Back
Print 

Learning About Leukotriene Modifiers

Skip Navigation

Top of the page

Leukotriene (say "loo-koh-TRY-een") modifiers are medicines used for asthma and seasonal allergies.

They help reduce asthma symptoms. They are not used to treat asthma attacks.

They may also reduce allergy symptoms. These include sneezing and a runny or stuffy nose.

Examples

  • Montelukast (Singulair). This drug is approved for asthma and allergies.
  • Zafirlukast (Accolate) and zileuton (Zyflo). These drugs are approved for asthma only.

What are the side effects?

  • Vomiting.
  • Diarrhea.
  • A headache.

Call your doctor right away if you or your child has behavior or mood changes while taking montelukast.

What to know about taking these medicines

  • These drugs may help if your asthma is caused by exercise, aspirin, or allergies.
  • You may need to have blood tests during the first 6 months of treatment. The tests check for liver damage.
  • Take your medicines exactly as prescribed. Call your doctor if you think you are having a problem with your medicine.
  • Check with your doctor or pharmacist before you use any other medicines. This includes over-the-counter drugs. Make sure your doctor knows all of the medicines you take. This includes vitamins, herbs, and supplements. Taking some drugs together can cause problems.

Current as of: September 29, 2025

Author: Ignite Healthwise, LLC Staff

Clinical Review Board
All Ignite Healthwise, LLC education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

Current as of: September 29, 2025

Author: Ignite Healthwise, LLC Staff

Clinical Review Board
All Ignite Healthwise, LLC education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.