
Pharmacokinetic data
Bioavailability	Unknown
Protein binding	99%
Metabolism	Hepatic (CYP2C9-mediated)
Half life	10 hours
Excretion	Biliary
Therapeutic considerations
Pregnancy cat.	B1 (Au), B (U.S.)
Legal status	POM (UK)
Routes	Oral

Zafirlukast is an oral leukotriene receptor antagonist (LTRA) for the maintenance treatment of asthma, often used in conjunction with an inhaled steroid and/or long-acting bronchodilator. It is available as a tablet and is usually dosed twice daily. Another leukotriene receptor antagonist is montelukast (Singulair), taken once daily. Zyflo, also used in the treatment of asthma via its inhibition of 5-lipoxygenase, is taken four times per day.

Zafirlukast blocks the action of the cysteinyl leukotrienes on the CysLT1 receptors, thus reducing constriction of the airways, build-up of mucus in the lungs and inflammation of the breathing passages.

Zafirlukast is marketed by Astra-Zeneca with the brand names Accolate, Accoleit, and Vanticon. It was the first LTRA to be marketed in the USA and is now approved in over 60 countries, including the UK, Japan, Taiwan, Italy, Spain, Canada, Brazil, China and Turkey.

A letter was submitted to the FDA by Zeneca Pharmaceuticals on July 22, 1997, notifying them of a change in product labeling that includes the following potential reaction in patients undergoing a dosage reduction of oral steroids who are currently taking zafirlukast:

PRECAUTIONS-Eosinophilic Conditions: The reduction of the oral steroid dose, in some patients on ACCOLATE therapy, has been followed in rare cases by the occurrence of eosinophilia, vasculitic rash, worsening pulmonary symptoms, cardiac complications, and/or neuropathy sometimes presenting as Churg Strauss Syndrome, a systemic eosinophilic vasculitis. Although a causal relationship with ACCOLATE has not been established, caution is required when oral steroid reduction is being considered.¹

1- http://www.fda.gov/medWatch/safety/1997/accola.htm

External links

• Accolate, Accoleit, Vanticon (manufacturer's website)
• Zafirlukast (patient information)

This pharmacology-related article is a stub. You can help Wikipedia by expanding it. v  d  e