Medications and Drugs
Brand Names: Zyflo, Zyflo CR
Generic Name: zileuton (Pronunciation: zye LOO ton)
What is zileuton (Zyflo, Zyflo CR)?
Zileuton is a leukotriene (loo-koe-TRY-een) inhibitor. Leukotrienes are chemicals your body releases when you breathe in an allergen (such as pollen). These chemicals cause swelling in your lungs and tightening of the muscles around your airways, which can result in asthma symptoms.
Zileuton is used to prevent asthma attacks in adults and children as young as 12 years old.
Zileuton may also be used for purposes not listed in this medication guide.
What are the possible side effects of zileuton (Zyflo, Zyflo CR)?
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have a serious side effect such as:
Less serious side effects may include:
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
What is the most important information I should know about zileuton (Zyflo, Zyflo CR)?
Call your doctor at once if you have nausea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes). These may be early signs of liver problems.
Do not use zileuton to treat an asthma attack that has already begun. It will not work fast enough. Use only a fast acting inhalation medication. Talk with your doctor if any of your asthma medications do not seem to work as well in treating or preventing attacks.
It may take up to a few weeks before your symptoms improve. Keep using the medication as directed even if you feel fine or have no symptoms. Having no asthma symptoms is a sign that the medication is working.
Avoid drinking alcohol. It may increase your risk of liver damage.
Call your doctor at once if you have any mood or behavior changes, anxiety, depression, or thoughts about suicide or hurting yourself.
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Need help identifying pills and medications?
Asthma and Allergy Resources
- What Are the Asthma Treatments for Kids?
- No Smoking: Help for the First Hard Days
- Are You At Risk for COPD?