What is zafirlukast, and how does it work (mechanism of action)?

  • Zafirlukast is an oral leukotriene receptor antagonist used for treating asthma. Leukotrienes are a group of chemicals manufactured in the body from arachidonic acid. Release of leukotrienes within the body, for example, by allergic reactions, promotes inflammation in many diseases such as asthma, a disease in which inflammation occurs in the lungs. Zafirlukast blocks the binding of leukotriene types D4 (LTD4), and E4 (LTE4) and the promotion of inflammation.
  • Accolate is the brand name for zafirlukast.
  • Zafirlukast is available in generic form. You need a prescription for zafirlukast.

What is zafirlukast used for?

  • Accolate is an FDA approved prescription drug used for the medical treatment of chronic asthma.
  • It also is effective in preventing exercise-induced asthma and in relieving the symptoms of allergic rhinitis.
  • For the treatment of asthma, it starts working only after 3 to 14 days of therapy. Therefore, it should not be used for the treatment an acute asthma attack because immediate relief is needed.


Asthma is a chronic respiratory disease. See Answer

What are the side effects of zafirlukast?

The most common health side effects include:

Other health side effects and adverse effects include:

What is the dosage for zafirlukast?

  • The recommended dose for the treatment of asthma is 10 mg twice daily for children 5-11 years of age and 20 mg twice daily for individual 12 years of age and older.
  • Food reduces the absorption of this medicine.
  • Therefore, it should be taken either 1 hour before or 2 hours after meals.

Which drugs or supplement interactions occur with this drug?

Accolate inhibits the activity of cytochrome isozymes CYP 3A4 and CYP 2C9. The CYP 3A4 isozyme is responsible for metabolism (elimination) of many drugs. Thus far, data in humans are very limited. In one small study, zafirlukast was shown to interact with warfarin (Coumadin, Jantoven), resulting in increased "thinning" of blood and a decreased ability of blood to clot. This can increase the risk of bleeding.

Until more data are available, this medication should be used very cautiously in patients taking drugs metabolized by CYP3A4 including:

Erythromycin reduces the absorption of zafirlukast, potentially reducing its effect.

What brand names are available for zafirlukast?

  • Accolate is the brand name available for this medication.

Is this medication safe to use during pregnancy or while breastfeeding?

  • Safe use of Accolate for prevention and medical treatment for asthma during pregnancy has not been established. Doctors or other health care professionals may prescribe it during pregnancy if it is felt that its benefits outweigh the potential unknown risks.
  • It is secreted into breast milk and should not be used by women who are breastfeeding.

What else should you know about zafirlukast?

  • Accolate is available in tablets of 10 mg and 20 mg.
  • Keep the medication tablets stored at room temperature, between 15 C and 30 C (59 F and 86 F).
  • This medication was approved by the FDA in September 1996.
  • If you have questions about this medicine seek medical advise from your doctor or pharmacist.

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Zafirlukast (Accolate) is a drug prescribed for the treatment of chronic asthma, preventing exercise-induced asthma, and the symptoms of allergic rhinitis (hay fever). It is not prescribed for acute asthma attacks. Common side effects include nausea, diarrhea, abdominal pain, sore throat, respiratory infections, rhinitis, Drug interactions, dosing, uses, and pregnancy and breastfeeding safety information should be reviewed prior to taking this medication.

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FDA Prescribing Information.